import os, sets, string
import color, method
from lex3 import Lexer
from point import Point

DEBUG = False

class ActionError(Exception):
    pass

class Handler(object):
    def __init__(self):
        self.prefixes      = sets.Set(["C-x", "C-c", "C-u"])
        self.last_sequence = ''
        self.curr_tokens   = []
        self.bindings      = {}

    # handle adding and removing actions
    def add_action(self, action):
        if self.window is None:
            return
        elif action.name in self.window.application.methods:
            return
        else:
            self.window.application.methods[action.name] = action
    def del_action(self, name):
        if self.window is None:
            return
        for binding in self.bindings.keys():
            if self.bindings[binding] == name:
                del self.bindings[binding]
    def add_binding(self, name, sequence):
        if self.window is None:
            return
        elif not hasattr(self.window, 'application'):
            raise Exception, "argh %r %r" % (self, self.window)
        elif name not in self.window.application.methods:
            raise Exception, "No action called %r found" % name
        else:
            self.bindings[sequence] = name
    def add_bindings(self, name, sequences):
        if self.window is None:
            return
        for sequence in sequences:
            self.add_binding(name, sequence)
    def del_binding(self, sequence):
        if self.window is None:
            return
        del self.bindings[sequence]
    def add_action_and_bindings(self, action, sequences):
        if self.window is None:
            return
        self.add_action(action)
        for sequence in sequences:
            self.add_binding(action.name, sequence)
        
    def handle_token(self, t):
        '''self.handle_token(token): returns None, or the action to
        take. raises an exception on unknown input'''
        self.curr_tokens.append(t)
        sequence = " ".join(self.curr_tokens)
        if sequence in self.bindings:
            act = self.window.application.methods[self.bindings[sequence]]
            self.last_sequence = sequence
            self.curr_tokens = []
            return act
        elif t in self.prefixes:
            for binding in self.bindings:
                if binding.startswith(sequence):
                    return None
        self.curr_tokens = []
        self.last_sequence = sequence
        raise ActionError, "no action defined for %r" % (sequence)

class Fundamental(Handler):
    '''This is the default mode'''
    modename      = "Fundamental"
    paths         = []
    basenames     = []
    extensions    = []
    detection     = []
    savetabs      = False
    tabwidth      = 4
    tabbercls     = None
    grammar       = None
    lexer         = None
    tabber        = None
    default_color = ('default', 'default',)
    colors        = {}

    def install(cls, app):
        app.setmode(cls.modename.lower(), cls, paths=cls.paths,
                    basenames=cls.basenames, extensions=cls.extensions,
                    detection=cls.detection)
    install = classmethod(install)

    def __init__(self, w):
        self.window = w

        # we need to defer this due to curses startup
        #self.default_color = color.pairs('default', 'default')
        Handler.__init__(self)

        # first let's add all the "default" actions
        self.add_bindings('start-of-line', ('C-a', 'HOME',))
        self.add_bindings('end-of-line', ('C-e', 'END',))
        self.add_bindings('backward', ('C-b', 'L_ARROW',))
        self.add_bindings('forward', ('C-f', 'R_ARROW',))
        self.add_bindings('center-view', ('C-l',))
        self.add_bindings('next-line', ('C-n', 'D_ARROW',))
        self.add_bindings('previous-line', ('C-p', 'U_ARROW',))
        self.add_bindings('next-section', ('M-n', 'M-D_ARROW',))
        self.add_bindings('previous-section', ('M-p', 'M-U_ARROW',))
        self.add_bindings('page-down', ('C-v', 'PG_DN',))
        self.add_bindings('page-up', ('M-v', 'PG_UP',))
        self.add_bindings('goto-beginning', ('M-<',))
        self.add_bindings('goto-end', ('M->',))
        self.add_bindings('delete-left', ('DELETE', 'BACKSPACE',))
        self.add_bindings('delete-left-word', ('M-DELETE', 'M-BACKSPACE',))
        self.add_bindings('delete-right', ('C-d',))
        self.add_bindings('delete-right-word', ('M-d',))
        self.add_bindings('kill-region', ('C-w',))
        self.add_bindings('copy-region', ('M-w',))
        self.add_bindings('kill', ('C-k',))
        self.add_bindings('copy', ('M-k',))
        self.add_bindings('yank', ('C-y',))
        self.add_bindings('pop-kill', ('M-y',))
        self.add_bindings('right-word', ('M-f',))
        self.add_bindings('left-word', ('M-b',))
        self.add_bindings('set-mark', ('C-@',))
        self.add_bindings('switch-buffer', ('C-x b',))
        self.add_bindings('switch-mark', ('C-x C-x',))
        self.add_bindings('undo', ('C-/', 'C-x u',))
        self.add_bindings('redo', ('M-/', 'M-_', 'C-x r',))
        self.add_bindings('goto-line', ('M-g',))
        self.add_bindings('forward-chars', ('C-x M-c',))
        self.add_bindings('forward-lines', ('C-x M-n',))
        self.add_bindings('search', ('C-s',))
        self.add_bindings('reverse-search', ('C-r',))
        self.add_bindings('regex-search', ('M-C-s',))
        self.add_bindings('regex-reverse-search', ('M-C-r',))
        self.add_bindings('toggle-margins', ('M-m',))
        self.add_bindings('replace', ('M-%',))
        self.add_bindings('regex-replace', ('M-$',))
        self.add_bindings('open-file', ('C-x C-f',))
        self.add_bindings('kill-buffer', ('C-x k',))
        self.add_bindings('list-buffers', ('C-x C-b',))
        self.add_bindings('meta-x', ('M-x',))
        self.add_bindings('wrap-line', ('M-q',))
        self.add_bindings('transpose-words', ('M-t',))
        self.add_bindings('save-buffer', ('C-x C-s',))
        self.add_bindings('save-buffer-as', ('C-x C-w',))
        self.add_bindings('relex-buffer', ('M-r',))
        self.add_bindings('exit', ('C-x C-c',))
        self.add_bindings('split-window', ('C-x s', 'C-x 2',))
        self.add_bindings('unsplit-window', ('C-u s', 'C-x 1',))
        self.add_bindings('toggle-window', ('C-x o',))
        self.add_bindings('delete-left-whitespace', ('C-c DELETE', 'C-c BACKSPACE',))
        self.add_bindings('delete-right-whitespace', ('C-c d',))
        self.add_bindings('insert-space', ('SPACE',))
        self.add_bindings('insert-tab', ('TAB',))
        self.add_bindings('insert-newline', ('RETURN',))
        self.add_bindings('comment-region', ('C-c #',))
        self.add_bindings('uncomment-region', ('C-u C-c #',))
        self.add_bindings('justify-right', ('C-c f',))
        self.add_bindings('justify-left', ('C-c b',))
        self.add_bindings('indent-block', ('C-c >',))
        self.add_bindings('unindent-block', ('C-c <',))
        self.add_bindings('token-complete', ('M-c', 'C-c c'))
        self.add_bindings('shell-cmd', ('C-c !',))
        self.add_bindings('open-aes-file', ('C-c a',))
        self.add_bindings('open-console', ('M-e',))
        self.add_bindings('show-bindings-buffer', ('C-c M-h','C-c M-?',))
        self.add_bindings('which-command', ('M-?',))
        self.add_bindings('cmd-help-buffer', ('M-h',))
        self.add_bindings('set-mode', ('C-x m',))
        self.add_bindings('cancel', ('C-]',))
        self.add_bindings('exec', ('C-c e',))
        self.add_bindings('grep', ('C-c g',))
        self.add_bindings('pipe', ('C-c p',))
        self.add_bindings('view-buffer-parent', ('C-c .',))

