#include "state.hpp"

#include <cstring>
#include <cassert>
#include <string>
#include <cmath>
#include <cstdio>

#include <raylib.h>

#include "helpers.hpp"

#define STARTING_HELP_FADE_RATE 0.2f

Tri::State::State(int argc, char **argv) :
width(DEFAULT_WIDTH),
height(DEFAULT_HEIGHT),
dt(1.0f/60.0f),
notificationAlpha(1.0f),
trisIndex(0),
currentTri_state(CurrentState::NONE),
currentTri_maxState(CurrentState::NONE),
colorPickerColor{1.0f, 1.0f, 1.0f, 1.0f},
bgColorPickerColor{0.0f, 0.0f, 0.0f},
bgColor(BLACK),
pi(std::acos(-1.0f)),
inputWidth(800),
inputHeight(600)
{
    InitWindow(width, height, "Triangles");
    SetTargetFPS(60);

    flags.set(F_IS_RUNNING); // is running

    set_notification_text("Press \"H\" for help");

    pointCircle.setRadius(7.0f);
    pointCircle.translate({7.0f, 7.0f});
    pointCircle.fillColor = WHITE;
    pointCircle.outlineColor = BLACK;

    saveFilenameBuffer.fill(0);

    drawCache = LoadRenderTexture(width, height);
    flags.set(F_DRAW_CACHE_INITIALIZED);
    flags.set(F_DRAW_CACHE_DIRTY);

    GuiSetStyle(DEFAULT, BACKGROUND_COLOR, 0x303030);
}

Tri::State::~State() {
    UnloadRenderTexture(drawCache);
    CloseWindow();
}

void Tri::State::handle_events() {
    if(WindowShouldClose()) {
        flags.reset(F_IS_RUNNING);
    }

    int keyPressed = GetKeyPressed();
    while(keyPressed > 0) {
        if(!flags.test(F_DISPLAY_SAVE)) {
            switch(keyPressed) {
            case KEY_H:
                flags.flip(F_DISPLAY_HELP);
                break;
            case KEY_U:
                flags.set(F_DRAW_CACHE_DIRTY);
                if(currentTri_state > 0) {
                    switch(currentTri_state) {
                    case FIRST:
                        currentTri_state = CurrentState::NONE;
                        break;
                    case SECOND:
                        currentTri_state = CurrentState::FIRST;
                        break;
                    default:
                        assert(!"Unreachable code");
                        break;
                    }
                } else if(trisIndex > 0) {
                    --trisIndex;
                }
                break;
            case KEY_R:
                flags.set(F_DRAW_CACHE_DIRTY);
                if(currentTri_state != CurrentState::NONE
                        && currentTri_state < currentTri_maxState) {
                    switch(currentTri_state) {
                    case NONE:
                        currentTri_state = CurrentState::FIRST;
                        break;
                    case FIRST:
                        currentTri_state = CurrentState::SECOND;
                        break;
                    default:
                        assert(!"Unreachable code");
                        break;
                    }
                } else if(tris.size() > trisIndex) {
                    ++trisIndex;
                } else if(currentTri_state < currentTri_maxState) {
                    switch(currentTri_state) {
                    case NONE:
                        currentTri_state = CurrentState::FIRST;
                        break;
                    case FIRST:
                        currentTri_state = CurrentState::SECOND;
                        break;
                    default:
                        assert(!"Unreachable code");
                        break;
                    }
                }
                break;
            case KEY_C:
                if(flags.test(F_DISPLAY_COLOR_P)) {
                    close_color_picker();
                } else {
                    flags.set(F_DISPLAY_COLOR_P);
                }
                break;
            case KEY_B:
                if(flags.test(F_DISPLAY_BG_COLOR_P)) {
                    close_bg_color_picker();
                } else {
                    flags.set(F_DISPLAY_BG_COLOR_P);
                }
                break;
            case KEY_S:
                flags.flip(F_DISPLAY_SAVE);
                break;
            case KEY_P:
                flags.flip(F_COPY_COLOR_MODE);
                if(flags.test(F_COPY_COLOR_MODE)) {
                    set_notification_text(
                        "Copy color mode\n"
                        "Click to change\n"
                        "current draw color\n"
                        "to what was\n"
                        "clicked on");
                } else {
                    notificationAlpha = 0.0f;
                }
                break;
            case KEY_I:
                flags.flip(F_DISPLAY_CHANGE_SIZE);
                if(!flags.test(F_DISPLAY_CHANGE_SIZE)) {
                    close_input_width_height_window();
                } else {
                    failedMessage = "Press TAB to switch between width/height";
                }
                break;
            case KEY_E:
                if(flags.test(F_TRI_EDIT_MODE)) {
                    close_selected_tri_mode();
                } else {
                    flags.flip(F_SELECT_TRI_MODE);
                    if(flags.test(F_SELECT_TRI_MODE)) {
                        set_notification_text("Click on a tri\nto edit it");
                    }
                }
                break;
            case KEY_TAB:
                flags.flip(F_TAB_TOGGLE);
                break;
            }
        }
        keyPressed = GetKeyPressed();
    }

