import math
import collections
import string

from ..filters import FFmpegGraph, FFmpegChain, FFmpegFilter
from .base import OBSSource


IDENTIFY_MAPPING = collections.defaultdict(lambda: '_', {ord(k): k for k in string.ascii_letters + string.digits})

def identifiery(n):
    return n.translate(IDENTIFY_MAPPING)

def deg2rad(n):
    return n * (math.pi / 180)


@OBSSource.type('scene')
class OBSSceneSource(OBSSource):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.name = None
        self.items = []

    def load(self, data):
        self.name = data['name']
        self.items = data['settings']['items']

    def to_ffmpeg(self, scene):
        prefix = identifiery(self.name)
        i = 1
        graph = [FFmpegChain(
            FFmpegFilter('color', c='black', s='{}x{}'.format(*scene.dimensions), outs=[prefix + str(i)])
        )]
        runners = []

        for item in self.items:
            if not item['visible']:
                continue

            rs, chains = scene.sources[item['name']].to_ffmpeg(scene)
            runners.extend(rs)
            c = chains[-1]

            if item['scale']['x'] != 1.0 or item['scale']['y'] != 1.0:
                c.append(FFmpegFilter('scale',
                    w='{} * in_w'.format(item['scale']['x']),
                    h='{} * in_h'.format(item['scale']['y'])
                ))
            if item['crop_top'] != 0 or item['crop_bottom'] != 0 or item['crop_left'] or item['crop_right'] != 0:
                c.append(FFmpegFilter('crop',
                    w='in_w - {} - {}'.format(item['crop_left'], item['crop_right']),
                    h='in_h - {} - {}'.format(item['crop_top'], item['crop_bottom']),
                    x=item['crop_left'],
                    y=item['crop_top']
                ))
            if item['rot'] != 0.0:
                c.append(FFmpegFilter('rotate',
                    angle=deg2rad(item['rot'])
                ))
            c.append(FFmpegFilter('overlay',
                eval='init',
                x=item['pos']['x'],
                y=item['pos']['y'],
                ins=[prefix + str(i)],
                outs=[prefix + str(i + 1)])
            )
            i += 1

            graph.extend(chains)

        return runners, graph