import os, commands, re, sets, tempfile
from subprocess import Popen, PIPE, STDOUT

import buffer, default, dirutil, regex, util, window
from point import Point

DATATYPES = {
    "path":         None,
    "buffer":       None,
    "method":       None,
    "command":      None,
    "shell":        None,
    "shellcommand": None,
}

class MethodError(Exception):
    pass

class Argument(object):
    def __init__(self, name, type=type(""), datatype=None, prompt=None, help="",
                 default=default.none, load_default=False):
        self.name = name
        self.type = type
        self.datatype = datatype
        if prompt is None:
            self.prompt = "%s: " % (name)
        else:
            self.prompt = prompt
        self.help = help

        self.load_default = load_default
        self.default = default

    def coerce_to_type(self, value):
        if self.type == type(0):
            try:
                return int(value, 0)
            except:
                raise Exception, "expected int; got %s" % (repr(value))
        else:
            return value

    def ask_for_value(self, method, w, **vargs):
        app = w.application
        assert app.mini_buffer_is_open() is False, "Recursive minibuffer antics"
        vargs2 = vargs.copy()
        assert callable(self.default), "default value func must be callable"
        if self.load_default:
            d = None
            starting_value = self.default(w)
        else:
            d = self.default(w)
            starting_value = None
        def return_value(v):
            if d is not None and v == "":
                v = d
            vargs2[self.name] = self.coerce_to_type(v)
            app.close_mini_buffer()
            method.execute(w, **vargs2)
        tabber = DATATYPES.get(self.datatype, None)
        if d is not None:
            p = self.prompt + "(%s) " % (d)
        else:
            p = self.prompt
        app.open_mini_buffer(p, return_value, method, tabber)
        if starting_value:
            app.mini_buffer.set_data(starting_value)
        
class Method(object):
    _is_method = True
    args = []
    def __init__(self):
        self.name = self._name()
        self.help = self.__doc__

    def _name(cls):
        s = cls.__name__
        s2 = s[0].lower()
        for c in s[1:]:
            if c.isupper():
                s2 += '-' + c.lower()
            elif c == '_':
                s2 += '-'
            else:
                s2 += c
        return s2
    _name = classmethod(_name)

    def _pre_execute(self, w, **vargs):
        pass

    def execute(self, w, **vargs):
        try:
            self._pre_execute(w, **vargs)
        except MethodError, e:
            w.set_error(str(e))
            return
        for arg in self.args:
            if arg.name not in vargs:
                self.old_window = w
                arg.ask_for_value(self, w, **vargs)
                return
        self._execute(w, **vargs)
        
    def _execute(self, w, **vargs):
        raise Exception, "Unimplemented Method: %s %r" % (self.name, vargs)

class AboutPmacs(Method):
    '''print some information about pmacs'''
    def _execute(self, w, **vargs):
        a = w.application
        if not a.has_buffer_name('*About*'):
            b = buffer.AboutBuffer()
            a.add_buffer(b)
            window.Window(b, a)
        b = a.bufferlist.get_buffer_by_name('*About*')
        if a.window().buffer is not b:
            a.switch_buffer(b)

class GotoChar(Method):
    '''Jump to the specified character'''
    args = [Argument("charno", type=type(0), prompt="Goto char: ")]
    def _execute(self, w, **vargs):
        w.goto_char(vargs["charno"])
class ForwardChars(Method):
    '''Move forward the specified number of characters'''
    args = [Argument("charno", type=type(0), prompt="Forward chars: ")]
    def _execute(self, w, **vargs):
        w.forward_chars(vargs["charno"])

class GotoLine(Method):
    '''Jump to the specified line number'''
    args = [Argument("lineno", type=type(0), prompt="Goto line: ")]
    def _execute(self, w, **vargs):
        n = vargs["lineno"]
        if n < 0:
            n = len(w.buffer.lines) + n + 1
        if n > len(w.buffer.lines):
            n = len(w.buffer.lines)
        elif n < 1:
            n = 1
        w.goto_line(n)
class ForwardLines(Method):
    '''Move forward the specified number of characters'''
    args = [Argument("lineno", type=type(0), prompt="Forward lines: ")]
    def _execute(self, w, **vargs):
        w.forward_lines(vargs["lineno"])

# search and replace
class Search(Method):
    '''Interactive search; finds next occurance of text in buffer'''
    is_literal = True
    direction = 'next'
    prompt = 'I-Search: '
    def execute(self, w, **vargs):
        self.old_cursor = w.logical_cursor()
        self.old_window = w
        w.application.open_mini_buffer(self.prompt, lambda x: None, self, None, 'search')
class ReverseSearch(Search):
    '''Interactive search; finds previous occurance of text in buffer'''
    direction = 'previous'
class RegexSearch(Search):
    '''Interactive search; finds next occurance of regex in buffer'''
    is_literal = False
    prompt = 'I-RegexSearch: '
class RegexReverseSearch(RegexSearch):
    '''Interactive search; finds prevoius occurance of regex in buffer'''
    direction = 'previous'
    
class Replace(Method):
    '''Replace occurances of string X with string Y'''
    is_literal = True
    args = [Argument('before', prompt="Replace String: ",
                     default=default.last_replace_before, load_default=True),
            Argument('after', prompt="Replace With: ",
                     default=default.last_replace_after, load_default=True)]
    def _execute(self, w, **vargs):
        a = w.application
        a.last_replace_before = self.before = vargs['before']
        a.last_replace_after = self.after = vargs['after']
        self.old_window = w
        a.open_mini_buffer('I-Replace: ', lambda x: None, self, None, 'replace')
class RegexReplace(Method):
    '''Replace occurances of string X with string Y'''
    is_literal = False
    args = [Argument('before', prompt="Replace Regex: ",
                     default=default.last_replace_before, load_default=True),
            Argument('after', prompt="Replace With: ",
                     default=default.last_replace_after, load_default=True)]
    def _execute(self, w, **vargs):
        w.application.last_replace_before = self.before = vargs['before']
        w.application.last_replace_after  = self.after = vargs['after']
        self.old_window                   = w
        f = lambda x: None
        w.application.open_mini_buffer('I-RegexReplace: ', f, self, None, 'replace')

