#include <iostream>
#include <sstream>
#include "calculator.cpp"
#include "commands.cpp"
#include "cursor.cpp"
#include "debug.cpp"
#include "getch.h"
#include "terminal.cpp"

/**
 * @brief Prints entered keys to the console.
 * 
 * @param keys currently typed keys.
 */
void writeInput(terminal::state keys) {
    // FIXME: Do not duplicate lines when line overflows
    // possible mitigation: only write one line

    // FIXME: flickering
    cursor::setX(1);
    std::cout << "\033[0K" << "> ";
    for(auto it = keys.keys.begin(); it != keys.keys.end(); it++) {
        std::cout << *it;
    }

    cursor::setX(3+keys.cursorPos);
}

/**
 * @brief Writes result line with the result while in typing mode
 * 
 * @param string the result
 * @param paranthesis missing paranthesis count, negative if misses left paranthesis
 * @param calcuationValid is calculation valid
 * @param inputSize the current input size (used to where display missing paranthesis)
 */
void writeResultLine(
        const std::string string,
        const int paranthesis = 0,
        const bool calcuationValid = true,
        const unsigned int inputSize = 20
) {
    auto savedCursorPosition = cursor::getPosition().x;

    if (paranthesis != 0) {
        cursor::setX(inputSize+5);
        std::cout << "\033[31m";
        if (paranthesis > 4) {
            std::cout << ") * " << paranthesis;
        }
        else if (paranthesis > 0) {
            for(unsigned short i = 0; i < paranthesis; i++) std::cout << ")";
        }
        else if (paranthesis < 4) {
            std::cout << "( * " << -paranthesis;
        }
        else { //paranthesis is one of -1,-2,-3,-4
            for(unsigned short i = 0; i < -paranthesis; i++) std::cout << ")";
        }
        std::cout << "\033[0m";
    }

    std::cout << "\n\033[0K\033[90m";
    // FIXME: line overflow handling
    if (calcuationValid) std::cout << string;
    else std::cout << "-";
    cursor::up();
    cursor::setX(savedCursorPosition);
    std::cout << "\033[0m";
}

/**
 * @brief  Writes result line with the result while in typing mode
 * 
 * @param result the calculation result
 * @param inputSize the current input size (used to where display missing paranthesis)
 */
void writeResultLine(Calculator::parseAndCalculateResult result, const unsigned int inputSize) {
    std::stringstream result_string;
    result_string << result.value;
    writeResultLine(result_string.str(), result.unmatchedParanthesis, result.valid, inputSize);
}

int main() {
    #ifdef _WIN32
    // https://stackoverflow.com/a/47158348
    { // enable virtual terminal for legacy Windows terminals
    HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE);
    DWORD consoleMode;
    GetConsoleMode(console, &consoleMode);
    consoleMode |= 0x0004;
    SetConsoleMode(console, consoleMode);
    }
    #endif
    std::setlocale(LC_ALL, "");
    std::cout << "type :q to exit, type :h for help\n";

    bool exit = false; //should we exit?
    terminal::state keys;
    while (!exit) {
        writeInput(keys);
        // writeResultLine("");
        // background calculation
        // new std::thread([keys]{
        writeResultLine(Calculator::parseAndCaluclate(keys.keys), keys.keys.size());
        // });
        auto input = cursor::getchar();

        // if speciality char
        if (input.special != 0) {
            switch (input.code)
            {
            case 75: // ARROW_LEFT
                terminal::key_left(keys);
                break;
            case 77: // ARROW_RIGHT
                terminal::key_right(keys);
                break;
            default:
                #ifdef DEBUG
                debugKey(input);
                #endif
                break;
            }
            continue;
        }
        else switch (input.code) {
        case 8: // BACKSPACE
            terminal::key_backspace(keys);
            break;
        case 13: // ENTER
            std::cout << "\n\033[2K" << Calculator::parseAndCaluclate(keys.keys, true).value << "\n";
            keys.cursorPos = 0;
            keys.keys.clear();
            break;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
        case '.':
        case '+':
        case '-':
        case '*':
        case '/':
        case '(':
        case ')':
            terminal::key_insert(keys, input.code);
            break;
        case ':':
            exit |= commands::loop();
            break;
        default:
            #ifdef DEBUG
            debugKey(input);
            #endif
            break;
        };
    }
    std::cout << "\033[0m";
    return 0;
}