/**
 * In-Memory User Repository
 * 
 * Stores users in memory for demo/development purposes.
 */

import type { IUserRepository, StoredUser } from '../../domain/repositories/IUserRepository';

export class InMemoryUserRepository implements IUserRepository {
  private users: Map<string, StoredUser> = new Map();
  private emailIndex: Map<string, string> = new Map(); // email -> userId

  constructor(initialUsers: StoredUser[] = []) {
    for (const user of initialUsers) {
      this.users.set(user.id, user);
      this.emailIndex.set(user.email.toLowerCase(), user.id);
    }
  }

  async findByEmail(email: string): Promise<StoredUser | null> {
    const userId = this.emailIndex.get(email.toLowerCase());
    if (!userId) return null;
    return this.users.get(userId) ?? null;
  }

  async findById(id: string): Promise<StoredUser | null> {
    return this.users.get(id) ?? null;
  }

  async create(user: StoredUser): Promise<StoredUser> {
    if (this.emailIndex.has(user.email.toLowerCase())) {
      throw new Error('Email already exists');
    }
    this.users.set(user.id, user);
    this.emailIndex.set(user.email.toLowerCase(), user.id);
    return user;
  }

  async update(user: StoredUser): Promise<StoredUser> {
    const existing = this.users.get(user.id);
    if (!existing) {
      throw new Error('User not found');
    }
    // If email changed, update index
    if (existing.email.toLowerCase() !== user.email.toLowerCase()) {
      this.emailIndex.delete(existing.email.toLowerCase());
      this.emailIndex.set(user.email.toLowerCase(), user.id);
    }
    this.users.set(user.id, user);
    return user;
  }

  async emailExists(email: string): Promise<boolean> {
    return this.emailIndex.has(email.toLowerCase());
  }
}