import { NextResponse } from "next/server";
import { sql } from "@/db";
import { requireAdmin } from "@/lib/admin-auth";
import { getRazorpayConfig, razorpayAuthHeader, RAZORPAY_API_BASE } from "@/lib/billing/config";

/**
 * GET /api/admin/subscriptions — subscription monitoring data:
 *   - subscriptions: every family_subscriptions row joined to family + plan
 *   - webhookEvents: recent razorpay_webhook_events (debugging delivery)
 *   - summary: counts by status + MRR/ARR in paise (active+authenticated+pending)
 */
export async function GET(request: Request) {
  const auth = await requireAdmin(request);
  if (!auth.success) return NextResponse.json({ error: auth.error }, { status: auth.status });

  const subscriptions = await sql`
    SELECT
      fs.id,
      fs.family_id,
      f.name                       AS family_name,
      p.name                       AS plan_name,
      p.price_paise,
      fs.status,
      fs.razorpay_subscription_id,
      fs.razorpay_customer_id,
      fs.current_start,
      fs.current_end,
      fs.cancelled_at,
      fs.ended_at,
      fs.created_at,
      fs.updated_at
    FROM family_subscriptions fs
    LEFT JOIN families f ON f.id = fs.family_id
    LEFT JOIN subscription_plans p ON p.id = fs.plan_id
    ORDER BY fs.created_at DESC
    LIMIT 200
  `;

  const webhookEvents = await sql`
    SELECT
      razorpay_event_id,
      event_type,
      received_at,
      payload->'payload'->'subscription'->'entity'->>'id'     AS sub_id,
      payload->'payload'->'subscription'->'entity'->>'status' AS sub_status
    FROM razorpay_webhook_events
    ORDER BY received_at DESC
    LIMIT 50
  `;

  // Summary: status counts + MRR (only entitled/recurring-active statuses).
  const byStatus: Record<string, number> = {};
  let mrrPaise = 0;
  for (const s of subscriptions as Record<string, unknown>[]) {
    const status = s.status as string;
    byStatus[status] = (byStatus[status] || 0) + 1;
    if (status === "active" || status === "authenticated" || status === "pending") {
      mrrPaise += Number(s.price_paise) || 0;
    }
  }

  // Real monthly revenue trend from subscription.charged webhook events.
  // Each charged event = one plan-price collection. We join back to the sub's
  // plan to value it (price_paise), grouped by IST month.
  let revenueTrend: { month: string; paise: number; charges: number }[] = [];
  try {
    const trend = await sql`
      SELECT
        to_char((e.received_at AT TIME ZONE 'Asia/Kolkata'), 'YYYY-MM') AS month,
        COUNT(*)::int AS charges,
        COALESCE(SUM(p.price_paise), 0)::bigint AS paise
      FROM razorpay_webhook_events e
      JOIN family_subscriptions fs
        ON fs.razorpay_subscription_id = e.payload->'payload'->'subscription'->'entity'->>'id'
      JOIN subscription_plans p ON p.id = fs.plan_id
      WHERE e.event_type = 'subscription.charged'
        AND e.received_at > NOW() - INTERVAL '12 months'
      GROUP BY 1
      ORDER BY 1
    `;
    revenueTrend = (trend as Record<string, unknown>[]).map((r) => ({
      month: r.month as string,
      paise: Number(r.paise) || 0,
      charges: Number(r.charges) || 0,
    }));
  } catch { /* billing tables absent */ }

  // Churn: cancelled+halted+expired ÷ all subs that ever became live.
  const everLive = (subscriptions as Record<string, unknown>[]).filter(
    (s) => s.status !== "created",
  ).length;
  const churned = (subscriptions as Record<string, unknown>[]).filter((s) =>
    ["cancelled", "halted", "expired"].includes(s.status as string),
  ).length;
  const churnRate = everLive > 0 ? Math.round((churned / everLive) * 1000) / 10 : 0;

  return NextResponse.json({
    subscriptions,
    webhookEvents,
    summary: {
      total: subscriptions.length,
      byStatus,
      mrrPaise,
      arrPaise: mrrPaise * 12,
      churnRate,       // %
      churned,
      everLive,
    },
    revenueTrend,
  });
}

/**
 * POST /api/admin/subscriptions
 *   body { action: "reconcile" }                  — re-run entitlement sync
 *   body { action: "cancel", subscriptionId }     — cancel a sub (admin, any family)
 */
export async function POST(request: Request) {
  const auth = await requireAdmin(request);
  if (!auth.success) return NextResponse.json({ error: auth.error }, { status: auth.status });

  const body = await request.json().catch(() => ({}));
  const action = body.action || "reconcile";

  if (action === "cancel") {
    const subId = body.subscriptionId as string | undefined;
    if (!subId) return NextResponse.json({ error: "subscriptionId required" }, { status: 400 });

    let cfg;
    try {
      cfg = getRazorpayConfig();
    } catch (e) {
      return NextResponse.json({ error: String(e) }, { status: 500 });
    }

    try {
      const res = await fetch(`${RAZORPAY_API_BASE}/subscriptions/${subId}/cancel`, {
        method: "POST",
        headers: { Authorization: razorpayAuthHeader(cfg), "Content-Type": "application/json" },
        body: JSON.stringify({ cancel_at_cycle_end: 1 }),
      });
      const data = await res.json();
      if (!res.ok) {
        return NextResponse.json(
          { error: data?.error?.description || "Cancel failed", razorpay: data },
          { status: 502 },
        );
      }
      // The subscription.cancelled webhook will sync state; this just initiates.
      return NextResponse.json({ success: true, message: "Cancellation scheduled at cycle end." });
    } catch (e) {
      return NextResponse.json({ error: String(e) }, { status: 502 });
    }
  }

  // Default: reconcile. Delegate to the recovery endpoint.
  const { POST: reconcilePOST } = await import("../reconcile-subscriptions/route");
  return reconcilePOST(request);
}