import { NextResponse } from "next/server";
import { ObjectId } from "mongodb";
import { getCollection } from "@/lib/mongodb";

// GET - Get a single vendor
export async function GET(
  request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params;

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

    const vendorsCollection = await getCollection<any>("vendors");
    const vendor = await vendorsCollection.findOne({ _id: new ObjectId(id) });

    if (!vendor) {
      return NextResponse.json({ error: "Vendor not found" }, { status: 404 });
    }

    return NextResponse.json({
      ...vendor,
      _id: vendor._id.toString(),
    });
  } catch (error) {
    console.error("Error fetching vendor:", error);
    return NextResponse.json(
      {
        error: "Failed to fetch vendor",
        details: error instanceof Error ? error.message : "Unknown error",
      },
      { status: 500 }
    );
  }
}

// PATCH - Update a vendor
export async function PATCH(
  request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params;

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

    const body = await request.json();
    const vendorsCollection = await getCollection<any>("vendors");

    const existingVendor = await vendorsCollection.findOne({ _id: new ObjectId(id) });
    if (!existingVendor) {
      return NextResponse.json({ error: "Vendor not found" }, { status: 404 });
    }

    const updateData: any = {
      updatedAt: new Date().toISOString(),
    };

    if (body.name !== undefined) updateData.name = body.name;
    if (body.email !== undefined) updateData.email = body.email;
    if (body.phone !== undefined) updateData.phone = body.phone;
    if (body.address !== undefined) updateData.address = body.address;
    if (body.status !== undefined) updateData.status = body.status;
    if (body.companyName !== undefined) updateData.companyName = body.companyName;
    if (body.taxId !== undefined) updateData.taxId = body.taxId;
    if (body.notes !== undefined) updateData.notes = body.notes;

    const result = await vendorsCollection.updateOne(
      { _id: new ObjectId(id) },
      { $set: updateData }
    );

    if (result.matchedCount === 0) {
      return NextResponse.json({ error: "Vendor not found" }, { status: 404 });
    }

    const updatedVendor = await vendorsCollection.findOne({ _id: new ObjectId(id) });

    return NextResponse.json({
      success: true,
      message: "Vendor updated successfully",
      vendor: {
        ...updatedVendor,
        _id: updatedVendor._id.toString(),
      },
    });
  } catch (error) {
    console.error("Error updating vendor:", error);
    return NextResponse.json(
      {
        error: "Failed to update vendor",
        details: error instanceof Error ? error.message : "Unknown error",
      },
      { status: 500 }
    );
  }
}

// DELETE - Delete a vendor
export async function DELETE(
  request: Request,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params;

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

    const vendorsCollection = await getCollection<any>("vendors");

    const existingVendor = await vendorsCollection.findOne({ _id: new ObjectId(id) });
    if (!existingVendor) {
      return NextResponse.json({ error: "Vendor not found" }, { status: 404 });
    }

    const result = await vendorsCollection.deleteOne({ _id: new ObjectId(id) });

    if (result.deletedCount === 0) {
      return NextResponse.json({ error: "Failed to delete vendor" }, { status: 500 });
    }

    return NextResponse.json({
      success: true,
      message: "Vendor deleted successfully",
    });
  } catch (error) {
    console.error("Error deleting vendor:", error);
    return NextResponse.json(
      {
        error: "Failed to delete vendor",
        details: error instanceof Error ? error.message : "Unknown error",
      },
      { status: 500 }
    );
  }
}