import { cookies } from 'next/headers';
import { randomUUID } from 'crypto';

import type { AuthService, AuthSession, AuthUser } from './AuthService';
import { createStaticRacingSeed } from '@gridpilot/testing-support';

const SESSION_COOKIE = 'gp_demo_session';
const STATE_COOKIE = 'gp_demo_auth_state';

function parseCookieValue(raw: string | undefined): AuthSession | null {
  if (!raw) return null;
  try {
    const parsed = JSON.parse(raw) as AuthSession;
    if (!parsed.expiresAt || Date.now() > parsed.expiresAt) {
      return null;
    }
    return parsed;
  } catch {
    return null;
  }
}

function serializeSession(session: AuthSession): string {
  return JSON.stringify(session);
}

export class InMemoryAuthService implements AuthService {
  private readonly seedDriverId: string;

  constructor() {
    const seed = createStaticRacingSeed(42);
    this.seedDriverId = seed.drivers[0]?.id ?? 'driver-1';
  }

  async getCurrentSession(): Promise<AuthSession | null> {
    const store = await cookies();
    const raw = store.get(SESSION_COOKIE)?.value;
    return parseCookieValue(raw);
  }

  async startIracingAuthRedirect(
    returnTo?: string,
  ): Promise<{ redirectUrl: string; state: string }> {
    const state = randomUUID();

    const params = new URLSearchParams();
    params.set('code', 'dummy-code');
    params.set('state', state);
    if (returnTo) {
      params.set('returnTo', returnTo);
    }

    return {
      redirectUrl: `/auth/iracing/callback?${params.toString()}`,
      state,
    };
  }

  async loginWithIracingCallback(params: {
    code: string;
    state: string;
    returnTo?: string;
  }): Promise<AuthSession> {
    if (!params.code) {
      throw new Error('Missing auth code');
    }
    if (!params.state) {
      throw new Error('Missing auth state');
    }

    const user: AuthUser = {
      id: 'demo-user',
      displayName: 'GridPilot Demo Driver',
      iracingCustomerId: '000000',
      primaryDriverId: this.seedDriverId,
      avatarUrl: `/api/avatar/${this.seedDriverId}`,
    };

    const now = Date.now();
    const expiresAt = now + 24 * 60 * 60 * 1000;

    const session: AuthSession = {
      user,
      issuedAt: now,
      expiresAt,
      token: randomUUID(),
    };

    return session;
  }

  async logout(): Promise<void> {
    // Intentionally does nothing; cookie deletion is handled by route handlers.
    return;
  }
}