from __future__ import print_function, division

from plumbum import colors
from .termsize import get_terminal_size
from .. import cli
import sys

class Image(object):

    __slots__ = "size char_ratio".split()

    def __init__(self, size=None, char_ratio=2.45):
        self.size = size
        self.char_ratio = char_ratio

    def best_aspect(self, orig, term):
        """Select a best possible size matching the orignal aspect ratio.
        Size is width, height.
        The char_ratio option gives the height of each char with respect
        to its width, zero for no effect."""

        if not self.char_ratio: # Don't use if char ratio is 0
            return term

        orig_ratio = orig[0]/orig[1]/self.char_ratio

        if int(term[1]/orig_ratio) <= term[0]:
            new_size = int(term[1]/orig_ratio), term[1]
        else:
            new_size = term[0], int(term[0]*orig_ratio)
        return new_size

    def show(self, filename, double=False):
        """Display an image on the command line. Can select a size or show in double resolution."""

        import PIL.Image
        if double:
            return self.show_pil_double(PIL.Image.open(filename))
        else:
            return self.show_pil(PIL.Image.open(filename))

    def _init_size(self, im):
        """Return the expected image size"""
        if self.size is None:
            term_size = get_terminal_size()
            return self.best_aspect(im.size, term_size)
        else:
            return self.size

    def show_pil(self, im):
        'Standard show routine'
        size = self._init_size(im)
        new_im = im.resize(size).convert("RGB")

        for y in range(size[1]):
            for x in range(size[0]-1):
                pix = new_im.getpixel((x,y))
                print(colors.bg.rgb(*pix), ' ', sep='', end='') # u'\u2588'
            print(colors.reset, ' ', sep='')
        print(colors.reset)

    def show_pil_double(self, im):
        'Show double resolution on some fonts'

        size = self._init_size(im)
        size= (size[0], size[1]*2)
        new_im = im.resize(size).convert("RGB")

        for y in range(size[1]//2):
            for x in range(size[0]-1):
                pix = new_im.getpixel((x,y*2))
                pixl = new_im.getpixel((x,y*2+1))
                print(colors.bg.rgb(*pixl) & colors.fg.rgb(*pix), u'\u2580', sep='', end='')
            print(colors.reset, ' ', sep='')
        print(colors.reset)

class ShowImageApp(cli.Application):
    'Display an image on the terminal'
    double = cli.Flag(['-d','--double'], help="Double resolution (only looks good with some fonts)")

    @cli.switch(['-c','--colors'], cli.Range(1,4), help="Level of color, 1-4")
    def colors_set(self, n):
        colors.use_color = n

    size = cli.SwitchAttr(['-s','--size'], help="Size, should be in the form 100x150")

    ratio = cli.SwitchAttr(['--ratio'], float, default=2.45, help="Aspect ratio of the font")

    @cli.positional(cli.ExistingFile)
    def main(self, filename):

        size=None
        if self.size:
            size = map(int, self.size.split('x'))

        Image(size, self.ratio).show(filename, self.double)

if __name__ == '__main__':
    ShowImageApp()