# navigating between buffers
class OpenFile(Method):
    '''Open file in a new buffer, or go to file's open buffer'''
    args = [Argument('filename', datatype="path", prompt="Open File: ",
                     default=default.path_dirname, load_default=True)]
    def _execute(self, w, **vargs):
        b = w.application.open_path(vargs['filename'])
        SwitchBuffer().execute(w, buffername=b.name())
class OpenAesFile(Method):
    '''Open AES encrypted file in a new buffer, or go to file's open buffer'''
    args = [Argument('filename', datatype="path", prompt="Open AES File: "),
            Argument('password', prompt="Use AES Password: ")]
    def _execute(self, w, **vargs):
        b = w.application.open_path(vargs['filename'], 'aes', vargs['password'])
        SwitchBuffer().execute(w, buffername=b.name())
        return

class ViewBufferParent(Method):
    def _execute(self, w, **vargs):
        b = w.buffer
        if not hasattr(b, 'path'):
            w.set_error('Buffer has no path')
        elif b.path == '/':
            w.set_error("Root directory has no parent")
        else:
            path = os.path.dirname(b.path)
            w.application.methods['open-file'].execute(w, filename=path)

class SwitchBuffer(Method):
    '''Switch to a different'''
    args = [Argument('buffername', datatype="buffer", prompt="Switch To Buffer: ",
                     default=default.last_buffer)]
    def _pre_execute(self, w, **vargs):
        a = w.application
        if len(a.bufferlist.buffers) < 1:
            raise Exception, "No other buffers"
    def _execute(self, w, **vargs):
        name = vargs['buffername']
        buf = None
        if w.application.has_buffer_name(name):
            b = w.application.bufferlist.get_buffer_by_name(name)
            w.application.switch_buffer(b)
        else:
            w.set_error("buffer %r was not found" % name)
class KillBuffer(Method):
    '''Close the current buffer'''
    force=False
    args = [Argument('buffername', datatype="buffer", prompt="Kill Buffer: ",
                     default=default.current_buffer)]
    def _execute(self, w, **vargs):
        name = vargs['buffername']
        a  = w.application
        assert name in a.bufferlist.buffer_names, "Buffer %r does not exist" % name
        assert name != '*Scratch*', "Can't kill scratch buffer"
        self._to_kill    = a.bufferlist.buffer_names[name]
        self._old_window = w
        if self.force or not self._to_kill.changed():
            self._doit()
        else:
            self._prompt = "Buffer has unsaved changes; kill anyway? "
            a.open_mini_buffer(self._prompt, self._callback)
    def _doit(self):
        a = self._old_window.application
        b = self._to_kill
        if a.bufferlist.is_buffer_visible(b):
            a.bufferlist.set_slot(a.active_slot, a.bufferlist.hidden_buffers[0])
        a.bufferlist.remove_buffer(b)
        b.close()
    def _callback(self, v):
        a = self._old_window.application
        if v == 'yes':
            self._doit()
            a.close_mini_buffer()
        elif v == 'no':
            a.close_mini_buffer()
        else:
            a.close_mini_buffer()
            a.set_error('Please type "yes" or "no"')

class ForceKillBuffer(KillBuffer):
    force=True
    args = [Argument('buffername', datatype="buffer", prompt="Force Kill Buffer: ",
                     default=default.current_buffer)]
class ListBuffers(Method):
    '''List all open buffers in a new buffer'''
    def _execute(self, w, **vargs):
        bl = w.application.bufferlist
        bnames = [b.name() for b in bl.buffers]
        bnames.sort()
        data = '\n'.join(bnames)
        w.application.data_buffer("*Buffers*", data, switch_to=True)
class SaveBufferAs(Method):
    '''Save the contents of a buffer to the specified path'''
    args = [Argument('path', datatype="path", prompt="Write file: ",
                     default=default.current_working_dir, load_default=True)]
    def _execute(self, w, **vargs):
        curr_buffer = w.buffer
        curr_buffer_name = curr_buffer.name()
        data = curr_buffer.make_string()
        path = os.path.realpath(os.path.expanduser(vargs['path']))
        w.set_error("got %r (%d)" % (path, len(data)))
        if w.application.has_buffer_name(path):
            w.set_error("buffer for %r is already open" % path)
            return
        w.application.file_buffer(path, data, switch_to=True)
        if curr_buffer_name != '*Scratch*':
            w.application.methods['kill-buffer'].execute(w, buffername=curr_buffer_name)
        else:
            curr_buffer.set_data('')
        w.set_error('Wrote %r' % path)
class SaveBuffer(Method):
    '''Save the contents of a buffer'''    
    def _execute(self, w, **vargs):
        if w.buffer.changed():
            w.buffer.save()
            w.set_error("Wrote %s" % (w.buffer.path))
        else:
            w.set_error("(No changes need to be saved)")
class RelexBuffer(Method):
    '''Relex the buffer; this resets syntax highlighting'''    
    def _execute(self, w, **vargs):
        h = w.get_highlighter()
        if h is None:
            w.set_error("No lexer for buffer.")
        else:
            h.highlight(w.buffer.lines)
            w.set_error("Buffer relexed.")
class ToggleWindow(Method):
    '''Move between visible windows'''
    def _execute(self, w, **vargs):
        w.application.toggle_window()

# complex text maniuplation
class TransposeWords(Method):
    '''Switch the place of the two words nearest the cursor'''
    pass

# you wanna quit right?
class Exit(Method):
    '''Exit the program, unless there are unsaved changes'''
    def _execute(self, w, **vargs):
        a = w.application
        assert a.mini_buffer_is_open() is False, "Recursive minibuffer antics"

        changed = False
        for b in w.application.bufferlist.buffers:
            changed = b.changed()
            if changed:
                break
        if not changed:
            w.application.exit()
            return
        else:
            self._old_window = w
            self._prompt = "There are buffers with unsaved changes; exit anyway? "
            a.open_mini_buffer(self._prompt, self._callback)

    def _callback(self, v):
        a = self._old_window.application
        if v == 'yes':
            a.exit()
        a.close_mini_buffer()
        if v == 'no':
            return
        a.open_mini_buffer(self._prompt, self._callback)
        a.set_error('Please type "yes" or "no"')

# insert text
class InsertString(Method):
    _is_method = False
    def __init__(self, s):
        self.name = "insert-string-%s" % s
        self.args = []
        self.help = "Insert %r into the current buffer." % s
        self.string = s
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor(self.string)
class OverwriteChar(Method):
    _is_method = False
    def __init__(self, c):
        self.name = 'overwrite-char-%s' % c
        self.args = []
        self.help = "Overwrite %r into the current buffer." % c
        self.char = c
    def _execute(self, w, **vargs):
        w.overwrite_char_at_cursor(self.char)

# killing/copying/etc.
class Kill(Method):
    '''Kill the contents of the current line'''    
    def _execute(self, w, **vargs):
        w.kill_line()
class KillRegion(Method):
    '''Kill the region between the mark and the cursor'''    
    def _execute(self, w, **vargs):
        w.kill_region()
        w.set_error("Region killed by %s" % self.name)
class Copy(Method):
    '''Copy the contents of the current line'''
    def _execute(self, w, **vargs):
        w.copy_line()
class CopyRegion(Method):
    '''Copy the region between the mark and the cursor'''
    def _execute(self, w, **vargs):
        w.copy_region()
        w.set_active_point(w.mark)
        w.set_error("Region copied")
class Yank(Method):
    '''Paste the top item in the kill ring into the buffer'''
    def _execute(self, w, **vargs):
        if w.application.has_kill():
            w.yank()
        else:
            w.set_error("Kill ring is empty")
class ShowKill(Method):
    '''Display the top item in the kill ring'''
    def _execute(self, w, **vargs):
        if w.application.has_kill():
            s = w.application.get_kill()
            x = w.application.x
            if len(s) > x - 40:
                s = s[:x - 40] + "..."
            w.set_error("Kill ring contains %r" % s)
        else:
            w.set_error("Kill ring is empty")
class PopKill(Method):
    '''Pop the top item in the kill ring off'''
    def _execute(self, w, **vargs):
        if w.application.has_kill():
            s = w.pop_kill()
            x = w.application.x
            if len(s) > x - 40:
                s = s[:x - 40] + "..."
            w.set_error("Removed %r from Kill ring" % s)
        else:
            w.set_error("Kill ring is empty")

