#include "filecomplete.h"
#include <string>
#include <vector>

#ifdef _MSC_VER
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#endif
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_OF(x, y) (((x) > (y)) ? (x) : (y))

#if defined(_WIN32) || defined(__CYGWIN__) || defined(_WIN64)
#ifndef OS_WINDOWS
#define OS_WINDOWS

#include <conio.h>
#include <stdint.h>
#include <windows.h>
#endif
#elif defined(__APPLE__) || defined(__unix__) || defined(__unix) ||            \
    defined(unix) || defined(__linux__)
#ifndef OS_UNIX
#define OS_UNIX

#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
#endif
#else
#error Unknown environment!
#endif

#if defined(OS_WINDOWS)
#define ENTER 13
#define BACKSPACE 8
#define LEFT 75
#define RIGHT 77
#define UP 72
#define DOWN 80
#define DEL 83
#define CTRL_C 3
#define SPECIAL_SEQ_1 0
#define SPECIAL_SEQ_2 224
#define COLOR_TYPE uint16_t
#define DEFAULT_TITLE_COLOR 160
#define DEFAULT_PREDICT_COLOR 8
#define DEFAULT_MAIN_COLOR 7
#elif defined(OS_UNIX)
#define ENTER 10
#define BACKSPACE 127
#define LEFT 68
#define RIGHT 67
#define UP 65
#define DOWN 66
#define DEL 51
#define DEL_AFTER 126
#define SPECIAL_SEQ_1 27
#define SPECIAL_SEQ_2 91
#define COLOR_TYPE char*
#define DEFAULT_TITLE_COLOR "0;30;102"
#define DEFAULT_PREDICT_COLOR "90"
#define DEFAULT_MAIN_COLOR "0"
#endif
#define SPACE 32
#define TAB 9

constexpr int buf_size = 1024 * 100;
static std::vector<std::vector<char>> buf{};
static std::vector<char> word{};
static size_t wo{};
static size_t len{};
static short cy{};
static short cx{};

void clear_line();
void set_cursor_x(short x);
short get_cursor_y();
char* fc_readline();
void color_print(char* text, COLOR_TYPE color);

std::pair<short, short> get_wh()
{
    HANDLE h_console = GetStdHandle(STD_OUTPUT_HANDLE);
    if (h_console == NULL) {
        fprintf(stderr, "[ERROR] Couldn't handle terminal\n");
        exit(1);
    }
    CONSOLE_SCREEN_BUFFER_INFO console_info;
    if (GetConsoleScreenBufferInfo(h_console, &console_info) == 0) {
        fprintf(stderr, "[ERROR] Couldn't get terminal info\n");
        exit(1);
    }
    int cw = console_info.srWindow.Right - console_info.srWindow.Left + 1;
    int ch = console_info.srWindow.Bottom - console_info.srWindow.Top + 1;
    auto w = static_cast<short>(cw);
    auto h = static_cast<short>(ch);
    return std::make_pair(w, h);
}

void supply(std::vector<char>& wch, char ch)
{
    wch.push_back(ch);
    if (ch >= 0 && ch < 128) {
        return;
    }
    auto tch = _getch();
    wch.push_back(tch);
}

void clear_line()
{
#if defined(OS_WINDOWS)
    // Get current terminal width
    short width = get_wh().first;
    if (width < 1) {
        fprintf(stderr, "[ERROR] Size of terminal is too small\n");
        exit(1);
    }

    // Create long empty string
    char* empty = (char*)malloc(sizeof(char) * width);
    if (empty) {
        memset(empty, ' ', width);
        empty[width - 1] = '\0';
    }

    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    CONSOLE_CURSOR_INFO cursorInfo;
    GetConsoleCursorInfo(hConsole, &cursorInfo);
    cursorInfo.bVisible = FALSE;
    SetConsoleCursorInfo(hConsole, &cursorInfo);

