using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Text.Encodings.Web;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using Wabbajack.BuildServer.Model.Models;
using Wabbajack.BuildServer.Models;

namespace Wabbajack.BuildServer
{

    public class ApiKeyAuthenticationOptions : AuthenticationSchemeOptions
    {
        public const string DefaultScheme = "API Key";
        public string Scheme => DefaultScheme;
        public string AuthenticationType = DefaultScheme;
    }

    public class ApiKeyAuthenticationHandler : AuthenticationHandler<ApiKeyAuthenticationOptions>
    {
        private const string ProblemDetailsContentType = "application/problem+json";
        private readonly SqlService _db;
        private const string ApiKeyHeaderName = "X-Api-Key";

        public ApiKeyAuthenticationHandler(
            IOptionsMonitor<ApiKeyAuthenticationOptions> options,
            ILoggerFactory logger,
            UrlEncoder encoder,
            ISystemClock clock,
            SqlService db) : base(options, logger, encoder, clock)
        {
            _db = db;
        }

        protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
        {
            if (!Request.Headers.TryGetValue(ApiKeyHeaderName, out var apiKeyHeaderValues))
            {
                return AuthenticateResult.NoResult();
            }

            var providedApiKey = apiKeyHeaderValues.FirstOrDefault();

            if (apiKeyHeaderValues.Count == 0 || string.IsNullOrWhiteSpace(providedApiKey))
            {
                return AuthenticateResult.NoResult();
            }

            var owner = await _db.LoginByAPIKey(providedApiKey);

            if (owner != null)
            {
                var claims = new List<Claim> {new Claim(ClaimTypes.Name, owner)};

                /*
                claims.AddRange(existingApiKey.Roles.Select(role => new Claim(ClaimTypes.Role, role)));
                */

                var identity = new ClaimsIdentity(claims, Options.AuthenticationType);
                var identities = new List<ClaimsIdentity> {identity};
                var principal = new ClaimsPrincipal(identities);
                var ticket = new AuthenticationTicket(principal, Options.Scheme);

                return AuthenticateResult.Success(ticket);
            }

            return AuthenticateResult.Fail("Invalid API Key provided.");
        }

        protected override async Task HandleChallengeAsync(AuthenticationProperties properties)
        {
            Response.StatusCode = 401;
            Response.ContentType = ProblemDetailsContentType;
            await Response.WriteAsync("Unauthorized");
        }

        protected override async Task HandleForbiddenAsync(AuthenticationProperties properties)
        {
            Response.StatusCode = 403;
            Response.ContentType = ProblemDetailsContentType;
            await Response.WriteAsync("forbidden");
        }
    }
}