# delete
class DeleteLeft(Method):
    '''Delete the character to the left of the cursor'''
    def _execute(self, w, **vargs):
        (x, y) = w.logical_cursor().xy()
        line = w.buffer.lines[y]
        tabwidth = w.mode.tabwidth
        if x >= tabwidth and x % tabwidth == 0 and line[0:x].isspace():
            w.kill(Point(x - tabwidth, y), Point(x, y))
        else:
            w.left_delete()
class DeleteRight(Method):
    '''Delete the character under the cursor'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        line = w.buffer.lines[cursor.y]
        if len(line[cursor.x:]) >= 4 and line[:cursor.x + 4].isspace():
            w.kill(Point(cursor.x, cursor.y),
                        Point(cursor.x + 4, cursor.y))
        else:
            w.right_delete()
class DeleteLeftWord(Method):
    '''Delete the from the cursor left to the end of the word'''
    def _execute(self, w, **vargs):
        w.kill_left_word()
class DeleteRightWord(Method):
    '''Delete the from under cursor right to the end of the word'''
    def _execute(self, w, **vargs):
        w.kill_right_word()
class DeleteLeftWhitespace(Method):
    '''Delete all contiguous of whitespace left of the cursor'''
    def _execute(self, w, **vargs):
        c = w.logical_cursor()
        p = c
        l = w.point_left(p)
        if l is None:
            return
        while l is not None and w.point_char(l) in (' ', '\n'):
            p = l
            l = w.point_left(p)
        if p < c:
            w.kill(p, c)
class DeleteRightWhitespace(Method):
    '''Delete all contiguous of whitespace under and right of the cursor'''
    def _execute(self, w, **vargs):
        c = w.logical_cursor()
        p = c
        while w.point_char(p) in (' ', '\n'):
            r = w.point_right(p)
            if r is None:
                break
            p = r
        if p > c:
            w.kill(c, p)
class DeleteLeftSpace(Method):
    '''Delete all contiguous spaces left of the cursor'''
    def _execute(self, w, **vargs):
        c = w.logical_cursor()
        p = c
        l = w.point_left(p)
        if l is None:
            return
        while l is not None and w.point_char(l) == ' ':
            p = l
            l = w.point_left(p)
        if p < c:
            w.kill(p, c)
class DeleteRightSpace(Method):
    '''Delete all contiguous spaces under and right of the cursor'''
    def _execute(self, w, **vargs):
        c = w.logical_cursor()
        p = c
        while w.point_char(p) == ' ':
            r = w.point_right(p)
            if r is None:
                break
            p = r
        if p > c:
            w.kill(c, p)

# random stuff
class DumpRegions(Method):
    '''debug region highlighting'''
    def _execute(self, w, **vargs):
        lines = []
        for (w, p1, p2) in w.application.highlighted_ranges:
            lines.append("%r %s %s" % (w, p1, p2))
        output = "\n".join(lines)
        w.application.data_buffer("region-dump", output, switch_to=True)
class DumpMarkers(Method):
    '''Dump all tab markers (tab debugging)'''
    def _execute(self, w, **vargs):
        lines = []
        if w.mode.tabber:
            keys = w.mode.tabber.lines.keys()
            keys.sort()
            for i in keys:
                line = w.mode.tabber.lines[i]
                lines.append("LINE %d: %r" % (i, line))
                lines.append("    %s" % repr(w.mode.tabber.record[i]))
        else:
            lines.append("no tokens")
        output = "\n".join(lines)
        w.application.data_buffer("marker-dump", output, switch_to=True)
class DumpTokens(Method):
    '''Dump all lexical tokens (syntax highlighting debugging)'''
    def _execute(self, w, **vargs):
        modename = w.mode.name()
        lines = []
        if modename in w.buffer.highlights:
            tokens = w.buffer.highlights[modename].tokens
            for i in range(0, len(tokens)):
                lines.append("LINE %d" % i)
                group = tokens[i]
                for token in group:
                    fqname = token.fqname()
                    p1 = Point(token.x, token.y)
                    if token.parent is None:
                        pcoord = ''
                    else:
                        pcoord = '[%d, %d]' % (token.parent.x, token.parent.y)
                    if fqname in w.mode.ghist and p1 in w.mode.ghist[fqname]:
                        g = '[' + w.mode.ghist[fqname][p1].name() + ']'
                    else:
                        g = ''
                    fields = (str(p1), pcoord, token.fqname(), g, token.string)
                    lines.append('    %-10s %-10s %-20s %-10s %r' % fields)
        else:
            lines.append("no tokens")
        output = "\n".join(lines)
        w.application.data_buffer("token-dump", output, switch_to=True)
class MetaX(Method):
    '''Invoke commands by name'''
    args = [Argument('method', datatype="method", prompt="M-x ")]
    def _execute(self, w, **vargs):
        name = vargs['method']
        if name in w.application.methods:
            w.application.methods[name].execute(w)
        else:
            w.set_error('no method named %r found' % name)
            
class ToggleMargins(Method):
    '''Show or hide column margins'''
    def _execute(self, w, **vargs):
        w.margins_visible = not w.margins_visible
class CenterView(Method):
    '''Move view to center on cursor'''
    def _execute(self, w, **vargs):
        w.center_view()
class SetMark(Method):
    '''Set the mark to the current cursor location'''
    def _execute(self, w, **vargs):
        w.set_mark()
class SwitchMark(Method):
    '''Switch the mark and the cursor locations'''
    def _execute(self, w, **vargs):
        w.switch_mark()

# insertion methods
class InsertNewline(Method):
    '''Insert newline into buffer at the cursor'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor('\n')
class InsertSpace(Method):
    '''Insert space into buffer at the cursor'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor(' ')
class GetIndentionLevel(Method):
    '''Calculate the indention level for this line'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if not w.mode.tabber:
            w.set_error('No tabber available')
            return
        else:
            i = w.mode.tabber.get_level(cursor.y)
            w.set_error('Indention level: %r' % i)

class InsertTab(Method):
    '''Insert tab into buffer, or tabbify line, depending on mode'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if w.mode.tabber:
            i = w.mode.tabber.get_level(cursor.y)
        else:
            i = None

        if i is None:
            w.insert_string_at_cursor(' ' * w.mode.tabwidth)
        else:
            j = w.buffer.count_leading_whitespace(cursor.y)
            if i != j:
                KillWhitespace().execute(w)
                w.insert_string(Point(0, cursor.y), ' ' * i)
            else:
                w.goto(Point(j, cursor.y))
class KillWhitespace(Method):
    '''Delete leading whitespace on current line'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        i = w.buffer.count_leading_whitespace(cursor.y)
        if i > 0:
            w.kill(Point(0, cursor.y), Point(i, cursor.y))

# tabification
class TabBuffer(Method):
    '''Tabbify every line in the current buffer'''
    def _execute(self, w, **vargs):
        y = w.logical_cursor().y
        it = InsertTab()
        for i in range(0, len(w.buffer.lines)):
            w.goto_line(i)
            it.execute(w)
        w.goto_line(y)

