import { BadRequestException, Injectable } from "@nestjs/common";

import { CommonMessage, LearningMessage } from "../../../common/enums/message.enum";
import { UsersService } from "../../users/providers/users.service";
import { CreateLearningCategoryDto } from "../DTO/create-learning-category.dto";
import { CreateLearningDto } from "../DTO/create-learning.dto";
import { LearningCategoryRepository } from "../repositories/learning-category.repository";
import { LearningProgressRepository } from "../repositories/learning-progress.repository";
import { LearningRepository } from "../repositories/learning.repository";

@Injectable()
export class LearningService {
  constructor(
    private readonly learningRepository: LearningRepository,
    private readonly learningProgressRepository: LearningProgressRepository,
    private readonly learningCategoryRepository: LearningCategoryRepository,
    private readonly usersService: UsersService,
  ) {}

  //******************** */

  async createLearning(createDto: CreateLearningDto) {
    const { category } = await this.findOneCategory(createDto.categoryId);

    const learning = this.learningRepository.create({
      ...createDto,
      category,
    });
    await this.learningRepository.save(learning);

    return {
      message: CommonMessage.CREATED,
      learning,
    };
  }

  //******************** */

  async findAllLearnings() {
    const learnings = await this.learningRepository.find();

    return { learnings };
  }

  //******************** */

  async findOneLearning(id: string) {
    const learning = await this.learningRepository.findOneBy({
      id,
    });
    if (!learning) throw new BadRequestException(LearningMessage.NOT_FOUND);

    return { learning };
  }

  //******************** */

  async createLearningCategory(createDto: CreateLearningCategoryDto) {
    const category = this.learningCategoryRepository.create(createDto);
    await this.learningCategoryRepository.save(category);

    return { category };
  }

  //******************** */

  async findAllCategories() {
    const categories = await this.learningCategoryRepository.find();

    return { categories };
  }

  //******************** */

  async findOneCategory(id: string) {
    const category = await this.learningCategoryRepository.findOneBy({
      id,
    });
    if (!category) throw new BadRequestException(LearningMessage.CATEGORY_NOT_FOUND);

    return { category };
  }

  //******************** */

  async trackProgress(userId: string, learningId: string) {
    const { user } = await this.usersService.findOneById(userId);
    const { learning } = await this.findOneLearning(learningId);

    const progress = this.learningProgressRepository.create({
      user,
      learning,
      watchedAt: new Date(),
    });
    return this.learningProgressRepository.save(progress);
  }

  //******************** */

  async getUserProgress(userId: string) {
    return this.learningProgressRepository.find({
      where: { user: { id: userId } },
      relations: ["learning"],
    });
  }
}