using Grpc.Core;
using JOBot.Backend.DAL.Context;
using JOBot.Backend.DAL.Models;
using JOBot.Proto;
using Microsoft.EntityFrameworkCore;
using User = JOBot.Backend.DAL.Models.User;

namespace JOBot.Backend.Services.gRPC;
public class UserService(AppDbContext dbContext) : Proto.User.UserBase
{

    /// <summary>
    /// Create user
    /// </summary>
    /// <param name="request"></param>
    /// <param name="_"></param>
    /// <returns>Status of operation (fail if user exists)</returns>
    public override async Task<RegisterResponse> Register(
        RegisterRequest request,
        ServerCallContext _)
    {
        if(!await dbContext.Users
               .AnyAsync(x => x.UserId == request.UserId))
        {
            dbContext.Users.Add(new User
            {
                UserId = request.UserId,
                Username = !string.IsNullOrEmpty(request.Username) ? request.Username : null
            });
            
            await dbContext.SaveChangesAsync();
            return new RegisterResponse
            {
                Success = true
            };
        }

        return new RegisterResponse
        {
            Success = false
        };
    }

    /// <summary>
    /// Get user for client
    /// </summary>
    /// <param name="request"></param>
    /// <param name="_"></param>
    /// <returns>User, or throws RPC exception if not found</returns>
    public override async Task<GetUserResponse> GetUser(
        GetUserRequest request, 
        ServerCallContext _)
    {
        var user = await dbContext.Users.FirstOrDefaultAsync(x => x.UserId == request.UserId);
        ValidateUserFound(user);
        
        return user!.MapToResponse();
    }

    /// <summary>
    /// Accept EULA for user
    /// </summary>
    /// <param name="request"></param>
    /// <param name="_"></param>
    /// <returns>Status of operation</returns>
    public override async Task<AcceptEulaResponse> AcceptEula(AcceptEulaRequest request, ServerCallContext _)
    {
        var user = await dbContext.Users.FirstOrDefaultAsync(x => x.UserId == request.UserId);
        if (user == null)
        {
            return new AcceptEulaResponse
            {
                Success = false
            };
        }

        user.Eula = request.EulaAccepted;
        await dbContext.SaveChangesAsync();
        
        return new AcceptEulaResponse
        {
            Success = true
        };
    }

    /// <summary>
    /// Throw RPCException if user not found
    /// </summary>
    /// <param name="user"></param>
    /// <exception cref="RpcException"></exception>
    private void ValidateUserFound(User? user)
    {
        if (user == null)
            throw new RpcException(new Status(StatusCode.NotFound, "User not found"));
    }
}