import os.path, string
import regex
from point2 import Point

WORD_LETTERS = list(string.letters + string.digits)

# note about the cursor: the cursor position will insert in front of the
# character it highlights. to this end, it needs to be able to highlight behind
# the last character on a line. thus, the x coordinate of the (logical) cursor
# can equal the length of lines[y], even though lines[y][x] throws an index
# error. both buffer and window need to be aware of this possibility for points.

class Window(object):
    def __init__(self, b, a, height=24, width=80, mode_name=None):
        self.buffer      = b
        self.application = a

        self.first        = Point(0, 0)
        self.last         = None
        self.cursor       = Point(0, 0)
        self.mark         = None
        self.active_point = None

        self.height = height
        self.width  = width

        self.input_line = ""

        if mode_name is not None:
            pass
        elif hasattr(self.buffer, 'modename') and self.buffer.modename is not None:
            mode_name = self.buffer.modename
        elif self.buffer.name() == "*Minibuffer*":
            mode_name = 'mini'
        elif self.buffer.name() == "*Console*":
            mode_name = "fundamental"
        elif hasattr(self.buffer, 'path'):
            path = self.buffer.path
            basename = os.path.basename(path)
            ext = self._get_path_ext(path)

            if path in self.application.mode_paths:
                mode_name = self.application.mode_paths[path]
            elif basename in self.application.mode_basenames:
                mode_name = self.application.mode_basenames[basename]
            elif ext in self.application.mode_extensions:
                mode_name = self.application.mode_extensions[ext]
            elif len(self.buffer.lines) > 0 and \
                self.buffer.lines[0].startswith('#!'):
                line = self.buffer.lines[0]
                for word in self.application.mode_detection:
                    if word in line:
                        mode_name = self.application.mode_detection[word]

        if mode_name is None:
            mode_name = "fundamental"

        m = self.application.modes[mode_name](self)
        self.set_mode(m)
        self.buffer.add_window(self)

    # private method used in window constructor
    def _get_path_ext(self, path):
        name = os.path.basename(path).lower()
        tokens = name.split('.')
        if len(tokens) > 2 and tokens[-1] in ('gz', 'in', 'zip'):
            return '.%s.%s' % (tokens[-2], tokens[-1])
        else:
            return os.path.splitext(path)[1].lower()

    # mode stuff
    def set_mode(self, m):
        self.mode = m
        #self.redraw()
    def get_highlighter(self):
        if self.mode.lexer is None:
            return None
        else:
            return self.buffer.highlights[self.mode.name()]

    # this is used to temporarily draw the user's attention to another point
    def set_active_point(self, p, msg='marking on line %(y)d, character %(x)d'):
        self.active_point = p
        if not self.point_is_visible(p):
            self.application.set_error(msg % {'x': p.x, 'y': p.y})

    # point left
    def point_left(self, p):
        if p.y == 0 and p.x == 0:
            return None
        elif p.x == 0:
            return Point(len(self.buffer.lines[p.y - 1]), p.y - 1)
        else:
            return Point(p.x - 1, p.y)

    # point right
    def point_right(self, p):
        if p.y == len(self.buffer.lines)-1 and p.x == len(self.buffer.lines[-1]):
            return None
        elif p.x == len(self.buffer.lines[p.y]):
            return Point(0, p.y + 1)
        else:
            return Point(p.x + 1, p.y)

    # cursors
    def logical_cursor(self):
        if len(self.buffer.lines) > self.cursor.y:
            l = len(self.buffer.lines[self.cursor.y])
        else:
            l = 0
        x = min(self.cursor.x, l)
        return Point(x, self.cursor.y)

    # last visible point
    def _calc_last(self):
        (x, y) = self.first.xy()
        count = 0
        while count < self.height - 1 and y < len(self.buffer.lines):
            line = self.buffer.lines[y]
            if x >= len(line) or len(line[x:]) <= self.width:
                x = 0
                y += 1
                count += 1
            else:
                count += 1
                x += self.width

        if y < len(self.buffer.lines):
            x = min(x + self.width, len(self.buffer.lines[y]))
        self.last = Point(x, y)

