#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <MLV/MLV_all.h>
#include "grid.h"
#include "snake.h"

Grid *allocate_grid(int n, int m)
{
    Grid *g = malloc(sizeof(Grid));
    int i;
    if (!g)
    {
        fprintf(stderr, "Error: could not allocate Grid.\n");
        exit(EXIT_FAILURE);
    }
    g->nbl = n;
    g->nbc = m;
    g->grid = malloc(n * sizeof(char *));
    if (!g->grid)
    {
        fprintf(stderr, "Error: could not allocate g->grid.\n");
        exit(EXIT_FAILURE);
    }
    for (i = 0; i < n; i++)
    {
        g->grid[i] = calloc(m + 2, sizeof(char));
        if (!g->grid[i])
        {
            fprintf(stderr, "Error: could not allocate row.\n");
            exit(EXIT_FAILURE);
        }
    }
    return g;
}

void free_grid(Grid *g)
{
    int i;
    if (!g)
        return;
    for (i = 0; i < g->nbl; i++)
    {
        free(g->grid[i]);
    }
    free(g->grid);
    free(g);
}

void debug_grid(Grid *g)
{
    int i;
    for (i = 0; i < g->nbl; i++)
    {
        printf("%s\n", g->grid[i]);
    }
}

int compute_size(Grid *g, int w, int h)
{
    int size_width = w / g->nbc;
    int size_height = h / g->nbl;
    return (size_width < size_height) ? size_width : size_height;
}

void draw_grid(Grid *g)
{
    int i, j;
    int window_width = MLV_get_window_width();
    int window_height = MLV_get_window_height();
    int cell_size = compute_size(g, window_width, window_height);
    MLV_Image *image_wall, *image_fruit, *image_snake, *image_snake_head, *image_boost, *image_empty;
    image_wall = MLV_load_image("./assets/wall.png");
    image_fruit = MLV_load_image("./assets/fruit.png");
    image_snake = MLV_load_image("./assets/snake.png");
    image_snake_head = MLV_load_image("./assets/snake_head.png");
    image_boost = MLV_load_image("./assets/boost.png");
    image_empty = MLV_load_image("./assets/grass.png");
    if (image_wall != NULL)
    {
        MLV_resize_image_with_proportions(image_wall, cell_size, cell_size);
    }
    if (image_fruit != NULL)
    {
        MLV_resize_image_with_proportions(image_fruit, cell_size, cell_size);
    }
    if (image_snake != NULL)
    {
        MLV_resize_image_with_proportions(image_snake, cell_size, cell_size);
    }
    if (image_snake_head != NULL)
    {
        MLV_resize_image_with_proportions(image_snake_head, cell_size, cell_size);
    }
    if (image_boost != NULL)
    {
        MLV_resize_image_with_proportions(image_boost, cell_size, cell_size);
    }
    if (image_empty != NULL)
    {
        MLV_resize_image_with_proportions(image_empty, cell_size, cell_size);
    }

    MLV_draw_filled_rectangle(0, 0, window_width, window_height, MLV_COLOR_BLACK);

    for (i = 0; i < g->nbl; i++)
    {
        for (j = 0; j < g->nbc; j++)
        {
            int x = j * cell_size;
            int y = i * cell_size;

            switch (g->grid[i][j])
            {
            case WALL:
                if (image_wall == NULL)
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_BROWN);
                }
                else
                {
                    MLV_draw_image(image_wall, x, y);
                }
                break;
            case EMPTY:
                if (image_empty != NULL)
                {
                    MLV_draw_image(image_empty, x, y);
                }
                else
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_WHITE);
                }

                break;
            case FRUIT:
                if (image_fruit == NULL)
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_RED);
                }
                else
                {
                    MLV_draw_image(image_fruit, x, y);
                }
                break;
            case SNAKE:
                if (image_snake == NULL)
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_GREEN);
                }
                else
                {
                    MLV_draw_image(image_snake, x, y);
                }
                break;
            case SNAKEHEAD:
                if (image_snake == NULL)
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_GREEN);
                }
                else
                {
                    MLV_draw_image(image_snake_head, x, y);
                }
                break;
            case BOOST:
                if (image_boost == NULL)
                {
                    MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_YELLOW);
                }
                else
                {
                    MLV_draw_image(image_boost, x, y);
                }
                break;
            default:
                MLV_draw_filled_rectangle(x, y, cell_size, cell_size, MLV_COLOR_BLACK);
                break;
            }
        }
    }
}

void place_snake(Grid *g, struct SnakeStruct *snake)
{
    Position *current = snake->segments_list;

    if (current != NULL)
    {
        g->grid[current->y][current->x] = SNAKEHEAD;
        current = current->next;
    }

    while (current != NULL)
    {
        g->grid[current->y][current->x] = SNAKE;
        current = current->next;
    }
}

