using System.Security.Claims;
using Azaion.Common;
using Azaion.Common.Configs;
using Azaion.Common.Database;
using Azaion.Common.Entities;
using Azaion.Common.Requests;
using LinqToDB;
using Microsoft.AspNetCore.Http;

namespace Azaion.Services;

public interface IUserService
{
    User? CurrentUser { get; }
    Task RegisterUser(RegisterUserRequest request, CancellationToken cancellationToken = default);
    Task<User> ValidateUser(string username, string password, string? hardwareId = null, CancellationToken cancellationToken = default);
    Task UpdateHardwareId(string username, string hardwareId, CancellationToken cancellationToken = default);
}

public class UserService(IDbFactory dbFactory, IHttpContextAccessor httpContextAccessor) : IUserService
{
    public User? CurrentUser
    {
        get
        {
            var claims = httpContextAccessor.HttpContext?.User.Claims.ToDictionary(x => x.Type);
            if (claims == null)
                return null;

            Enum.TryParse(claims[ClaimTypes.Role].Value, out RoleEnum role);
            return new User
            {
                Id = claims[ClaimTypes.NameIdentifier].Value,
                Email = claims[ClaimTypes.Name].Value,
                Role = role,
                HardwareId = claims[Constants.HARDWARE_ID].Value,
            };
        }
    }

    public async Task RegisterUser(RegisterUserRequest request, CancellationToken cancellationToken = default)
    {
        await dbFactory.Run(async db =>
        {
            var existingUser = await db.Users.FirstOrDefaultAsync(u => u.Email == request.Email, token: cancellationToken);
            if (existingUser != null)
                throw new BusinessException(ExceptionEnum.UserExists, "User already exists");

            await db.InsertAsync(new User
            {
                Email = request.Email,
                PasswordHash = request.Password.ToHash(),
                Role = request.Role
            }, token: cancellationToken);
        });
    }

    public async Task<User> ValidateUser(string username, string password, string? hardwareId = null, CancellationToken cancellationToken = default) =>
        await dbFactory.Run(async db =>
        {
            var user = await db.Users.FirstOrDefaultAsync(x => x.Email == username, token: cancellationToken);
            if (user == null)
                throw new BusinessException(ExceptionEnum.NoUserFound, "No user found");

            if (password.ToHash() != user.PasswordHash)
                throw new BusinessException(ExceptionEnum.PasswordIncorrect, "Passwords do not match");

            if (user.Role == RoleEnum.ApiAdmin)
                return user;

            // For Non-API admins hardwareId should match if it was already set
            if (user.HardwareId != null && user.HardwareId != hardwareId)
                throw new BusinessException(ExceptionEnum.HardwareIdMismatch, "Hardware id mismatch");
            return user;
        });

    public async Task UpdateHardwareId(string username, string hardwareId, CancellationToken cancellationToken = default) =>
        await dbFactory.Run(async db =>
            await db.Users.UpdateAsync(x => x.Email == username, u => new User { HardwareId = hardwareId}, token: cancellationToken));
}