# commenting
class CommentRegion(Method):
    '''Prepend a comment to every line in the current buffer'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if cursor < w.mark:
            p1 = cursor
            p2 = w.mark
        elif w.mark < cursor:
            p1 = w.mark
            p2 = cursor
        else:
            w.input_line = "Empty kill region"
            return
        for y in range(p1.y, p2.y):
            w.buffer.insert_string(Point(0, y), "#")
class UncommentRegion(Method):
    '''Remove a comment from every line in the current buffer'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if cursor < w.mark:
            p1 = cursor
            p2 = w.mark
        elif w.mark < cursor:
            p1 = w.mark
            p2 = cursor
        else:
            w.input_line = "Empty kill region"
            return
        for y in range(p1.y, p2.y):
            if w.buffer.lines[y].startswith("#"):
                w.buffer.delete(Point(0, y), Point(1, y))

# wrapping/justifying/etc
class WrapLine(Method):
    limit = 80
    space_re = re.compile(' +')
    def _token_len(self, tokens):
        l = 0
        for t in tokens:
            l += len(t)
        return l
    def _find_line_bounds(self, tokens, x, y):
        if len(tokens[0]) > self.limit:
            i = 1
        else:
            i = 0
            l = self._token_len(tokens[:i+1])
            while i < len(tokens) and l <= self.limit:
                i += 1
                l = self._token_len(tokens[:i+1])
            while i > 1 and tokens and tokens[i-1].isspace():
                token = tokens.pop(i-1)
                l -= len(token)
                if x > l:
                    x -= len(token)
                i -= 1
        return i, x, y
    def _clear_preceeding_spaces(self, tokens, x, y):
        while tokens and self.space_re.match(tokens[0]):
            if x > 0:
                x = max(0, x - len(tokens[0]))
            del tokens[0]
        return x, y

    def _wrap_line(self, line, x, y):
        tokens = re.findall('[^ ]+| +', line)
        if self._token_len(tokens) <= self.limit:
            return None, None, None

        lines = []
        while tokens and self._token_len(tokens) > self.limit:
            i, x, y = self._find_line_bounds(tokens, x, y)
            s = ''.join(tokens[:i])
            lines.append(s)
            if x > len(s):
                y += 1
                x -= len(s)
            del tokens[:i]
            x, y = self._clear_preceeding_spaces(tokens, x, y)
        if tokens:
            lines.append(''.join(tokens) + ' ')

        return lines, x, y
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        x, y = cursor.xy()
        lines, x, y = self._wrap_line(w.buffer.lines[y], x, y)
        if lines is None:
            return
        p1 = Point(0, cursor.y)
        p2 = Point(len(w.buffer.lines[cursor.y]), cursor.y)
        w.buffer.delete(p1, p2)
        p3 = Point(0, cursor.y)
        w.buffer.insert_lines(p3, lines)
        w.goto(Point(x, y))
class WrapParagraph(WrapLine):
    limit     = 80
    empty_re  = regex.whitespace
    prefix_re = regex.leading_whitespace
    def _execute(self, w, **vargs):
        c = w.logical_cursor()
        y2 = y1 = c.y
        x2 = x1 = 0
        line = w.buffer.lines[y1]
        if self.empty_re.match(line):
            return

        m = self.prefix_re.match(line)
        prefix = m.group(0)
        lines  = [line.strip()]
        y2 += 1

        while y2 + 1 < len(w.buffer.lines):
            line = w.buffer.lines[y2 + 1]
            if self.empty_re.match(line):
                break
            y2 += 1
            s = line.strip()
            if s:
                lines.append(s)

        x, y = c.xy()
        longline = ' '.join(lines)
        lines, x, y = self._wrap_line(longline, x, y)
        if lines is None:
            return

        p1 = Point(x1, y1)
        if y2 == len(w.buffer.lines):
            y2 -= 1
            x2 = len(w.buffer.lines[y2])
        p2 = Point(x2, y2)
        w.buffer.delete(p1, p2)
        w.buffer.insert_lines(Point(0, c.y), lines)
        while y >= len(w.buffer.lines):
            x = 0
            w.buffer.insert_string(Point(len(w.buffer.lines[-1], len(w.buffer.lines) - 1)), '\n')
        w.goto(Point(x, y))
class WrapParagraph2(Method):
    limit     = 80
    valid_re  = re.compile('^( *)([^ ].*)$')
    empty_re  = regex.whitespace
    prefix_re = None
    def _execute(self, w, **vargs):
        # we will store the start of our paragaph in p1, and also the original
        # cursor position.
        p1 = oldc = w.logical_cursor()
        cur_offset = 0

        m = self.valid_re.match(w.buffer.lines[p1.y])
        if not m:
            # the line was empty, so return
            return
        elif m.group(1):
            # the line had leading whitespace, so return
            return

        # see if we are starting in the middle of the paragraph; if so, then
        # let's find the actual begining, and update p1 accordingly.
        i = p1.y
        if i > 1 and w.buffer.lines[i] and not w.buffer.lines[i].startswith(' '):
            while i > 1 and w.buffer.lines[i - 1] and not w.buffer.lines[i - 1].startswith(' '):
                i -= 1
            p1 = Point(0, i)

        # get the first line; strip it, and put it in our new lines list.
        s1 = w.buffer.lines[p1.y][p1.x:]
        s2 = s1.rstrip()
        if p1.y <= oldc.y:
            cur_offset += len(s1) - len(s2)
        lines = [s2]

        # ok, so now let's move forward and find the end of the paragraph.
        i = p1.y + 1
        while i < len(w.buffer.lines) and w.buffer.lines[i] and not w.buffer.lines[i].startswith(' '):
            s1 = w.buffer.lines[i]
            s2 = s1.rstrip()
            if oldc.y == i:
                # once we've adjusted all our previous lines, adjust our
                # stored cursor to keep it's X and Y in sync (set Y to the line
                # the paragraph started on, increase X by the previous lines
                # plus added spaces minus removed whitespace.
                x = p1.x + oldc.x + sum([len(x) + 1 for x in lines]) - cur_offset
                oldc = Point(x, p1.y)
            elif i < oldc.y:
                cur_offset += len(s1) - len(s2)
            lines.append(s2)
            i += 1

        # stringify our paragraph
        s = " ".join(lines)

        # ok, so now we need to find the line breaks
        newlines = []
        while s:
            # if we have less than the limit left, add it and we're done!
            if len(s) < self.limit:
                newlines.append(s)
                break

            # look for the rightmost space within our bounds
            j = s.rfind(' ', 0, self.limit)
            # if we failed to find one, look for the leftmost space
            if j == -1:
                j = s.find(' ')
            # if we failed to find any, use the whole rest of the paragraph
            if j == -1:
                j = len(s)
            # add the next chunk we found and adjust the paragraph
            newlines.append(s[:j])
            s = s[j + 1:]

        # translate our cursor according to the line breaks we just did.
        (x, y) = oldc.xy()
        k = 0
        while k < len(newlines) - 1 and x > len(newlines[k]):
            x = x - len(newlines[k]) - 1
            y += 1
            k += 1

