#ifndef UTILITIES_H
#define UTILITIES_H

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

#include "file.h"
#include "action_list.h"

#define RESET "\033[0m"
#define RED_BG "\033[41m"
#define GREEN_BG "\033[42m"
#define BLACK_FG "\033[30m"

typedef enum {
    PT_NOEXIST,
    PT_FILE,
    PT_DIR,
    PT_OTHER,
    PT_ERROR
} PathType;

PathType get_path_type(const char* path) {
    struct stat st;
    int rc = stat(path, &st);
    if (rc != 0) {
        return (errno == ENOENT) ? PT_NOEXIST : PT_ERROR;
    }
    if (S_ISREG(st.st_mode))  return PT_FILE;
    if (S_ISDIR(st.st_mode))  return PT_DIR;
    return PT_OTHER;
}

void visualize_diff(File* old_version, File* new_version, ActionList* actions) {
    int* deleted_lines = calloc(old_version->lines, sizeof(int));
    int* inserted_lines = calloc(new_version->lines, sizeof(int));

    if (!deleted_lines || !inserted_lines) {
        free(deleted_lines);
        free(inserted_lines);
        return;
    }

    for (uint64_t i = 0; i < actions->len; i++) {
        if (actions->actions[i].type == DELETE) {
            deleted_lines[actions->actions[i].line_original] = 1;
        } else if (actions->actions[i].type == INSERT) {
            inserted_lines[actions->actions[i].line_changed] = 1;
        }
    }

    uint64_t old_idx = 0, new_idx = 0;

    while (old_idx < old_version->lines || new_idx < new_version->lines) {
        // DELETE
        if (old_idx < old_version->lines && deleted_lines[old_idx]) {
            printf("%s%s%4ld      | %s%s\n", RED_BG, BLACK_FG, old_idx+1, old_version->content[old_idx], RESET);
            old_idx++;
        }
        // INSERT
        else if (new_idx < new_version->lines && inserted_lines[new_idx]) {
            printf("%s%s     %4ld | %s%s\n", GREEN_BG, BLACK_FG, new_idx+1, new_version->content[new_idx], RESET);
            new_idx++;
        }
        // STAYS
        else if (old_idx < old_version->lines && new_idx < new_version->lines) {
            printf("%4ld %4ld | %s\n", old_idx+1, new_idx+1, old_version->content[old_idx]);
            old_idx++;
            new_idx++;
        }
        // DELETE
        else if (old_idx < old_version->lines) {
            printf("%s%s%4ld      | %s%s\n", RED_BG, BLACK_FG, old_idx+1, old_version->content[old_idx], RESET);
            old_idx++;
        }
        // INSERT
        else if (new_idx < new_version->lines) {
            printf("%s%s     %4ld | %s%s\n", GREEN_BG, BLACK_FG, new_idx+1, new_version->content[new_idx], RESET);
            new_idx++;
        }
    }

    free(deleted_lines);
    free(inserted_lines);
}

// In this function we assume that base is a prefix of path
// Thus we just need the length of the base to jump ahead in the path
void cut_path(char* base, char* path) {
    size_t base_len = strlen(base);
    if (strlen(path) < base_len) perror("ERROR: the provided path is smaller than the base path!");
    int add = strlen(path) != base_len ? 1 : 0;

    printf("base: %li\n", base_len);
    strcpy(path, path+base_len+add);

    if (add) {
        char tmp[PATH_MAX];
        snprintf(tmp, sizeof(tmp), "%s/", path);
        strcpy(path, tmp);
    }
}

// In this function we assume that the end of the base and the beginning of the
// path are the same so we can concat them together at that part
// The path gets mutated in place
void combine_path(char* base, char* path) {
    size_t base_len = 0;

    for (size_t idx = strlen(base); idx > 0; idx--) {
        if (base[idx] == '/') {
            base_len = idx;
            break;
        }
    }

    char tmp[PATH_MAX];
    snprintf(tmp, sizeof(tmp), "%*s/%s", base_len, base, path);
    strcpy(path, tmp);
}

#endif // UTILITIES_H