#include "parser.h"
#include "utils.h"
#include <iostream>
#include <sstream>
#include <vector>

std::vector<std::string> parseArgs(const std::string& line) {
    std::vector<std::string> args;
    size_t open = line.find('(');
    size_t close = line.find(')');
    if (open == std::string::npos || close == std::string::npos) return args;

    std::string inside = line.substr(open + 1, close - open - 1);
    if (inside.empty()) return args;

    std::stringstream ss(inside);
    std::string segment;
    while (std::getline(ss, segment, ',')) {
        segment = trim(segment);
        // segment to np. "int a". Szukamy ostatniej spacji, by wziąć nazwę "a"
        size_t space = segment.find_last_of(" \t");
        if (space != std::string::npos) {
            args.push_back(trim(segment.substr(space + 1)));
        }
    }
    return args;
}

void processSource(const std::string& src, CompilerState& state) {
    std::istringstream iss(src);
    std::string line;

    while (std::getline(iss, line)) {
        line = trim(line);
        if (line.empty() || line.substr(0, 2) == "//" || line[0] == '#') continue;

        // --- 1. DEFINICJA FUNKCJI ---
        // Warunki: zaczyna się od typu, ma '(', ma '{' i NIE ma '=' (żeby nie mylić ze zmienną)
        bool startsWithType = (line.rfind("int ", 0) == 0 || line.rfind("void ", 0) == 0 || line.rfind("bool ", 0) == 0);
        if (startsWithType && line.find("(") != std::string::npos && line.find("{") != std::string::npos && line.find("=") == std::string::npos) {

            size_t openParen = line.find('(');
            std::string typeRaw = line.substr(0, line.find(' '));
            std::string nameRaw = line.substr(typeRaw.length(), openParen - typeRaw.length());
            std::string funcName = trim(nameRaw);

            Function newFunc;
            newFunc.name = funcName;
            newFunc.returnType = typeRaw;
            newFunc.args = parseArgs(line);

            state.functions[funcName] = newFunc;
            state.currentFunction = &state.functions[funcName];

            std::cout << "[PARSER] New Function: " << funcName << "\n";
            continue;
        }
        // --- 2. ZAMYKANIE BLOKU '}' ---
        if (line == "}") {
            // Najpierw sprawdzamy, czy zamykamy IF-a (czy jest coś na stosie bloków)
            if (!state.blockStack.empty()) {
                std::string label = state.blockStack.top();
                state.blockStack.pop();
                if (state.currentFunction) {
                    state.currentFunction->instructions.push_back({ OpType::LABEL, label, "", "" });
                }
                std::cout << " [PARSER] } End IF block -> " << label << "\n";
            }
            else {
                // Jeśli stos pusty, to koniec funkcji
                state.currentFunction = nullptr;
                std::cout << " [PARSER] } End Function\n";
            }
            continue;
        }
        // --- JESTEŚMY W ŚRODKU FUNKCJI ---
        if (state.currentFunction) {
            Function& f = *state.currentFunction;

            // A. RETURN
            if (line.substr(0, 6) == "return") {
                std::string val = trim(line.substr(6));
                if (!val.empty() && val.back() == ';') val.pop_back();
                f.instructions.push_back({ OpType::RETURN, val, "", "" });
                std::cout << " [PARSER] Return: " << val << "\n";
            }
            // B. PRINT
            else if (line.substr(0, 5) == "print") {
                size_t start = line.find('(') + 1;
                size_t end = line.find(')');
                if (start != std::string::npos && end != std::string::npos) {
                    std::string arg = trim(line.substr(start, end - start));

                    // Czy to bezpośredni napis? np. print("Hello")
                    if (arg.size() >= 2 && arg.front() == '"' && arg.back() == '"') {
                        std::string content = arg.substr(1, arg.size() - 2);

                        // Rejestrujemy
                        std::string label;
                        if (state.stringLiterals.count(content)) {
                            label = state.stringLiterals[content];
                        }
                        else {
                            label = "str_" + std::to_string(state.stringCounter++);
                            state.stringLiterals[content] = label;
                        }

                        // Dajemy znać generatorowi, że to typ STRING
                        f.instructions.push_back({ OpType::PRINT, label, "STRING", "" });
                    }
                    else {
                        // Zwykła zmienna (int lub string - generator musi zgadnąć lub my musimy wiedzieć)
                        // Na razie załóżmy, że jeśli zmienna ma w nazwie "msg" lub "txt", to string
                        // (To hack, w przyszłości dodamy tabelę typów zmiennych)
                        f.instructions.push_back({ OpType::PRINT, arg, "VAR", "" });
                    }
                }
            }

            // C. IF STATEMENT
            else if (line.substr(0, 2) == "if") {
                size_t openParen = line.find("(");
                size_t closeParen = line.find(")");
                if (openParen != std::string::npos && closeParen > openParen) {
                    std::string condition = trim(line.substr(openParen + 1, closeParen - openParen - 1));
                    std::string labelName = "L_" + std::to_string(state.labelCounter++);

