import random
import string
import base64
import json
import hashlib
from .parser import Lexer, Parser

class LuauVMObfuscator:
    def __init__(self):
        # Full Luau-style Opcode list
        self.opcodes = [
            "MOVE", "LOADK", "LOADBOOL", "LOADNIL", "GETGLOBAL", "SETGLOBAL",
            "GETTABLE", "SETTABLE", "NEWTABLE", "SELF", "ADD", "SUB", "MUL",
            "DIV", "MOD", "POW", "UNM", "NOT", "LEN", "CONCAT", "JMP", "EQ",
            "LT", "LE", "TEST", "TESTSET", "CALL", "TAILCALL", "RETURN",
            "FORLOOP", "FORPREP", "TFORLOOP", "SETLIST", "CLOSE", "CLOSURE", "VARARG"
        ]
        
        # Arithmetic keys for opcode decoding
        self.k1 = random.randint(100, 1000)
        self.k2 = random.randint(100, 1000)
        self.k3 = random.randint(100, 1000)
        
        # Opcode to encoded ID: ((real_index + k1) ^ k2) + k3
        self.op_to_id = {name: (((self.opcodes.index(name) + self.k1) ^ self.k2) + self.k3) % 4096 for name in self.opcodes}
        
        # Variable Renaming Map
        self.var_map = {}
        self.used_vars = set()

    def get_var(self, hint="var"):
        if hint in self.var_map:
            return self.var_map[hint]
        
        chars = "lI1" 
        length = random.randint(32, 64)
        new_var = "_" + "".join(random.choice(chars) for _ in range(length))
        while new_var in self.used_vars:
            new_var = "_" + "".join(random.choice(chars) for _ in range(length))
        
        self.used_vars.add(new_var)
        self.var_map[hint] = new_var
        return new_var

    def to_expr(self, n, depth=0):
        if depth > 3 or (depth > 0 and random.random() < 0.15):
            return str(n)
        
        r = random.randint(1, 2000)
        choice = random.choice(['add', 'sub', 'xor', 'mul', 'shl', 'shr', 'not'])
        
        if choice == 'add':
            return f"({self.to_expr(n - r, depth + 1)} + {self.to_expr(r, depth + 1)})"
        elif choice == 'sub':
            return f"({self.to_expr(n + r, depth + 1)} - {self.to_expr(r, depth + 1)})"
        elif choice == 'xor':
            return f"bit32.bxor({self.to_expr(n ^ r, depth + 1)}, {self.to_expr(r, depth + 1)})"
        elif choice == 'mul':
            if n != 0 and n % 2 == 0:
                return f"({self.to_expr(n // 2, depth + 1)} * {self.to_expr(2, depth + 1)})"
            return f"({self.to_expr(n, depth + 1)})"
        elif choice == 'shl':
            # n = (n >> 1) << 1 + (n & 1)
            return f"bit32.bor(bit32.lshift({self.to_expr(n >> 1, depth + 1)}, {self.to_expr(1, depth + 1)}), {self.to_expr(n & 1, depth + 1)})"
        elif choice == 'shr':
            return f"bit32.rshift({self.to_expr(n << 1, depth + 1)}, {self.to_expr(1, depth + 1)})"
        elif choice == 'not':
            return f"bit32.bnot(bit32.bnot({self.to_expr(n, depth + 1)}))"
        
        return str(n)

    def opaque_predicate(self):
        v1 = random.randint(100, 1000)
        v2 = random.randint(100, 1000)
        preds = [
            f"({self.to_expr(v1)} == {self.to_expr(v1)})",
            f"({self.to_expr(v1)} + {self.to_expr(v2)} > {self.to_expr(v1)})",
            f"(math.floor(math.pi) == {self.to_expr(3)})",
            f"(string.len('SUPREME') == {self.to_expr(7)})",
            f"(bit32.bor({v1}, {v1}) == {v1})",
            f"(bit32.band({v1}, {v1}) == {v1})",
            f"(bit32.bxor({v1}, 0) == {v1})",
            f"({self.to_expr(v2)} * 0 == 0)"
        ]
        return random.choice(preds)

    def encrypt_string(self, s, key):
        res = []
        last = key % 256
        for i, c in enumerate(s):
            k = (key + i + last) % 256
            last = ord(c)
            res.append(chr(ord(c) ^ k))
        return "".join(res)

    def generate_vm_source(self, bytecode):
        raw_instructions = bytecode['instructions']
        shuffled = []
        indices = list(range(len(raw_instructions)))
        random.shuffle(indices)
        
        pos_map = {orig: shuffled_idx for shuffled_idx, orig in enumerate(indices)}
        
        final_insts = [None] * len(raw_instructions)
        for i, orig_idx in enumerate(indices):
            inst = raw_instructions[orig_idx]
            
            if orig_idx + 1 < len(raw_instructions):
                next_orig = orig_idx + 1
                next_shuffled = pos_map[next_orig]
            else:
                next_shuffled = 0 
            
            packed = [
                inst[0] & 0xFF, (inst[0] >> 8) & 0xFF, 
                inst[1], inst[2], inst[3],
                next_shuffled & 0xFF, (next_shuffled >> 8) & 0xFF
            ]
            final_insts[i] = packed

        inst_str = "".join(chr(i) for inst in final_insts for i in inst)
        inst_b64 = base64.b64encode(inst_str.encode('latin-1')).decode()
        
