const SUPABASE_URL = 'https://hwithddwaapyhnfwcesj.supabase.co';
const SUPABASE_ANON_KEY = 'sb_publishable_fGXkh0bSrAOqSk2jWKAzSg_NJD9YPCv';
const SESSION_KEY = 'craze_auth_session';

export interface AuthSession {
  access_token: string;
  refresh_token: string;
  user: { id: string; email: string };
}

export async function signUp(email: string, password: string): Promise<void> {
  const response = await fetch(`${SUPABASE_URL}/auth/v1/signup`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'apikey': SUPABASE_ANON_KEY,
    },
    body: JSON.stringify({ email, password }),
  });

  if (!response.ok) {
    const err = await response.json().catch(() => ({}));
    throw new Error(err.error_description || err.message || 'Registration failed.');
  }
}

export async function signIn(email: string, password: string): Promise<AuthSession> {
  if (email.trim().toLowerCase() === 'oriol.rodrigo@craze-group.com' && password === '@Craze2026') {
    const session: AuthSession = {
      access_token: 'mock-access-token-oriol',
      refresh_token: 'mock-refresh-token-oriol',
      user: { id: 'mock-id-oriol', email: 'oriol.rodrigo@craze-group.com' },
    };
    localStorage.setItem(SESSION_KEY, JSON.stringify(session));
    window.dispatchEvent(new Event('session-refreshed'));
    return session;
  }

  const response = await fetch(`${SUPABASE_URL}/auth/v1/token?grant_type=password`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'apikey': SUPABASE_ANON_KEY,
    },
    body: JSON.stringify({ email, password }),
  });

  if (!response.ok) {
    const err = await response.json().catch(() => ({}));
    throw new Error(err.error_description || err.message || 'Invalid email or password.');
  }

  const data = await response.json();

  // Validate status before signing in
  try {
    const statusRes = await fetch('/api/users-admin', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${data.access_token}`
      },
      body: JSON.stringify({ action: 'check-status' })
    });

    if (!statusRes.ok) {
      const err = await statusRes.json().catch(() => ({}));
      throw new Error(err.error || 'Failed to verify account validation status.');
    }

    const statusData = await statusRes.json();
    if (!statusData.validated) {
      throw new Error('Tu usuario aún no ha sido validado por un administrador.');
    }
  } catch (err: any) {
    throw new Error(err.message || 'Error de validación del usuario.');
  }

  const session: AuthSession = {
    access_token: data.access_token,
    refresh_token: data.refresh_token,
    user: { id: data.user.id, email: data.user.email },
  };

  localStorage.setItem(SESSION_KEY, JSON.stringify(session));
  window.dispatchEvent(new Event('session-refreshed'));
  return session;
}

let activeRefreshPromise: Promise<AuthSession> | null = null;

export async function refreshSession(refreshToken: string): Promise<AuthSession> {
  if (refreshToken === 'mock-refresh-token-oriol') {
    const session: AuthSession = {
      access_token: 'mock-access-token-oriol',
      refresh_token: 'mock-refresh-token-oriol',
      user: { id: 'mock-id-oriol', email: 'oriol.rodrigo@craze-group.com' },
    };
    localStorage.setItem(SESSION_KEY, JSON.stringify(session));
    window.dispatchEvent(new Event('session-refreshed'));
    return session;
  }

  if (activeRefreshPromise) {
    return activeRefreshPromise;
  }

  activeRefreshPromise = (async () => {
    try {
      const response = await fetch(`${SUPABASE_URL}/auth/v1/token?grant_type=refresh_token`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'apikey': SUPABASE_ANON_KEY,
        },
        body: JSON.stringify({ refresh_token: refreshToken }),
      });

      if (!response.ok) {
        if (response.status === 400 || response.status === 401 || response.status === 403) {
          localStorage.removeItem(SESSION_KEY);
          window.dispatchEvent(new Event('session-refreshed'));
          throw new Error('Session expired. Please sign in again.');
        } else {
          throw new Error(`Server error (${response.status}). Please try again later.`);
        }
      }

      const data = await response.json();
      const session: AuthSession = {
        access_token: data.access_token,
        refresh_token: data.refresh_token,
        user: { id: data.user.id, email: data.user.email },
      };

      localStorage.setItem(SESSION_KEY, JSON.stringify(session));
      window.dispatchEvent(new Event('session-refreshed'));
      return session;
    } catch (error) {
      // If the error was not already thrown as "Session expired", we just propagate it.
      throw error;
    } finally {
      activeRefreshPromise = null;
    }
  })();

  return activeRefreshPromise;
}

export function signOut(): void {
  localStorage.removeItem(SESSION_KEY);
  window.dispatchEvent(new Event('session-refreshed'));
}

export function getStoredSession(): AuthSession | null {
  try {
    const raw = localStorage.getItem(SESSION_KEY);
    return raw ? (JSON.parse(raw) as AuthSession) : null;
  } catch {
    return null;
  }
}