/*
 * OmniNX Installer - Backup and Restore Operations
 */

#include "backup.h"
#include "fs.h"
#include <libs/fatfs/ff.h>
#include <string.h>
#include <stdarg.h>
#include <utils/sprintf.h>

#define BACKUP_PATH_MAX 270

// Check if file/directory exists
static bool path_exists(const char *path) {
    FILINFO fno;
    return (f_stat(path, &fno) == FR_OK);
}

// Create all parent directories for a path (mkdir -p style)
static void ensure_parent_dirs(const char *full_path) {
    char buf[BACKUP_PATH_MAX];
    int n = (int)strlen(full_path);
    if (n >= BACKUP_PATH_MAX) return;
    memcpy(buf, full_path, n + 1);

    for (int i = 4; i < n; i++) {
        if (buf[i] == '/') {
            buf[i] = '\0';
            f_mkdir(buf);
            buf[i] = '/';
        }
    }
}

// Copy a single path (file or dir) to backup base, preserving SD structure
static int backup_single_path(const char *src_path, const char *backup_base) {
    FILINFO fno;
    if (f_stat(src_path, &fno) != FR_OK)
        return FR_OK;

    const char *relative = src_path;
    if (strncmp(relative, "sd:/", 4) == 0)
        relative += 4;

    if (fno.fattrib & AM_DIR) {
        const char *last_slash = strrchr(relative, '/');
        char parent[BACKUP_PATH_MAX];
        if (last_slash && last_slash > relative) {
            s_printf(parent, "%s/%.*s", backup_base, (int)(last_slash - relative), relative);
            /* Create full parent hierarchy (e.g. atmosphere, atmosphere/contents) */
            ensure_parent_dirs(parent);
            f_mkdir(parent);  /* Ensure parent exists; FR_EXIST is fine */
            return folder_copy(src_path, parent);
        } else {
            ensure_parent_dirs(backup_base);
            return folder_copy(src_path, backup_base);
        }
    } else {
        char dst_path[BACKUP_PATH_MAX];
        s_printf(dst_path, "%s/%s", backup_base, relative);
        ensure_parent_dirs(dst_path);
        return file_copy(src_path, dst_path);
    }
}

// Backup all paths from varargs lists (same structure as delete_path_lists_grouped)
int backup_deletion_lists(const char *backup_base, ...) {
    va_list ap;
    const char **list;
    int res = FR_OK;

    /* FatFS f_mkdir only creates the last component; parent must exist first */
    ensure_parent_dirs(BACKUP_BASE_PATH);
    res = f_mkdir(BACKUP_BASE_PATH);
    if (res != FR_OK && res != FR_EXIST)
        return res;

    ensure_parent_dirs(backup_base);
    res = f_mkdir(backup_base);
    if (res != FR_OK && res != FR_EXIST)
        return res;

    va_start(ap, backup_base);
    while ((list = va_arg(ap, const char **)) != NULL) {
        for (int i = 0; list[i] != NULL; i++) {
            if (path_exists(list[i])) {
                int copy_res = backup_single_path(list[i], backup_base);
                if (copy_res != FR_OK && res == FR_OK)
                    res = copy_res;  // Remember first error but keep going
            }
        }
    }
    va_end(ap);

    /* Best-effort: return FR_OK so install continues even if some copies failed */
    return FR_OK;
}

// Backup user data before clean install
int backup_user_data(void) {
    int res;
    
    // Create temp backup directory
    res = f_mkdir(TEMP_BACKUP_PATH);
    if (res != FR_OK && res != FR_EXIST) {
        return res;
    }
    
    // Backup DBI if it exists
    if (path_exists("sd:/switch/DBI")) {
        res = folder_copy("sd:/switch/DBI", TEMP_BACKUP_PATH);
        if (res != FR_OK) {
            return res;
        }
    }
    
    // Backup Tinfoil if it exists
    if (path_exists("sd:/switch/tinfoil")) {
        res = folder_copy("sd:/switch/tinfoil", TEMP_BACKUP_PATH);
        if (res != FR_OK) {
            return res;
        }
    }
    
    // Backup prod.keys if it exists
    if (path_exists("sd:/switch/prod.keys")) {
        res = file_copy("sd:/switch/prod.keys", "sd:/temp_backup/prod.keys");
        if (res != FR_OK) {
            return res;
        }
    }
    
    return FR_OK;
}

// Restore user data after clean install
int restore_user_data(void) {
    int res;
    
    // Recreate switch directory (should already exist, but be safe)
    res = f_mkdir("sd:/switch");
    if (res != FR_OK && res != FR_EXIST) {
        return res;
    }
    
    // Restore DBI if backup exists
    if (path_exists("sd:/temp_backup/DBI")) {
        res = folder_copy("sd:/temp_backup/DBI", "sd:/switch");
        if (res == FR_OK) {
            // Delete old DBI .nro files
            f_unlink("sd:/switch/DBI/DBI_810_EN.nro");
            f_unlink("sd:/switch/DBI/DBI_810_DE.nro");
            f_unlink("sd:/switch/DBI/DBI_845_EN.nro");
            f_unlink("sd:/switch/DBI/DBI_845_DE.nro");
            f_unlink("sd:/switch/DBI/DBI.nro");
        }
    }
    
    // Restore Tinfoil if backup exists
    if (path_exists("sd:/temp_backup/tinfoil")) {
        res = folder_copy("sd:/temp_backup/tinfoil", "sd:/switch");
        if (res == FR_OK) {
            // Delete old tinfoil.nro
            f_unlink("sd:/switch/tinfoil/tinfoil.nro");
        }
    }
    
    // Restore prod.keys if backup exists
    if (path_exists("sd:/temp_backup/prod.keys")) {
        res = file_copy("sd:/temp_backup/prod.keys", "sd:/switch/prod.keys");
        if (res != FR_OK) {
            return res;
        }
    }
    
    return FR_OK;
}

// Clean up temporary backup directory
int cleanup_backup(void) {
    if (path_exists(TEMP_BACKUP_PATH)) {
        return folder_delete(TEMP_BACKUP_PATH);
    }
    return FR_OK;
}