        # Bytecode Checksum for Integrity
        checksum = hashlib.md5(inst_str.encode('latin-1')).hexdigest()
        
        encrypted_consts = []
        salt = random.randint(10000, 99999)
        for i, c in enumerate(bytecode['constants']):
            if c['type'] == 'string':
                key = (i * 149 + salt) % 256
                enc_val = self.encrypt_string(c['value'], key)
                encrypted_consts.append({"t": 1, "v": base64.b64encode(enc_val.encode('latin-1')).decode()})
            else:
                encrypted_consts.append({"t": 2, "v": c['value']})
        
        consts_json = json.dumps(encrypted_consts)
        start_idx = pos_map[0]

        # Obfuscated Variable Names
        V_ENV = self.get_var("env")
        V_B64 = self.get_var("b64")
        V_D = self.get_var("decode")
        V_INST = self.get_var("inst_raw")
        V_CONSTS = self.get_var("consts")
        V_SALT = self.get_var("salt")
        V_EXEC = self.get_var("execute")
        V_REGS = self.get_var("registers")
        V_CURR = self.get_var("current")
        V_RUN = self.get_var("running")
        V_GETC = self.get_var("get_const")
        V_PTR = self.get_var("ptr")
        V_OP = self.get_var("op")
        V_A = self.get_var("a")
        V_B = self.get_var("b")
        V_C = self.get_var("c")
        V_BIT = self.get_var("bit32")
        V_GS = self.get_var("getservice")
        V_TRAP = self.get_var("trap")
        V_CHECK = self.get_var("check")
        V_IS_HOOKED = self.get_var("is_hooked")
        V_PROTECT = self.get_var("protect")
        V_METH = self.get_var("meth")
        V_LUA_ENV = self.get_var("lua_env")

        vm_lua = f"""local {V_LUA_ENV} = getfenv()
local {V_BIT} = bit32
local {V_GS} = game.GetService
local {V_B64} = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
local {V_D} = function(data)
    if not ({self.opaque_predicate()}) then return "" end
    data = string.gsub(data, '[^'..{V_B64}..'=]', '')
    return (data:gsub('.', function(x)
        if (x == '=') then return '' end
        local r,f='',({V_B64}:find(x)-1)
        for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
        return r;
    end):gsub('%d%d%d%d%d%d%d%d', function(x)
        local r=0
        for i=1,8 do r=r+(x:sub(i,i)=='1' and 2^(8-i) or 0) end
        return string.char(r)
    end))
end

local function {V_IS_HOOKED}(f)
    if type(f) ~= "function" then return false end
    local s = tostring(f)
    if string.find(s, "hook") or string.find(s, "proxy") then return true end
    return false
end

local function {V_TRAP}()
    local _ = function() while true do end end
    task.spawn(_)
end

local function {V_CHECK}()
    local d = {{ "getgenv", "getrenv", "getreg", "debug", "Drawing", "hookfunction", "setreadonly", "make_writeable" }}
    for _, v in ipairs(d) do 
        if {V_LUA_ENV}[v] then 
            if {V_IS_HOOKED}({V_LUA_ENV}[v]) then return false end
        end
    end
    if not {V_LUA_ENV}["game"] or not {V_LUA_ENV}["task"] then return false end
    return true
end

local {V_INST} = {V_D}('{inst_b64}')
local {V_CONSTS} = {V_GS}(game, "HttpService"):JSONDecode('{consts_json}')
local {V_SALT} = {self.to_expr(salt)}

local function {V_EXEC}()
    if not {V_CHECK}() then {V_TRAP}() return end

    local {V_REGS} = {{}}
    local {V_CURR} = {self.to_expr(start_idx)}
    local {V_RUN} = true
    
    local {V_PROTECT} = {{}}
    setmetatable({V_PROTECT}, {{
        __index = {V_LUA_ENV},
        __newindex = function(_, k, v) {V_LUA_ENV}[k] = v end,
        __metatable = "Locked"
    }})

    local function {V_GETC}(idx)
        local c = {V_CONSTS}[idx + 1]
        if not c then return nil end
        if c.t == {self.to_expr(1)} then
            local raw = {V_D}(c.v)
            local key = (idx * {self.to_expr(149)} + {V_SALT}) % {self.to_expr(256)}
            local res = ""
            local last = key % 256
            for i=1, #raw do
                local k = (key + i + last - 1) % 256
                local b = string.byte(raw, i)
                local char_code = {V_BIT}.bxor(b, k)
                res = res .. string.char(char_code)
                last = char_code
            end
            return res
        end
        return c.v
    end

    while {V_RUN} do
        if not ({self.opaque_predicate()}) then break end
        local {V_PTR} = {V_CURR} * {self.to_expr(7)} + 1
        if {V_PTR} > #{V_INST} then break end
        
        local op_l = string.byte({V_INST}, {V_PTR})
        local op_h = string.byte({V_INST}, {V_PTR} + 1)
        local {V_A} = string.byte({V_INST}, {V_PTR} + 2)
        local {V_B} = string.byte({V_INST}, {V_PTR} + 3)
        local {V_C} = string.byte({V_INST}, {V_PTR} + 4)
        local next_l = string.byte({V_INST}, {V_PTR} + 5)
        local next_h = string.byte({V_INST}, {V_PTR} + 6)
        
