#include <dirent.h>
#include <raylib.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "scenes.h"
#include "../ui_elements/UI.h"
#include "../resources/resources.h"
#include "../utils/arena.h"
#include "../resources/TextruesAtlas.h"

static const float MENU_SCROLL_SENC = 75.0f;
static const size_t ARENA_SIZE = 1024 * 64;
static const int SCENE_PADDING = 30;
static const int FOOTER_PADDING = 60;
static const float ARROWS_HEIGHT = 0.4f;
static const uint8_t ARROWS_ALPHA = 128;
/// Height / width
static const float ELEMENT_WIDTH_RATIO = 0.45f;

typedef struct {
    CollectionElement *collection;
    CollectionElement *selected;
    Button *backButton;
    size_t count;
    float blackout_state;
    PopUpState state;
    float scroll;
} CollectionSceneData;

CollectionSceneData *getData(void *self) {
    return ((Scene *)self)->data;
}

static void backButton_onClick(Scene *self) {
    // CollectionSceneData *data = getData(self);
    DeleteSceneFromStack();
}

void collectionElement_onSelect(CollectionElement *caller) {
    if (caller == NULL) return;
    TraceLog(LOG_INFO, "Selected element %s", caller->name);
    switch (caller->type) {
        case COLLECTION_ELEMENT_PUZZLE: 
            AddScene(CreatePuzzlePreview(ReadPuzzleFromFile(caller->path))); 
            break;
        case COLLECTION_ELEMENT_COLLECTION: 
            AddScene(CreatePuzzleCollectionScene(caller, false)); 
            break;
        default:
            TraceLog(LOG_WARNING, "Invalid CollectionElement type for %s", caller->path);
            break;
    }
}

void DrawCollectionName(char *name) {
    Vector2 width = MeasureTextEx(*GetMainFont(), name, HEADER_FONT_SIZE, 1);
    int screen_width = GetScreenWidth();
    Vector2 pos = { .y = SCENE_PADDING , .x = (screen_width - width.x) / 2, };
    DrawTextEx(*GetMainFont(), name, pos, HEADER_FONT_SIZE, 1, COLORSCHEME_BROWN);
}

// Does not allocate the memory
char *getCollectionName(char *path) {
    char *outp = path;
    size_t len = strlen(path);
    for (size_t i = 0; i < len; ++i) {
        if ((path[i] == '/' || path[i] == '\\') && path[i+1] != 0x0) {
            outp = path + i + 1;
        }
    }
    return outp;
}

bool updateCollectionScene(void *self) {
    CollectionSceneData *data = getData(self);
    if (data->state == POPUP_REVEALING) {
        data->blackout_state -= BLACKOUT_SPEED * GetFrameTime();
        if (data->blackout_state <= 0) {
            data->blackout_state = 0;
            data->state = POPUP_ACTIVE;
            TraceLog(LOG_INFO, "Done revealing");
        }
        return true;
    } 

    if (data->collection != NULL) {
        for (size_t i = 0; i < data->collection->childCount; ++i) {
            UpdateCollectionElement(&data->collection->children[i]);
        }
    }
    if (data->backButton != NULL) UpdateButton(data->backButton);

    return true;
}

bool drawCollectionScene(void *self) {
    CollectionSceneData *data = getData(self);
    DrawBackground();
    DrawCollectionName(data->collection->name);
    DrawPageView(GetScreenHeight() - 60, 5, 2);
    if (data->backButton != NULL) 
        DrawButton(data->backButton, &(Rectangle) { 
                .x = 10, 
                .y = GetScreenHeight() - 60,
                .width = 36,
                .height = 36, // TODO: make it match the page view scale
                });

    float element_height = GetScreenHeight() - SCENE_PADDING * 2 - HEADER_FONT_SIZE - FOOTER_PADDING;
    float element_width = element_height * ELEMENT_WIDTH_RATIO;
    for (size_t i = 0; i < data->collection->childCount; ++i) {
        DrawCollectionElement(&data->collection->children[i], data->collection, (Rectangle) {
                .x = SCENE_PADDING + (element_width + PADDING) * i - data->scroll,
                .y = SCENE_PADDING + HEADER_FONT_SIZE,
                .width = element_width,
                .height = element_height,
                });
    }

    data->scroll -= GetMouseWheelMove() * MENU_SCROLL_SENC;
    if (data->scroll < 0) data->scroll = 0;
    float max_scroll = (element_width + PADDING) * data->collection->childCount + SCENE_PADDING * 2 - GetScreenWidth();
    if (max_scroll < 0) max_scroll = 0;
    if (data->scroll > max_scroll) data->scroll = max_scroll;

    float arrows_height_px = GetScreenHeight() * ARROWS_HEIGHT;
    Color arrows_color = { .r = 255, .g = 255, .b = 255, .a = ARROWS_ALPHA, };


    if (data->scroll != 0)
        DrawTexturePro(*GetButtonsAtlas(), 
                LEFT_ARROW_ICON_LOCATION, 
                (Rectangle) {
                .x = 0,
                .y = (GetScreenHeight() - arrows_height_px) / 2,
                .width = SCENE_PADDING,
                .height = arrows_height_px
                }, (Vector2) {0}, 0, arrows_color);

    if (data->scroll != max_scroll)
        DrawTexturePro(*GetButtonsAtlas(), 
                RIGHT_ARROW_ICON_LOCATION, 
                (Rectangle) {
                .x = GetScreenWidth() - SCENE_PADDING,
                .y = (GetScreenHeight() - arrows_height_px) / 2,
                .width = SCENE_PADDING,
                .height = arrows_height_px
                }, (Vector2) {0}, 0, arrows_color);

    if (data->state != POPUP_ACTIVE) {
        DrawRectangle(0, 0, 
                GetScreenWidth(), GetScreenHeight(), 
                (Color) {0, 0, 0, 255 * (data->blackout_state >= 1 ? 1 : data->blackout_state) });
    }

    return true;
}

void deinitCollectionScene(void *self) {
    TraceLog(LOG_INFO, "Deleting a collection scene");
    CollectionSceneData *data = getData(self);
    if (data != NULL) {
        if (data->collection != NULL) 
            DeinitCollectionElement(data->collection);
        free(data);
    }
    free((Scene *)self);
}

Scene *CreatePuzzleCollectionScene(CollectionElement *el, bool smooothEntry) {
    TraceLog(LOG_INFO, "Creating a collection scene");
    Scene *outp = malloc(sizeof(Scene));
    if (outp == NULL) return NULL;
    outp->Update = updateCollectionScene;
    outp->Draw = drawCollectionScene;
    outp->Deint = deinitCollectionScene;
    outp->IsTransparent = false;
    
    CollectionSceneData *data = malloc(sizeof(CollectionSceneData));
    if (data == NULL) {
        free(outp);
        return NULL;
    }

    if (!el->IsInitialized) InitializeCollection(el, collectionElement_onSelect);
    data->collection = el;
    data->selected = NULL;
    data->state = smooothEntry? POPUP_REVEALING : POPUP_ACTIVE;
    data->blackout_state = 1.0f;
    data->scroll = 0.0f;

    Button *backButton = malloc(sizeof(Button));
    if (backButton != NULL) {
        backButton->parent = outp;
        backButton->OnClick = backButton_onClick;
        backButton->atlas = GetButtonsAtlas();
        backButton->textrueLocation = BACK_BUTTON_SMALL_LOCATION;
    }
    data->backButton = backButton;

    outp->data = data;

    return outp;
}