#include <iostream>
#include <windows.h>
#include <thread>
#include <chrono>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"
#include <atomic>
#include <nlohmann/json.hpp>
#include <fstream>

#include "tinyfiledialogs.h"


void generateRandomColors(unsigned char& r, unsigned char& g, unsigned char& b);
void sendDMXData(HANDLE hSerial, unsigned char* data, int length);
void setupImGui(GLFWwindow* window);
void renderImGui();


// ui timeline stuff
std::vector<std::tuple<float, unsigned char, unsigned char, unsigned char>> markers; // Time, R, G, B
float timeline_position = 0.0f;
bool is_playing = false;
float playback_start_time = 0.0f;
float current_time = 0.0f;
float timeline_duration = 10.0f; // 10 seconds by default
float bpm = 120.0f; // Default BPM
float zoom_level = 1.0f; // Zoom level
float pan_offset = 0.0f; // Pan offset


const int num_channels = 512;
unsigned char buffer[num_channels] = { 0 };

GLFWwindow* initOpenGL();

HANDLE hSerial;
std::atomic<bool> running(true);

void dmxThreadFunc() {
    while (running) {
        // 25ms refresh rate
        sendDMXData(hSerial, buffer, num_channels);
        std::this_thread::sleep_for(std::chrono::milliseconds(25));
    }
}

int main() {
    hSerial = CreateFileA("\\\\.\\COM3", GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
    if (hSerial == INVALID_HANDLE_VALUE) {
        std::cerr << "Error opening COM3 port" << std::endl;
        return 1;
    }

    DCB dcbSerialParams = { 0 };
    dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
    if (!GetCommState(hSerial, &dcbSerialParams)) {
        std::cerr << "Error getting COM3 state" << std::endl;
        CloseHandle(hSerial);
        return 1;
    }

    dcbSerialParams.BaudRate = 250000;
    dcbSerialParams.ByteSize = 8;
    dcbSerialParams.StopBits = TWOSTOPBITS; // <-- don't forget about this
    dcbSerialParams.Parity = NOPARITY;

    if (!SetCommState(hSerial, &dcbSerialParams)) {
        std::cerr << "Error setting COM3 state" << std::endl;
        CloseHandle(hSerial);
        return 1;
    }

    COMMTIMEOUTS timeouts = { 0 };
    timeouts.ReadIntervalTimeout = 50;
    timeouts.ReadTotalTimeoutConstant = 50;
    timeouts.ReadTotalTimeoutMultiplier = 10;
    timeouts.WriteTotalTimeoutConstant = 50;
    timeouts.WriteTotalTimeoutMultiplier = 10;

    if (!SetCommTimeouts(hSerial, &timeouts)) {
        std::cerr << "Error setting COM3 timeouts" << std::endl;
        CloseHandle(hSerial);
        return 1;
    }

    GLFWwindow* window = initOpenGL();
    if (!window) {
        CloseHandle(hSerial);
        return 1;
    }

    setupImGui(window);
    std::thread dmxThread(dmxThreadFunc);

    while (!glfwWindowShouldClose(window)) {
        glfwPollEvents();

        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplGlfw_NewFrame();
        ImGui::NewFrame();

        renderImGui();

        ImGui::Render();
        int display_w, display_h;
        glfwGetFramebufferSize(window, &display_w, &display_h);
        glViewport(0, 0, display_w, display_h);
        glClearColor(0.45f, 0.55f, 0.60f, 1.00f);
        glClear(GL_COLOR_BUFFER_BIT);
        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

        glfwSwapBuffers(window);
    }

    running = false;
    dmxThread.join();

    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImGui::DestroyContext();
    glfwDestroyWindow(window);
    glfwTerminate();
    CloseHandle(hSerial);

    return 0;
}

void generateRandomColors(unsigned char& r, unsigned char& g, unsigned char& b) {
    r = rand() % 256;
    g = rand() % 256;
    b = rand() % 256;
}

void sendDMXData(HANDLE hSerial, unsigned char* data, int length) {
    // break condition
    EscapeCommFunction(hSerial, SETBREAK);
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
    EscapeCommFunction(hSerial, CLRBREAK);
    std::this_thread::sleep_for(std::chrono::milliseconds(1)); // this is the mab

    DWORD bytesWritten;
    unsigned char startCode = 0;
    WriteFile(hSerial, &startCode, 1, &bytesWritten, NULL);
    WriteFile(hSerial, data, length, &bytesWritten, NULL);
}

