// Auto-generated Product service
import { queryAll, queryOne, execute } from "../db/client.js";
import type { Product, CreateProductInput, UpdateProductInput } from "../types/index.js";

export class ProductService {
  /** List all products */
  list(): Product[] {
    return queryAll<Product>("SELECT * FROM products ORDER BY created_at DESC");
  }

  /** Get by ID */
  getById(id: string): Product | undefined {
    return queryOne<Product>("SELECT * FROM products WHERE id = ?", [id]);
  }

  /** Create */
  create(input: CreateProductInput): Product {
    const id = crypto.randomUUID();
    const now = new Date().toISOString();
    const cols = ["id", "user_id", "title", "description", "price", "stock", "images", "created_at", "updated_at"];
    const values = [id, input.userId ?? null, input.title ?? null, input.description ?? null, input.price ?? null, input.stock ?? null, input.images ?? null, now, now];

    execute(`INSERT INTO products (${cols.join(", ")}) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`, values);
    return this.getById(id)!;
  }

  /** Update */
  update(id: string, input: UpdateProductInput): Product | undefined {
    const existing = this.getById(id);
    if (!existing) return undefined;

    const sets: string[] = [];
    const values: unknown[] = [];
    if (input.userId !== undefined) { sets.push("user_id = ?"); values.push(input.userId); }
    if (input.title !== undefined) { sets.push("title = ?"); values.push(input.title); }
    if (input.description !== undefined) { sets.push("description = ?"); values.push(input.description); }
    if (input.price !== undefined) { sets.push("price = ?"); values.push(input.price); }
    if (input.stock !== undefined) { sets.push("stock = ?"); values.push(input.stock); }
    if (input.images !== undefined) { sets.push("images = ?"); values.push(input.images); }

    if (sets.length === 0) return existing;

    sets.push("updated_at = ?");
    values.push(new Date().toISOString());

    values.push(id);
    execute(`UPDATE products SET ${sets.join(", ")} WHERE id = ?`, values);
    return this.getById(id)!;
  }

  /** Delete */
  delete(id: string): boolean {
    const result = execute("DELETE FROM products WHERE id = ?", [id]);
    return result.changes > 0;
  }
}