    // Clear line
    printf("\r%s\r", empty);

    // Free line
    free(empty);
#elif defined(OS_UNIX)
    printf("\033[2K\r");
#endif
}

void set_cursor_x(short x)
{
#if defined(OS_WINDOWS)
    HANDLE h_console = GetStdHandle(STD_OUTPUT_HANDLE);
    if (h_console == NULL) {
        fprintf(stderr, "[ERROR] Couldn't handle terminal\n");
        exit(1);
    }

    auto wh = get_wh();
    // Create position
    COORD xy;
    xy.Y = get_cursor_y();
    short px = x % wh.first - 1;
    xy.X = px < 0 ? 0 : px;

    // Set cursor position
    if (SetConsoleCursorPosition(h_console, xy) == 0) {
        auto code = GetLastError();
        fprintf(stderr,
                "[ERROR] Couldn't set terminal cursor position, err=%lu\n",
                code);
        exit(1);
    }
#elif defined(OS_UNIX)
    printf("\033[%d;%dH", get_cursor_y(), x);
#endif
}

short get_cursor_y()
{
#if defined(OS_WINDOWS)
    HANDLE h_console = GetStdHandle(STD_OUTPUT_HANDLE);
    if (h_console == NULL) {
        fprintf(stderr, "[ERROR] Couldn't handle terminal\n");
        exit(1);
    }

    // Get terminal info
    CONSOLE_SCREEN_BUFFER_INFO console_info;
    if (GetConsoleScreenBufferInfo(h_console, &console_info) == 0) {
        fprintf(stderr, "[ERROR] Couldn't get terminal Y position\n");
        exit(1);
    }

    // Return Y position
    return console_info.dwCursorPosition.Y;
#elif defined(OS_UNIX)
    struct termios old_attr, new_attr;
    char ch, buf[30] = {0};
    int i = 0, pow = 1, y = 0;

    // Backup terminal attributes
    if (tcgetattr(STDIN_FILENO, &new_attr) == -1) {
        fprintf(stderr, "[ERROR] Couldn't get terminal attributes\n");
        exit(1);
    }

    // Disable echo
    old_attr = new_attr;
    old_attr.c_lflag &= ~(ICANON | ECHO);
    if (tcsetattr(STDIN_FILENO, TCSANOW, &old_attr) == -1) {
        fprintf(stderr, "[ERROR] Couldn't set terminal attributes\n");
        exit(1);
    }

    // Get info about cursor
    if (write(STDOUT_FILENO, "\033[6n", 4) != 4) {
        fprintf(stderr, "[ERROR] Couldn't get cursor information\n");
        exit(1);
    }

    // Get ^[[{this};1R value

    for (ch = 0; ch != 'R'; i++) {
        if (read(STDIN_FILENO, &ch, 1) != 1) {
            fprintf(stderr, "[ERROR] Couldn't read cursor information");
            exit(1);
        }
        buf[i] = ch;
    }

    i -= 2;
    while (buf[i] != ';') {
        i -= 1;
    }

    i -= 1;
    while (buf[i] != '[') {
        y = y + (buf[i] - '0') * pow;
        pow *= 10;
        i -= 1;
    }

    // Reset attributes
    if (tcsetattr(0, TCSANOW, &new_attr) == -1) {
        fprintf(stderr, "[ERROR] Couldn't reset terminal attributes\n");
        exit(1);
    }

    return (short)y;
#endif
}

char* fc_readline()
{
    char* buffer = (char*)calloc((size_t)buf_size, sizeof(char));
    if (buffer == NULL) {
        fprintf(stderr, "[ERROR] Couldn't allocate memory for buffer\n");
        exit(1);
    }

    // Current hint number
    int hint_num = 0;
    while (1) {

        word.clear();
        clear_line();
        // Print current buffer
        color_print(buffer, DEFAULT_MAIN_COLOR);

