import { NextResponse } from "next/server";
import { z } from "zod";
import { LocationKind } from "@prisma/client";
import { db } from "@/lib/db";
import { requireAuth } from "@/lib/auth";
import { recomputeAllPaths } from "@/lib/locations/db";

const createSchema = z.object({
  name: z.string().min(1),
  kind: z.nativeEnum(LocationKind).optional(),
  parentId: z.string().optional(),
  notes: z.string().optional(),
});

// GET /api/locations — flat list of active locations (client builds the tree).
export async function GET() {
  try {
    await requireAuth();
    const locations = await db.location.findMany({
      where: { active: true },
      orderBy: { name: "asc" },
      include: { _count: { select: { plants: { where: { active: true } } } } },
    });
    return NextResponse.json(locations);
  } catch (err) {
    if (err instanceof Error && err.message === "Unauthorized")
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    console.error(err);
    return NextResponse.json({ error: "Server error" }, { status: 500 });
  }
}

// POST /api/locations — create a location node.
export async function POST(req: Request) {
  try {
    const session = await requireAuth();
    const data = createSchema.parse(await req.json());

    const name = data.name.trim();
    if (!name) return NextResponse.json({ error: "Name is required" }, { status: 400 });

    // Validate parent exists (if given).
    if (data.parentId) {
      const parent = await db.location.findUnique({ where: { id: data.parentId } });
      if (!parent) return NextResponse.json({ error: "Parent location not found" }, { status: 400 });
    }

    const location = await db.$transaction(async (tx) => {
      const created = await tx.location.create({
        data: {
          name,
          kind: data.kind ?? LocationKind.AREA,
          parentId: data.parentId || null,
          notes: data.notes?.trim() || null,
        },
      });
      await recomputeAllPaths(tx as unknown as typeof db);
      await tx.auditEvent.create({
        data: {
          action: "location.create",
          entityId: created.id,
          actorId: session.user.id,
          payload: { name: created.name, kind: created.kind, parentId: created.parentId },
        },
      });
      return created;
    });

    return NextResponse.json(location, { status: 201 });
  } catch (err) {
    if (err instanceof z.ZodError)
      return NextResponse.json({ error: err.issues[0]?.message ?? "Invalid data" }, { status: 400 });
    if (err instanceof Error && err.message === "Unauthorized")
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    console.error(err);
    return NextResponse.json({ error: "Server error" }, { status: 500 });
  }
}