# -*- coding: utf-8 -*-

import curses

import locale

from .widget import Widget

class EditField(Widget):

    def __init__(self, width=10, value=''):

        Widget.__init__(self, width, 1)

        self.code = locale.getpreferredencoding()

        if not type(value) is str:

            value = str(value, self.code)

        self.value = value

        self.maxlen = None   # unlimited

        self.tw = self.width - 2  # real width of text field (minus space for arrows)

        self.cursor = 0   # position of cursor on screen

        self.pos = 0      # position of cursor in value

        self.ofs = 0      # position of value beginning on screen

        self.connect('draw', self.on_draw)

        self.connect('keypress', self.on_keypress)

    def on_draw(self, screen, x, y):

        # draw value

        val = self.value + ' ' * self.tw         # add spaces to fill rest of field

        val = val[self.ofs : self.ofs + self.tw]  # cut value - begin from ofs, limit to tw chars

        screen.puts(x + 1, y, val.encode(self.code))

        # draw arrows if content overflows

        c = ' '

        if self.ofs > 0:

            c = '<'

        screen.putch(x, y, c)

        c = ' '

        if len(self.value[self.ofs:]) > self.tw:

            c = '>'

        screen.putch(x + self.width-1, y, c)

        # move cursor to the position

        screen.showcursor(x + 1 + self.cursor, y)

    def on_keypress(self, keyname, char):

        if keyname:

            if keyname == 'left':

                self.move_left()

            if keyname == 'right':

                self.move_right()

            if keyname == 'backspace':

                if self.pos > 0:

                    self.move_left()

                    self.del_char()

            if keyname == 'delete':

                self.del_char()

        if char:

            self.add_char(char)

            self.move_right()

        self.redraw()

    def move_left(self):

        if self.cursor > 1 or (self.cursor == 1 and self.pos == 1):

            # move cursor

            self.pos -= 1

            self.cursor -= 1

        else:

            # move content in field

            if self.pos > self.cursor:

                self.pos -= 1

                self.ofs -= 1

    def move_right(self):

        if self.pos < len(self.value):

            if self.cursor < self.tw - 2 \

            or (self.cursor == self.tw - 2 and self.pos == len(self.value)-1):

                # move cursor

                self.pos += 1

                self.cursor += 1

            else:

                # move content in field

                self.pos += 1

                self.ofs += 1

    def add_char(self, c):

        self.value = self.value[:self.pos] + c + self.value[self.pos:]

    def del_char(self):

        self.value = self.value[:self.pos] + self.value[self.pos+1:]