/**
 * User Settings Service
 * 
 * Manages user-specific settings including Jira PAT, AI features, and API keys.
 */

import { logger } from './logger.js';
import { getAuthDatabase } from './database/migrations.js';
import { encryptionService } from './encryptionService.js';
import { config } from '../config/env.js';

const isPostgres = (): boolean => {
  return process.env.DATABASE_TYPE === 'postgres' || process.env.DATABASE_TYPE === 'postgresql';
};

export interface UserSettings {
  user_id: number;
  jira_pat: string | null;
  jira_pat_encrypted: boolean;
  ai_enabled: boolean;
  ai_provider: string | null;
  ai_api_key: string | null;
  web_search_enabled: boolean;
  tavily_api_key: string | null;
  updated_at: string;
}

export interface UpdateUserSettingsInput {
  jira_pat?: string;
  ai_enabled?: boolean;
  ai_provider?: 'openai' | 'anthropic';
  ai_api_key?: string;
  web_search_enabled?: boolean;
  tavily_api_key?: string;
}

class UserSettingsService {
  /**
   * Get user settings
   */
  async getUserSettings(userId: number): Promise<UserSettings | null> {
    const db = getAuthDatabase();
    try {
      const settings = await db.queryOne<UserSettings>(
        'SELECT * FROM user_settings WHERE user_id = ?',
        [userId]
      );

      if (!settings) {
        // Create default settings
        return await this.createDefaultSettings(userId);
      }

      // Decrypt sensitive fields if encrypted
      if (settings.jira_pat && settings.jira_pat_encrypted && encryptionService.isConfigured()) {
        try {
          settings.jira_pat = await encryptionService.decrypt(settings.jira_pat);
        } catch (error) {
          logger.error('Failed to decrypt Jira PAT:', error);
          settings.jira_pat = null;
        }
      }

      if (settings.ai_api_key && encryptionService.isConfigured()) {
        try {
          settings.ai_api_key = await encryptionService.decrypt(settings.ai_api_key);
        } catch (error) {
          logger.error('Failed to decrypt AI API key:', error);
          settings.ai_api_key = null;
        }
      }

      if (settings.tavily_api_key && encryptionService.isConfigured()) {
        try {
          settings.tavily_api_key = await encryptionService.decrypt(settings.tavily_api_key);
        } catch (error) {
          logger.error('Failed to decrypt Tavily API key:', error);
          settings.tavily_api_key = null;
        }
      }

      return settings;
    } finally {
      await db.close();
    }
  }

  /**
   * Create default settings for user
   */
  async createDefaultSettings(userId: number): Promise<UserSettings> {
    const db = getAuthDatabase();
    const now = new Date().toISOString();
    
    try {
      await db.execute(
        `INSERT INTO user_settings (
          user_id, jira_pat, jira_pat_encrypted, ai_enabled, ai_provider,
          ai_api_key, web_search_enabled, tavily_api_key, updated_at
        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
        [
          userId,
          null,
          isPostgres() ? true : 1,
          isPostgres() ? false : 0,
          null,
          null,
          isPostgres() ? false : 0,
          null,
          now,
        ]
      );

      return await this.getUserSettings(userId) as UserSettings;
    } finally {
      await db.close();
    }
  }

  /**
   * Update user settings
   */
  async updateUserSettings(userId: number, input: UpdateUserSettingsInput): Promise<UserSettings> {
    const db = getAuthDatabase();
    const now = new Date().toISOString();
    
    try {
      // Ensure settings exist
      let settings = await this.getUserSettings(userId);
      if (!settings) {
        settings = await this.createDefaultSettings(userId);
      }

      const updates: string[] = [];
      const values: any[] = [];

      if (input.jira_pat !== undefined) {
        let encryptedPat: string | null = null;
        if (input.jira_pat) {
          if (encryptionService.isConfigured()) {
            encryptedPat = await encryptionService.encrypt(input.jira_pat);
          } else {
            // Store unencrypted if encryption not configured (development)
            encryptedPat = input.jira_pat;
          }
        }
        updates.push('jira_pat = ?');
        updates.push('jira_pat_encrypted = ?');
        values.push(encryptedPat);
        values.push(encryptionService.isConfigured() ? (isPostgres() ? true : 1) : (isPostgres() ? false : 0));
      }

