import sys
import json

this = sys.modules[__name__]

this.values = {
    "stack": 0,
    "r": 0,
    "g": 0,
    "b": 0
}


def constant(target, arg):
    return arg


def add(target, arg):
    res = target + arg
    if res > 255:
        res = 255
    elif res < 0:
        res = 0
    return res


def sub(target, arg):
    res = target - arg
    if res > 255:
        res = 255
    elif res < 0:
        res = 0
    return res


def apply(targets, args, func):
    for target in range(len(targets)):
        if this.values[targets[target].channel] != None:
            this.values[targets[target].channel] = func(
                this.values[targets[target].channel], args[target])


this.instructions = {
    "CONSTANT": constant,
    "ADD": add,
    "SUB": sub
}


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


def pat(index, tick, previous_values):
    if this.pattern != None:
        for i in range(len(this.pattern)):
            name = this.pattern[i].instruction.name
            targets = this.pattern[i].instruction.targets
            args = this.pattern[i].instructions.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
        return (r, g, b)
    else:
        return default(index, tick)


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