using System;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Text;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;

namespace jsonjumble.Library
{
	public class JwtTokenHandler
	{
		private readonly IConfiguration Configuration;

		public JwtTokenHandler(IConfiguration configuration)
		{
			Configuration = configuration;
		}

		public JwtSecurityToken ParseToken(string token)
		{
			SecurityToken validatedToken;
			new JwtSecurityTokenHandler().ValidateToken(token, GetParameters(), out validatedToken);
			return validatedToken as JwtSecurityToken;
		}

		public TokenValidationParameters GetParameters()
		{
			return new TokenValidationParameters()
			{
				ValidateIssuerSigningKey = true,
				IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["JwtSettings:SecretKey"])),
				ValidateIssuer = true,
				ValidIssuer = Configuration["JwtSettings:Issuer"],
				ValidateAudience = true,
				ValidAudience = Configuration["JwtSettings:Audience"],
				ValidateLifetime = true,
				ClockSkew = TimeSpan.FromMinutes(Configuration.GetValue<int>("JwtSettings:ExpirationInHours"))
			};
		}

		public string GetTokenValue(string token, string key) 
		{
			var parsedToken = ParseToken(token);
			dynamic value;
			parsedToken.Payload.TryGetValue(key, out value);
			return value.ToString();
		}

		public string GetTokenPath(string token)
		{
			return GetTokenValue(token, "path");
		}
	}
}