import { Collection, Db } from "mongodb";
import OidcSession from "../schemas/OidcSession";

/**
 * Repository for OIDC sessions
 *
 * Manages temporary sessions during the OIDC authorization flow.
 * Sessions are automatically deleted by MongoDB TTL index after expiration.
 */
export default class OidcSessionRepo {
    private collection: Collection<OidcSession>;

    constructor(collectionName: string, db: Db) {
        this.collection = db.collection<OidcSession>(collectionName);
    }

    /**
     * Create a new OIDC session
     *
     * @param session - Session data
     * @returns Created session with _id
     */
    async create(session: Omit<OidcSession, "_id">): Promise<OidcSession> {
        const result = await this.collection.insertOne(session as any);
        return {
            ...session,
            _id: result.insertedId.toString(),
        };
    }

    /**
     * Find session by state parameter
     *
     * Used during callback to validate the state and retrieve session data.
     *
     * @param state - State parameter from callback
     * @returns Session or null if not found
     */
    async getByState(state: string): Promise<OidcSession | null> {
        const session = await this.collection.findOne({ state });
        if (!session) {
            return null;
        }
        return {
            ...session,
            _id: session._id?.toString(),
        };
    }

    /**
     * Find one session by query
     *
     * @param query - MongoDB query
     * @returns Session or null if not found
     */
    async getOne(query: Partial<OidcSession>): Promise<OidcSession | null> {
        const session = await this.collection.findOne(query as any);
        if (!session) {
            return null;
        }
        return {
            ...session,
            _id: session._id?.toString(),
        };
    }

    /**
     * Delete session by session ID
     *
     * Sessions are one-time use - delete after successful validation.
     *
     * @param sessionId - Session identifier
     */
    async deleteBySessionId(sessionId: string): Promise<void> {
        await this.collection.deleteOne({ sessionId });
    }

    /**
     * Delete session by state
     *
     * @param state - State parameter
     */
    async deleteByState(state: string): Promise<void> {
        await this.collection.deleteOne({ state });
    }

    /**
     * Delete all expired sessions
     *
     * This is handled automatically by MongoDB TTL index,
     * but can be called manually for testing or cleanup.
     */
    async deleteExpired(): Promise<number> {
        const result = await this.collection.deleteMany({
            createdAt: { $lt: new Date(Date.now() - 600000) }, // 10 minutes
        });
        return result.deletedCount;
    }
}