import type { APIRoute } from "astro";
import { renderToStream } from "@ceereals/vue-pdf";
import { db } from "../../../../db";
import {
  invoices,
  invoiceItems,
  clients,
  organizations,
  members,
} from "../../../../db/schema";
import { eq, and } from "drizzle-orm";
import { createInvoiceDocument } from "../../../../pdf/generateInvoicePDF";

export const GET: APIRoute = async ({ params, locals }) => {
  const user = locals.user;
  if (!user) {
    return new Response("Unauthorized", { status: 401 });
  }

  const { id } = params;
  if (!id) {
    return new Response("Invoice ID is required", { status: 400 });
  }

  // Fetch invoice with related data
  const invoiceResult = await db
    .select({
      invoice: invoices,
      client: clients,
      organization: organizations,
    })
    .from(invoices)
    .leftJoin(clients, eq(invoices.clientId, clients.id))
    .innerJoin(organizations, eq(invoices.organizationId, organizations.id))
    .where(eq(invoices.id, id))
    .get();

  if (!invoiceResult) {
    return new Response("Invoice not found", { status: 404 });
  }

  const { invoice, client, organization } = invoiceResult;

  // Verify membership
  const membership = await db
    .select()
    .from(members)
    .where(
      and(
        eq(members.userId, user.id),
        eq(members.organizationId, invoice.organizationId),
      ),
    )
    .get();

  if (!membership) {
    return new Response("Not authorized", { status: 403 });
  }

  // Fetch items
  const items = await db
    .select()
    .from(invoiceItems)
    .where(eq(invoiceItems.invoiceId, invoice.id))
    .all();

  try {
    const document = createInvoiceDocument({
      invoice: {
        ...invoice,
        notes: invoice.notes || null,
        discountValue: invoice.discountValue ?? null,
        discountType: invoice.discountType ?? null,
        discountAmount: invoice.discountAmount ?? null,
        taxRate: invoice.taxRate ?? null,
      },
      items,
      client: {
        name: client?.name || "Deleted Client",
        email: client?.email || null,
        street: client?.street || null,
        city: client?.city || null,
        state: client?.state || null,
        zip: client?.zip || null,
        country: client?.country || null,
      },
      organization: {
        name: organization.name,
        street: organization.street || null,
        city: organization.city || null,
        state: organization.state || null,
        zip: organization.zip || null,
        country: organization.country || null,
        logoUrl: organization.logoUrl || null,
      },
    });

    const stream = await renderToStream(document);
    const chunks: Uint8Array[] = [];

    for await (const chunk of stream) {
      chunks.push(chunk as Uint8Array);
    }
    const buffer = Buffer.concat(chunks);

    return new Response(buffer, {
      headers: {
        "Content-Type": "application/pdf",
        "Content-Disposition": `attachment; filename="${invoice.number.replace(/[^a-zA-Z0-9_\-\.]/g, "_")}.pdf"`,
      },
    });
  } catch (error) {
    console.error("Error generating PDF:", error);
    return new Response("Failed to generate PDF", { status: 500 });
  }
};