// /home/romkazvo/www/cgi-bin/index.c
// Основной файловый сервер
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <locale.h>

#define MAX_ENTRIES 1000
#define TEMPLATE_PATH "/home/romkazvo/www/cgi-bin/template.html"
#define OUTPUT_BUFFER_SIZE 65536

typedef struct {
    char name[256];
    int is_dir;
    long size;
    char icon[8];
    char encoded_path[1024];
    char file_url[1024];
} entry_t;

typedef struct {
    char *data;
    size_t size;
    size_t capacity;
} buffer_t;

void buffer_init(buffer_t *buf) {
    buf->capacity = OUTPUT_BUFFER_SIZE;
    buf->data = malloc(buf->capacity);
    buf->size = 0;
}

void buffer_append(buffer_t *buf, const char *str) {
    size_t len = strlen(str);
    if (buf->size + len >= buf->capacity) {
        buf->capacity *= 2;
        buf->data = realloc(buf->data, buf->capacity);
    }
    memcpy(buf->data + buf->size, str, len);
    buf->size += len;
}

void buffer_append_size(buffer_t *buf, const char *str, size_t len) {
    if (buf->size + len >= buf->capacity) {
        buf->capacity *= 2;
        buf->data = realloc(buf->data, buf->capacity);
    }
    memcpy(buf->data + buf->size, str, len);
    buf->size += len;
}

void buffer_free(buffer_t *buf) {
    free(buf->data);
}

const char* get_file_icon(const char* filename) {
    const char *ext = strrchr(filename, '.');
    if (!ext) return "📄";
    
    ext++;
    
    if (strcasecmp(ext, "jpg") == 0 || strcasecmp(ext, "jpeg") == 0 ||
        strcasecmp(ext, "png") == 0 || strcasecmp(ext, "gif") == 0 ||
        strcasecmp(ext, "webp") == 0 || strcasecmp(ext, "bmp") == 0)
        return "🖼️";
    
    if (strcasecmp(ext, "mp3") == 0 || strcasecmp(ext, "wav") == 0 ||
        strcasecmp(ext, "flac") == 0 || strcasecmp(ext, "ogg") == 0)
        return "🎵";
    
    if (strcasecmp(ext, "mp4") == 0 || strcasecmp(ext, "avi") == 0 ||
        strcasecmp(ext, "mkv") == 0 || strcasecmp(ext, "mov") == 0)
        return "🎬";
    
    if (strcasecmp(ext, "zip") == 0 || strcasecmp(ext, "rar") == 0 ||
        strcasecmp(ext, "7z") == 0 || strcasecmp(ext, "tar") == 0 ||
        strcasecmp(ext, "gz") == 0)
        return "📦";
    
    if (strcasecmp(ext, "pdf") == 0) return "📕";
    if (strcasecmp(ext, "doc") == 0 || strcasecmp(ext, "docx") == 0) return "📘";
    if (strcasecmp(ext, "xls") == 0 || strcasecmp(ext, "xlsx") == 0) return "📗";
    if (strcasecmp(ext, "txt") == 0) return "📝";
    
    return "📄";
}

int compare_entries(const void *a, const void *b) {
    const entry_t *entryA = (const entry_t *)a;
    const entry_t *entryB = (const entry_t *)b;
    
    if (entryA->is_dir && !entryB->is_dir) return -1;
    if (!entryA->is_dir && entryB->is_dir) return 1;
    
    return strcasecmp(entryA->name, entryB->name);
}

void format_size(long size, char* buffer) {
    if (size < 1024) {
        snprintf(buffer, 32, "%ld B", size);
    } else if (size < 1024 * 1024) {
        snprintf(buffer, 32, "%.1f KB", size / 1024.0);
    } else if (size < 1024 * 1024 * 1024) {
        snprintf(buffer, 32, "%.1f MB", size / (1024.0 * 1024.0));
    } else {
        snprintf(buffer, 32, "%.1f GB", size / (1024.0 * 1024.0 * 1024.0));
    }
}

