using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using Roadie.Library.Identity;
using System;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;

namespace Roadie.Api.Services
{
    public class TokenService : ITokenService
    {
        private readonly IConfiguration _configuration;

        public TokenService(IConfiguration configuration)
        {
            _configuration = configuration;
        }

        public async Task<string> GenerateTokenAsync(User user, UserManager<User> userManager)
        {
            var utcNow = DateTime.UtcNow;

            var roles = await userManager.GetRolesAsync(user).ConfigureAwait(false);
            var userRoles = roles.Select(r => new Claim(ClaimTypes.Role, r)).ToArray();

            var tokenHandler = new JwtSecurityTokenHandler();

            var claims = new[]
            {
                new Claim(JwtRegisteredClaimNames.Sub, user.Id.ToString()),
                new Claim("roadie_id", user.RoadieId.ToString()),
                new Claim(JwtRegisteredClaimNames.UniqueName, user.UserName),
                new Claim(JwtRegisteredClaimNames.Email, user.Email),
                new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
                new Claim(JwtRegisteredClaimNames.Iat, utcNow.ToString())
            }.Union(userRoles);

            var now = DateTime.UtcNow;
            var securityKey =
                new SymmetricSecurityKey(
                    Encoding.Default.GetBytes(_configuration.GetValue<string>("Tokens:PrivateKey")));
            var signingCredentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256Signature);

            var jwt = new JwtSecurityToken(
                signingCredentials: signingCredentials,
                claims: claims,
                notBefore: utcNow,
                expires: utcNow.AddSeconds(_configuration.GetValue<int>("Tokens:Lifetime")),
                audience: _configuration.GetValue<string>("Tokens:Audience"),
                issuer: _configuration.GetValue<string>("Tokens:Issuer")
            );

            return new JwtSecurityTokenHandler().WriteToken(jwt);
        }
    }
}