Element move_snake(struct SnakeStruct *snake, Grid *g)
{
    Position *tail = snake->segments_list;
    Position *head;
    Element element_at_head;

    while (tail->next != NULL)
    {
        tail = tail->next;
    }

    g->grid[tail->y][tail->x] = EMPTY;

    crawl(snake, g);

    head = snake->segments_list;
    element_at_head = g->grid[head->y][head->x];

    g->grid[head->y][head->x] = SNAKEHEAD;

    if (head->next != NULL)
    {
        g->grid[head->next->y][head->next->x] = SNAKE;
    }

    return element_at_head;
}

int count_nb_lines(FILE *stream)
{
    int count = 0;
    char buffer[256];
    while (fgets(buffer, sizeof(buffer), stream))
    {
        count++;
    }
    rewind(stream);
    return count;
}

int count_fruits(FILE *stream, Grid *g)
{
    int i, j, nb_fruit = 0;

    for (i = 0; i < g->nbl; i++)
    {
        if (!fgets(g->grid[i], g->nbc + 2, stream))
        {
            fprintf(stderr, "Error: Stream does not contain enough lines\n");
            exit(EXIT_FAILURE);
        }
        g->grid[i][strcspn(g->grid[i], "\n")] = '\0';

        for (j = 0; j < g->nbc; j++)
        {
            if (g->grid[i][j] == FRUIT)
            {
                nb_fruit++;
            }
        }
    }

    return nb_fruit;
}

void copy(const char *src, char *dst)
{
    int i = 0;
    while (src[i] != '\0' && src[i] != '\n')
    {
        dst[i] = src[i];
        i++;
    }
    dst[i] = '\0';
}

static bool are_adjacent(Position *a, Position *b)
{
    return (a->x == b->x && abs(a->y - b->y) == 1) ||
           (a->y == b->y && abs(a->x - b->x) == 1);
}

int is_snake_connected(struct SnakeStruct *snake)
{
    Position *current = snake->segments_list;
    while (current && current->next)
    {
        if (!are_adjacent(current, current->next))
        {
            return 0;
        }
        current = current->next;
    }
    return 1;
}

void read_snake_from_grid(Grid *g, struct SnakeStruct *snake)
{
    Position *positions = malloc(g->nbl * g->nbc * sizeof(Position));
    int positions_count = 0;
    Position *head = NULL;
    Position *current;
    int i;
    int *used = NULL;

    for (i = 0; i < g->nbl; i++)
    {
        int j;
        for (j = 0; j < g->nbc; j++)
        {
            if (g->grid[i][j] == SNAKE || g->grid[i][j] == SNAKEHEAD)
            {
                positions[positions_count].x = j;
                positions[positions_count].y = i;
                positions[positions_count].next = NULL;

                if (g->grid[i][j] == SNAKEHEAD)
                {
                    head = &positions[positions_count];
                }

                positions_count++;
            }
        }
    }

    if (head == NULL)
    {
        fprintf(stderr, "Error: Snake head (S) not found in the grid.\n");
        free(positions);
        exit(EXIT_FAILURE);
    }
    
    used = malloc(positions_count * sizeof(int));
    if (!used) {
        fprintf(stderr, "Error: Could not allocate memory for used array.\n");
        free(positions);
        exit(EXIT_FAILURE);
    }
    for (i = 0; i < positions_count; i++)
    {
        used[i] = 0;
    }

    add_segment(snake, head->x, head->y);
    used[head - positions] = 1;

    current = head;
    while (1)
    {
        int found = 0;
        int j;
        for (j = 0; j < positions_count; j++)
        {
            if (!used[j] && are_adjacent(current, &positions[j]))
            {
                add_segment(snake, positions[j].x, positions[j].y);
                used[j] = 1;
                current = &positions[j];
                found = 1;
                break;
            }
        }

        if (!found)
        {
            break;
        }
    }

    for (i = 0; i < positions_count; i++)
    {
        if (!used[i])
        {
            fprintf(stderr, "Error: Snake is not fully connected in the grid.\n");
            free(positions);
            exit(EXIT_FAILURE);
        }
    }

    snake->dir = determine_initial_direction(g, snake->segments_list);

    free(positions);
    free(used);
}