using Google.Protobuf.WellKnownTypes;
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, HeadHunterService hhService) : 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))
            return new RegisterResponse { Success = false };

        dbContext.Users.Add(new User
        {
            UserId = request.UserId,
            Username = !string.IsNullOrEmpty(request.Username) ? request.Username : null
        });
        await dbContext.SaveChangesAsync();

        return new RegisterResponse { Success = true };
    }

    /// <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);
        ThrowIfUserNotFound(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 };
    }

    public override Task<GetHeadHunterAuthHookResponse> GetHeadHunterAuthHook(
        GetHeadHunterAuthHookRequest request, 
        ServerCallContext context)
    {
        return Task.Run(() => new GetHeadHunterAuthHookResponse
        {
            RegistrationUrl = hhService.GenerateAuthLink(request.UserId)
        });
    }

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