        # kill the old paragraph region, insert the new, and goto the new cursor
        w.kill(p1, Point(len(w.buffer.lines[i-1]), i-1))
        w.insert_lines(p1, newlines)
        w.goto(Point(x, y))

class JustifyRight(Method):
    '''Justify text with the previous line right from the cursor by whitespace'''
    def _execute(self, w, **vargs):
        DeleteLeftSpace().execute(w)
        cursor = w.logical_cursor()
        prev_line = w.buffer.lines[cursor.y-1]
        this_line = w.buffer.lines[cursor.y]
        if cursor.y <= 0:
            return
        if cursor.x >= len(prev_line):
            return
        i = cursor.x
        while prev_line[i] != ' ':
            i += 1
            if i >= len(prev_line):
                return
        while prev_line[i] == ' ':
            i += 1
            if i >= len(prev_line):
                return
        s = ' ' * (i - cursor.x)
        w.insert_string_at_cursor(s)
class JustifyLeft(Method):
    '''Justify text with the previous line left from the cursor by whitespace'''
    def _execute(self, w, **vargs):
        DeleteRightWhitespace().execute(w)
        cursor = w.logical_cursor()
        prev_line = w.buffer.lines[cursor.y-1]
        this_line = w.buffer.lines[cursor.y]
        if cursor.y <= 0:
            return
        if cursor.x <= 0:
            return
        i = cursor.x
        while i >= len(prev_line):
            i -= 1
            if i <= 0:
                return
            if this_line[i] != ' ':
                return
        while prev_line[i] != ' ':
            i -= 1
            if i <= 0:
                return
            if this_line[i] != ' ':
                return
        while prev_line[i] == ' ':
            i -= 1
            if i >= len(prev_line):
                return
            if this_line[i] != ' ':
                return
        w.buffer.delete(Point(i, cursor.y), cursor)

# undo/redo
class Undo(Method):
    '''Undo last action'''
    def _execute(self, w, **vargs):
        try:
            w.undo()
        except Exception, e:
            w.set_error("%s" % (e))
class Redo(Method):
    '''Redo last undone action'''
    def _execute(self, w, **vargs):
        try:
            w.redo()
        except Exception, e:
            w.set_error("%s" % (e))

# w navigation methods
class StartOfLine(Method):
    '''Move the cursor to the start of the current line'''
    def _execute(self, w, **vargs):
        w.start_of_line()
class EndOfLine(Method):
    '''Move the cursor to the end of the current line'''
    def _execute(self, w, **vargs):
        w.end_of_line()
class Forward(Method):
    '''Move the cursor right one character'''
    def _execute(self, w, **vargs):
        w.forward()
class Backward(Method):
    '''Move the cursor left one character'''
    def _execute(self, w, **vargs):
        w.backward()
class NextLine(Method):
    '''Move the cursor down one line'''
    def _execute(self, w, **vargs):
        w.next_line()
class PreviousLine(Method):
    '''Move the cursor up one line'''
    def _execute(self, w, **vargs):
        w.previous_line()
class PageUp(Method):
    '''Move the cursor up one page'''
    def _execute(self, w, **vargs):
        w.page_up()
class PageDown(Method):
    '''Move the cursor down one page'''
    def _execute(self, w, **vargs):
        w.page_down()
class GotoBeginning(Method):
    '''Move the cursor to the beginning of the buffer'''
    def _execute(self, w, **vargs):
        w.goto_beginning()
class GotoEnd(Method):
    '''Move the cursor to the end of the buffer'''
    def _execute(self, w, **vargs):
        w.goto_end()
class RightWord(Method):
    '''Move the cursor to the start of the word to the right'''
    def _execute(self, w, **vargs):
        w.right_word()
class LeftWord(Method):
    '''Move the cursor to the start of the word to the left'''
    def _execute(self, w, **vargs):
        w.left_word()
class NextSection(Method):
    '''Move the cursor to the next section'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        i = cursor.y + 1
        seen_null_line = False
        while i < len(w.buffer.lines):
            if seen_null_line:
                w.goto_line(i)
                break
            seen_null_line = regex.whitespace.match(w.buffer.lines[i])
            i += 1
class PreviousSection(Method):
    '''Move the cursor to the previous section'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        i = cursor.y - 1
        seen_null_line = False
        while i >= 0:
            if seen_null_line:
                w.goto_line(i)
                break
            seen_null_line = regex.whitespace.match(w.buffer.lines[i])
            i -= 1
class UnindentBlock(Method):
    '''Prepend 4 spaces to each line in region'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if cursor < w.mark:
            p1 = cursor
            p2 = w.mark
        elif w.mark < cursor:
            p1 = w.mark
            p2 = cursor
        else:
            w.input_line = "Empty kill region"
            return
        lines = w.buffer.lines[p1.y:p2.y]
        for i in range(0, len(lines)):
            if lines[i].startswith('    '):
                lines[i] = lines[i][4:]
        w.buffer.delete(Point(0, p1.y), Point(0, p2.y))
        w.buffer.insert_string(Point(0, p1.y), '\n'.join(lines) + '\n')
class IndentBlock(Method):
    '''Add 4 spaces to each line in region'''
    def _execute(self, w, **vargs):
        cursor = w.logical_cursor()
        if cursor < w.mark:
            p1 = cursor
            p2 = w.mark
        elif w.mark < cursor:
            p1 = w.mark
            p2 = cursor
        else:
            w.input_line = "Empty kill region"
            return
        lines = w.buffer.lines[p1.y:p2.y]
        tstr = ' ' * w.mode.tabwidth
        for i in range(0, len(lines)):
            lines[i] = tstr + lines[i]
        w.buffer.delete(Point(0, p1.y), Point(0, p2.y))
        w.buffer.insert_string(Point(0, p1.y), '\n'.join(lines) + '\n')

class OpenConsole(Method):
    '''Evaluate python expressions (for advanced use and debugging only)'''
    def execute(self, w, **vargs):
        a = w.application
        if not a.has_buffer_name('*Console*'):
            b = buffer.ConsoleBuffer()
            a.add_buffer(b)
            window.Window(b, a)
        b = a.bufferlist.get_buffer_by_name('*Console*')
        if a.window().buffer is not b:
            a.switch_buffer(b)
        f = lambda x: None
        w.application.open_mini_buffer('>>> ', f, self, None, 'consolemini')

class ShellCmd(Method):
    '''Run a command in a shell and put the output in a new buffer'''
    args = [Argument("cmd", type=type(""), prompt="$ ", datatype='shell')]
    def _execute(self, w, **vargs):
        cmd = "PBUF='%s'; %s" % (w.buffer.name(), vargs['cmd'])
        (status, data) = commands.getstatusoutput(cmd)
        if status == 0:
            mesg = 'ok'
        else:
            mesg = 'error'
        data += "\nprocess exited with status %d (%s)" % (status, mesg)
        w.application.data_buffer("*Shell*", data, switch_to=True)
class FileDiff(Method):
    '''diff the buffer's contents with the given file'''
    args = [Argument("path", type=type(""), prompt="Filename: ", datatype='path')]
    def _execute(self, w, **vargs):
        cmd = ("/usr/bin/diff", '-u', '-', vargs['path'])
        pipe = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
        pid = pipe.pid

        indata = w.buffer.make_string()
        pipe.stdin.write(indata)
        pipe.stdin.close()

