//------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------
//
// ⚠️ DO NOT USE IN PRODUCTION ⚠️
//
// This controller exists solely to issue self-signed JWTs for the SCIM sample/
// integration-test flow. It is anonymously reachable and uses a symmetric key
// from configuration with no rotation, no revocation, and no authentication
// of the requester. Combined with the dev-mode JWT validation in Startup.cs
// (guarded by #if DEBUG), it allows any anonymous caller to mint a token that
// the sample host will accept.
//
// Any consumer who copies this sample for a production SCIM endpoint MUST
// either delete this controller entirely or replace it with a properly
// authenticated, audience-scoped token issuer.
//
//------------------------------------------------------------

namespace Microsoft.SCIM.WebHostSample.Controllers
{
    using System;
    using System.IdentityModel.Tokens.Jwt;
    using System.Text;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Extensions.Configuration;
    using Microsoft.IdentityModel.Tokens;

    // Controller for generating a bearer token for authorization during testing.
    // This is not meant to replace proper Oauth for authentication purposes.
    [Obsolete("Sample only - remove this controller or replace with a properly authenticated OAuth token issuer before deploying to any non-sample environment.", error: true)]
    [Route("scim/token")]
    [ApiController]
    public class TokenController : ControllerBase
    {
        private readonly IConfiguration configuration;        
        private const int defaultTokenExpirationTimeInMins = 120;

        public TokenController(IConfiguration Configuration)
        {
            this.configuration = Configuration;
        }

        private string GenerateJSONWebToken()
        {
            SymmetricSecurityKey securityKey =
                new SymmetricSecurityKey(Encoding.UTF8.GetBytes(this.configuration["Token:IssuerSigningKey"]));
            SigningCredentials credentials =
                new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);

            DateTime startTime = DateTime.UtcNow;
            DateTime expiryTime;
            if (double.TryParse(this.configuration["Token:TokenLifetimeInMins"], out double tokenExpiration))
                expiryTime = startTime.AddMinutes(tokenExpiration);
            else
                expiryTime = startTime.AddMinutes(defaultTokenExpirationTimeInMins);

            JwtSecurityToken token =
                new JwtSecurityToken(
                    this.configuration["Token:TokenIssuer"],
                    this.configuration["Token:TokenAudience"],
                    null,
                    notBefore: startTime,
                    expires: expiryTime,
                    signingCredentials: credentials);

            string result = new JwtSecurityTokenHandler().WriteToken(token);
            return result;
        }

        [HttpGet]
        public ActionResult Get()
        {
            string tokenString = this.GenerateJSONWebToken();
            return this.Ok(new { token = tokenString });
        }

    }
}