    # redrawing
    def redraw(self):
        self._calc_last()
        
    def set_size(self, width, height):
        assert type(width) == type(0), width
        assert type(height) == type(0), height
        self.width  = width
        self.height = height
        self.redraw()

    # region added
    def region_added(self, p, newlines):
        (x, y) = self.logical_cursor().xy()
        l = len(newlines)
        assert l > 0, repr(newlines)
        if l > 1:
            if y > p.y:
                self.cursor = Point(x, y + l - 1)
            elif y == p.y and x >= p.x:
                self.cursor = Point(len(newlines[-1]) + x - p.x, y + l - 1)
        elif y == p.y and x >= p.x:
            self.cursor = Point(x + len(newlines[0]), y)
        self.mode.region_added(p, newlines)
        self.assure_visible_cursor()

    # region removed
    def region_removed(self, p1, p2):
        cursor = self.logical_cursor()
        (x, y) = cursor.xy()
        if cursor < p1:
            pass
        elif cursor < p2:
            self.cursor = p1
        elif cursor.y == p2.y:
            self.cursor = Point(self.cursor.x - p2.x + p1.x, p1.y)
        else:
            self.cursor = Point(self.cursor.x, self.cursor.y - p2.y + p1.y)
        self.mode.region_removed(p1, p2)
        self.assure_visible_cursor()

    def point_is_visible(self, p):
        return self.first <= p and p <= self.last
    def cursor_is_visible(self):
        return self.point_is_visible(self.logical_cursor())
    def first_is_visible(self):
        return self.point_is_visible(self.buffer.get_buffer_start())
    def last_is_visible(self):
        return self.point_is_visible(self.buffer.get_buffer_end())
        
    def center_view(self):
        (x, y) = self.logical_cursor().xy()
        counter = 0
        while counter < self.height / 2:
            if x > self.width:
                x -= self.width
            elif y > 0:
                y -= 1
                x = len(self.buffer.lines[y])
            else:
                (x, y) = (0, 0)
                break
            counter += 1
        self.first = Point(x - (x % self.width), y)
        self.redraw()
    def assure_visible_cursor(self):
        if not self.cursor_is_visible():
            self.center_view()
        
    # moving in buffer
    def forward(self):
        cursor = self.logical_cursor()
        if cursor.x < len(self.buffer.lines[cursor.y]):
            self.cursor = Point(cursor.x + 1, cursor.y)
        elif cursor.y < len(self.buffer.lines) -1:
            self.cursor = Point(0, cursor.y + 1)
        self.assure_visible_cursor()
    def backward(self):
        cursor = self.logical_cursor()
        if cursor.x > 0:
            self.cursor = Point(cursor.x - 1, cursor.y)
        elif cursor.y > 0:
            self.cursor = Point(len(self.buffer.lines[cursor.y - 1]), cursor.y - 1)
        self.assure_visible_cursor()
    def end_of_line(self):
        cursor = self.logical_cursor()
        self.cursor = Point(len(self.buffer.lines[cursor.y]), cursor.y)
        self.assure_visible_cursor()
    def start_of_line(self):
        cursor = self.logical_cursor()
        self.cursor = Point(0, cursor.y)
        self.assure_visible_cursor()
    def previous_line(self):
        cursor = self.logical_cursor()
        if cursor.y > 0:
            self.cursor = Point(cursor.x, cursor.y - 1)
        self.assure_visible_cursor()
    def next_line(self):
        cursor = self.logical_cursor()
        if cursor.y < len(self.buffer.lines) - 1:
            self.cursor = Point(cursor.x, cursor.y + 1)
        self.assure_visible_cursor()