        outdata = pipe.stdout.read()
        errdata = pipe.stderr.read()
        status = pipe.wait() >> 8

        if status == 0:
            w.set_error("No difference found")
        elif status == 1:
            w.application.data_buffer("*Diff*", outdata, switch_to=True, modename='diff')
            w.set_error("Differences were found")
        else:
            w.application.data_buffer("*Diff*", errdata, switch_to=True)
            w.set_error("There was an error: %d exited with status %s" % (pid, status))

class SvnCommit(Method):
    '''diff the current file with the version in SVN'''
    args = [Argument("msg", type=type(""), prompt="Commit Message: ")]
    regex = re.compile(r'^Committed revision ([0-9]+)\.$')
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "svn ci -m %r %r" % (vargs['msg'], path)
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8
        lines = data.split('\n')

        try:
            if status == 0:
                raise Exception
            for line in lines:
                m = self.regex.match(lines[-1])
                if m:
                    w.set_error("Committed [%s]" % (m.group(1)))
                    return
            w.set_error("Up-to-date")
        except:
            w.set_error("Problems with SVN commit: %d" % status)
            w.application.data_buffer("*Commit*", data, switch_to=True)
    
class SvnStatus(Method):
    column = {
        ' ': 'Unmodified',
        'A': 'Added',
        'C': 'Conflicted',
        'D': 'Deleted',
        'I': 'Ignored',
        'M': 'Modified',
        'R': 'Replaced',
        'X': 'External',
        '?': 'Unknown',
        '!': 'Missing',
        '~': 'Obstructed',
    }
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]
        cmd = "svn status -v %r" % path
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8

        if status != 0:
            w.set_error("Problems with 'svn status': %d" % status)
            return

        c = data[0]
        status = self.column.get(c, 'Error (%s)' % c)
        fields = data[6:].split()
        try:
            (rrev, lrev, lauthor, filename) = fields
        except:
            raise Exception, '%r %r' % (fields, data[6:])

        w.set_error('%s  %s  %s/%s  [%s]' % (filename, status, rrev, lrev, lauthor))

class SvnDiff(Method):
    '''diff the current file with the version in SVN'''
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cmd = "svn diff %r" % w.buffer.path
        (status, data) = commands.getstatusoutput(cmd)

        if status == 0:
            if data:
                w.application.data_buffer("*Diff*", data, switch_to=True, modename='diff')
                w.set_error("Differences were found")
            else:
                w.set_error("No difference found")
        else:
            w.set_error("There was an error (%s)" % (status))
class SvnBlame(Method):
    '''show blame output for the current version in SVN'''
    line_re = re.compile('^ *(\d+) *([a-zA-Z0-9_]+) *([-0-9]+) *([:0-9]+) *(-\d{4}) *\(([^\)]+)\) (.*)$')
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cmd = ("/usr/bin/svn", 'blame', '-v', w.buffer.path)
        pipe = Popen(cmd, stdin=PIPE, stdout=PIPE)

        lines = []
        for line in pipe.stdout:
            m = self.line_re.match(line)
            if not m:
                raise Exception, line
            (rev, user, date, t, tz, vdate, content) = m.groups()
            lines.append("%-4s %-10s %10s %s\n" % (rev, user, date, content))
        data = ''.join(lines)
            
        status = pipe.wait() >> 8
        if status == 0:
            w.application.data_buffer("*Blame*", data, switch_to=True, modename='blame')
        else:
            w.set_error("There was an error (%s)" % (status))

class CvsCommit(Method):
    '''diff the current file with the version in CVS'''
    args = [Argument("msg", type=type(""), prompt="Commit Message: ")]
    regex = re.compile('^new revision: ([0-9.]+); previous revision: ([0-9.]+)$')
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "cvs ci -m %r %r" % (vargs['msg'], path)
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8
        lines = data.split('\n')

        if status == 0:
            for line in lines:
                m = self.regex.match(lines[-1])
                if m:
                    w.set_error("Committed [%s -> %s]" % (m.group(2), m.group(1)))
                    return
            w.set_error("Up-to-date")
        else:
            w.set_error("Problems with CVS commit: %d" % status)
            w.application.data_buffer("*Commit*", data, switch_to=True)
    
class CvsStatus(Method):
    regex1 = re.compile('^File: (.+?) *\tStatus: (.*?)$')
    regex2 = re.compile('^   Working revision:\t([0-9\.]+)$')
    regex3 = re.compile('^   Repository revision:\t([0-9\.]+)\t(.*)$')
    regex4 = re.compile('^   Sticky Tag:\t\t\((.*)\)$')
    regex5 = re.compile('^   Sticky Date:\t\t\((.*)\)$')
    regex6 = re.compile('^   Sticky Options:\t\((.*)\)$')
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "cvs status %r" % path
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8

        if status != 0:
            w.set_error("Problems with CVS status: %d" % status)
            return

        lines = data.split('\n')

        if lines[0].startswith('cvs status: nothing known about '):
            w.set_error('File is not under CVS control')
            return

        m = self.regex1.match(lines[1])
        assert m, "regex1 %r" % lines[1]
        ffile = m.group(1)
        fstatus = m.group(2)

        m = self.regex2.match(lines[3])
        assert m, "regex2 %r" % lines[3]
        wrev = m.group(1)

        m = self.regex3.match(lines[4])
        assert m, "regex3 %r" % lines[4]
        rrev = m.group(1)
        rpath = m.group(2)

        m = self.regex4.match(lines[5])
        assert m, "regex4 %r" % lines[5]
        stag = m.group(1)

        m = self.regex5.match(lines[6])
        assert m, "regex5 %r" % lines[6]
        sdate = m.group(1)

        m = self.regex6.match(lines[7])
        assert m, "regex6 %r" % lines[7]
        soptions = m.group(1)

        w.set_error('%s  %s  %s/%s  [%s|%s|%s]' % (ffile, fstatus,
                                                               wrev, rrev, stag,
                                                               sdate, soptions))

class CvsDiff(Method):
    '''diff the current file with the version in CVS'''
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "cvs diff -u %r" % path
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8

        if status == 0:
            w.set_error("No difference found")
        else:
            w.application.data_buffer("*Diff*", data, switch_to=True, modename='diff')
            w.set_error("Differences were found")
class CvsDiff2(Method):
    '''diff the current file with the version in CVS'''
    rev_regex = re.compile('^[0-9]+\.[0-9]+$')
    args = [Argument("revision", type=type(""), prompt="Old Revision: ")]
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        rev = vargs['revision']
        if not self.rev_regex.match(rev):
            w.set_error("Could not parse revision: %r" % rev)
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "cvs diff -r %s -u %r" % (rev, path)
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8

        if status == 0:
            w.set_error("No difference found")
        else:
            w.application.data_buffer("*Diff*", data, switch_to=True, modename='diff')
            w.set_error("Differences were found")
class CvsDiff3(Method):
    '''diff the current file with the version in CVS'''
    rev_regex = re.compile('^[0-9]+\.[0-9]+$')
    args = [Argument("revision1", type=type(""), prompt="Old Revision: "),
            Argument("revision2", type=type(""), prompt="New Revision: ")]
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        rev1 = vargs['revision1']
        if not self.rev_regex.match(rev1):
            w.set_error("Could not parse revision1: %r" % rev)
            return

        rev2 = vargs['revision2']
        if not self.rev_regex.match(rev2):
            w.set_error("Could not parse revision2: %r" % rev)
            return



