#include "codegen.h"
#include <iostream>
#include <sstream>
#include <vector>

// Pomocnicza funkcja: sprawdza czy string to czysta liczba
bool isNumber(const std::string& s) {
    if (s.empty()) return false;
    size_t start = (s[0] == '-') ? 1 : 0;
    for (size_t i = start; i < s.length(); i++) {
        if (!isdigit(s[i])) return false;
    }
    return true;
}

// Zamienia nazwę zmiennej na adres pamięci [rbp-X] lub liczbę
std::string getVarLocation(const std::string& name, const std::map<std::string, int>& locals) {
    std::string cleanName = name;
    // Usuwamy ewentualne spacje
    size_t first = cleanName.find_first_not_of(" \t");
    if (first != std::string::npos) cleanName = cleanName.substr(first);
    size_t last = cleanName.find_last_not_of(" \t");
    if (last != std::string::npos) cleanName = cleanName.substr(0, last + 1);

    if (cleanName.empty()) return "0";
    if (isNumber(cleanName)) return cleanName;

    if (cleanName == "RAX") return "eax";

    if (locals.count(cleanName)) {
        int offset = locals.at(cleanName);
        return "[rbp-" + std::to_string(offset) + "]";
    }

    // Zwracamy oryginał (jeśli to np. nazwa etykiety), ale to zazwyczaj błąd dla zmiennych
    return cleanName;
}

std::string generateAssembly(const CompilerState& state) {
    // 1. NAGŁÓWEK I DEKLARACJE EXTERN
    std::string result = "default rel\n";
    result += "global main\n";
    result += "extern printf\n";
    result += "extern getchar\n";
    result += "extern _getch\n";
    result += "extern rand\n";
    result += "extern srand\n";
    result += "extern time\n";

    // 2. SEKCJA DATA (Tylko raz!)
    result += "section .data\n";
    result += "  fmt_int db \"%lld\", 10, 0\n";  // Format dla liczb
    result += "  fmt_str db \"%s\", 10, 0\n";    // Format dla stringów

    // Zrzucamy stringi: ETYKIETA db "TRESC", 0
    for (const auto& p : state.stringLiterals) {
        // p.first  -> Etykieta (np. str_0)
        // p.second -> Treść (np. Hello World)
        result += "  " + p.first + " db \"" + p.second + "\", 0\n";
    }

    // 3. SEKCJA TEXT (Kod programu)
    result += "section .text\n";

    for (const auto& pair : state.functions) {
        const Function& func = pair.second;
        result += func.name + ":\n";

        result += "  push rbp\n";
        result += "  mov rbp, rsp\n";
        result += "  sub rsp, 256\n";

        std::map<std::string, int> stackMap;
        int currentStack = 8;

        // ARGUMENTY FUNKCJI
        if (func.args.size() > 0) {
            stackMap[func.args[0]] = currentStack;
            result += "  mov [rbp-" + std::to_string(currentStack) + "], rcx ; arg " + func.args[0] + "\n";
            currentStack += 8;
        }
        if (func.args.size() > 1) {
            stackMap[func.args[1]] = currentStack;
            result += "  mov [rbp-" + std::to_string(currentStack) + "], rdx ; arg " + func.args[1] + "\n";
            currentStack += 8;
        }

        // GENEROWANIE INSTRUKCJI
        for (const auto& instr : func.instructions) {

            // Rezerwacja miejsca na stosie
            bool isWriteOp = (instr.type == OpType::ASSIGN ||
                instr.type == OpType::ADD ||
                instr.type == OpType::EQ ||
                instr.type == OpType::SUB ||
                instr.type == OpType::MUL ||
                instr.type == OpType::DIV ||
                instr.type == OpType::MOD ||
                instr.type == OpType::LOGIC_AND ||
                instr.type == OpType::LOGIC_OR);

            if (isWriteOp && stackMap.find(instr.arg1) == stackMap.end() && instr.arg1 != "RAX") {
                stackMap[instr.arg1] = currentStack;
                currentStack += 8;
            }

            switch (instr.type) {
            case OpType::ASSIGN: {
                std::string src = instr.arg2;
                if (instr.arg3 == "STRING") {
                    // Przypisanie stringa: ładujemy ADRES (LEA)
                    result += "  lea rax, [rel " + src + "]\n";
                    std::string dst = getVarLocation(instr.arg1, stackMap);
                    // Zapisujemy adres w zmiennej lokalnej (wskaźnik 64-bit qword)
                    result += "  mov qword " + dst + ", rax\n";
                }
                else {
                    // Zwykłe przypisanie liczby
                    std::string srcLoc = getVarLocation(instr.arg2, stackMap);
                    std::string dst = getVarLocation(instr.arg1, stackMap);