    if(IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
        if(can_draw()) {
            switch(currentTri_state) {
            case CurrentState::NONE:
                currentTri[0] = {GetMouseX(), GetMouseY()};
                if(trisIndex < tris.size()) {
                    tris.resize(trisIndex);
                }
                currentTri_state = CurrentState::FIRST;
                currentTri_maxState = CurrentState::FIRST;
                break;
            case CurrentState::FIRST:
                currentTri[1] = {GetMouseX(), GetMouseY()};
                if(trisIndex < tris.size()) {
                    tris.resize(trisIndex);
                }
                currentTri_state = CurrentState::SECOND;
                currentTri_maxState = CurrentState::SECOND;
                break;
            case CurrentState::SECOND:
                currentTri[2] = {GetMouseX(), GetMouseY()};
                if(trisIndex < tris.size()) {
                    tris.resize(trisIndex);
                }
                ++trisIndex;
                make_counter_clockwise(currentTri);
                tris.emplace_back(currentTri, pointCircle.fillColor);
                currentTri_state = CurrentState::NONE;
                currentTri_maxState = CurrentState::NONE;
                flags.set(F_DRAW_CACHE_DIRTY);
                break;
            }
        } else if(flags.test(F_COPY_COLOR_MODE)) {
            check_draw_cache();
            Image drawImage = GetTextureData(drawCache.texture);
            Color *colors = LoadImageColors(drawImage);
            int mx = GetMouseX();
            int my = GetMouseY();
            if(mx < 0) { mx = 0; }
            else if(mx >= (int)width) { mx = width - 1; }
            if(my < 0) { my = 0; }
            else if(my >= (int)height) { my = height - 1; }

            colorPickerColor[0] = colors[mx + my * width].r;
            colorPickerColor[1] = colors[mx + my * width].g;
            colorPickerColor[2] = colors[mx + my * width].b;
            colorPickerColor[3] = 1.0f;
            pointCircle.fillColor = colors[mx + my * width];
            flags.reset(F_COPY_COLOR_MODE);
            set_notification_text("Color set");

            UnloadImageColors(colors);
            UnloadImage(drawImage);
        } else if(flags.test(F_SELECT_TRI_MODE)) {
            int mx = GetMouseX();
            int my = GetMouseY();
            if(mx < 0) { mx = 0; }
            else if(mx >= (int)width) { mx = width - 1; }
            if(my < 0) { my = 0; }
            else if(my >= (int)height) { my = height - 1; }

            for(unsigned int i = trisIndex; i-- > 0; ) {
                if(is_within_shape(tris.at(i), {mx, my})) {
                    selectedTri = i;
                    tris[i].outlineColor = invert_color(tris[i].fillColor);
                    flags.reset(F_SELECT_TRI_MODE);
                    flags.set(F_TRI_EDIT_MODE);
                    flags.set(F_TRI_EDIT_DRAW_TRI);
                    selectedTriBlinkTimer = 1.0f;
                    selectedTriColor[0] = tris[i].fillColor.r / 255.0f;
                    selectedTriColor[1] = tris[i].fillColor.g / 255.0f;
                    selectedTriColor[2] = tris[i].fillColor.b / 255.0f;
                    selectedTriColor[3] = tris[i].fillColor.a / 255.0f;
                    break;
                }
            }
            if(!flags.test(F_TRI_EDIT_MODE)) {
                set_notification_text("Did not select\nanything");
            }
        }
    }
}

void Tri::State::update() {
    dt = GetFrameTime();

    if(notificationAlpha > 0.0f) {
        notificationAlpha -= dt * STARTING_HELP_FADE_RATE;
        if(notificationAlpha < 0.0f) {
            notificationAlpha = 0.0f;
        }
    }

    if(flags.test(F_COLOR_P_COLOR_DIRTY)) {
        flags.reset(F_COLOR_P_COLOR_DIRTY);
        pointCircle.fillColor = Color{
            (unsigned char)(255 * colorPickerColor[0]),
            (unsigned char)(255 * colorPickerColor[1]),
            (unsigned char)(255 * colorPickerColor[2]),
            (unsigned char)(255 * colorPickerColor[3])};
    }

