from tuikit.core.widget import Widget

from tuikit.core.signal import Signal

class TextBox(Widget):

    """Multiline text view/edit widget."""

    def __init__(self, text=''):

        Widget.__init__(self)

        self.allow_focus = True

        # Text content, splitted as lines

        self._lines = []

        self.text = text

        self._cursor_visible = True

        # for the case when cursor moves to shorter line.

        self.cursor_column = 0

        # selection - line and column of selection start

        self.sel_line = 0

        self.sel_column = 0

        #self.add_events('scroll', Event)

    @property

    def text(self):

        return '\n'.join(self._lines)

    @text.setter

    def text(self, value):

        self._lines = value.split('\n')

        maxlen = max([len(line) for line in self._lines])

        self.sizereq.update(w=maxlen, h=len(self._lines))

    @property

    def cur_line(self):

        return self._lines[self._cursor.y]

    @cur_line.setter

    def cur_line(self, value):

        self._lines[self._cursor.y] = value

    def draw(self, buffer):

        exposed = self.exposed(buffer)

        with buffer.attr(self.theme.normal):

            buffer.fill()

            end_y = min(len(self._lines), exposed.y + exposed.h)

            for j in range(exposed.y, end_y):

                line = self._lines[j]

                buffer.puts(line, 0, j)

    def keypress_event(self, ev):

        if ev.keyname and not ev.mods:

            consumed = True

            if   ev.keyname == 'left':        self.move_left()

            elif ev.keyname == 'right':       self.move_right()

            elif ev.keyname == 'home':        self.move_home()

            elif ev.keyname == 'end':         self.move_end()

            elif ev.keyname == 'up':          self.move_up()

            elif ev.keyname == 'down':        self.move_down()

            elif ev.keyname == 'pageup':      self.move_pageup()

            elif ev.keyname == 'pagedown':    self.move_pagedown()

            elif ev.keyname == 'backspace':   self.backspace()

            elif ev.keyname == 'delete':      self.del_char()

            elif ev.keyname == 'enter':       self.add_newline(move=True)

            else:

                consumed = False

            if consumed:

                return True

        if ev.mods:

            consumed = True

            mk = ev.mod_key()

            if   mk == 'ctrl+home':    self.move_top()

            elif mk == 'ctrl+end':     self.move_bottom()

            else:

                consumed = False

            if consumed:

                return True

        if ev.char and not ev.keyname:

            self.add_char(ev.char)

            self.move_right()

            return True

    def on_mousedown(self, ev):

        y = ev.wy

        x = min(ev.wx, len(self._lines[y]))

        self._cursor.update(x=x, y=y)

        self.redraw()

    def on_mousewheel(self, ev):

        if ev.button == 4:

            # wheel up

            self.emit('scrollreq', -5)

        if ev.button == 5:

            # wheel down

            self.emit('scrollreq', +5)

        self.redraw()

    def move_left(self):

        if self._cursor.x > 0:

            self._cursor.x -= 1

        else:

            if self._cursor.y > 0:

                self._cursor.y -= 1

                self._cursor.x = len(self.cur_line)

        self.cursor_column = self._cursor.x

    def move_right(self):

        if self._cursor.x < len(self.cur_line):

            self._cursor.x += 1

        else:

            if self._cursor.y < len(self._lines) - 1:

                self._cursor.y += 1

                self._cursor.x = 0

        self.cursor_column = self._cursor.x

    def move_home(self):

        self._cursor.x = 0

        self.cursor_column = self._cursor.x

    def move_end(self):

        self._cursor.x = len(self.cur_line)

        self.cursor_column = self._cursor.x

    def move_up(self):

        if self._cursor.y > 0:

            self._cursor.y -= 1

        self._update_cursor_x()

    def move_down(self):

        if self._cursor.y < len(self._lines) - 1:

            self._cursor.y += 1

        self._update_cursor_x()

    def move_pageup(self):

        if self._cursor.y >= self.view_height - 1:

            self.emit('scrollreq', - (self.view_height - 1))

            self._cursor.y -= self.view_height - 1

        else:

            self._cursor.y = 0

        self._update_cursor_x()

    def move_pagedown(self):

        if len(self._lines) - self._cursor.y > (self.view_height - 1):

            self.emit('scrollreq', (self.view_height - 1))

            self._cursor.y += self.view_height - 1

        else:

            self._cursor.y = len(self._lines) - 1

        self._update_cursor_x()

    def move_top(self):

        self._cursor.y = 0

        self._update_cursor_x()

    def move_bottom(self):

        self._cursor.y = len(self._lines) - 1

        self._update_cursor_x()

    def add_char(self, c):

        ln = self.cur_line

        sx = self._cursor.x

        self.cur_line = ln[:sx] + c + ln[sx:]

        self.cursor_column = sx

    def add_newline(self, move=False):

        ln = self.cur_line

        sx = self._cursor.x

        self.cur_line = ln[sx:]

        self._lines.insert(self._cursor.y, ln[:sx])

        self.sizereq.update(h=len(self._lines))

        if move:

            self.move_right()

    def add_line(self, text):

        ln = self.cur_line

        sx = self._cursor.x

        self.cur_line = ln[sx:]

        self._lines.insert(self._cursor.y, ln[:sx] + text)

        self.cursor_column = 0

        self._cursor.x = 0

        self._cursor.y += 1

        w = max(self.sizereq.w, len(ln[:sx] + text))

        self.sizereq.update(w=w, h=len(self._lines))

    def backspace(self):

        if self._cursor.y > 0 or self._cursor.x > 0:

            self.move_left()

            self.del_char()

    def del_char(self):

        ln = self.cur_line

        sx = self._cursor.x

        if sx == len(self.cur_line):

            if self._cursor.y + 1 < len(self._lines):

                self.cur_line += self._lines[self._cursor.y+1]

                del self._lines[self._cursor.y+1]

                self.sizereq.update(h=len(self._lines))

        else:

            self.cur_line = ln[:sx] + ln[sx+1:]

    def _update_cursor_x(self):

        if self.cursor_column > len(self.cur_line):

            self._cursor.x = len(self.cur_line)

        else:

            self._cursor.x = self.cursor_column