void url_encode(const char *src, char *dst, size_t dst_size) {
    static const char *hex = "0123456789ABCDEF";
    char *p = dst;
    size_t i = 0;
    
    while (*src && i < dst_size - 3) {
        unsigned char c = (unsigned char)*src;
        
        if ((c >= 'A' && c <= 'Z') ||
            (c >= 'a' && c <= 'z') ||
            (c >= '0' && c <= '9') ||
            strchr("-_.~", c)) {
            *p++ = c;
            i++;
        }
        else if (c == ' ') {
            *p++ = '%';
            *p++ = '2';
            *p++ = '0';
            i += 3;
        }
        else {
            *p++ = '%';
            *p++ = hex[(c >> 4) & 0xF];
            *p++ = hex[c & 0xF];
            i += 3;
        }
        src++;
    }
    *p = '\0';
}

void url_decode_enhanced(const char *src, char *dst, size_t dst_size) {
    char *p = dst;
    size_t decoded_len = 0;
    
    while (*src && decoded_len < dst_size - 1) {
        if (*src == '%') {
            if (src[1] && src[2] && isxdigit(src[1]) && isxdigit(src[2])) {
                char hex[3] = {src[1], src[2], '\0'};
                unsigned char c = (unsigned char)strtol(hex, NULL, 16);
                
                if (c >= 0x80) {
                    *p++ = c;
                    decoded_len++;
                } else if (c >= 0x20 || c == 0x0A || c == 0x0D) {
                    *p++ = c;
                    decoded_len++;
                } else {
                    *p++ = '_';
                    decoded_len++;
                }
                src += 3;
            } else {
                *p++ = *src++;
                decoded_len++;
            }
        } else if (*src == '+') {
            *p++ = ' ';
            decoded_len++;
            src++;
        } else {
            *p++ = *src++;
            decoded_len++;
        }
    }
    *p = '\0';
}

void safe_path_join(char *result, size_t result_size, const char *base, const char *path) {
    snprintf(result, result_size, "%s/%s", base, path);
}

void print_breadcrumb(buffer_t *buf, const char *display_path) {
    buffer_append(buf, "<div class=\"breadcrumb\">\n");
    buffer_append(buf, "    <a href=\"/cgi-bin/index.cgi\">🏠 Главная</a>");
    
    if (display_path && display_path[0]) {
        char temp_path[1024] = "";
        char encoded[2048];
        char *path_copy = strdup(display_path);
        char *token = strtok(path_copy, "/");
        
        while (token) {
            buffer_append(buf, " / ");
            
            if (temp_path[0]) strcat(temp_path, "/");
            strcat(temp_path, token);
            
            url_encode(temp_path, encoded, sizeof(encoded));
            char link[4096];
            snprintf(link, sizeof(link), "<a href=\"/cgi-bin/index.cgi?path=%s\">%s</a>", encoded, token);
            buffer_append(buf, link);
            
            token = strtok(NULL, "/");
        }
        free(path_copy);
    }
    buffer_append(buf, "\n</div>\n");
}

void print_content(buffer_t *buf, const char *base_path, const char *display_path) {
    DIR *dir;
    struct dirent *entry;
    struct stat file_stat;
    char full_path[1024];
    
    entry_t entries[MAX_ENTRIES];
    int entry_count = 0;
    int dir_count = 0, file_count = 0;
    long long total_size = 0;
    
    dir = opendir(base_path);
    if (!dir) {
        char alt_path[1024];
        snprintf(alt_path, sizeof(alt_path), "/home/romkazvo/www");
        if (display_path[0]) {
            char *encoded = strdup(display_path);
            url_decode_enhanced(encoded, alt_path + strlen(alt_path), 
                              sizeof(alt_path) - strlen(alt_path));
            free(encoded);
        }
        
