#!/usr/bin/env python3

# Nga: a Virtual Machine
# Copyright (c) 2010 - 2020, Charles Childers
# Floating Point I/O by Arland Childers, (c) 2020
# Optimizations and process() rewrite by Greg Copeland
# -----------------------------------------------------

import os, sys, math, time, struct, random, datetime
from struct import pack, unpack

from ClockDevice import Clock
from RNGDevice import RNG
from FileSystemDevice import FileSystem

from FloatStack import FloatStack
from IntegerStack import IntegerStack
from Memory import Memory


ip = 0
stack = IntegerStack()
address = []
memory = Memory("ngaImage", 1000000)

clock = Clock()
rng = RNG()

floats = FloatStack()
afloats = FloatStack()
files = FileSystem()


class Retro:
    def __init__(self):
        self.ip = 0
        self.stack = IntegerStack()
        self.address = IntegerStack()
        self.memory = Memory("ngaImage", 1000000)
        self.clock = Clock()
        self.rng = RNG()
        self.files = FileSystem()
        self.floats = FloatStack()
        self.afloats = FloatStack()
        self.Dictionary = dict()
        self.Cached = dict()
        self.Cached['interpreter'] = self.memory.fetch(self.find_entry("interpret") + 1)
        self.Cached['not_found'] = self.memory.fetch(self.find_entry("err:notfound") + 1)
        self.Cached['s:eq?'] = self.memory.fetch(self.find_entry("s:eq?") + 1)

        self.instructions = [
            self.i_nop,
            self.i_lit,
            self.i_dup,
            self.i_drop,
            self.i_swap,
            self.i_push,
            self.i_pop,
            self.i_jump,
            self.i_call,
            self.i_ccall,
            self.i_return,
            self.i_eq,
            self.i_neq,
            self.i_lt,
            self.i_gt,
            self.i_fetch,
            self.i_store,
            self.i_add,
            self.i_subtract,
            self.i_multiply,
            self.i_divmod,
            self.i_and,
            self.i_or,
            self.i_xor,
            self.i_shift,
            self.i_zreturn,
            self.i_halt,
            self.i_ienumerate,
            self.i_iquery,
            self.i_iinvoke,
        ]

    def div_mod(self, a, b):
        x = abs(a)
        y = abs(b)
        q, r = divmod(x, y)
        if a < 0 and b < 0:
            r *= -1
        elif a > 0 and b < 0:
            q *= -1
        elif a < 0 and b > 0:
            r *= -1
            q *= -1
        return q, r

    def find_entry(self, named):
        header = self.memory.fetch(2)
        Done = False
        while header != 0 and not Done:
            if named == self.extract_string(header + 3):
                Done = True
            else:
                header = self.memory.fetch(header)
        return header

    def get_input(self):
        return ord(sys.stdin.read(1))

    def display_character(self):
        if self.stack.tos() > 0 and self.stack.tos() < 128:
            if self.stack.tos() == 8:
                sys.stdout.write(chr(self.stack.pop()))
                sys.stdout.write(chr(32))
                sys.stdout.write(chr(8))
            else:
                sys.stdout.write(chr(self.stack.pop()))
        else:
            sys.stdout.write("\033[2J\033[1;1H")
            self.stack.pop()
        sys.stdout.flush()

    def i_nop(self):
        pass

    def i_lit(self):
        self.ip += 1
        self.stack.push(self.memory.fetch(self.ip))

    def i_dup(self):
        self.stack.dup()

    def i_drop(self):
        self.stack.drop()

    def i_swap(self):
        self.stack.swap()

    def i_push(self):
        self.address.push(self.stack.pop())

    def i_pop(self):
        self.stack.push(self.address.pop())

    def i_jump(self):
        self.ip = self.stack.pop() - 1

    def i_call(self):
        self.address.push(self.ip)
        self.ip = self.stack.pop() - 1

    def i_ccall(self):
        target = self.stack.pop()
        if self.stack.pop() != 0:
            self.address.push(self.ip)
            self.ip = target - 1

    def i_return(self):
        self.ip = self.address.pop()

    def i_eq(self):
        a = self.stack.pop()
        b = self.stack.pop()
        if b == a:
            self.stack.push(-1)
        else:
            self.stack.push(0)

    def i_neq(self):
        a = self.stack.pop()
        b = self.stack.pop()
        if b != a:
            self.stack.push(-1)
        else:
            self.stack.push(0)

    def i_lt(self):
        a = self.stack.pop()
        b = self.stack.pop()
        if b < a:
            self.stack.push(-1)
        else:
            self.stack.push(0)

    def i_gt(self):
        a = self.stack.pop()
        b = self.stack.pop()
        if b > a:
            self.stack.push(-1)
        else:
            self.stack.push(0)