// Function to export markers to a JSON file
void exportMarkersToFile(const std::string& filename) {
    nlohmann::json j;

    for (const auto& marker : markers) {
        j.push_back({
            {"time", std::get<0>(marker)},
            {"r", std::get<1>(marker)},
            {"g", std::get<2>(marker)},
            {"b", std::get<3>(marker)}
            });
    }

    std::ofstream file(filename);
    if (file.is_open()) {
        file << j.dump(4); // Pretty print with indentation of 4 spaces
        file.close();
    }
    else {
        std::cerr << "Could not open file for writing: " << filename << std::endl;
    }
}

// Function to load markers from a JSON file
void loadMarkersFromFile(const std::string& filename) {
    nlohmann::json j;
    std::ifstream file(filename);

    if (file.is_open()) {
        file >> j;
        file.close();

        markers.clear();
        for (const auto& element : j) {
            markers.emplace_back(
                element["time"].get<float>(),
                element["r"].get<unsigned char>(),
                element["g"].get<unsigned char>(),
                element["b"].get<unsigned char>()
            );
        }
    }
    else {
        std::cerr << "Could not open file for reading: " << filename << std::endl;
    }
}


GLFWwindow* initOpenGL() {
    if (!glfwInit()) {
        std::cerr << "Failed to initialize GLFW" << std::endl;
        return nullptr;
    }

    GLFWwindow* window = glfwCreateWindow(1280, 720, "DMX Controller", NULL, NULL);
    if (!window) {
        std::cerr << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return nullptr;
    }

    glfwMakeContextCurrent(window);
    glfwSwapInterval(1); // I think this is vsync??

    if (glewInit() != GLEW_OK) {
        std::cerr << "Failed to initialize GLEW" << std::endl;
        glfwDestroyWindow(window);
        glfwTerminate();
        return nullptr;
    }

    return window;
}

void setupImGui(GLFWwindow* window) {
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;

    ImGui::StyleColorsDark();

    ImGui_ImplGlfw_InitForOpenGL(window, true);
    ImGui_ImplOpenGL3_Init("#version 130");
}

void renderImGui() {
    // Calculate time per beat based on BPM
    float beat_interval = 60.0f / bpm;

    // Temporary variables to hold the slider values
    int channel1 = buffer[0];
    int channel2 = buffer[1];
    int channel3 = buffer[2];

    // Create a window
    ImGui::Begin("DMX Controller");

    // Create buttons to export and load markers
    if (ImGui::Button("Export Lightshow")) {

        const char* filterPatterns[2] = { "*.ls", "*.json" };
        const char* saveFileName = tinyfd_saveFileDialog(
            "Save As",                     // Dialog title
            "lightshow.ls",                // Default file name
            2,                             // Number of filter patterns
            filterPatterns,                // Filter patterns
            NULL                           // Single filter description (optional)
        );

        if (saveFileName) {
            std::cout << "File saved as: " << saveFileName << std::endl;
            exportMarkersToFile(saveFileName);
        }
        else {
            std::cout << "Save operation was canceled." << std::endl;
        }
    }

    ImGui::SameLine();

    if (ImGui::Button("Load Lightshow")) {
        const char* filterPatterns[2] = { "*.ls", "*.json" };
        std::string filename = tinyfd_openFileDialog("Select a file", "", 2, filterPatterns, NULL, 0);
        if (!filename.empty()) {
            loadMarkersFromFile(filename);
        }
    }


    // Create sliders for the first three DMX channels
    ImGui::SliderInt("Channel 1", &channel1, 0, 255);
    ImGui::SliderInt("Channel 2", &channel2, 0, 255);
    ImGui::SliderInt("Channel 3", &channel3, 0, 255);

    // Assign the slider values back to the DMX buffer
    buffer[0] = static_cast<unsigned char>(channel1);
    buffer[1] = static_cast<unsigned char>(channel2);
    buffer[2] = static_cast<unsigned char>(channel3);

    // Allow user to set the total duration of the timeline and BPM
    ImGui::SliderFloat("Timeline Duration (seconds)", &timeline_duration, 1.0f, 300.0f);
    ImGui::SliderFloat("BPM", &bpm, 30.0f, 240.0f);

