import sys
import json
import random
import logger

this = sys.modules[__name__]

this.encoded = None
this.pattern = None
this.values = {
    "stack": 0,
    "r": 0,
    "g": 0,
    "b": 0,
    "tick": 0,
    "index": 0
}


def constant(target, arg):
    return arg


def add(target, arg):
    return target + arg


def sub(target, arg):
    return target - arg


def mult(target, arg):
    return target * arg


def div(target, arg):
    return target / arg


def mod(target, arg):
    if arg <= 0:
        return target
    return target % arg


def rand(target, arg):
    return random.randrange(0, 255)


def _apply(target, arg, func):
    if type(arg is int):
        return func(target, arg)
    elif type(arg is str) and arg in this.values:
        return func(target, this.values[arg])


def apply(targets, args, func):
    for target in range(len(targets)):
        if this.values[targets[target]['channel']] != None:
            if target <= len(args):
                this.values[targets[target]['channel']] = _apply(
                    this.values[targets[target]['channel']], args[target], func)
            else:
                this.values[targets[target]['channel']] = _apply(
                    this.values[targets[target]['channel']], 0, func)
            logger.debug("{} : {}".format(
                targets[target]['channel'],
                this.values[targets[target]['channel']]
            ))


this.instructions = {
    "CONSTANT": constant,
    "ADD": add,
    "SUBTRACT": sub,
    "MULTIPLY": mult,
    "DIVIDE": div,
    "MODULO": mod,
    "RANDOM": rand
}


def default(index, tick):
    return (((index + tick) * 5) % 255, (tick * 42) % 255, (tick * 50) % 255)


def pat(index, tick, previous_values):
    this.values['tick'] = tick
    this.values['index'] = index
    if this.pattern != None:
        for i in range(len(this.pattern)):
            name = this.pattern[i]['instruction']['name']
            targets = this.pattern[i]['instruction']['targets']
            args = []
            if 'args' in this.pattern[i]['instruction']:
                args = this.pattern[i]['instruction']['args']
            if this.instructions[name] != None:
                apply(targets, args, this.instructions[name])
        r = this.values["r"]
        g = this.values["g"]
        b = this.values["b"]
        this.values["r"] = 0
        this.values["g"] = 0
        this.values["b"] = 0
        this.values["stack"] = 0
        if r > 255:
            r = 255
        elif r < 0:
            r = 0
        if g > 255:
            g = 255
        elif g < 0:
            g = 0
        if b > 255:
            b = 255
        elif b < 0:
            b = 0
        return (r, g, b)
    else:
        return default(index, tick)


def parse(str):
    this.encoded = str
    logger.debug(this.encoded)
    this.pattern = json.loads(this.encoded)