      if (input.ai_enabled !== undefined) {
        updates.push('ai_enabled = ?');
        values.push(isPostgres() ? input.ai_enabled : (input.ai_enabled ? 1 : 0));
      }

      if (input.ai_provider !== undefined) {
        updates.push('ai_provider = ?');
        values.push(input.ai_provider);
      }

      if (input.ai_api_key !== undefined) {
        let encryptedKey: string | null = null;
        if (input.ai_api_key) {
          if (encryptionService.isConfigured()) {
            encryptedKey = await encryptionService.encrypt(input.ai_api_key);
          } else {
            encryptedKey = input.ai_api_key;
          }
        }
        updates.push('ai_api_key = ?');
        values.push(encryptedKey);
      }

      if (input.web_search_enabled !== undefined) {
        updates.push('web_search_enabled = ?');
        values.push(isPostgres() ? input.web_search_enabled : (input.web_search_enabled ? 1 : 0));
      }

      if (input.tavily_api_key !== undefined) {
        let encryptedKey: string | null = null;
        if (input.tavily_api_key) {
          if (encryptionService.isConfigured()) {
            encryptedKey = await encryptionService.encrypt(input.tavily_api_key);
          } else {
            encryptedKey = input.tavily_api_key;
          }
        }
        updates.push('tavily_api_key = ?');
        values.push(encryptedKey);
      }

      if (updates.length === 0) {
        return settings;
      }

      updates.push('updated_at = ?');
      values.push(now);
      values.push(userId);

      await db.execute(
        `UPDATE user_settings SET ${updates.join(', ')} WHERE user_id = ?`,
        values
      );

      logger.info(`User settings updated for user: ${userId}`);
      return await this.getUserSettings(userId) as UserSettings;
    } finally {
      await db.close();
    }
  }

  /**
   * Validate Jira PAT by testing connection
   */
  async validateJiraPat(userId: number, pat?: string): Promise<boolean> {
    try {
      const settings = await this.getUserSettings(userId);
      const tokenToTest = pat || settings?.jira_pat;

      if (!tokenToTest) {
        return false;
      }

      // Test connection to Jira
      const testUrl = `${config.jiraHost}/rest/api/2/myself`;
      const response = await fetch(testUrl, {
        headers: {
          'Authorization': `Bearer ${tokenToTest}`,
          'Accept': 'application/json',
        },
      });

      return response.ok;
    } catch (error) {
      logger.error('Jira PAT validation failed:', error);
      return false;
    }
  }

  /**
   * Get Jira PAT status
   */
  async getJiraPatStatus(userId: number): Promise<{ configured: boolean; valid: boolean }> {
    const settings = await this.getUserSettings(userId);
    const configured = !!settings?.jira_pat;
    
    if (!configured) {
      return { configured: false, valid: false };
    }

    const valid = await this.validateJiraPat(userId);
    return { configured: true, valid };
  }

  /**
   * Check if AI features are enabled for user
   */
  async isAiEnabled(userId: number): Promise<boolean> {
    const settings = await this.getUserSettings(userId);
    return settings?.ai_enabled || false;
  }

  /**
   * Get AI provider for user
   */
  async getAiProvider(userId: number): Promise<'openai' | 'anthropic' | null> {
    const settings = await this.getUserSettings(userId);
    return (settings?.ai_provider as 'openai' | 'anthropic') || null;
  }

  /**
   * Get AI API key for user
   */
  async getAiApiKey(userId: number): Promise<string | null> {
    const settings = await this.getUserSettings(userId);
    return settings?.ai_api_key || null;
  }

  /**
   * Check if web search is enabled for user
   */
  async isWebSearchEnabled(userId: number): Promise<boolean> {
    const settings = await this.getUserSettings(userId);
    return settings?.web_search_enabled || false;
  }

  /**
   * Get Tavily API key for user
   */
  async getTavilyApiKey(userId: number): Promise<string | null> {
    const settings = await this.getUserSettings(userId);
    return settings?.tavily_api_key || null;
  }
}

export const userSettingsService = new UserSettingsService();