        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = "cvs diff -r %s -r %s -u %r" % (rev1, rev2, path)
        (status, data) = commands.getstatusoutput(cmd)
        status = status >> 8

        if status == 0:
            w.set_error("No difference found")
        else:
            w.application.data_buffer("*Diff*", data, switch_to=True, modename='diff')
            w.set_error("Differences were found")
class CvsBlame(Method):
    '''show blame output for the current version in SVN'''
    line_re = re.compile('^([0-9.]+) +\(*([a-zA-Z0-9_]+) +([-0-9A-Za-z]+)\): (.*)$')
    def _execute(self, w, **vargs):
        if not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return

        cwd = os.getcwd() + os.path.sep
        path = w.buffer.path
        if path.startswith(cwd):
            path = path[len(cwd):]

        cmd = ("/usr/bin/cvs", 'annotate', path)
        pipe = Popen(cmd, stdout=PIPE)

        tokens = []
        max_rev = 0
        max_user = 0
        for line in pipe.stdout:
            m = self.line_re.match(line)
            if not m:
                raise Exception, line
            (rev, user, date, content) = m.groups()
            max_rev = max(max_rev, len(rev))
            max_user = max(max_user, len(user))
            tokens.append((rev, user, date, content))

        lines = []
        fmt = "%%-%ds %%-%ds %%9s %%s\n" % (max_rev, max_user)
        for (rev, user, date, content) in tokens:
            lines.append(fmt % (rev, user, date, content))
        data = ''.join(lines)
            
        status = pipe.wait() >> 8
        if status == 0:
            w.application.data_buffer("*Blame*", data, switch_to=True, modename='blame')
        else:
            w.set_error("There was an error (%s)" % (status))

class ShowBindingsBuffer(Method):
    '''Dump all keybindings for current mode into a new buffer'''
    def _execute(self, w, **vargs):
        lines = []
        mode_name = w.mode.name()

        lines.append('Key bindings for mode %r:' % (mode_name))
        lines.append('')

        names_to_sequences = {}

        seq_len = len('BINDINGS')
        name_len = len('ACTION')
        for seq in w.mode.bindings:
            name = w.mode.bindings[seq]
            if name.startswith('insert-string-'):
                # we aren't going to show all the generic keypress actions
                continue
            # determine this for formatting
            seq_len = max(seq_len, len(seq))
            name_len = max(name_len, len(name))

            # set up our new data structure
            names_to_sequences.setdefault(name, [])
            names_to_sequences[name].append(seq)

        # generate the format string (note the 'meta formatting')
        format_str = '%%-%ds  %%-%ds  %%s' % (seq_len, name_len)

        lines.append(format_str % ('BINDINGS', 'ACTIONS', 'HELP'))

        names = names_to_sequences.keys()
        names.sort()
        for name in names:
            sequences = names_to_sequences[name]
            sequences.sort()
            seq = sequences[0]
            help = w.application.methods[name].help
            if help is None:
                help = ''

            lines.append(format_str % (seq, name, help))
            for seq2 in sequences[1:]:
                lines.append(format_str % (seq2, '', ''))
        
        data = '\n'.join(lines)
        w.application.data_buffer("*Bindings-Help*", data, switch_to=True)

class CmdHelpBuffer(Method):
    '''Get help with the specified command'''
    args = [Argument('method', datatype="method", prompt="Help for command: ")]
    def _execute(self, w, **vargs):
        lines = []
        name = vargs['method']
        if name not in w.application.methods:
            err = "No command called %r in mode %r" % (name, w.mode.name)
            raise Exception, err

        m = w.application.methods[name]
        lines.append('HELP FOR %r' % name)
        lines.append('')

        # sequences
        sequences = []
        for seq in w.mode.bindings:
            if w.mode.bindings[seq] == name:
                sequences.append(seq)
        sequences.sort()
        lines.append('Keys bound to this command:')
        for seq in sequences:
            lines.append('    %s' % (seq))
        lines.append('')

        # arguments
        if m.args:
            lines.append('Arguments for this command:')
            for arg in m.args:
                if arg.datatype is None:
                    if arg.type == type(""):
                        t = 'str'
                    elif arg.type == type(0):
                        t = 'int'
                    elif arg.type == type(0.0):
                        t = 'float'
                    else:
                        t = 'str'
                else:
                    t = arg.datatype
                if arg.help:
                    lines.append('    %s %r: %s' % (t, arg.name, arg.help))
                else:
                    lines.append('    %s %r' % (t, arg.name))
            lines.append('')

        # help text
        lines.append('Help text for this command:')
        h = m.help
        if not h:
            h = 'No help available'
        lines.append('    %s' % h)
        data = '\n'.join(lines)
        w.application.data_buffer("*Command-Help*", data, switch_to=True)

class SetMode(Method):
    '''Set the mode of the current buffer'''
    args = [Argument('mode', datatype='mode', prompt="Enter new mode: ")]
    def _execute(self, w, **vargs):
        mode_name = vargs['mode']
        m = w.application.modes[mode_name](w)
        w.set_mode(m)
        w.set_error('Set mode to %r' % (mode_name))

class WhichCommand(Method):
    '''Display which command is run for a given key-sequence'''
    def _execute(self, w, **vargs):
        self.old_window = w
        w.application.open_mini_buffer('Enter a key sequence to be explained: ',
                                       lambda x: None,
                                       self,
                                       None,
                                       'which')
        
class Cancel(Method):
    '''Cancel command in-progress, and return to the main buffer'''
    def execute(self, w, **vargs):
        w.application.close_mini_buffer()
        w.set_error('Cancel')

class SplitWindow(Method):
    '''Split the main window horizontally into upper and lower windows'''
    def execute(self, w, **vargs):
        a = w.application
        a.add_slot()
        if not w.cursor_is_visible():
            p = w.first
            w.goto(p)
        n = len(a.bufferlist.slots)
        a.set_error('Window has been split into %d windows!' % n)

class UnsplitWindow(Method):
    '''Maximize the current window to fill the screen'''
    def execute(self, w, **vargs):
        w.application.single_slot()
        w.set_error('Window has been unsplit back to one window!')

class SomethingCrazy(Method):
    def _execute(self, w, **vargs):
        pass

class InsertSquotes(Method):
    '''Insert a pair of single-quotes into the buffer'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor("''")
        w.backward()
class InsertDquotes(Method):
    '''Insert a pair of double-quotes into the buffer'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor('""')
        w.backward()
class InsertEscapedSquote(Method):
    '''Insert an escaped single-quote'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor("\\'")
class InsertEscapedDquote(Method):
    '''Insert an escaped double-quote'''
    def _execute(self, w, **vargs):
        w.insert_string_at_cursor('\\"')

class CloseTag(Method):
    mytag     = ')'
    def _execute(self, w, **vargs):
        # first, de-reference some variables and actually do the insertion
        # NOTE: we derence the cursor *before* inserting the character, so it is
        # expecected that the cursor variable should be the point the new
        # character is on.
        (x, y) = w.logical_cursor().xy()
        w.insert_string_at_cursor(self.mytag)
        app         = w.application
        buffer      = w.buffer
        highlighter = buffer.highlights[w.mode.name()]
        tokens      = highlighter.tokens

