/**
 * GET /api/dashboard
 *
 * Returns all dashboard metrics for the ISP owner's business health overview.
 * Aggregates revenue, overdue, subscriber status, cash flow, and collector metrics.
 *
 * Query params:
 *   startDate? - ISO date string for cash flow start (default: start of current month)
 *   endDate?   - ISO date string for cash flow end (default: end of current month)
 *
 * Access: ADMIN and OFFICE_STAFF (read Report permission).
 */
import { NextRequest, NextResponse } from "next/server";
import { withPermission } from "@/lib/middleware/authorize";
import { withTenantContext } from "@/lib/prisma-tenant";
import { DashboardService } from "@/lib/services/dashboard-service";

export const GET = withPermission("read", "Report")(
  async (req: NextRequest, { user }) => {
    if (!user.tenantId) {
      return NextResponse.json(
        { error: "No tenant context -- super-admins must use the admin API" },
        { status: 400 }
      );
    }

    const { searchParams } = new URL(req.url);
    const startDateParam = searchParams.get("startDate");
    const endDateParam = searchParams.get("endDate");

    const tenantPrisma = withTenantContext(user.tenantId);

    try {
      const summary = await DashboardService.getDashboardSummary(
        tenantPrisma,
        user.tenantId,
        {
          startDate: startDateParam ? new Date(startDateParam) : undefined,
          endDate: endDateParam ? new Date(endDateParam) : undefined,
        }
      );
      return NextResponse.json(summary);
    } catch (err) {
      const message =
        err instanceof Error ? err.message : "Failed to load dashboard";
      return NextResponse.json({ error: message }, { status: 500 });
    }
  }
);