/**
 * Analytics Refresh Handler
 *
 * Refreshes materialized views and pre-computed analytics tables.
 * Should run daily or on-demand after major data changes.
 */

import { TaskContext, TaskResult } from '../task-worker';

export async function handleAnalyticsRefresh(ctx: TaskContext): Promise<TaskResult> {
  const { pool } = ctx;

  console.log(`[AnalyticsRefresh] Starting analytics refresh...`);

  const refreshed: string[] = [];
  const failed: string[] = [];

  // List of materialized views to refresh
  const materializedViews = [
    'mv_state_metrics',
    'mv_brand_metrics',
    'mv_category_metrics',
    'v_brand_summary',
    'v_dashboard_stats',
  ];

  for (const viewName of materializedViews) {
    try {
      // Heartbeat before each refresh
      await ctx.heartbeat();

      // Check if view exists
      const existsResult = await pool.query(`
        SELECT EXISTS (
          SELECT 1 FROM pg_matviews WHERE matviewname = $1
          UNION
          SELECT 1 FROM pg_views WHERE viewname = $1
        ) as exists
      `, [viewName]);

      if (!existsResult.rows[0].exists) {
        console.log(`[AnalyticsRefresh] View ${viewName} does not exist, skipping`);
        continue;
      }

      // Try to refresh (only works for materialized views)
      try {
        await pool.query(`REFRESH MATERIALIZED VIEW CONCURRENTLY ${viewName}`);
        refreshed.push(viewName);
        console.log(`[AnalyticsRefresh] Refreshed ${viewName}`);
      } catch (refreshError: any) {
        // Try non-concurrent refresh
        try {
          await pool.query(`REFRESH MATERIALIZED VIEW ${viewName}`);
          refreshed.push(viewName);
          console.log(`[AnalyticsRefresh] Refreshed ${viewName} (non-concurrent)`);
        } catch (nonConcurrentError: any) {
          // Not a materialized view or other error
          console.log(`[AnalyticsRefresh] ${viewName} is not a materialized view or refresh failed`);
        }
      }
    } catch (error: any) {
      console.error(`[AnalyticsRefresh] Error refreshing ${viewName}:`, error.message);
      failed.push(viewName);
    }
  }

  // Run analytics capture functions if they exist
  const captureFunctions = [
    'capture_brand_snapshots',
    'capture_category_snapshots',
  ];

  for (const funcName of captureFunctions) {
    try {
      await pool.query(`SELECT ${funcName}()`);
      console.log(`[AnalyticsRefresh] Executed ${funcName}()`);
    } catch (error: any) {
      // Function might not exist
      console.log(`[AnalyticsRefresh] ${funcName}() not available`);
    }
  }

  console.log(`[AnalyticsRefresh] Complete: ${refreshed.length} refreshed, ${failed.length} failed`);

  return {
    success: failed.length === 0,
    refreshed,
    failed,
    error: failed.length > 0 ? `Failed to refresh: ${failed.join(', ')}` : undefined,
  };
}