import type { DisplayStatus, Inode, SupportedFileType } from './types';
import supported_file_types_json from './../../../../../shared/supported_file_types.json';

const supported_file_types: Record<string, SupportedFileType> = supported_file_types_json as Record<
	string,
	SupportedFileType
>;

const invalid_first_regex = /^[^a-zA-ZäöüßÄÖÜ0-9_]/u;
const invalid_rest_regex = /[^a-zA-ZäöüßÄÖÜ0-9 _\-()$${}.,+$€!=/]/gu;

export function is_valid_name(input: string): boolean {
	return !invalid_rest_regex.test(input) && first_letter_is_valid(input);
}

export function first_letter_is_valid(input: string): boolean {
	if (input.length === 0) return false;
	return !invalid_first_regex.test(input);
}

export function make_valid_name(input: string): string {
	const s = input.normalize('NFC');
	if (s.length === 0) return 'Datei';
	let out = s.replace(invalid_rest_regex, '_');
	out = out.replace(invalid_first_regex, '_');

	return out;
}

export function get_file_type(file: Inode): SupportedFileType | null {
	for (const key of Object.keys(supported_file_types)) {
		if (file.type === supported_file_types[key].mime_type) {
			return supported_file_types[key];
		}
	}
	// Fallback:
	const extension = file.name.split('.').pop();
	if (extension) {
		if (Object.keys(supported_file_types).includes('.' + extension)) {
			return supported_file_types['.' + extension];
		}
	}
	return null;
}

export function get_accepted_file_type_string(): string {
	return Object.values(supported_file_types)
		.map((e) => e.mime_type)
		.join(',');
}

export function get_uuid(): string {
	return crypto.randomUUID();
}

export function get_file_size_display_string(size: number, toFixed: number | null = null): string {
	if (size < 0)
		return toFixed === null ? 'versch.' : 'Verschiedene Größen auf verschiedenen Bildschirmen';
	if (size === 0) return '0 B';

	const k = 1024;
	const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];

	const i = Math.floor(Math.log(size) / Math.log(k));
	const value = size / Math.pow(k, i);

	const size_string = `${value.toFixed(toFixed !== null ? toFixed : Math.max(0, 2 - Math.floor(Math.log10(value))))} ${sizes[i]}`;

	return size_string.replace('.', ',');
}

export async function image_content_hash(blob: Blob, size = 32): Promise<number> {
	// Blob → ImageBitmap (GPU-dekodiert, superschnell)
	const bitmap = await createImageBitmap(blob);

	// OffscreenCanvas ist sehr schnell (kein Layout nötig)
	const canvas = new OffscreenCanvas(size, size);
	const ctx = canvas.getContext('2d')!;
	ctx.drawImage(bitmap, 0, 0, size, size);

	// Pixel-Daten holen
	const { data } = ctx.getImageData(0, 0, size, size);

	// Einfacher, schneller Integer-Hash (FNV-1a)
	let hash = 2166136261;
	for (let i = 0; i < data.length; i++) {
		hash ^= data[i];
		hash = Math.imul(hash, 16777619);
	}

	bitmap.close(); // GPU-Ressourcen freigeben
	return hash >>> 0; // unsigned int
}

export function display_status_to_info(status: DisplayStatus): string {
	switch (status) {
		case 'app_online':
			return 'Online';
		case 'app_offline':
			return 'Lädt';
		case 'host_offline':
			return 'Offline';
		case null:
			return '???';
	}
}

export function get_sanitized_file_url(file_path: string, is_preview = false) {
	const pathSegments = file_path
		.split('/')
		.filter(Boolean)
		.map((seg) => encodeURIComponent(seg));

	return `/file/${is_preview ? 'preview/' : ''}${[...pathSegments].join('/')}`;
}