        dir = opendir(alt_path);
        if (!dir) {
            buffer_append(buf, "<div class=\"empty-state\">\n");
            buffer_append(buf, "    <div class=\"icon\">📁</div>\n");
            buffer_append(buf, "    <h3>Ошибка открытия директории</h3>\n");
            char error_msg[512];
            snprintf(error_msg, sizeof(error_msg), "    <p>Путь: %s</p>\n", base_path);
            buffer_append(buf, error_msg);
            snprintf(error_msg, sizeof(error_msg), "    <p>Ошибка: %s</p>\n", strerror(errno));
            buffer_append(buf, error_msg);
            buffer_append(buf, "    <p><a href=\"/cgi-bin/index.cgi\">← Вернуться на главную</a></p>\n");
            buffer_append(buf, "</div>\n");
            return;
        }
    }
    
    while ((entry = readdir(dir)) != NULL && entry_count < MAX_ENTRIES) {
        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) 
            continue;
        if (strcmp(entry->d_name, "cgi-bin") == 0)
            continue;
        
        snprintf(full_path, sizeof(full_path), "%s/%s", base_path, entry->d_name);
        
        if (stat(full_path, &file_stat) == 0) {
            strncpy(entries[entry_count].name, entry->d_name, sizeof(entries[0].name) - 1);
            entries[entry_count].name[sizeof(entries[0].name) - 1] = '\0';
            
            if (S_ISDIR(file_stat.st_mode)) {
                entries[entry_count].is_dir = 1;
                entries[entry_count].size = 0;
                strcpy(entries[entry_count].icon, "📁");
                
                char new_path[2048];
                snprintf(new_path, sizeof(new_path), "%s%s%s", display_path, 
                        display_path[0] ? "/" : "", entries[entry_count].name);
                url_encode(new_path, entries[entry_count].encoded_path, sizeof(entries[0].encoded_path));
                
                dir_count++;
            } else if (S_ISREG(file_stat.st_mode)) {
                entries[entry_count].is_dir = 0;
                entries[entry_count].size = file_stat.st_size;
                strcpy(entries[entry_count].icon, get_file_icon(entry->d_name));
                
                snprintf(entries[entry_count].file_url, sizeof(entries[0].file_url), 
                        "%s%s%s", display_path, display_path[0] ? "/" : "", entries[entry_count].name);
                
                file_count++;
                total_size += file_stat.st_size;
            } else {
                continue;
            }
            entry_count++;
        }
    }
    closedir(dir);
    
    if (entry_count == 0) {
        buffer_append(buf, "<div class=\"empty-state\">\n");
        buffer_append(buf, "    <div class=\"icon\">📄</div>\n");
        buffer_append(buf, "    <h3>Здесь пусто</h3>\n");
        buffer_append(buf, "    <p>В этой директории нет файлов или папок</p>\n");
        buffer_append(buf, "</div>\n");
        return;
    }
    
    qsort(entries, entry_count, sizeof(entry_t), compare_entries);
    
    buffer_append(buf, "<ul>\n");
    
    if (dir_count > 0) {
        char section_title[128];
        snprintf(section_title, sizeof(section_title), "    <li class=\"section-title\">📁 Папки (%d)</li>\n", dir_count);
        buffer_append(buf, section_title);
        
        for (int i = 0; i < entry_count; i++) {
            if (entries[i].is_dir) {
                buffer_append(buf, "    <li>\n");
                char dir_link[512];
                snprintf(dir_link, sizeof(dir_link), 
                        "        <a class=\"dir-link\" href=\"/cgi-bin/index.cgi?path=%s\">\n", 
                        entries[i].encoded_path);
                buffer_append(buf, dir_link);
                buffer_append(buf, "            <span class=\"file-icon\">");
                buffer_append(buf, entries[i].icon);
                buffer_append(buf, "</span>\n");
                buffer_append(buf, "            <span class=\"file-name\">");
                buffer_append(buf, entries[i].name);
                buffer_append(buf, "</span>\n");
                buffer_append(buf, "        </a>\n");
                buffer_append(buf, "    </li>\n");
            }
        }
    }
    
