#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <SDL.h>
#include <SDL_image.h>

#define ASCII_SPACE 32
#define WINDOW_WIDTH 800
#define WINDOW_HEIGHT 600
#define SRC_FONT_WIDTH 7
#define SRC_FONT_HEIGHT 9
#define DST_FONT_WIDTH 28
#define DST_FONT_HEIGHT 32
#define ATLAS_WIDTH 18
#define DATASET_SIZE 100
#define STATS_SIZE 80

int main(int argc, char **argv) {
        srand(time(0));
        SDL_Init(SDL_INIT_VIDEO);
        IMG_Init(IMG_INIT_PNG);
        SDL_Window *win = SDL_CreateWindow(
                        "Sorting algorithms",
                        SDL_WINDOWPOS_CENTERED,
                        SDL_WINDOWPOS_CENTERED,
                        WINDOW_WIDTH,
                        WINDOW_HEIGHT,
                        0);
        SDL_Renderer *ren = SDL_CreateRenderer(
                        win,
                        -1,
                        SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
        SDL_Texture *font_atlas = IMG_LoadTexture(ren, "./font.png");

        int to_be_sorted[DATASET_SIZE] = {0};
        for (int i = 0; i < DATASET_SIZE;i++) {
                to_be_sorted[i] = i + 1;
        }
        for (int i = 0; i < DATASET_SIZE; i++) {
                int tmp = to_be_sorted[i];
                int j = rand() % DATASET_SIZE;
                to_be_sorted[i] = to_be_sorted[j];
                to_be_sorted[j] = tmp;
        }
        int sort_index = 0;
        int sort_index_internal = 0;
        int comparisons = 0;
        int swaps = 0;

        while (1) {
                SDL_Event e;
                if (SDL_PollEvent(&e)) {
                        if (e.type == SDL_QUIT) {
                                break;
                        }
                }

                if (sort_index < DATASET_SIZE - 1) {
                        if (sort_index_internal >= 0
                         && to_be_sorted[sort_index_internal] > to_be_sorted[sort_index_internal + 1]) {
                                int tmp = to_be_sorted[sort_index_internal + 1];
                                to_be_sorted[sort_index_internal + 1] = to_be_sorted[sort_index_internal];
                                to_be_sorted[sort_index_internal] = tmp;
                                sort_index_internal--;
                                comparisons++;
                                swaps++;
                        } else {
                                sort_index++;
                                sort_index_internal = sort_index;
                                comparisons++;
                        }
                }

                SDL_SetRenderDrawColor(ren, 0, 0, 0, 255);
                SDL_RenderClear(ren);

                char stats[STATS_SIZE] = {0};
                sprintf(stats, "Comparisons: %d\nSwaps: %d", comparisons, swaps);
                int line = 0;
                int col = 0;
                for (int i = 0; i < STATS_SIZE; i++) {
                        if (stats[i] == '\n') {
                                line++;
                                col = 0;
                        } else {
                                col++;
                        }
                        SDL_Rect src = {
                                (stats[i] - ASCII_SPACE) % ATLAS_WIDTH * SRC_FONT_WIDTH,
                                (stats[i] - ASCII_SPACE) / ATLAS_WIDTH * SRC_FONT_HEIGHT,
                                SRC_FONT_WIDTH,
                                SRC_FONT_HEIGHT
                        };
                        SDL_Rect dst = {
                                col * DST_FONT_WIDTH,
                                line * DST_FONT_HEIGHT,
                                DST_FONT_WIDTH,
                                DST_FONT_HEIGHT
                        };
                        SDL_RenderCopy(ren, font_atlas, &src, &dst);
                }

                for (int i = 0; i < DATASET_SIZE; i++) {
                        SDL_Rect bar = {
                                i * WINDOW_WIDTH / DATASET_SIZE,
                                WINDOW_HEIGHT,
                                WINDOW_WIDTH / DATASET_SIZE,
                                -to_be_sorted[i] * (int) (WINDOW_HEIGHT * 0.8) / DATASET_SIZE
                        };
                        if (sort_index_internal == i - 1) {
                                SDL_SetRenderDrawColor(ren, 0, 255, 0, 255);
                        } else if (sort_index == i - 1) {
                                SDL_SetRenderDrawColor(ren, 255, 0, 0, 255);
                        } else {
                                SDL_SetRenderDrawColor(ren, 255, 255, 255, 255);
                        }
                        SDL_RenderFillRect(ren, &bar);
                }

                SDL_RenderPresent(ren);
        }
        SDL_DestroyWindow(win);
        SDL_DestroyRenderer(ren);
        IMG_Quit();
        SDL_Quit();
        return 0;
}