    def i_fetch(self):
        target = self.stack.pop()
        if target == -1:
            self.stack.push(self.stack.depth())
        elif target == -2:
            self.stack.push(self.address.depth())
        elif target == -3:
            self.stack.push(self.memory.size())
        elif target == -4:
            self.stack.push(2147483648)
        elif target == -5:
            self.stack.push(2147483647)
        else:
            self.stack.push(self.memory.fetch(target))

    def i_store(self):
        mi = self.stack.pop()
        self.memory.store(self.stack.pop(), mi)

    def i_add(self):
        t = self.stack.pop()
        v = self.stack.pop()
        self.stack.push(unpack("=l", pack("=L", (t + v) & 0xFFFFFFFF))[0])

    def i_subtract(self):
        t = self.stack.pop()
        v = self.stack.pop()
        self.stack.push(unpack("=l", pack("=L", (v - t) & 0xFFFFFFFF))[0])

    def i_multiply(self):
        t = self.stack.pop()
        v = self.stack.pop()
        self.stack.push(unpack("=l", pack("=L", (v * t) & 0xFFFFFFFF))[0])

    def i_divmod(self):
        t = self.stack.pop()
        v = self.stack.pop()
        b, a = self.div_mod(v, t)
        self.stack.push(unpack("=l", pack("=L", a & 0xFFFFFFFF))[0])
        self.stack.push(unpack("=l", pack("=L", b & 0xFFFFFFFF))[0])

    def i_and(self):
        t = self.stack.pop()
        m = self.stack.pop()
        self.stack.push(m & t)

    def i_or(self):
        t = self.stack.pop()
        m = self.stack.pop()
        self.stack.push(m | t)

    def i_xor(self):
        t = self.stack.pop()
        m = self.stack.pop()
        self.stack.push(m ^ t)

    def i_shift(self):
        t = self.stack.pop()
        v = self.stack.pop()

        if t < 0:
            v <<= t * -1
        else:
            v >>= t

        self.stack.push(v)

    def i_zreturn(self):
        if self.stack.tos() == 0:
            self.stack.pop()
            self.ip = self.address.pop()

    def i_halt(self):
        self.ip = 9000000

    def i_ienumerate(self):
        self.stack.push(6)

    def i_iquery(self):
        device = self.stack.pop()
        if device == 0:  # generic output
            self.stack.push(0)
            self.stack.push(0)
        if device == 1:  # floating point
            self.stack.push(1)
            self.stack.push(2)
        if device == 2:  # files
            self.stack.push(0)
            self.stack.push(4)
        if device == 3:  # rng
            self.stack.push(0)
            self.stack.push(10)
        if device == 4:  # time
            self.stack.push(0)
            self.stack.push(5)
        if device == 5:  # scripting
            self.stack.push(0)
            self.stack.push(9)

    float_instr = {
        0: lambda: floats.push(float(stack.pop())),  # number to float
        1: lambda: floats.push(float(extract_string(stack.pop()))),  # string to float
        2: lambda: stack.push(int(floats.pop())),  # float to number
        3: lambda: inject_string(str(floats.pop()), stack.pop()),  # float to string
        4: lambda: floats.add(),  # add
        5: lambda: floats.sub(),  # sub
        6: lambda: floats.mul(),  # mul
        7: lambda: floats.div(),  # div
        8: lambda: floats.floor(),  # floor
        9: lambda: floats.ceil(),  # ceil
        10: lambda: floats.sqrt(),  # sqrt
        11: lambda: stack.push(floats.eq()),  # eq
        12: lambda: stack.push(floats.neq()),  # -eq
        13: lambda: stack.push(floats.lt()),  # lt
        14: lambda: stack.push(floats.gt()),  # gt
        15: lambda: stack.push(floats.depth()),  # depth
        16: lambda: floats.dup(),  # dup
        17: lambda: floats.drop(),  # drop
        18: lambda: floats.swap(),  # swap
        19: lambda: floats.log(),  # log
        20: lambda: floats.pow(),  # pow
        21: lambda: floats.sin(),  # sin
        22: lambda: floats.cos(),  # cos
        23: lambda: floats.tan(),  # tan
        24: lambda: floats.asin(),  # asin
        25: lambda: floats.atan(),  # atan
        26: lambda: floats.acos(),  # acos
        27: lambda: afloats.push(floats.pop()),  # to alt
        28: lambda: floats.push(afloats.pop()),  # from alt
        29: lambda: stack.push(afloats.depth()),  # alt. depth
    }
    files_instr = {
        0: lambda: stack.push(file_open()),
        1: lambda: file_close(),
        2: lambda: stack.push(file_read()),
        3: lambda: file_write(),
        4: lambda: stack.push(file_pos()),
        5: lambda: file_seek(),
        6: lambda: stack.push(file_size()),
        7: lambda: file_delete(),
        8: lambda: 1 + 1,
    }

