import { NextResponse } from 'next/server';
import { ObjectId } from 'mongodb';
import { getDb } from '@/lib/mongodb';

export async function GET(
  _request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params;

  if (!ObjectId.isValid(id)) {
    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
  }

  const db = await getDb();
  const ingredient = await db.collection('ingredients').aggregate([
    { $match: { _id: new ObjectId(id) } },
    {
      $lookup: {
        from: 'categories',
        localField: 'categoryId',
        foreignField: '_id',
        as: 'categoryDoc',
      },
    },
    {
      $lookup: {
        from: 'subcategories',
        localField: 'subcategoryId',
        foreignField: '_id',
        as: 'subcategoryDoc',
      },
    },
    {
      $lookup: {
        from: 'suppliers',
        localField: 'supplierId',
        foreignField: '_id',
        as: 'supplierDoc',
      },
    },
    {
      $project: {
        code: 1,
        name: 1,
        category: { $arrayElemAt: ['$categoryDoc.name', 0] },
        subcategory: { $arrayElemAt: ['$subcategoryDoc.name', 0] },
        categoryId: 1,
        subcategoryId: 1,
        supplierId: 1,
        quantity: 1,
        unit: 1,
        unitPrice: 1,
        vat: 1,
        supplier: { $arrayElemAt: ['$supplierDoc.name', 0] },
        discountType: 1,
        discountValue: 1,
        applyDiscountToNet: 1,
        minStockLevel: 1,
        storageInstructions: 1,
        shelfLifeDays: 1,
        notes: 1,
        createdAt: 1,
        updatedAt: 1,
      },
    },
  ]).next();

  if (!ingredient) {
    return NextResponse.json({ error: 'Ingredient not found' }, { status: 404 });
  }

  return NextResponse.json(ingredient);
}

export async function PUT(
  request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params;

  if (!ObjectId.isValid(id)) {
    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
  }

  const body = await request.json();
  const update: Record<string, unknown> = { updatedAt: new Date() };

  if (body.code !== undefined) update.code = body.code;
  if (body.name !== undefined) update.name = body.name;
  if (body.categoryId !== undefined) update.categoryId = new ObjectId(body.categoryId);
  if (body.subcategoryId !== undefined) update.subcategoryId = new ObjectId(body.subcategoryId);
  if (body.quantity !== undefined) update.quantity = body.quantity;
  if (body.unit !== undefined) update.unit = body.unit;
  if (body.unitPrice !== undefined) update.unitPrice = body.unitPrice;
  if (body.vat !== undefined) update.vat = body.vat;
  if (body.supplierId !== undefined) update.supplierId = new ObjectId(body.supplierId);
  if (body.discountType !== undefined) update.discountType = body.discountType;
  if (body.discountValue !== undefined) update.discountValue = body.discountValue;
  if (body.applyDiscountToNet !== undefined) update.applyDiscountToNet = body.applyDiscountToNet;
  if (body.minStockLevel !== undefined) update.minStockLevel = body.minStockLevel;
  if (body.storageInstructions !== undefined) update.storageInstructions = body.storageInstructions;
  if (body.shelfLifeDays !== undefined) update.shelfLifeDays = body.shelfLifeDays;
  if (body.notes !== undefined) update.notes = body.notes;

  const db = await getDb();
  const result = await db.collection('ingredients').findOneAndUpdate(
    { _id: new ObjectId(id) },
    { $set: update },
    { returnDocument: 'after' }
  );

  if (!result) {
    return NextResponse.json({ error: 'Ingredient not found' }, { status: 404 });
  }

  return NextResponse.json(result);
}

export async function DELETE(
  _request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params;

  if (!ObjectId.isValid(id)) {
    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
  }

  const db = await getDb();
  const result = await db.collection('ingredients').deleteOne({ _id: new ObjectId(id) });

  if (result.deletedCount === 0) {
    return NextResponse.json({ error: 'Ingredient not found' }, { status: 404 });
  }

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