    if(flags.test(F_BG_COLOR_P_COLOR_DIRTY)) {
        flags.reset(F_BG_COLOR_P_COLOR_DIRTY);
        bgColor.r = (unsigned char)(255 * bgColorPickerColor[0]);
        bgColor.g = (unsigned char)(255 * bgColorPickerColor[1]);
        bgColor.b = (unsigned char)(255 * bgColorPickerColor[2]);
    }

    if(flags.test(F_TRI_EDIT_MODE)) {
        selectedTriBlinkTimer -= dt * TRIANGLES_EDIT_TRI_BLINK_RATE;
        if(selectedTriBlinkTimer <= 0.0f) {
            selectedTriBlinkTimer = 1.0f;
            flags.flip(F_TRI_EDIT_DRAW_TRI);
        }
    }
}

void Tri::State::draw() {
    // Should be able to directly draw a texture held by the RenderTexture2D
    if(flags.test(F_DRAW_CACHE_INITIALIZED)) {
        // draw cache initialized
        check_draw_cache();
        BeginDrawing();
        // hack to flip in the y direction, since RenderTexture2D's texture
        // is flipped
        DrawTextureRec(
            drawCache.texture,
            {
                0.0f,
                0.0f,
                (float)drawCache.texture.width,
                (float)-drawCache.texture.height
            },
            {0.0f, 0.0f},
            WHITE);
    } else {
        BeginDrawing();
        draw_to_target(nullptr);
    }

    if(flags.test(F_TRI_EDIT_MODE) && flags.test(F_TRI_EDIT_DRAW_TRI)) {
//        tris.at(selectedTri).setOutlineThickness(4.0f);
        tris[selectedTri].draw();
//        tris.at(selectedTri).setOutlineThickness(0.0f);
    }

    if(can_draw()) {
        for(unsigned int i = 0; i < currentTri_state; ++i) {
            pointCircle.resetTransform();
            pointCircle.translate(currentTri[i]);
            pointCircle.draw();
        }
    }

    Tri::draw_notification(this);
    Tri::draw_color_picker(this);
    Tri::draw_bg_color_picker(this);
    Tri::draw_edit_tri(this);
    Tri::draw_change_size(this);
    Tri::draw_save(this);
    Tri::draw_help(this);

    EndDrawing();
}

void Tri::State::draw_to_target(RenderTexture2D *target) {
    if(target) {
        BeginTextureMode(*target);
        ClearBackground(bgColor);

        // draw tris
        for(unsigned int i = 0; i < trisIndex; ++i) {
            tris[i].draw();
        }
        EndTextureMode();
    } else {
        // Expects BeginDrawing() already having been called prior to this fn
        ClearBackground(bgColor);

        // draw tris
        for(unsigned int i = 0; i < trisIndex; ++i) {
            tris[i].draw();
        }
    }
}

unsigned int Tri::State::get_width() const {
    return width;
}

unsigned int Tri::State::get_height() const {
    return height;
}

const Tri::State::BitsetType Tri::State::get_flags() const {
    return flags;
}

float Tri::State::get_notification_alpha() const {
    return notificationAlpha;
}

const char* Tri::State::get_notification_text() const {
    return notificationText.data();
}

void Tri::State::set_notification_text(const char *text) {
    notificationText.fill(0);
    std::strncpy(notificationText.data(),
        text,
        notificationText.max_size() - 1);
    notificationAlpha = 1.0f;
}

void Tri::State::append_notification_text(const char *text) {
    auto length = std::strlen(notificationText.data());
    if(length + 1 >= notificationText.max_size()) {
        return;
    }
    std::strncpy(
        notificationText.data() + length,
        text,
        notificationText.max_size() - length - 1);
    notificationAlpha = 1.0f;
}

std::array<float, 4>& Tri::State::get_color() {
    flags.set(F_COLOR_P_COLOR_DIRTY);
    return colorPickerColor;
}

std::array<float, 3>& Tri::State::get_bg_color() {
    flags.set(F_BG_COLOR_P_COLOR_DIRTY);
    return bgColorPickerColor;
}

std::array<char, 256>* Tri::State::get_save_filename_buffer() {
    return &saveFilenameBuffer;
}

bool Tri::State::do_save() {
    RenderTexture2D saveTexture = LoadRenderTexture(width, height);

    draw_to_target(&saveTexture);

