import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';
import { getEmails } from '@/lib/services/email-service';
import { invalidateFolderCache } from '@/lib/redis';
import { refreshEmailsInBackground } from '@/lib/services/prefetch-service';

/**
 * API endpoint to force refresh email data
 * This is useful when the user wants to manually refresh or
 * when the app detects that it's been a while since the last refresh
 */
export async function POST(request: Request) {
  try {
    // Authenticate user
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: "Not authenticated" },
        { status: 401 }
      );
    }

    // Extract folder and account ID from request body
    const { folder = 'INBOX', accountId } = await request.json();
    
    // CRITICAL FIX: Proper folder and account ID handling
    let normalizedFolder: string;
    let effectiveAccountId: string;
    
    if (folder.includes(':')) {
      // Extract parts if folder already has a prefix
      const parts = folder.split(':');
      const folderAccountId = parts[0];
      normalizedFolder = parts[1];
      
      // If explicit accountId is provided, it takes precedence
      effectiveAccountId = accountId || folderAccountId;
    } else {
      // No prefix in folder name
      normalizedFolder = folder;
      effectiveAccountId = accountId || 'default';
    }
    
    console.log(`[API] Refreshing folder=${normalizedFolder}, accountId=${effectiveAccountId}`);
    
    // First invalidate the cache for this folder with the effective account ID
    await invalidateFolderCache(session.user.id, effectiveAccountId, normalizedFolder);
    
    // Then trigger a background refresh with explicit account ID
    refreshEmailsInBackground(session.user.id, normalizedFolder, 1, 20, effectiveAccountId);
    
    // Also prefetch page 2 if this is the inbox
    if (normalizedFolder === 'INBOX') {
      refreshEmailsInBackground(session.user.id, normalizedFolder, 2, 20, effectiveAccountId);
    }
    
    return NextResponse.json({ 
      success: true,
      message: `Refresh scheduled for folder: ${folder}`
    });
  } catch (error) {
    console.error('Error scheduling refresh:', error);
    return NextResponse.json(
      { error: "Failed to schedule refresh" },
      { status: 500 }
    );
  }
}