import session from "express-session";
import type { Sequelize } from "sequelize";
import { QueryTypes } from "sequelize";

import { restoreSession, sessionRow, writeSession } from "./session-normalization";

type Callback = (error?: Error | null) => void;

function failure(error: unknown) {
  return error instanceof Error ? error : new Error("Fallo del almacén de sesiones.");
}

/** Almacén propio: persistencia relacional del contrato de sesión usado por Metis Desk. */
export class SequelizeSessionStore extends session.Store {
  constructor(private readonly database: Sequelize) {
    super();
  }

  async get(
    sid: string,
    callback: (error: Error | null, data?: session.SessionData | null) => void
  ) {
    let result: session.SessionData | null = null;
    let error: Error | null = null;

    try {
      const rows = await this.database.query<Record<string, unknown>>(
        "SELECT * FROM http_sessions WHERE sid=:sid AND expires>NOW()",
        { replacements: { sid }, type: QueryTypes.SELECT }
      );

      result = rows[0] ? restoreSession(rows[0]) : null;
    } catch (caught) {
      error = failure(caught);
    }
    callback(error, result);
  }

  set(sid: string, data: session.SessionData, callback?: Callback) {
    return this.complete(async () => {
      await writeSession(this.database, sid, data);
      await this.database.query("DELETE FROM http_sessions WHERE expires<=NOW()");
    }, callback);
  }

  destroy(sid: string, callback?: Callback) {
    return this.complete(async () => {
      await this.database.query("DELETE FROM http_sessions WHERE sid=:sid", {
        replacements: { sid },
      });
    }, callback);
  }

  touch(sid: string, data: session.SessionData, callback?: Callback) {
    return this.complete(async () => {
      const cookie = sessionRow(data);
      const expires = cookie.cookieExpires
        ? new Date(cookie.cookieExpires)
        : new Date(Date.now() + 8 * 60 * 60 * 1000);

      // Tocar la sesión renueva la cookie; no sobrescribe la autenticación de otra petición.
      await this.database.query(
        "UPDATE http_sessions SET expires=:expires,cookieExpires=:cookieExpires,updatedAt=NOW() WHERE sid=:sid",
        { replacements: { sid, expires, cookieExpires: cookie.cookieExpires } }
      );
    }, callback);
  }

  private async complete(operation: () => Promise<void>, callback?: Callback) {
    let error: Error | null = null;

    try {
      await operation();
    } catch (caught) {
      if (!callback) {
        throw caught;
      }
      error = failure(caught);
    }
    callback?.(error);
  }
}