                    if (isNumber(src)) {
                        result += "  mov eax, " + src + "\n";
                    }
                    else {
                        result += "  mov eax, " + srcLoc + "\n";
                    }
                    result += "  mov " + dst + ", eax\n";
                }
                break;
            }
            case OpType::ADD: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  add eax, " + op2 + "\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::SUB: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  sub eax, " + op2 + "\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::MUL: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  imul eax, " + op2 + "\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::DIV: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  cdq\n";
                if (isdigit(op2[0]) || op2[0] == '-') {
                    result += "  mov ecx, " + op2 + "\n";
                    result += "  idiv ecx\n";
                }
                else {
                    result += "  idiv dword " + op2 + "\n";
                }
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::MOD: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  cdq\n";
                if (isdigit(op2[0]) || op2[0] == '-') {
                    result += "  mov ecx, " + op2 + "\n";
                    result += "  idiv ecx\n";
                }
                else {
                    result += "  idiv dword " + op2 + "\n";
                }
                result += "  mov " + dst + ", edx\n"; // Reszta
                break;
            }
            case OpType::EQ: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  cmp eax, " + op2 + "\n";
                result += "  sete al\n";
                result += "  movzx eax, al\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::LOGIC_AND: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  cmp eax, 0\n";
                result += "  setne al\n";
                if (isdigit(op2[0])) result += "  mov ecx, " + op2 + "\n";
                else result += "  mov ecx, " + op2 + "\n";
                result += "  cmp ecx, 0\n";
                result += "  setne cl\n";
                result += "  and al, cl\n";
                result += "  movzx eax, al\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::LOGIC_OR: {
                std::string op1 = getVarLocation(instr.arg2, stackMap);
                std::string op2 = getVarLocation(instr.arg3, stackMap);
                std::string dst = getVarLocation(instr.arg1, stackMap);
                result += "  mov eax, " + op1 + "\n";
                result += "  cmp eax, 0\n";
                result += "  setne al\n";
                if (isdigit(op2[0])) result += "  mov ecx, " + op2 + "\n";
                else result += "  mov ecx, " + op2 + "\n";
                result += "  cmp ecx, 0\n";
                result += "  setne cl\n";
                result += "  or al, cl\n";
                result += "  movzx eax, al\n";
                result += "  mov " + dst + ", eax\n";
                break;
            }
            case OpType::JMP_FALSE: {
                std::string condRaw = instr.arg2;
                size_t eqPos = condRaw.find("==");
                if (eqPos != std::string::npos) {
                    std::string leftStr = condRaw.substr(0, eqPos);
                    std::string rightStr = condRaw.substr(eqPos + 2);
                    std::string op1 = getVarLocation(leftStr, stackMap);
                    std::string op2 = getVarLocation(rightStr, stackMap);
                    result += "  mov eax, " + op1 + "\n";
                    result += "  cmp eax, " + op2 + "\n";
                    result += "  jne " + instr.arg1 + "\n";
                }
                else {
                    std::string cond = getVarLocation(condRaw, stackMap);
                    result += "  mov eax, " + cond + "\n";
                    result += "  test eax, eax\n";
                    result += "  jz " + instr.arg1 + "\n";
                }
                break;
            }
            case OpType::JMP: {
                result += "  jmp " + instr.arg1 + "\n";
                break;
            }
            case OpType::LABEL: {
                result += instr.arg1 + ":\n";
                break;
            }
            case OpType::PRINT: {
                // Instrukcja PRINT zwykła (liczba)
                std::string val = getVarLocation(instr.arg1, stackMap);
                result += "  mov edx, " + val + "\n";
                result += "  lea rcx, [rel fmt_int]\n";
                result += "  call printf\n";
                break;
            }
            case OpType::PRINT_STRING: {
                // Instrukcja PRINT_STRING (tekst)
                std::string target = instr.arg1;
                if (target.find("str_") == 0) {
                    // Literał: print("tekst")
                    result += "  lea rdx, [rel " + target + "]\n";
                }
                else {
                    // Zmienna: print(s) -> s trzyma adres
                    std::string val = getVarLocation(target, stackMap);
                    result += "  mov rdx, " + val + "\n";
                }
                result += "  lea rcx, [rel fmt_str]\n";
                result += "  call printf\n";
                break;
            }
            case OpType::CALL: {
                if (instr.arg1 == "input") {
                    result += "  call getchar\n";
                    break;
                }
                if (instr.arg1 == "read_key") {
                    result += "  call _getch\n";
                    break;
                }
                if (instr.arg1 == "sys_seed") {
                    result += "  mov rcx, 0\n";
                    result += "  call time\n";
                    result += "  mov rcx, rax\n";
                    result += "  call srand\n";
                    break;
                }
                if (instr.arg1 == "sys_rand") {
                    result += "  call rand\n";
                    break;
                }

                // Standardowe wywołanie funkcji
                std::string argsRaw = instr.arg2;
                std::vector<std::string> callArgs;
                if (!argsRaw.empty()) {
                    size_t comma = argsRaw.find(',');
                    if (comma != std::string::npos) {
                        callArgs.push_back(argsRaw.substr(0, comma));
                        callArgs.push_back(argsRaw.substr(comma + 1));
                    }
                    else {
                        callArgs.push_back(argsRaw);
                    }
                }
                if (callArgs.size() > 1) {
                    std::string val = getVarLocation(callArgs[1], stackMap);
                    if (isNumber(val)) result += "  mov rdx, " + val + "\n";
                    else result += "  movsxd rdx, dword " + val + "\n";
                }
                if (callArgs.size() > 0) {
                    std::string val = getVarLocation(callArgs[0], stackMap);
                    if (isNumber(val)) result += "  mov rcx, " + val + "\n";
                    else result += "  movsxd rcx, dword " + val + "\n";
                }
                result += "  call " + instr.arg1 + "\n";
                break;
            }
            case OpType::RETURN: {
                std::string val = getVarLocation(instr.arg1, stackMap);
                if (!val.empty() && val != ";") {
                    result += "  mov eax, " + val + "\n";
                }
                result += "  leave\n";
                result += "  ret\n";
                break;
            }
            }
        }

        if (func.returnType == "void") {
            result += "  leave\n  ret\n";
        }
        result += "\n";
    }

    return result;
}