import { z } from "zod";
import prisma from "~/server/utils/prisma";

// Query parameter validation schema
const listNotificationSchema = z.object({
  page: z
    .string()
    .transform((val) => parseInt(val) || 1)
    .optional(),
  limit: z
    .string()
    .transform((val) => parseInt(val) || 20)
    .optional(),
  status: z.string().optional(),
  priority: z.string().optional(),
  category: z.string().optional(),
  search: z.string().optional(),
  sortBy: z.string().default("created_at"),
  sortOrder: z.enum(["asc", "desc"]).default("desc"),
});

export default defineEventHandler(async (event) => {
  try {
    // Parse and validate query parameters
    const queryParams = getQuery(event) || {};
    const params = listNotificationSchema.parse(queryParams);

    // Build the where clause for filtering
    const where = {};

    if (params.status) {
      where.status = params.status;
    }

    if (params.priority) {
      where.priority = params.priority;
    }

    if (params.category) {
      where.notification_categories = {
        value: params.category
      };
    }

    if (params.search) {
      where.OR = [
        { title: { contains: params.search } },
        { email_subject: { contains: params.search } },
        { push_title: { contains: params.search } }
      ];
    }

    // Get total count for pagination
    const total = await prisma.notifications.count({ where });

    // Fetch notifications with relations
    const notifications = await prisma.notifications.findMany({
      where,
      select: {
        id: true,
        title: true,
        priority: true,
        status: true,
        delivery_type: true,
        scheduled_at: true,
        created_at: true,
        notification_categories: {
          select: {
            name: true
          }
        },
        notification_channels: {
          select: {
            channel_type: true
          }
        },
        notification_recipients: {
          select: {
            status: true
          }
        }
      },
      orderBy: {
        [params.sortBy]: params.sortOrder
      },
      skip: (params.page - 1) * params.limit,
      take: params.limit
    });

    // Format the response with only essential fields
    const formattedNotifications = notifications.map(notification => {
      const totalRecipients = notification.notification_recipients.length;
      const deliveredCount = notification.notification_recipients.filter(
        r => r.status === 'delivered'
      ).length;
      
      const successRate = totalRecipients > 0 
        ? Math.round((deliveredCount / totalRecipients) * 100) 
        : 0;

      return {
        title: notification.title,
        category: notification.notification_categories?.name || 'Uncategorized',
        channels: notification.notification_channels.map(c => c.channel_type),
        priority: notification.priority,
        status: notification.status,
        recipients: totalRecipients,
        // successRate: {
        //   successRate,
        //   delivered: deliveredCount,
        //   total: totalRecipients
        // },
        createdAt: notification.created_at,
        action: notification.id,
      };
    });

    // Calculate pagination metadata
    const totalPages = Math.ceil(total / params.limit);

    return {
      success: true,
      data: {
        notifications: formattedNotifications,
        pagination: {
          page: params.page,
          totalPages,
          totalItems: total,
          hasMore: params.page < totalPages
        },
      },
    };

  } catch (error) {
    console.error("Error fetching notifications:", error);

    if (error.code?.startsWith('P')) {
      throw createError({
        statusCode: 400,
        statusMessage: "Database operation failed",
        data: {
          error: error.message,
          code: error.code
        }
      });
    }

    if (error.statusCode) {
      throw error;
    }

    throw createError({
      statusCode: 500,
      statusMessage: "Failed to fetch notifications",
      data: {
        error: error.message
      }
    });
  } finally {
  }
});