                    // Skok warunkowy
                    f.instructions.push_back({ OpType::JMP_FALSE, labelName, condition, "" });
                    state.blockStack.push(labelName);

                    std::cout << " [PARSER] IF (" << condition << ") -> Jump to " << labelName << "\n";
                }
            }
            // D. PRZYPISANIE ZMIENNEJ (LUB DEKLARACJA)
            // np. "int a = 5;" LUB "a = b + c;"
            else if (line.find("=") != std::string::npos) {
                size_t eqPos = line.find('=');
                std::string leftSide = trim(line.substr(0, eqPos));
                std::string rightSide = trim(line.substr(eqPos + 1));

                bool isStringDecl = false; // Flaga, czy to string
                if (!rightSide.empty() && rightSide.back() == ';') rightSide.pop_back();

                // Obsługa nazwy zmiennej (usuwanie "int ", "bool ")
                std::string varName = leftSide;
                if (leftSide.rfind("int ", 0) == 0) varName = trim(leftSide.substr(4));
                else if (leftSide.rfind("bool ", 0) == 0) varName = trim(leftSide.substr(5));
                else if (leftSide.rfind("string ", 0) == 0) { // NOWOŚĆ
                    varName = trim(leftSide.substr(7));
                    isStringDecl = true;
                }


                // 1. Czy to wywołanie funkcji? int x = func();
                if (rightSide.find("(") != std::string::npos && rightSide.find(")") != std::string::npos) {
                    size_t open = rightSide.find('(');
                    std::string funcName = trim(rightSide.substr(0, open));
                    std::string argsContent = rightSide.substr(open + 1, rightSide.find(')') - open - 1);

                    // CALL func
                    f.instructions.push_back({ OpType::CALL, funcName, argsContent, "" });
                    // ASSIGN result (RAX) to variable
                    f.instructions.push_back({ OpType::ASSIGN, varName, "RAX", "" });
                    std::cout << " [PARSER] Call & Assign: " << varName << " = " << funcName << "()\n";
                }
                // 2. Czy to dodawanie? a + b
                else if (rightSide.find("+") != std::string::npos) {
                    size_t opPos = rightSide.find("+");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 1));
                    f.instructions.push_back({ OpType::ADD, varName, a, b });
                }
                // 3. NOWOŚĆ: Czy to odejmowanie? a - b
                else if (rightSide.find("-") != std::string::npos) {
                    size_t opPos = rightSide.find("-");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 1));
                    f.instructions.push_back({ OpType::SUB, varName, a, b }); // <--- Używamy SUB
                }
                // 4. NOWOŚĆ: Czy to mnożenie? a * b
                else if (rightSide.find("*") != std::string::npos) {
                    size_t opPos = rightSide.find("*");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 1));
                    f.instructions.push_back({ OpType::MUL, varName, a, b }); // <--- Używamy MUL
                }
                else if (rightSide.find("/") != std::string::npos) {
                    size_t opPos = rightSide.find("/");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 1));
                    f.instructions.push_back({ OpType::DIV, varName, a, b });
                }
                // MODULO: a % b
                else if (rightSide.find("%") != std::string::npos) {
                    size_t opPos = rightSide.find("%");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 1));
                    f.instructions.push_back({ OpType::MOD, varName, a, b });
                }
                // 3. Czy to porównanie? a == b (Ważne: == może być w IFie, ale tu jesteśmy w linii z '=')
                // UWAGA: To rzadkie w C++ (bool x = a == b), ale obsłużmy proste przypisanie wartości logicznej
                else if (rightSide.find("==") != std::string::npos) {
                    size_t opPos = rightSide.find("==");
                    std::string a = trim(rightSide.substr(0, opPos));
                    std::string b = trim(rightSide.substr(opPos + 2));
                    f.instructions.push_back({ OpType::EQ, varName, a, b });
                }
                else if (rightSide.size() >= 2 && rightSide.front() == '"' && rightSide.back() == '"')
                {
                    {
                        // Wyciągamy treść bez cudzysłowów
                        std::string content = rightSide.substr(1, rightSide.size() - 2);

                        // Rejestrujemy stringa w sekcji danych, jeśli jeszcze go nie ma
                        std::string label;
                        if (state.stringLiterals.count(content)) {
                            label = state.stringLiterals[content];
                        }
                        else {
                            label = "str_" + std::to_string(state.stringCounter++);
                            state.stringLiterals[content] = label;
                        }

                        // Generujemy instrukcję przypisania ADRESU etykiety do zmiennej
                        f.instructions.push_back({ OpType::ASSIGN, varName, label, "STRING" });
                    }
                }
                // 4. Zwykłe przypisanie: a = 5
                else {
                    f.instructions.push_back({ OpType::ASSIGN, varName, rightSide, "" });
                }
            }
            // E. SAMODZIELNE WYWOŁANIE FUNKCJI (bez =)
            // np. func();
            else if (line.find("(") != std::string::npos && line.find(")") != std::string::npos) {
                size_t open = line.find('(');
                std::string funcName = trim(line.substr(0, open));
                std::string argsContent = line.substr(open + 1, line.find(')') - open - 1);

                f.instructions.push_back({ OpType::CALL, funcName, argsContent, "" });
                std::cout << " [PARSER] Call void: " << funcName << "\n";
            }
        }
    }
}
void calculateExpressions(CompilerState& state) {}