import { NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";
import { requireRole } from "@/lib/auth";

type Params = { params: Promise<{ id: string }> };

/** Update a route (name, vehicle, base fare, stops replaced). */
export async function PUT(req: Request, { params }: Params) {
  const session = await requireRole("INSTITUTION_ADMIN");
  if (!session || !session.institutionId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }
  const { id } = await params;

  try {
    const body = await req.json();
    const route = await prisma.transportRoute.findFirst({
      where: { id: Number(id), institutionId: session.institutionId },
    });
    if (!route) return NextResponse.json({ error: "Not found" }, { status: 404 });

    const name = String(body.name ?? route.name).trim();
    if (!name) return NextResponse.json({ error: "Name required" }, { status: 400 });

    let vehicleId: number | null | undefined = undefined;
    if (body.vehicleId !== undefined) {
      if (body.vehicleId === null || body.vehicleId === "") {
        vehicleId = null;
      } else {
        const vehicle = await prisma.transportVehicle.findFirst({
          where: { id: Number(body.vehicleId), institutionId: session.institutionId },
        });
        if (!vehicle) return NextResponse.json({ error: "Vehicle not found" }, { status: 404 });
        vehicleId = vehicle.id;
      }
    }

    const stopsIn = Array.isArray(body.stops) ? body.stops : null;

    await prisma.$transaction(async (tx) => {
      await tx.transportRoute.update({
        where: { id: route.id },
        data: {
          name,
          nameBn: body.nameBn !== undefined ? String(body.nameBn).trim() || null : route.nameBn,
          vehicleId: vehicleId ?? (vehicleId === null ? null : route.vehicleId),
          baseFare: body.baseFare !== undefined ? Math.max(0, Number(body.baseFare) || 0) : route.baseFare,
          isActive: body.isActive !== undefined ? Boolean(body.isActive) : route.isActive,
        },
      });
      if (stopsIn) {
        // Members referencing old stops are detached first
        await tx.transportMember.updateMany({
          where: { routeId: route.id, stopId: { not: null } },
          data: { stopId: null },
        });
        await tx.transportStop.deleteMany({ where: { routeId: route.id } });
        await tx.transportStop.createMany({
          data: stopsIn
            .map((s: { name?: string; nameBn?: string; extraFare?: number | string }, i: number) => ({
              institutionId: session.institutionId!,
              routeId: route.id,
              name: String(s.name ?? "").trim(),
              nameBn: String(s.nameBn ?? "").trim() || null,
              extraFare: Math.max(0, Number(s.extraFare) || 0),
              sortOrder: i,
            }))
            .filter((s: { name: string }) => s.name),
        });
      }
    });

    return NextResponse.json({ success: true });
  } catch {
    return NextResponse.json({ error: "Could not update route" }, { status: 500 });
  }
}

/** Delete a route (only when no member is assigned). */
export async function DELETE(_req: Request, { params }: Params) {
  const session = await requireRole("INSTITUTION_ADMIN");
  if (!session || !session.institutionId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }
  const { id } = await params;

  const route = await prisma.transportRoute.findFirst({
    where: { id: Number(id), institutionId: session.institutionId },
  });
  if (!route) return NextResponse.json({ error: "Not found" }, { status: 404 });

  const members = await prisma.transportMember.count({ where: { routeId: route.id } });
  if (members > 0) return NextResponse.json({ error: "IN_USE" }, { status: 409 });

  await prisma.transportStop.deleteMany({ where: { routeId: route.id } });
  await prisma.transportRoute.delete({ where: { id: route.id } });
  return NextResponse.json({ success: true });
}