using GozareshgirProgramManager.Application._Common.Interfaces;
using GozareshgirProgramManager.Application._Common.Models;
using GozareshgirProgramManager.Domain._Common;
using GozareshgirProgramManager.Domain._Common.Exceptions;
using GozareshgirProgramManager.Domain.ProjectAgg.Entities;
using GozareshgirProgramManager.Domain.ProjectAgg.Enums;
using GozareshgirProgramManager.Domain.ProjectAgg.Repositories;

namespace GozareshgirProgramManager.Application.Modules.Projects.Commands.CreateProject;

public class CreateProjectCommandHandler : IBaseCommandHandler<CreateProjectCommand>
{
    private readonly IProjectRepository _projectRepository;
    private readonly IProjectPhaseRepository _projectPhaseRepository;
    private readonly IProjectTaskRepository _projectTaskRepository;
    private readonly IUnitOfWork _unitOfWork;


    public CreateProjectCommandHandler(IProjectRepository projectRepository, IUnitOfWork unitOfWork,
        IProjectTaskRepository projectTaskRepository, IProjectPhaseRepository projectPhaseRepository)
    {
        _projectRepository = projectRepository;
        _unitOfWork = unitOfWork;
        _projectTaskRepository = projectTaskRepository;
        _projectPhaseRepository = projectPhaseRepository;
    }

    public async Task<OperationResult> Handle(CreateProjectCommand request, CancellationToken cancellationToken)
    {
        switch (request.Level)
        {
            case ProjectHierarchyLevel.Project:
                await CreateProject(request);
                break;
            case ProjectHierarchyLevel.Phase:
                await CreateProjectPhase(request);
                break;
            case ProjectHierarchyLevel.Task:
                await CreateProjectTask(request);
                break;
            default:
                return OperationResult.Failure("سطح پروژه نامعتبر است");
        }

        await _unitOfWork.SaveChangesAsync(cancellationToken);
        return OperationResult.Success();
    }

    private async Task CreateProject(CreateProjectCommand request)
    {
        var project = new Project(request.Name);
        await _projectRepository.CreateAsync(project);
    }

    private async Task CreateProjectPhase(CreateProjectCommand request)
    {
        if (!request.ParentId.HasValue)
            throw new BadRequestException("برای ایجاد فاز، شناسه پروژه الزامی است");

        if (!_projectRepository.Exists(x => x.Id == request.ParentId.Value))
        {
            throw new BadRequestException("والد پروژه یافت نشد");
        }

        var projectPhase = new ProjectPhase(request.Name, request.ParentId.Value);
        await _projectPhaseRepository.CreateAsync(projectPhase);
    }

    private async Task CreateProjectTask(CreateProjectCommand request)
    {
        if (!request.ParentId.HasValue)
            throw new BadRequestException("برای ایجاد تسک، شناسه فاز الزامی است");

        if (!_projectPhaseRepository.Exists(x => x.Id == request.ParentId.Value))
        {
            throw new BadRequestException("والد پروژه یافت نشد");
        }

        var priority = request.Priority ?? ProjectTaskPriority.Low;

        var projectTask = new ProjectTask(request.Name, request.ParentId.Value, priority);
        await _projectTaskRepository.CreateAsync(projectTask);
    }
}