import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { db, collections, collectionRecipes, recipes, eq, and, or, ne, inArray } from "@epicure/db";
import { requireSession } from "@/lib/api-auth";

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

export async function GET(_req: NextRequest, { params }: Params) {
  const { session, response } = await requireSession();
  if (response) return response;
  const { id } = await params;

  const col = await db.query.collections.findFirst({
    where: and(eq(collections.id, id), eq(collections.userId, session!.user.id)),
    with: { recipes: { with: { recipe: { with: { photos: true } } } } },
  });

  if (!col) return NextResponse.json({ error: "Not found" }, { status: 404 });
  return NextResponse.json(col);
}

export async function PUT(req: NextRequest, { params }: Params) {
  const { session, response } = await requireSession();
  if (response) return response;
  const { id } = await params;

  const existing = await db.query.collections.findFirst({
    where: and(eq(collections.id, id), eq(collections.userId, session!.user.id)),
  });
  if (!existing) return NextResponse.json({ error: "Not found" }, { status: 404 });

  const body = await req.json() as unknown;
  const parsed = z.object({
    name: z.string().min(1).max(100).optional(),
    description: z.string().max(500).optional(),
    isPublic: z.boolean().optional(),
    addRecipeId: z.string().optional(),
    addRecipeIds: z.array(z.string()).max(200).optional(),
    removeRecipeId: z.string().optional(),
  }).safeParse(body);
  if (!parsed.success) return NextResponse.json({ error: "Validation error" }, { status: 400 });

  const data = parsed.data;
  if (data.name || data.description !== undefined || data.isPublic !== undefined) {
    await db.update(collections).set({
      ...(data.name && { name: data.name }),
      ...(data.description !== undefined && { description: data.description }),
      ...(data.isPublic !== undefined && { isPublic: data.isPublic }),
      updatedAt: new Date(),
    }).where(eq(collections.id, id));
  }

  const idsToAdd = [...(data.addRecipeId ? [data.addRecipeId] : []), ...(data.addRecipeIds ?? [])];
  if (idsToAdd.length > 0) {
    const owned = await db.query.recipes.findMany({
      where: and(
        inArray(recipes.id, idsToAdd),
        or(eq(recipes.authorId, session!.user.id), ne(recipes.visibility, "private"))
      ),
      columns: { id: true },
    });
    if (owned.length > 0) {
      await db.insert(collectionRecipes)
        .values(owned.map((r) => ({ collectionId: id, recipeId: r.id })))
        .onConflictDoNothing();
    }
  }

  if (data.removeRecipeId) {
    await db.delete(collectionRecipes).where(
      and(eq(collectionRecipes.collectionId, id), eq(collectionRecipes.recipeId, data.removeRecipeId))
    );
  }

  return NextResponse.json({ updated: true });
}

export async function DELETE(_req: NextRequest, { params }: Params) {
  const { session, response } = await requireSession();
  if (response) return response;
  const { id } = await params;

  const existing = await db.query.collections.findFirst({
    where: and(eq(collections.id, id), eq(collections.userId, session!.user.id)),
  });
  if (!existing) return NextResponse.json({ error: "Not found" }, { status: 404 });

  await db.delete(collections).where(eq(collections.id, id));
  return new NextResponse(null, { status: 204 });
}