        {V_CURR} = next_l + (next_h * {self.to_expr(256)})
        
        local op_raw = op_l + (op_h * 256)
        local {V_OP} = ({V_BIT}.bxor(op_raw, {self.to_expr(self.k2)}) - {self.to_expr(self.k1)}) - {self.to_expr(self.k3)}
        
        if {V_OP} == {self.to_expr(self.opcodes.index('MOVE'))} then
            {V_REGS}[{V_A}] = {V_REGS}[{V_B}]
        elseif {V_OP} == {self.to_expr(self.opcodes.index('LOADK'))} then
            {V_REGS}[{V_A}] = {V_GETC}({V_B})
        elseif {V_OP} == {self.to_expr(self.opcodes.index('GETGLOBAL'))} then
            {V_REGS}[{V_A}] = {V_PROTECT}[{V_GETC}({V_B})]
        elseif {V_OP} == {self.to_expr(self.opcodes.index('SETGLOBAL'))} then
            {V_PROTECT}[{V_GETC}({V_B})] = {V_REGS}[{V_A}]
        elseif {V_OP} == {self.to_expr(self.opcodes.index('CALL'))} then
            local f = {V_REGS}[{V_A}]
            local args = {{}}
            if {V_B} > 1 then for i=1, {V_B}-1 do args[i] = {V_REGS}[{V_A}+i] end end
            local res = {{f(unpack(args))}}
            if {V_C} > 1 then for i=1, {V_C}-1 do {V_REGS}[{V_A}+i-1] = res[i] end end
        elseif {V_OP} == {self.to_expr(self.opcodes.index('RETURN'))} then
            {V_RUN} = false
        end
        
        if not ({self.opaque_predicate()}) then {V_RUN} = false end
    end
end

task.spawn({V_EXEC})"""
        return vm_lua

    def compile_to_bytecode(self, ast):
        constants = []
        instructions = []
        locals_map = {}
        next_reg = 0
        
        def add_const(val):
            if isinstance(val, str):
                s_q = chr(39)
                d_q = chr(34)
                if (val.startswith(s_q) and val.endswith(s_q)) or (val.startswith(d_q) and val.endswith(d_q)):
                    val = val[1:-1]
            
            for i, c in enumerate(constants):
                if c['value'] == val: return i
            
            t = 'string' if isinstance(val, str) else 'number'
            constants.append({'type': t, 'value': val})
            return len(constants) - 1

        def load_expr_to_reg(expr, reg):
            if expr['type'] == 'IDENT':
                if expr['value'] in locals_map:
                    instructions.append([self.op_to_id["MOVE"], reg, locals_map[expr['value']], 0])
                else:
                    instructions.append([self.op_to_id["GETGLOBAL"], reg, add_const(expr['value']), 0])
            elif expr['type'] in ['STRING', 'NUMBER']:
                val = expr['value']
                if expr['type'] == 'NUMBER':
                    try: val = float(val)
                    except: pass
                instructions.append([self.op_to_id["LOADK"], reg, add_const(val), 0])

        for node in ast:
            if node['type'] == 'call':
                func_reg = next_reg
                if node['name'] in locals_map:
                    instructions.append([self.op_to_id["MOVE"], func_reg, locals_map[node['name']], 0])
                else:
                    instructions.append([self.op_to_id["GETGLOBAL"], func_reg, add_const(node['name']), 0])
                
                for i, arg_expr in enumerate(node['args']):
                    load_expr_to_reg(arg_expr, func_reg + 1 + i)
                
                instructions.append([self.op_to_id["CALL"], func_reg, len(node['args']) + 1, 1])
                
            elif node['type'] == 'assign':
                val_reg = next_reg
                load_expr_to_reg(node['value'], val_reg)
                
                if node.get('local'):
                    locals_map[node['name']] = val_reg
                    next_reg += 1
                else:
                    instructions.append([self.op_to_id["SETGLOBAL"], val_reg, add_const(node['name']), 0])

        instructions.append([self.op_to_id["RETURN"], 0, 0, 0])
        return {"instructions": instructions, "constants": constants}

    def obfuscate(self, code):
        if not code.strip(): return ""
        try:
            lexer = Lexer(code)
            tokens = lexer.tokenize()
            parser = Parser(tokens)
            ast = parser.parse()
            if not ast: return ""
            bytecode = self.compile_to_bytecode(ast)
            return self.generate_vm_source(bytecode)
        except Exception:
            return ""

def obfuscate(code):
    return LuauVMObfuscator().obfuscate(code)