    # word handling
    def find_left_word(self, p=None):
        if p is None:
            (x, y) = self.logical_cursor().xy()
        else:
            (x, y) = p.xy()

        start = self.buffer.get_buffer_start()
        if (x, y) == start:
            return
        elif x == 0:
            y -= 1
            x = len(self.buffer.lines[y])
        else:
            x -= 1
        while (y, x) >= start and self.xy_char(x, y) not in WORD_LETTERS:
            if x == 0:
                y -= 1
                x = len(self.buffer.lines[y])
            else:
                x -= 1
        found_word = False
        while (y, x) >= start and self.xy_char(x, y) in WORD_LETTERS:
            found_word = True
            if x == 0:
                y -= 1
                x = len(self.buffer.lines[y])
            else:
                x -= 1
        if not found_word:
            return None
        elif x == len(self.buffer.lines[y]):
            x = 0
            y += 1
        else:
            x += 1
        return Point(x, y)
    def find_right_word(self, p=None):
        if p is None:
            (x, y) = self.logical_cursor().xy()
        else:
            (x, y) = p.xy()
        end = self.buffer.get_buffer_end()
        while (y, x) < end and self.xy_char(x, y) not in WORD_LETTERS:
            if x == len(self.buffer.lines[y]):
                x = 0
                y += 1
            else:
                x += 1
        while (y, x) < end and self.xy_char(x, y) in WORD_LETTERS:
            if x == len(self.buffer.lines[y]):
                x = 0
                y += 1
            else:
                x += 1
        return Point(x, y)
    def left_word(self):
        p = self.find_left_word()
        if p is not None:
            self.goto(p)
    def right_word(self):
        p = self.find_right_word()
        if p is not None:
            self.goto(p)
    def get_word_bounds_at_point(self, p):
        if len(self.buffer.lines[p.y]) == 0:
            return
        elif p.x == 0:
            p1 = self.find_left_word(Point(p.x + 1, p.y))
            p2 = self.find_right_word()
        else:
            p1 = self.find_left_word()
            p2 = self.find_right_word(Point(p.x - 1, p.y))
        return (p1, p2)
    def get_word_at_point(self, p):
        bounds = self.get_word_bounds_at_point(p)
        if bounds is None:
            return None
        else:
            return self.buffer.get_substring(bounds[0], bounds[1])
    def get_word_bounds(self):
        return self.get_word_bounds_at_point(self.logical_cursor())
    def get_word(self):
        return self.get_word_at_point(self.logical_cursor())

    # page up/down
    def _pshift_up(self, p, num):
        (x, y) = p.xy()
        orig_x  = x
        counter = 0
        while counter < num and y > 0:
            if x > self.width:
                x -= self.width
            else:
                y -= 1
                x = len(self.buffer.lines[y])
            counter += 1
        return Point(orig_x, y)
    def _pshift_down(self, p, num):
        (x, y) = p.xy()
        orig_x  = x
        counter = 0
        while counter < num and y < len(self.buffer.lines):
            if x + self.width >= len(self.buffer.lines[y]):
                y += 1
                x = 0
            else:
                x += self.width
            counter += 1
        return Point(orig_x, y)
    def page_up(self):
        first_point = self.buffer.get_buffer_start()
        if self.point_is_visible(first_point):
            self.goto_beginning()
            return
        self.cursor = self._pshift_up(self.cursor, self.height - 3)
        if self.first > first_point:
            self.first = self._pshift_up(self.first, self.height - 3)
            self.redraw()
    def page_down(self):
        last_point = self.buffer.get_buffer_end()
        if self.point_is_visible(last_point):
            self.goto_end()
            return
        self.cursor = self._pshift_down(self.cursor, self.height - 3)
        if self.last < last_point:
            self.first = self._pshift_down(self.first, self.height - 3)
            self.redraw()

    # jumping in buffer
    def goto(self, p):
        self.cursor = p
        self.assure_visible_cursor()
    def goto_line(self, n):
        assert n > 0 and n <= len(self.buffer.lines) , "illegal line: %d" % n
        self.cursor = Point(0, n - 1)
        self.assure_visible_cursor()
    def forward_lines(self, n):
        assert n > 0, "illegal number of lines: %d" % n
        y = min(self.logical_cursor().y + n, len(self.buffer.lines) - 1)
        self.goto(Point(0, y))
    def forward_chars(self, n):
        (x, y) = self.logical_cursor().xy()
        for i in range(0, n):
            if x == len(self.buffer.lines[y]):
                y += 1
                x = 0
                if y >= len(self.buffer.lines):
                    break
            else:
                x += 1
        self.goto(Point(x, y))
    def goto_char(self, n):
        self.goto_beginning()
        self.forward_chars(n)
    def goto_beginning(self):
        self.cursor = Point(0, 0)
        self.assure_visible_cursor()
    def goto_end(self):
        self.cursor = self.buffer.get_buffer_end()
        self.assure_visible_cursor()

