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 { 
  getCachedEmailList, 
  cacheEmailList, 
  invalidateFolderCache 
} from '@/lib/redis';

export async function GET(request: Request) {
  try {
    // Authenticate user
    const session = await getServerSession(authOptions);
    if (!session || !session.user?.id) {
      return NextResponse.json(
        { error: "Not authenticated" },
        { status: 401 }
      );
    }

    // Extract query parameters
    const { searchParams } = new URL(request.url);
    const page = parseInt(searchParams.get("page") || "1");
    const perPage = parseInt(searchParams.get("perPage") || "20");
    const folder = searchParams.get("folder") || "INBOX";
    const searchQuery = searchParams.get("search") || "";
    const accountId = searchParams.get("accountId") || "";
    const checkOnly = searchParams.get("checkOnly") === "true";
    
    // Log exact parameters received by the API
    console.log(`[API/emails] Received request with: folder=${folder}, accountId=${accountId}, page=${page}, checkOnly=${checkOnly}`);
    
    // Parameter normalization
    // If folder contains an account prefix, extract it but DO NOT use it
    // Always prioritize the explicit accountId parameter
    let normalizedFolder = folder;
    let effectiveAccountId = accountId || 'default';
    
    if (folder.includes(':')) {
      const parts = folder.split(':');
      normalizedFolder = parts[1];
      
      console.log(`[API/emails] Folder has prefix, normalized to ${normalizedFolder}`);
    }
    
    console.log(`[API/emails] Using normalized parameters: folder=${normalizedFolder}, accountId=${effectiveAccountId}`);
    
    // Try to get from Redis cache first, but only if it's not a search query and not checkOnly
    if (!searchQuery && !checkOnly) {
      console.log(`[API/emails] Checking Redis cache for ${session.user.id}:${effectiveAccountId}:${normalizedFolder}:${page}:${perPage}`);
      const cachedEmails = await getCachedEmailList(
        session.user.id,
        effectiveAccountId,
        normalizedFolder,
        page,
        perPage
      );
      if (cachedEmails) {
        console.log(`[API/emails] Using Redis cached emails for ${session.user.id}:${effectiveAccountId}:${normalizedFolder}:${page}:${perPage}`);
        return NextResponse.json(cachedEmails);
      }
    }

    console.log(`[API/emails] Redis cache miss for ${session.user.id}:${effectiveAccountId}:${normalizedFolder}:${page}:${perPage}, fetching emails from IMAP`);

    // Use the email service to fetch emails
    const emailsResult = await getEmails(
      session.user.id,
      normalizedFolder,
      page,
      perPage,
      effectiveAccountId,
      checkOnly
    );

    console.log(`[API/emails] Successfully fetched ${emailsResult.emails.length} emails from IMAP for account ${effectiveAccountId}`);

    // Return result
    return NextResponse.json(emailsResult);
  } catch (error: any) {
    console.error("[API/emails] Error fetching emails:", error);
    return NextResponse.json(
      { error: "Failed to fetch emails", message: error.message },
      { status: 500 }
    );
  }
}