    Image saveImage = GetTextureData(saveTexture.texture);
    UnloadRenderTexture(saveTexture);
    if(ExportImage(saveImage, saveFilenameBuffer.data())) {
#ifndef NDEBUG
        printf("Saved to \"%s\"\n", saveFilenameBuffer.data());
#endif
        failedMessage.clear();
        UnloadImage(saveImage);
        return true;
    } else {
#ifndef NDEBUG
        printf("ERROR: Failed to save \"%s\"\n", saveFilenameBuffer.data());
#endif
        failedMessage = std::string("Failed to save (does the name end in \".png\"?)");
        UnloadImage(saveImage);
        return false;
    }
}

const std::string& Tri::State::failed_message() const {
    return failedMessage;
}

void Tri::State::close_save() {
    flags.reset(F_DISPLAY_SAVE);
}

bool Tri::State::can_draw() const {
    return !flags.test(F_DISPLAY_HELP)
        && !flags.test(F_DISPLAY_COLOR_P)
        && !flags.test(F_DISPLAY_BG_COLOR_P)
        && !flags.test(F_DISPLAY_SAVE)
        && !flags.test(F_COPY_COLOR_MODE)
        && !flags.test(F_DISPLAY_CHANGE_SIZE)
        && !flags.test(F_SELECT_TRI_MODE)
        && !flags.test(F_TRI_EDIT_MODE);
}

void Tri::State::reset_modes() {
    flags.reset(F_DISPLAY_HELP);
    flags.reset(F_DISPLAY_COLOR_P);
    flags.reset(F_DISPLAY_BG_COLOR_P);
    flags.reset(F_DISPLAY_SAVE);
    flags.reset(F_COPY_COLOR_MODE);
    flags.reset(F_DISPLAY_CHANGE_SIZE);
    flags.reset(F_SELECT_TRI_MODE);
    flags.reset(F_TRI_EDIT_MODE);
}

void Tri::State::close_help() {
    flags.reset(F_DISPLAY_HELP);
}

void Tri::State::close_color_picker() {
    flags.reset(F_DISPLAY_COLOR_P);
    flags.set(F_DRAW_CACHE_DIRTY);
}

void Tri::State::close_bg_color_picker() {
    flags.reset(F_DISPLAY_BG_COLOR_P);
    flags.set(F_DRAW_CACHE_DIRTY);
}

bool Tri::State::change_width_height() {
    if(inputWidth < 0 || inputHeight < 0) {
        failedMessage = "Width or Height cannot be less than 0";
        return false;
    }
    if(inputWidth < 800) {
        inputWidth = 800;
    }
    if(inputHeight < 600) {
        inputHeight = 600;
    }

    notificationText.fill(0);
    std::array<char, 5> tempBuf = {0, 0, 0, 0, 0};

    append_notification_text("Width set to ");
    snprintf(tempBuf.data(), 5, "%u", inputWidth);
    append_notification_text(tempBuf.data());

    append_notification_text(", Height set to ");
    snprintf(tempBuf.data(), 5, "%u", inputHeight);
    append_notification_text(tempBuf.data());

    this->width = inputWidth;
    this->height = inputHeight;

    UnloadRenderTexture(drawCache);
    SetWindowSize(this->width, this->height);
    drawCache = LoadRenderTexture(this->width, this->height);

    flags.set(F_DRAW_CACHE_DIRTY);

    currentTri_state = CurrentState::NONE;

    return true;
}

void Tri::State::close_input_width_height_window() {
    failedMessage.clear();
    inputWidth = width;
    inputHeight = height;
    flags.reset(F_DISPLAY_CHANGE_SIZE);
}

float Tri::State::get_pi() const {
    return pi;
}

std::array<float, 4>& Tri::State::get_selected_tri_color() {
    tris.at(selectedTri).fillColor = Color{
        (unsigned char)(255.0f * selectedTriColor[0]),
        (unsigned char)(255.0f * selectedTriColor[1]),
        (unsigned char)(255.0f * selectedTriColor[2]),
        (unsigned char)(255.0f * selectedTriColor[3])};
    return selectedTriColor;
}

void Tri::State::close_selected_tri_mode() {
    tris.at(selectedTri).fillColor = Color{
        (unsigned char)(255.0f * selectedTriColor[0]),
        (unsigned char)(255.0f * selectedTriColor[1]),
        (unsigned char)(255.0f * selectedTriColor[2]),
        (unsigned char)(255.0f * selectedTriColor[3])};
    flags.set(F_DRAW_CACHE_DIRTY);
    reset_modes();
}

bool Tri::State::check_draw_cache() {
    if(flags.test(F_DRAW_CACHE_INITIALIZED) && flags.test(F_DRAW_CACHE_DIRTY)) {
        // draw cache initialized and dirty
        flags.reset(F_DRAW_CACHE_DIRTY);
        draw_to_target(&drawCache);
        return true;
    } else {
        return false;
    }
}

int* Tri::State::get_input_width() {
    return &inputWidth;
}

int* Tri::State::get_input_height() {
    return &inputHeight;
}