        # REFACTOR: we have methods in window to do this now
        i = 0
        while i < len(tokens[y]):
            token = tokens[y][i]
            if token.x == x and token.string == self.mytag:
                break
            elif token.x <= x and token.end_x() > x:
                return
            i += 1
        if i >= len(tokens[y]):
            return

        tag_stack = []
        while y >= 0:
            while i >= 0 and i < len(tokens[y]):
                token = tokens[y][i]
                n = token.name
                s = token.string
                if n in w.mode.closetokens and s in w.mode.closetags:
                    tag_stack.append(s)
                elif n in w.mode.opentokens and s in w.mode.opentags:
                    if tag_stack[-1] == w.mode.opentags[s]:
                        del tag_stack[-1]
                    else:
                        app.set_error("tag mismatch; got %r expected %r" %
                                      (s, w.mode.closetags[tag_stack[-1]]))
                        return
                if len(tag_stack) == 0:
                    p = Point(token.x, y)
                    s = w.buffer.lines[p.y][:p.x+1]
                    if len(s) > 60:
                        s = "..." + s[-60:]
                    msg = 'matches %r' % s
                    w.set_active_point(p, msg)
                    return
                i -= 1
            y -= 1
            i = len(tokens[y]) - 1

class CloseParen(CloseTag):
    mytag = ')'
class CloseBrace(CloseTag):
    mytag = '}'
class CloseBracket(CloseTag):
    mytag = ']'

class GetToken(Method):
    '''View type and data of the "current" token'''
    def _execute(self, w, **vargs):
        token = w.get_token()
        if token is None:
            w.set_error('No Token')
        else:
            w.set_error('Token: %r (%s)' % (token.string, token.fqname()))

class RegisterSave(Method):
    MAX_TXT = 30
    MAX_REG = 20
    '''Save the top item of the kill stack into the named register'''
    args = [Argument('name', datatype="str", prompt="Register name: ")]
    def _pre_execute(self, w, **vargs):
        if not w.has_kill():
            raise MethodError, "No text on the kill stack"
    def _execute(self, w, **vargs):
        name                          = vargs['name']
        text                          = w.get_kill()
        w.application.registers[name] = text
        if len(name) > self.MAX_REG:
            name = name[:self.MAX_REG] + '...'
        if len(text) > self.MAX_TXT:
            text = text[:self.MAX_TXT] + '...'
        w.set_error('Saved %r into register %r' % (text, name))

class RegisterRestore(Method):
    MAX_TXT = 30
    MAX_REG = 18
    '''Push the value saved in the named register onto the kill stack'''
    args = [Argument('name', datatype="str", prompt="Register name: ")]
    def _execute(self, w, **vargs):
        name = vargs['name']
        if name not in w.application.registers:
            w.set_error('Register %r does not exist' % name)
            return
        text = app.registers[name]
        w.push_kill(text)
        if len(text) > self.MAX_TXT:
            text = text[0:self.MAX_TXT] + '...'
        if len(name) > self.MAX_REG:
            name = name[0:self.MAX_REG] + '...'
        w.set_error('Restored %r from register %r' % (text2, name2))

class Pipe(Method):
    '''Pipe the buffer's contents through the command, and display the output in a new buffer'''
    args = [Argument('cmd', datatype="str", prompt="Command: ")]
    def _parse(self, w, **vargs):
        m = regex.shell_command.match(vargs['cmd'])
        if m:
            prog = m.group(0)
            return (prog, vargs['cmd'])
        else:
            return (None, None)
        
    def _execute(self, w, **vargs):
        (prog, cmd) = self._parse(w, **vargs)
        if prog is None:
            return

        pipe = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=STDOUT)
        pid = pipe.pid

        indata = w.buffer.make_string()
        pipe.stdin.write(indata)
        pipe.stdin.close()

        outdata = pipe.stdout.read()
        status = pipe.wait() >> 8

        bufname = '*%s*' % self.name.title()
        w.application.data_buffer(bufname, outdata, switch_to=True)
        w.set_error("%s exited with status %d" % (prog, status))

class Grep(Pipe):
    '''Grep the buffer's contents for instances of a pattern, and display them in a new buffer'''
    args = [Argument('pattern', datatype="str", prompt="Pattern: ")]
    def _parse(self, w, **vargs):
        return ('grep', ('/usr/bin/grep', '-E', '-n', vargs['pattern']))

class Exec(Method):
    args = [Argument('cmd', datatype="str", prompt="Exec: ")]
    def _doit(self, w, path, cmd):
        try:
            cmd = cmd % path
        except:
            w.set_error("Malformed command: %r" % cmd)
            return
        (status, output) = commands.getstatusoutput(cmd)
        bufname = '*%s*' % self.name.title()
        w.application.data_buffer(bufname, output, switch_to=True)
        w.set_error("Shell exited with %d" % status)
    def _execute(self, w, **vargs):
        if w.buffer.btype == 'dir':
            name = dirutil.resolve_name(w)
            path = dirutil.resolve_path(w)
            self._doit(w, path, vargs['cmd'])
            dirutil.find_name(w, name)
        elif hasattr(w.buffer, 'path'):
            path = w.buffer.path
            self._doit(w, path, vargs['cmd'])
        else:
            w.set_error("Don't know how to exec: %r" % w.buffer)
            return

class TokenComplete(Method):
    '''Complete token names based on other tokens in the buffer'''
    name_overrides = {}
    def _min_completion(self, w, t):
        h = w.get_highlighter()
        minlen = None
        if t.name in self.name_overrides:
            ok = name_overrides[t.name]
        else:
            ok = (t.name,)

        strings = {}
        for line in h.tokens:
            for t2 in line:
                if t2 is t:
                    continue
                elif False and t2.name not in ok:
                    continue
                elif t2.string.startswith(t.string):
                    strings[t2.string] = 1
                    if minlen is None:
                        minlen = len(t2.string)
                    else:
                        minlen = min(minlen, len(t2.string))

        strings = strings.keys()
        if not strings:
            return ([], t.string)

        i = len(t.string)
        while i < minlen:
            c = strings[0][i]
            for s in strings:
                if s[i] != c:
                    return (strings, strings[0][:i])
            i += 1
        return (strings, strings[0][:minlen])

    def _execute(self, w, **vargs):
        t = w.get_token2()

        if t is None:
            w.set_error("No token to complete!")
            return
        elif regex.reserved_token_names.match(t.name):
            w.set_error("Will not complete reserved token")
            return

        (candidates, result) = self._min_completion(w, t)

        if candidates:
            p1 = Point(t.x, t.y)
            p2 = Point(t.end_x(), t.y)
            w.buffer.delete(p1, p2)
            w.insert_string(p1, result)

        if not candidates:
            w.set_error("No completion: %r" % result)
        elif len(candidates) == 1:
            w.set_error("Unique completion: %r" % result)
        elif result in candidates:
            w.set_error("Ambiguous completion: %r" % candidates)
        else:
            w.set_error("Partial completion: %r" % candidates)