using MediatR;
using Mws.Application.Common;
using Mws.Domain.Projects;

namespace Mws.Application.Projects;

public record AddProjectMemberCommand(Guid UserId, Guid ProjectId, AddMemberRequest Request) : IRequest<ProjectMemberDto>;

public class AddProjectMemberHandler(IUnitOfWork uow) : IRequestHandler<AddProjectMemberCommand, ProjectMemberDto>
{
    public async Task<ProjectMemberDto> Handle(AddProjectMemberCommand command, CancellationToken ct)
    {
        if (await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct) != MemberRole.Owner)
        {
            throw new ForbiddenException("Only the project owner can add members");
        }

        var request = command.Request;
        var user = await uow.Users.GetByIdAsync(request.UserId, ct)
            ?? throw new NotFoundException("User not found");

        var already = await uow.Projects.IsMemberAsync(command.ProjectId, request.UserId, ct);
        if (already)
        {
            throw new BadRequestException("User is already a member of this project");
        }

        var role = request.Role is MemberRole.Owner or MemberRole.Member ? request.Role : MemberRole.Member;
        var member = new ProjectMember
        {
            ProjectId = command.ProjectId,
            UserId = request.UserId,
            Role = role,
        };

        uow.Projects.AddMember(member);
        uow.Projects.AddMemberPermission(new ProjectMemberPermission
        {
            ProjectId = command.ProjectId,
            UserId = request.UserId,
            Screen = ProjectPermissionScreens.Documents,
            CanView = true,
            CanCreate = role == MemberRole.Owner,
            CanEdit = role == MemberRole.Owner,
            CanDelete = role == MemberRole.Owner,
        });
        await uow.SaveChangesAsync(ct);

        return new ProjectMemberDto
        {
            UserId = user.Id,
            Username = user.Username,
            DisplayName = user.DisplayName,
            Role = member.Role,
            CanViewDocuments = true,
            CanCreateDocuments = role == MemberRole.Owner,
            CanEditDocuments = role == MemberRole.Owner,
            CanDeleteDocuments = role == MemberRole.Owner,
        };
    }
}