    // Play/Pause button
    if (ImGui::Button(is_playing ? "Pause" : "Play")) {
        is_playing = !is_playing;
        if (is_playing) {
            playback_start_time = static_cast<float>(glfwGetTime()) - timeline_position;
        }
    }

    // Time Slider (Timeline Position)
    ImGui::SliderFloat("Timeline Position", &timeline_position, 0.0f, timeline_duration, "%.2f sec");

    // Custom timeline rendering with grid lines
    ImGui::Text("Timeline");
    ImGui::PushID("CustomTimeline");
    ImGui::BeginChild("##Timeline", ImVec2(ImGui::GetContentRegionAvail().x, 100), true);

    // Draw grid lines for beats
    ImDrawList* draw_list = ImGui::GetWindowDrawList();
    ImVec2 cursor_pos = ImGui::GetCursorScreenPos();
    float timeline_width = ImGui::GetContentRegionAvail().x;

    for (int i = 0; i <= static_cast<int>(timeline_duration / beat_interval); ++i) {
        float beat_position = i * beat_interval * zoom_level - pan_offset;
        float x_position = cursor_pos.x + (beat_position / timeline_duration) * timeline_width;

        if (x_position >= cursor_pos.x && x_position <= cursor_pos.x + timeline_width) {
            // Draw major beat line
            if (i % 4 == 0) {
                draw_list->AddLine(ImVec2(x_position, cursor_pos.y), ImVec2(x_position, cursor_pos.y + 100), IM_COL32(255, 0, 0, 255), 2.0f);
            }
            else {
                // Draw minor beat line
                draw_list->AddLine(ImVec2(x_position, cursor_pos.y), ImVec2(x_position, cursor_pos.y + 100), IM_COL32(255, 255, 255, 255), 1.0f);
            }
        }
    }

    // Draw the current timeline position marker
    float position_marker = (timeline_position * zoom_level - pan_offset) / timeline_duration * timeline_width;
    draw_list->AddLine(ImVec2(cursor_pos.x + position_marker, cursor_pos.y), ImVec2(cursor_pos.x + position_marker, cursor_pos.y + 100), IM_COL32(0, 0, 255, 255), 2.0f);

    // Allow adding markers with snapping to grid
    if (ImGui::Button("Add Marker")) {
        float snap_position = std::round(timeline_position / beat_interval) * beat_interval;
        markers.emplace_back(snap_position / timeline_duration, buffer[0], buffer[1], buffer[2]);
    }

    // Draw markers on the timeline
    for (const auto& marker : markers) {
        float marker_position = std::get<0>(marker) * timeline_duration * zoom_level - pan_offset;
        float x_position = cursor_pos.x + (marker_position / timeline_duration) * timeline_width;

        if (x_position >= cursor_pos.x && x_position <= cursor_pos.x + timeline_width) {
            draw_list->AddRectFilled(ImVec2(x_position - 2.0f, cursor_pos.y), ImVec2(x_position + 2.0f, cursor_pos.y + 100), IM_COL32(0, 255, 0, 255));
        }
    }

    ImGui::EndChild();
    ImGui::PopID();

    // Playback logic: Update timeline position based on playback time
    if (is_playing) {
        current_time = static_cast<float>(glfwGetTime()) - playback_start_time;
        timeline_position = current_time;

        // Trigger markers during playback
        for (const auto& marker : markers) {
            float marker_time = std::get<0>(marker) * timeline_duration;
            if (current_time >= marker_time && current_time < marker_time + 0.025f) { // Slight tolerance for timing precision
                buffer[0] = std::get<1>(marker);
                buffer[1] = std::get<2>(marker);
                buffer[2] = std::get<3>(marker);
            }
        }

        // Stop playback when the timeline reaches the end
        if (timeline_position >= timeline_duration) {
            is_playing = false;
            timeline_position = timeline_duration;
        }
    }

    // Display added markers with their RGB values and time
    for (const auto& marker : markers) {
        float marker_time = std::get<0>(marker) * timeline_duration;
        ImGui::Text("Marker at %.2f sec: R=%d, G=%d, B=%d",
            marker_time,
            std::get<1>(marker),
            std::get<2>(marker),
            std::get<3>(marker));
    }

    // Place Zoom and Pan sliders below the timeline to avoid overlap
    ImGui::SliderFloat("Zoom", &zoom_level, 0.1f, 10.0f);
    ImGui::SliderFloat("Pan", &pan_offset, 0.0f, timeline_duration * zoom_level);

    ImGui::End();
}