        // Move cursor
        int cur_pos{};
        for (int i = 0; i < buf.size() && i < wo; ++i) {
            cur_pos += static_cast<int>(buf[i].size());
        }
        set_cursor_x(cur_pos + 1);

        // Read character from console
        int ch = _getch();

        switch (ch) {
        case ENTER:
            return nullptr;
#if defined(OS_WINDWS)
        case CTRL_C: {
            exit(0);
        }
#endif
        case BACKSPACE: {
            if (wo > 0) {
                for (size_t i = wo - 1; i < buf.size() - 1; ++i) {
                    buf[i] = buf[i + 1];
                }
                --wo;
                --len;
            }
            break;
        }
        case TAB: {
            break;
        }
#if defined(OS_WINDOWS)
        case SPECIAL_SEQ_1:
        case SPECIAL_SEQ_2:
#elif defined(OS_UNIX)
        case SPECIAL_SEQ_1:
#endif
        {
#if defined(OS_UNIX)
            if (_getch() != SPECIAL_SEQ_2) {
                continue;
            }
#endif
            switch (_getch()) {
            case LEFT:
                wo = wo < 1 ? 0 : (--wo);
                break;
            case RIGHT:
                wo = wo >= len ? len : (++wo);
                break;
            case UP:
                break;
            case DOWN:
                break;
            case DEL:
                // Edit buffer like DELETE key
#if defined(OS_UNIX)
                if (_getch() == DEL_AFTER)
#endif
                {
                }
                break;
            default:
                break;
            }
            break;
        }
        default: {
            supply(word, ch);
            if (wo < buf.size()) {
                if (len >= buf.size()) {
                    buf.resize(buf.size() * 2);
                }
                if (len > 0) {
                    for (size_t i = len - 1; i >= wo; --i) {
                        buf[i + 1] = buf[i];
                    }
                    buf[wo] = word;
                }
            } else {
                buf.push_back(word);
            }
            ++wo;
            ++len;
            break;
        }
        }
    }
    return buffer;
}

void fc_free(char* str)
{
    free(str);
}

void color_print(char* text, COLOR_TYPE color)
{
#if defined(OS_WINDOWS)
    HANDLE h_console = GetStdHandle(STD_OUTPUT_HANDLE);
    if (h_console == NULL) {
        fprintf(stderr, "[ERROR] Couldn't handle terminal\n");
        exit(1);
    }

    CONSOLE_SCREEN_BUFFER_INFO console_info;
    COLOR_TYPE backup;

    // Save current attributes
    if (GetConsoleScreenBufferInfo(h_console, &console_info) == 0) {
        fprintf(stderr, "[ERROR] Couldn't get terminal info\n");
        exit(1);
    }

    auto wh = get_wh();

    backup = console_info.wAttributes;

    // Print colored text
    if (SetConsoleTextAttribute(h_console, color) == 0) {
        fprintf(stderr, "[ERROR] Couldn't set terminal color\n");
        exit(1);
    }

    std::string tbuf;

    for (size_t i = 0; i < buf.size() && i < len; ++i) {
        for (const auto& c : buf[i]) {
            tbuf.push_back(c);
        }
    }

    tbuf.push_back('\0');
    printf("%s", tbuf.c_str());

    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    CONSOLE_CURSOR_INFO cursorInfo;
    GetConsoleCursorInfo(hConsole, &cursorInfo);
    cursorInfo.bVisible = TRUE;
    SetConsoleCursorInfo(hConsole, &cursorInfo);

    // Restore original color
    if (SetConsoleTextAttribute(h_console, backup) == 0) {
        fprintf(stderr, "[ERROR] Couldn't reset terminal color\n");
        exit(1);
    }
#elif defined(OS_UNIX)
    // Set new terminal color
    printf("\033[");
    printf("%s", color);
    printf("m");

    // Print colored text
    printf("%s", text);

    // Resets the text to default color
    printf("\033[0m");
#endif
}