import { Injectable, NotFoundException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Project } from './project.entity';
import { CreateProjectDto, UpdateProjectDto } from './dto';

@Injectable()
export class ProjectsService {
  constructor(
    @InjectRepository(Project)
    private projectsRepository: Repository<Project>,
  ) {}

  async findAll(query) {
    const { page = 1, limit = 10, status, customer_id } = query;
    const skip = (page - 1) * limit;

    const queryBuilder = this.projectsRepository.createQueryBuilder('project');

    if (status) {
      queryBuilder.where('project.status = :status', { status });
    }

    if (customer_id) {
      queryBuilder.where('project.customer_id = :customer_id', { customer_id });
    }

    const [projects, total] = await queryBuilder
      .leftJoinAndSelect('project.customer', 'customer')
      .skip(skip)
      .take(limit)
      .getManyAndCount();

    return {
      projects,
      total,
      page,
      limit,
    };
  }

  async findOne(id: string) {
    const project = await this.projectsRepository.findOne({
      where: { id },
      relations: ['customer', 'contracts', 'purchases', 'subcontracts'],
    });

    if (!project) {
      throw new NotFoundException(`Project with ID ${id} not found`);
    }

    return project;
  }

  async create(createProjectDto: CreateProjectDto) {
    const project = this.projectsRepository.create(createProjectDto);
    return this.projectsRepository.save(project);
  }

  async update(id: string, updateProjectDto: UpdateProjectDto) {
    const project = await this.findOne(id);
    Object.assign(project, updateProjectDto);
    return this.projectsRepository.save(project);
  }

  async remove(id: string) {
    const project = await this.findOne(id);
    return this.projectsRepository.remove(project);
  }

  async calculateDuration(id: string) {
    const project = await this.findOne(id);
    
    if (!project.start_date || !project.end_date) {
      return { message: 'Start date or end date is not set' };
    }

    const start = new Date(project.start_date);
    const end = new Date(project.end_date);
    const duration = Math.ceil((end.getTime() - start.getTime()) / (1000 * 60 * 60 * 24));

    return { duration_days: duration };
  }

  async updateStatus(id: string, status: string) {
    const project = await this.findOne(id);
    project.status = status;
    return this.projectsRepository.save(project);
  }
}