import { Injectable, InternalServerErrorException } from "@nestjs/common";
import { DrizzleService } from "src/drizzle/drizzle.service";
import { ProductsTable } from "src/schema";
import { CreateProductDto, EditProductDto } from "src/products/products.dto";
import { countDistinct, eq } from "drizzle-orm";

@Injectable()
export class ProductsService {

  constructor(
    private db: DrizzleService,
  ) {}

  async add(data: CreateProductDto) {
    try {
      const res = await this.db.use()
        .insert(ProductsTable)
        .values({
          slugName: data.slugName,
          displayName: data.displayName,
          price: String(data.price),
          imagePath: "placeholder"
        })
      console.log(`Adding new product "${data.slugName}" ...\n`, res)
      return res;
    } catch (err) {
      throw new InternalServerErrorException(err);
    }
  }

  async edit(productId: string, data: EditProductDto) {
      try {
        const res = await this.db.use()
          .update(ProductsTable)
          .set({
            slugName: data.slugName,
            displayName: data.displayName,
            price: String(data.price),
          })
          .where(eq(ProductsTable.uuid, productId))
          .prepare("editProductById")
          .execute();
        console.log(`Editing product n°${productId} ...\n`, res)
        return res;
      } catch (err) {
        throw new InternalServerErrorException(err);
      }
    }

  async delete(productId: string) {
    try {
      const res = await this.db.use()
        .delete(ProductsTable)
        .where(eq(ProductsTable.uuid, productId))
        .prepare("deleteProductById")
        .execute();
      console.log(`Deleting product n°${productId} ...\n`, res)
      return res;
    } catch (err) {
      throw new InternalServerErrorException(err);
    }
  }

  //TODO list all product with pagination.
  async findAll(page: number, limit: number) {
      try {
        //get the number of row first
        const count = await this.db.use()
          .select({
            total: countDistinct(ProductsTable.uuid)
          })
          .from(ProductsTable)
          .prepare("countProducts")
          .execute();

        console.log(count, {page: page}, {limit: limit})

        const res = await this.db.use()
          .select()
          .from(ProductsTable)
          .limit(limit)
          .offset((page - 1) * limit)
          .prepare("findAllProducts")
          .execute();
        console.log(`Fetching products (page ${page}, limit ${limit}) ...\n`)
        const response = {
          maxPage: (Math.round(count[0].total / limit)),
          currentPage: page,
          totalProducts: count[0].total,
          productsPerPage: limit,
          products: res
        }
        console.log(response)
        return response;
      } catch (err) {
        throw new InternalServerErrorException(err);
      }
  }

}