    if (file_count > 0) {
        char section_title[128];
        snprintf(section_title, sizeof(section_title), "    <li class=\"section-title\">📄 Файлы (%d)</li>\n", file_count);
        buffer_append(buf, section_title);
        
        for (int i = 0; i < entry_count; i++) {
            if (!entries[i].is_dir) {
                char size_str[32];
                format_size(entries[i].size, size_str);
                
                buffer_append(buf, "    <li>\n");
                char file_link[512];
                snprintf(file_link, sizeof(file_link), 
                        "        <a class=\"file-link\" href=\"/%s\" download>\n", 
                        entries[i].file_url);
                buffer_append(buf, file_link);
                buffer_append(buf, "            <span class=\"file-icon\">");
                buffer_append(buf, entries[i].icon);
                buffer_append(buf, "</span>\n");
                buffer_append(buf, "            <span class=\"file-name\">");
                buffer_append(buf, entries[i].name);
                buffer_append(buf, "</span>\n");
                buffer_append(buf, "        </a>\n");
                buffer_append(buf, "        <span class=\"size\">");
                buffer_append(buf, size_str);
                buffer_append(buf, "</span>\n");
                buffer_append(buf, "    </li>\n");
            }
        }
    }
    
    buffer_append(buf, "</ul>\n");
    
    char total_size_str[32];
    format_size(total_size, total_size_str);
    char stats[256];
    snprintf(stats, sizeof(stats), 
            "<div class=\"stats\">\n    Папки: %d | Файлы: %d | Общий размер: %s\n</div>\n", 
            dir_count, file_count, total_size_str);
    buffer_append(buf, stats);
}

void print_template(const char *base_path, const char *display_path) {
    FILE *file = fopen(TEMPLATE_PATH, "r");
    if (!file) {
        printf("Error: Cannot read template\n");
        return;
    }
    
    buffer_t output;
    buffer_init(&output);
    
    char line[4096];
    while (fgets(line, sizeof(line), file)) {
        if (strstr(line, "<!--BREADCRUMB-->")) {
            print_breadcrumb(&output, display_path);
        } else if (strstr(line, "<!--CONTENT-->")) {
            print_content(&output, base_path, display_path);
        } else {
            buffer_append(&output, line);
        }
    }
    fclose(file);
    
    fwrite(output.data, 1, output.size, stdout);
    buffer_free(&output);
}

int main() {
    setlocale(LC_ALL, "en_US.UTF-8");
    setlocale(LC_CTYPE, "en_US.UTF-8");
    
    printf("Content-type: text/html; charset=utf-8\n\n");
    
    char base_path[1024] = "/home/romkazvo/www";
    char display_path[1024] = "";
    char safe_display_path[1024] = "";
    
    char *query_string = getenv("QUERY_STRING");
    if (query_string) {
        char *path_start = strstr(query_string, "path=");
        if (path_start) {
            path_start += 5;
            char *path_end = strchr(path_start, '&');
            int path_len = path_end ? path_end - path_start : strlen(path_start);
            
            if (path_len > 0 && path_len < sizeof(display_path) - 1) {
                char encoded_path[1024];
                strncpy(encoded_path, path_start, path_len);
                encoded_path[path_len] = '\0';
                
                url_decode_enhanced(encoded_path, display_path, sizeof(display_path));
                
                strncpy(safe_display_path, display_path, sizeof(safe_display_path) - 1);
                safe_display_path[sizeof(safe_display_path) - 1] = '\0';
                
                safe_path_join(base_path, sizeof(base_path), "/home/romkazvo/www", safe_display_path);
            }
        }
    }
    
    print_template(base_path, display_path);
    return 0;
}