import {
	exportJWK,
	exportPKCS8,
	exportSPKI,
	generateKeyPair,
	importPKCS8,
	importSPKI,
	JWK,
	KeyLike
} from 'jose';

import { Storage, StorageAdapter } from './storage/storage.js';

const signingAlg = 'ES256';
const encryptionAlg = 'RSA-OAEP-512';

interface SerializedKeyPair {
	id: string;
	publicKey: string;
	privateKey: string;
	created: number;
	alg: string;
	expired?: number;
}

export interface KeyPair {
	id: string;
	alg: string;
	public: KeyLike;
	private: KeyLike;
	created: Date;
	expired?: Date;
	jwk: JWK;
}

/**
 * @deprecated use `signingKeys` instead
 */
export async function legacySigningKeys(storage: StorageAdapter): Promise<KeyPair[]> {
	const alg = 'RS512';
	const results = [] as KeyPair[];
	const scanner = Storage.scan<SerializedKeyPair>(storage, ['oauth:key']);
	for await (const [_key, value] of scanner) {
		const publicKey = await importSPKI(value.publicKey, alg, {
			extractable: true
		});
		const privateKey = await importPKCS8(value.privateKey, alg);
		const jwk = await exportJWK(publicKey);
		jwk.kid = value.id;
		results.push({
			id: value.id,
			alg,
			created: new Date(value.created),
			public: publicKey,
			private: privateKey,
			expired: new Date(1735858114000),
			jwk
		});
	}
	return results;
}

export async function signingKeys(storage: StorageAdapter): Promise<KeyPair[]> {
	const results = [] as KeyPair[];
	const scanner = Storage.scan<SerializedKeyPair>(storage, ['signing:key']);
	for await (const [_key, value] of scanner) {
		const publicKey = await importSPKI(value.publicKey, value.alg, {
			extractable: true
		});
		const privateKey = await importPKCS8(value.privateKey, value.alg);
		const jwk = await exportJWK(publicKey);
		jwk.kid = value.id;
		jwk.use = 'sig';
		results.push({
			id: value.id,
			alg: signingAlg,
			created: new Date(value.created),
			expired: value.expired ? new Date(value.expired) : undefined,
			public: publicKey,
			private: privateKey,
			jwk
		});
	}
	results.sort((a, b) => b.created.getTime() - a.created.getTime());
	if (results.filter((item) => !item.expired).length) return results;

	const key = await generateKeyPair(signingAlg, {
		extractable: true
	});
	const serialized: SerializedKeyPair = {
		id: crypto.randomUUID(),
		publicKey: await exportSPKI(key.publicKey),
		privateKey: await exportPKCS8(key.privateKey),
		created: Date.now(),
		alg: signingAlg
	};
	await Storage.set(storage, ['signing:key', serialized.id], serialized);
	return signingKeys(storage);
}

export async function encryptionKeys(storage: StorageAdapter): Promise<KeyPair[]> {
	const results = [] as KeyPair[];
	const scanner = Storage.scan<SerializedKeyPair>(storage, ['encryption:key']);
	for await (const [_key, value] of scanner) {
		const publicKey = await importSPKI(value.publicKey, value.alg, {
			extractable: true
		});
		const privateKey = await importPKCS8(value.privateKey, value.alg);
		const jwk = await exportJWK(publicKey);
		jwk.kid = value.id;
		results.push({
			id: value.id,
			alg: encryptionAlg,
			created: new Date(value.created),
			expired: value.expired ? new Date(value.expired) : undefined,
			public: publicKey,
			private: privateKey,
			jwk
		});
	}
	results.sort((a, b) => b.created.getTime() - a.created.getTime());
	if (results.filter((item) => !item.expired).length) return results;

	const key = await generateKeyPair(encryptionAlg, {
		extractable: true
	});
	const serialized: SerializedKeyPair = {
		id: crypto.randomUUID(),
		publicKey: await exportSPKI(key.publicKey),
		privateKey: await exportPKCS8(key.privateKey),
		created: Date.now(),
		alg: encryptionAlg
	};
	await Storage.set(storage, ['encryption:key', serialized.id], serialized);
	return encryptionKeys(storage);
}