    rng_instr = {0: lambda: stack.push(rng())}

    clock_instr = {
        0: lambda: stack.push(int(time.time())),
        1: lambda: stack.push(clock["day"]),
        2: lambda: stack.push(clock["month"]),
        3: lambda: stack.push(clock["year"]),
        4: lambda: stack.push(clock["hour"]),
        5: lambda: stack.push(clock["minute"]),
        6: lambda: stack.push(clock["second"]),
        7: lambda: stack.push(clock["day_utc"]),
        8: lambda: stack.push(clock["month_utc"]),
        9: lambda: stack.push(clock["year_utc"]),
        10: lambda: stack.push(clock["hour_utc"]),
        11: lambda: stack.push(clock["minute_utc"]),
        12: lambda: stack.push(clock["second_utc"]),
    }

    def i_iinvoke(self):
        device = self.stack.pop()
        if device == 0:  # generic output
            self.display_character()
        if device == 1:  # floating point
            action = self.stack.pop()
            float_instr[int(action)]()
        if device == 2:  # files
            action = self.stack.pop()
            files_instr[int(action)]()
        if device == 3:  # rng
            rng_instr[0]()
        if device == 4:  # clock
            action = self.stack.pop()
            clock_instr[int(action)]()
        if device == 5:  # scripting
            action = self.stack.pop()
            if action == 0:
                self.stack.push(len(sys.argv) - 2)
            if action == 1:
                a = self.stack.pop()
                b = self.stack.pop()
                self.stack.push(self.inject_string(sys.argv[a + 2], b))
            if action == 2:
                run_file(self.extract_string(self.stack.pop()))
            if action == 3:
                b = self.stack.pop()
                self.stack.push(self.inject_string(sys.argv[0], b))

    def validate_opcode(self, I0, I1, I2, I3):
        if (
            (I0 >= 0 and I0 <= 29)
            and (I1 >= 0 and I1 <= 29)
            and (I2 >= 0 and I2 <= 29)
            and (I3 >= 0 and I3 <= 29)
        ):
            return True
        else:
            return False

    def extract_string(self, at):
        s = ""
        while self.memory.fetch(at) != 0:
            s = s + chr(self.memory.fetch(at))
            at = at + 1
        return s

    def inject_string(self, s, to):
        for c in s:
            self.memory.store(ord(c), to)
            to = to + 1
        self.memory.store(0, to)

    def execute(self, word, notfound):
        self.ip = word
        if self.address.depth() == 0:
            self.address.push(0)
        while self.ip < 100000:
            if self.ip == notfound:
                print("ERROR: word not found!")
            opcode = self.memory.fetch(self.ip)
            I0 = opcode & 0xFF
            I1 = (opcode >> 8) & 0xFF
            I2 = (opcode >> 16) & 0xFF
            I3 = (opcode >> 24) & 0xFF
            if self.validate_opcode(I0, I1, I2, I3):
                # print("Bytecode: ", I0, I1, I2, I3, "at", self.ip)
                if I0 != 0:
                    self.instructions[I0]()
                if I1 != 0:
                    self.instructions[I1]()
                if I2 != 0:
                    self.instructions[I2]()
                if I3 != 0:
                    self.instructions[I3]()
            else:
                print("Invalid Bytecode: ", opcode, "at", self.ip)
                self.ip = 2000000
            if self.address.depth() == 0:
                self.ip = 2000000
            self.ip = self.ip + 1
        return

    def run(self):
        done = False
        while not done:
            line = input("\nOk> ")
            if line == "bye":
                done = True
            else:
                for token in line.split():
                    self.inject_string(token, 1024)
                    self.stack.push(1024)
                    self.execute(self.Cached['interpreter'], self.Cached['not_found'])

    def run_file(self, file):
        if not os.path.exists(file):
            print("File '{0}' not found".format(file))
            return

        in_block = False
        with open(file, "r") as source:
            for line in source.readlines():
                if line.rstrip() == "~~~":
                    in_block = not in_block
                elif in_block:
                    for token in line.strip().split():
                        self.inject_string(token, 1024)
                        self.stack.push(1024)
                        self.execute(self.Cached['interpreter'], self.Cached['not_found'])

    def update_image(self):
        import requests
        import shutil

        data = requests.get("http://forth.works/ngaImage", stream=True)
        with open("ngaImage", "wb") as f:
            data.raw.decode_content = True
            shutil.copyfileobj(data.raw, f)


if __name__ == "__main__":
    retro = Retro()
    if len(sys.argv) == 1:
        retro.run()

    if len(sys.argv) == 2:
        retro.run_file(sys.argv[1])

    sources = []

    if len(sys.argv) > 2:
        i = 1
        e = len(sys.argv)
        while i < e:
            param = sys.argv[i]
            if param == "-f":
                i += 1
                sources.append(sys.argv[i])
            i += 1

    if len(sys.argv) > 2 and sys.argv[1][0] != "-":
        retro.run_file(sys.argv[1])
    else:
        for source in sources:
            retro.run_file(source)