import { NextRequest, NextResponse } from "next/server";
import { getDb } from "@/lib/db";

interface SourceInfo {
  product_name: string;
  sku: string;
  qty_per_unit: number;
  batch_size: number;
  subtotal: number;
}

interface AcceptItem {
  component_id: number;
  part_number: string;
  component_name: string;
  category_name: string | null;
  package_type: string | null;
  shelf_location: string | null;
  unit_price: number;
  stock_quantity: number;
  total_needed: number;
  shortage: number;
  is_internal: boolean;
  manufacturer: string | null;
  supplier: string | null;
  supplier_part_number: string | null;
  sources: SourceInfo[];
}

interface AcceptProduct {
  product_name: string;
  sku: string;
  batch_size: number;
}

export async function POST(request: NextRequest) {
  try {
    const sql = getDb();
    const body = await request.json();
    const { name, items, products, summary, link_po_ids } = body as {
      name: string;
      items: AcceptItem[];
      products: AcceptProduct[];
      summary: {
        totalProducts: number;
        totalComponents: number;
        totalParts: number;
        totalCost: number;
        shortageCount: number;
      };
      link_po_ids?: number[];
    };

    if (!items || items.length === 0) {
      return NextResponse.json(
        { error: "No items to accept" },
        { status: 400 }
      );
    }

    const planName =
      name ||
      `Production Plan ${new Date().toLocaleDateString("en-GB", { day: "2-digit", month: "2-digit", year: "numeric" })}`;

    // 1. Create the planning history record
    const phRows = await sql(
      `INSERT INTO planning_history (name, status, products_json, summary_json)
       VALUES ($1, $2, $3, $4) RETURNING *`,
      [planName, "accepted", JSON.stringify(products || []), JSON.stringify(summary || {})]
    );
    const plan = phRows[0];

    // 2. Insert all items with full data snapshots
    for (const item of items) {
      await sql(
        `INSERT INTO planning_history_items
          (planning_id, component_id, part_number, component_name, category_name,
           package_type, shelf_location, unit_price, stock_at_time,
           quantity_needed, shortage, is_internal,
           manufacturer, supplier, supplier_part_number, sources_json)
         VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16)`,
        [
          plan.id,
          item.component_id,
          item.part_number,
          item.component_name,
          item.category_name || null,
          item.package_type || null,
          item.shelf_location || null,
          item.unit_price || 0,
          item.stock_quantity || 0,
          item.total_needed,
          item.shortage || 0,
          item.is_internal,
          item.manufacturer || null,
          item.supplier || null,
          item.supplier_part_number || null,
          JSON.stringify(item.sources || []),
        ]
      );
    }

    // 3. Decrement stock for ALL components (both internal and external)
    for (const item of items) {
      await sql(
        `UPDATE components SET stock_quantity = GREATEST(0, stock_quantity - $1) WHERE id = $2`,
        [item.total_needed, item.component_id]
      );
    }

    // 4. Link selected Supplier POs to this planning record
    if (link_po_ids && link_po_ids.length > 0) {
      for (const poId of link_po_ids) {
        await sql(
          `UPDATE supplier_pos SET planning_id = $1 WHERE id = $2`,
          [plan.id, poId]
        );
      }
    }

    return NextResponse.json({
      plan,
      message: "Planning accepted. History saved and stock decremented.",
    }, { status: 201 });
  } catch (error) {
    console.error("Error accepting production plan:", error);
    return NextResponse.json(
      { error: "Failed to accept production plan" },
      { status: 500 }
    );
  }
}