/**
 * Job-Info Auth Flow - Standalone
 * Complete auth lifecycle: acquire tokens, refresh, persist, retrieve
 * No external imports - loads PocketBase from global scope
 */

class JobInfoAuthFlow {
  constructor() {
    this.pb = null;
    this.tokens = {};
    this.init();
  }

  /**
   * Initialize: load persisted tokens, check if active, prompt login if needed
   */
  async init() {
    console.log('[JobInfoAuth] init() called');
    
    // PocketBase is loaded via script tag
    if (typeof PocketBase === 'undefined') {
      throw new Error('PocketBase SDK not loaded. Check script tag in HTML.');
    }

    this.pb = new PocketBase('http://localhost:8090');
    console.log('[JobInfoAuth] PocketBase initialized:', this.pb);

    // Load tokens from localStorage
    this.loadTokens();
    console.log('[JobInfoAuth] Tokens loaded from storage:', Object.keys(this.tokens));

    // Check if tokens are active
    const hasActiveTokens = this.isTokenActive('pb-user') || this.isTokenActive('graph-user');
    
    if (!hasActiveTokens) {
      console.log('[JobInfoAuth] No active tokens, prompting login...');
      await this.promptLogin();
    } else {
      console.log('[JobInfoAuth] Tokens active, refreshing...');
      await this.refreshAllTokens();
    }

    console.log('[JobInfoAuth] init() complete');
  }

  /**
   * Prompt user to log in via OAuth popup
   */
  async promptLogin() {
    console.log('[JobInfoAuth] promptLogin() called');
    
    try {
      const authData = await this.pb.collection('users').authWithOAuth2({
        provider: 'microsoft'
      });
      
      console.log('[JobInfoAuth] OAuth successful, authData:', authData);

      // Store PocketBase user token
      const pbToken = authData.token;
      const displayName = authData.record?.name || authData.record?.email || 'Unknown';
      
      this.storeToken('pb-user', pbToken, displayName);
      console.log('[JobInfoAuth] pb-user token stored');

      // Extract and store Graph token from OAuth metadata
      const graphToken = this.extractGraphToken(authData.meta || {});
      if (graphToken) {
        this.storeToken('graph-user', graphToken, displayName);
        console.log('[JobInfoAuth] graph-user token stored');
      } else {
        console.log('[JobInfoAuth] No graph token in OAuth response');
      }

    } catch (err) {
      console.error('[JobInfoAuth] OAuth failed:', err);
      throw new Error(`Login failed: ${err.message}`);
    }
  }

  /**
   * Extract Graph token from OAuth metadata
   */
  extractGraphToken(metadata) {
    console.log('[JobInfoAuth] extractGraphToken() called, metadata:', metadata);
    
    if (!metadata) return null;

    // Microsoft OAuth response includes access_token for Graph
    if (metadata.accessToken) {
      return metadata.accessToken;
    }
    if (metadata.access_token) {
      return metadata.access_token;
    }

    console.log('[JobInfoAuth] No Graph token found in metadata');
    return null;
  }

  /**
   * Refresh all tokens - keep them fresh, only replace pb-user on new token
   */
  async refreshAllTokens() {
    console.log('[JobInfoAuth] refreshAllTokens() called');
    
    try {
      // Refresh pb-user token
      if (this.tokens['pb-user']) {
        const oldToken = this.tokens['pb-user'].value;
        
        // Use PocketBase refresh
        const authData = await this.pb.collection('users').authRefresh();
        const newToken = authData.token;

        // Only replace if genuinely new
        if (newToken && newToken !== oldToken) {
          console.log('[JobInfoAuth] pb-user token refreshed (new token)');
          const displayName = this.tokens['pb-user'].displayName;
          this.storeToken('pb-user', newToken, displayName);
        } else {
          console.log('[JobInfoAuth] pb-user token still valid, not replacing');
        }
      }

      // Graph token: don't require for refresh, but use if available
      if (this.tokens['graph-user']) {
        console.log('[JobInfoAuth] graph-user token exists, keeping it');
        // Optionally refresh graph token here if needed
      }

    } catch (err) {
      console.warn('[JobInfoAuth] Token refresh had issues:', err.message);
      // Don't throw - tokens might still be valid
    }
  }

  /**
   * Store token with metadata
   */
  storeToken(type, token, displayName) {
    console.log('[JobInfoAuth] storeToken():', type);
    
    const lastFourDigits = token.slice(-4);
    const decoded = this.decodeToken(token);
    const expiresAt = decoded?.exp ? decoded.exp * 1000 : Date.now() + (3600 * 1000); // Default 1 hour

    this.tokens[type] = {
      value: token,
      displayName,
      lastFourDigits,
      expiresAt,
      storedAt: Date.now()
    };

    // Persist to localStorage
    localStorage.setItem(`job-info-${type}`, JSON.stringify(this.tokens[type]));
    console.log(`[JobInfoAuth] ${type} stored, expires at:`, new Date(expiresAt).toISOString());
  }

  /**
   * Load tokens from localStorage
   */
  loadTokens() {
    console.log('[JobInfoAuth] loadTokens() called');
    
    const types = ['pb-user', 'graph-user', 'pb-agent', 'graph-agent'];
    
    types.forEach(type => {
      const stored = localStorage.getItem(`job-info-${type}`);
      if (stored) {
        try {
          this.tokens[type] = JSON.parse(stored);
          console.log(`[JobInfoAuth] Loaded ${type} from localStorage`);
        } catch (err) {
          console.warn(`[JobInfoAuth] Failed to parse ${type}:`, err);
          localStorage.removeItem(`job-info-${type}`);
        }
      }
    });
  }

  /**
   * Check if token is active (exists and not expired)
   */
  isTokenActive(type) {
    const token = this.tokens[type];
    if (!token) {
      console.log(`[JobInfoAuth] isTokenActive(${type}): no token stored`);
      return false;
    }

    const isExpired = token.expiresAt && Date.now() > token.expiresAt;
    if (isExpired) {
      console.log(`[JobInfoAuth] isTokenActive(${type}): expired`);
      return false;
    }

    console.log(`[JobInfoAuth] isTokenActive(${type}): active`);
    return true;
  }

  /**
   * Get current auth state
   */
  getState() {
    return {
      'pb-user': this.tokens['pb-user'] || null,
      'graph-user': this.tokens['graph-user'] || null,
      'pb-agent': this.tokens['pb-agent'] || null,
      'graph-agent': this.tokens['graph-agent'] || null,
      userDisplayName: this.tokens['pb-user']?.displayName || 'Unknown'
    };
  }

  /**
   * Logout - clear all tokens
   */
  logout() {
    console.log('[JobInfoAuth] logout() called');
    
    const types = ['pb-user', 'graph-user', 'pb-agent', 'graph-agent'];
    types.forEach(type => {
      localStorage.removeItem(`job-info-${type}`);
    });

    this.tokens = {};
    
    if (this.pb) {
      this.pb.authStore.clear();
    }

    console.log('[JobInfoAuth] All tokens cleared');
  }

  /**
   * Decode JWT token to get exp claim
   */
  decodeToken(token) {
    try {
      const parts = token.split('.');
      if (parts.length !== 3) return null;

      const decoded = JSON.parse(atob(parts[1]));
      return decoded;
    } catch (err) {
      console.warn('[JobInfoAuth] Failed to decode token:', err);
      return null;
    }
  }
}

// Create singleton instance
const JobInfoAuth = new JobInfoAuthFlow();

// Expose globally
if (typeof window !== 'undefined') {
  window.JobInfoAuth = JobInfoAuth;
}