        # unbound actions
        self.add_action(method.GetToken())

        # create all the insert actions for the basic text input
        for c in string.letters + string.digits + string.punctuation:
            self.add_binding('insert-string-%s' % c, c)

        # lexing for highlighting, etc.
        if self.grammar:
            self.lexer  = Lexer(self, self.grammar)
            self.gstack = {}
            self.ghist  = {}

        # tab handling
        if self.tabbercls:
            self.tabber = self.tabbercls(self)

    # get mode name
    def name(self):
        return self.modename

    # handle input tokens
    def handle_token(self, t):
        '''self.handle_token(token): handles input "token"'''
        self.window.active_point = None
        #self.window.application.clear_error()
        self.window.clear_error()
        try:
            act = Handler.handle_token(self, t)
            if act is None:
                self.window.set_error(' '.join(self.curr_tokens))
                return
            else:
                act.execute(self.window)
                self.window.application.last_action = act.name
        except ActionError, e:
            if t != 'C-]':
                self.window.set_error(str(e))
            else:
                self.window.set_error('Cancelled')
        except Exception, e:
            if DEBUG:
                raise
            else:
                err = "%s in mode '%s'" % (e, self.name())
                self.window.set_error(err)

    def region_added(self, p, newlines):
        if self.tabber is not None:
            self.tabber.region_added(p, newlines)
        if self.lexer:
            ydelta = len(newlines) - 1
            xdelta = len(newlines[-1])
            ghist = {}
            for name in self.ghist:
                for gp in self.ghist[name]:
                    if gp < p:
                        newp = gp
                    elif ydelta == 0:
                        if p.y == gp.y:
                            newp = Point(gp.x + xdelta, gp.y)
                        else:
                            newp = gp
                    else:
                        if gp.y == p.y:
                            newp = Point(gp.x + xdelta, gp.y + ydelta)
                        else:
                            newp = Point(gp.x, gp.y + ydelta)
                    ghist.setdefault(name, {})
                    ghist[name][newp] = self.ghist[name][gp]
            self.ghist = ghist
    def region_removed(self, p1, p2):
        if self.tabber is not None:
            self.tabber.region_removed(p1, p2)
        if self.lexer:
            ydelta = p2.y - p1.y
            xdelta = p2.x - p1.x
            ghist = {}
            for name in self.ghist:
                for gp in self.ghist[name]:
                    if gp < p1:
                        newp = gp
                    elif p1 <= gp and gp < p2:
                        continue
                    elif ydelta == 0:
                        if gp.y == p2.y:
                            newp = Point(gp.x - xdelta, gp.y)
                        else:
                            newp = gp
                    else:
                        if gp.y == p2.y:
                            newp = Point(gp.x - xdelta, gp.y - ydelta)
                        else:
                            newp = Point(gp.x, gp.y - ydelta)
                    ghist.setdefault(name, {})
                    ghist[name][newp] = self.ghist[name][gp]
            self.ghist = ghist
install = Fundamental.install