    # mark manipulation
    def set_mark_point(self, p):
        self.mark = p
    def set_mark(self):
        self.set_mark_point(self.logical_cursor())
        self.application.set_error("Mark set")
    def goto_mark(self):
        self.goto(self.mark)
    def switch_mark(self):
        if self.mark:
            p = self.mark
            self.set_mark_point(self.logical_cursor())
            self.goto(p)

    # deletion
    def left_delete(self):
        (x, y) = self.logical_cursor().xy()
        if x > 0:
            self.buffer.delete_char(Point(x - 1, y))
        elif y > 0:
            self.buffer.delete_char(Point(len(self.buffer.lines[y - 1]), y - 1))
    def right_delete(self):
        cursor = self.logical_cursor()
        if cursor < self.last:
            self.buffer.delete_char(cursor)
        else:
            pass
        
    # killing
    def kill_line(self):
        return self.copy_line(kill=True)
    def kill_region(self):
        return self.copy_region(kill=True)
    def kill_left_word(self):
        p1 = self.find_left_word()
        p2 = self.logical_cursor()
        if p1 == p2:
            return
        return self.kill(p1, p2)
    def kill_right_word(self):
        p1 = self.logical_cursor()
        p2 = self.find_right_word()
        if p1 == p2:
            return
        return self.kill(p1, p2)
    def copy_line(self, kill=False):
        cursor = self.logical_cursor()
        (x, y) = cursor.xy()
        lines = self.buffer.lines
        if (x < len(lines[y]) and not regex.whitespace.match(lines[y][x:])):
            limit = Point(len(lines[y]), y)
        elif y < len(lines) - 1:
            limit = Point(0, y + 1)
        else:
            return
        if kill:
            return self.kill(cursor, limit)
        else:
            return self.copy(cursor, limit)
    def copy_region(self, kill=False):
        cursor = self.logical_cursor()
        if cursor < self.mark:
            p1 = cursor
            p2 = self.mark
        elif self.mark < cursor:
            p1 = self.mark
            p2 = cursor
        else:
            self.input_line = "Empty kill region"
            return
        if kill:
            return self.kill(p1, p2)
        else:
            return self.copy(p1, p2)
    def kill(self, p1, p2):
        killed = self.buffer.get_substring(p1, p2)
        self.buffer.delete(p1, p2)
        self.application.push_kill(killed)
        return killed
    def copy(self, p1, p2):
        copied = self.buffer.get_substring(p1, p2)
        self.application.push_kill(copied)
        return copied

    # insertion
    def insert_string_at_cursor(self, s):
        self.insert_string(self.logical_cursor(), s)
    def insert_string(self, p, s):
        lines = s.split('\n')
        self.insert_lines(p, lines)
    def insert_lines_at_cursor(self, lines):
        self.insert_lines(self.logical_cursor(), lines)
    def insert_lines(self, p, lines):
        self.buffer.insert_lines(p, lines)
        self.redraw()

    # yank/pop
    def yank(self):
        self.insert_string_at_cursor(self.application.get_kill())
    def pop_kill(self):
        return self.application.pop_kill()

    # querying
    def cursor_char(self):
        self.point_char(self.logical_cursor())
    def point_char(self, p):
        return self.xy_char(p.x, p.y)
    def xy_char(self, x, y):
        #assert 0 <= y and y < len(self.buffer.lines)
        #assert 0 <= x and x <= len(self.buffer.lines[y])
        if x == len(self.buffer.lines[y]):
            return "\n"
        else:
            return self.buffer.lines[y][x]

    # undo/redo
    # XYZ
    def undo(self):
        # TODO: put something here to move the cursor to the area of the undo
        self.buffer.undo()
    def redo(self):
        # TODO: put something here to move the cursor to the area of the redo
        self.buffer.redo()