using System;
using System.Linq;
using System.Net.Http;
using Kreta.Core.Client.ClientProxy;
using Kreta.Core.Client.Exceptions;
using Kreta.Core.Client.MessageInvoker;
using Kreta.Naplo.Domain;
using Kreta.Naplo.Infrastructure;
using Newtonsoft.Json;

namespace Kreta.Naplo.BusinessLogic
{
    /// <summary>
    /// Service base
    /// </summary>
    abstract class Service : HttpClientProxy, IService
    {
        /// <summary>
        /// Api key
        /// </summary>
        const string ApiKey = nameof(ApiKey);

        /// <summary>
        /// The request default error message
        /// </summary>
        const string RequestDefaultErrorMessage = "Proxy error requesting data from eKreta (for details see innerexception and request\response property).";

        /// <summary>
        /// The error during response deserialization
        /// </summary>
        const string ErrorDuringResponseDeserialization = "Proxy error during response deserialization when requesting data from eKreta web api (for details see innerexception and request\response property).";

        /// <summary>
        /// The error during response deserialization
        /// </summary>
        const string ErrorDuringRequestSerialization = "Proxy error during request serialization when requesting data from eKreta web api (for details see innerexception and request\response property)";

        /// <summary>
        /// Relative url
        /// </summary>
        protected string RelativeUrl { get; }

        /// <summary>
        /// Gets or sets the context.
        /// </summary>
        /// <value>
        /// The context.
        /// </value>
        public ServiceContext Context { get; set; }

        /// <summary>
        /// Handles the HTTP request error.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <param name="response">The response.</param>
        /// <param name="requestUrl">RequestUrl</param>
        /// <param name="exception">The exception.</param>
        /// <exception cref="Kreta.Mobile.Infrastructure.Exceptions.ApiServiceCallException">null</exception>
        protected override void HandleHttpRequestError(HttpRequestMessage request, HttpResponseMessage response, Exception exception)
        {
            if (request != null && request.Headers.Contains(ApiKey))
            {
                request.Headers.Remove(nameof(ApiKey));
                request.Headers.Add((nameof(ApiKey)), Infrastructure.Constants.SecretLogValue);
            }

            throw new HttpClientProxyException(RequestDefaultErrorMessage, exception, request, response);
        }

        /// <summary>
        /// Handles the deserialization error.
        /// </summary>
        /// <param name="response">The response.</param>
        /// <param name="exception">The exception.</param>
        /// <exception cref="Kreta.Mobile.Infrastructure.Exceptions.ApiServiceCallException"></exception>
        protected override void HandleDeserializationError(HttpRequestMessage request, HttpResponseMessage response, JsonException exception)
        {
            throw new HttpClientProxyException(ErrorDuringResponseDeserialization, exception, request, response);
        }

        /// <summary>
        /// Handles the serialization error.
        /// </summary>
        /// <param name="request">The request.</param>
        /// <param name="exception">The exception.</param>
        /// <exception cref="Kreta.Mobile.Infrastructure.Exceptions.ApiServiceCallException"></exception>
        protected override void HandleSerializationError(HttpRequestMessage request, JsonException exception)
        {
            throw new HttpClientProxyException(ErrorDuringRequestSerialization, exception, request, null);
        }

        /// <summary>
        /// Creates the request.
        /// </summary>
        /// <param name="httpMethod">The HTTP method.</param>
        /// <param name="relativeUrl">The relative URI.</param>
        /// <param name="parameters">The parameters.</param>
        /// <param name="data">The data.</param>
        /// <returns></returns>
        protected override HttpRequestMessage CreateRequest(HttpMethod httpMethod, string relativeUrl, HttpClientProxyParameterCollection parameters, object data)
        {
            //add parameters
            parameters.Add(new HttpClientProxyParameter(nameof(this.Context.UserId), this.Context.UserId));

            var requestMessage = base.CreateRequest(httpMethod, relativeUrl, parameters, data);

            //add header values
            requestMessage.Headers.Add(ApiKey, this.Context.ApiKey);
            requestMessage.Headers.Add(nameof(this.Context.InstituteCode), this.Context.InstituteCode);
            requestMessage.Headers.Add(nameof(this.Context.SchoolYearId), this.Context.SchoolYearId.ToString());
            requestMessage.Headers.Add(nameof(this.Context.UserId), this.Context.UserId.ToString());

            requestMessage.Headers.Add(nameof(this.Context.UserRoles), this.Context.UserRoles != null ? string.Join(",", this.Context.UserRoles) : string.Empty);

            string userAgentHeaderKey = requestMessage.Headers.FirstOrDefault(header => header.Key?.Equals(Constants.Http.Headers.UserAgent, StringComparison.OrdinalIgnoreCase) ?? false).Key;

            if (userAgentHeaderKey != null)
            {
                requestMessage.Headers.Remove(userAgentHeaderKey);
            }

            requestMessage.Headers.TryAddWithoutValidation(Constants.Http.Headers.UserAgent, this.Context.UserAgent ?? string.Empty);

            return requestMessage;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Service"/> class.
        /// </summary>                
        /// <param name="invoker">Message invoker</param>        
        /// <param name="relativeUrl">The relative URL.</param>
        public Service(IHttpMessageInvokerFactory invokerFactory, string relativeUrl) :
            base(invokerFactory, string.Empty)
        {
            this.RelativeUrl = relativeUrl ?? throw new ArgumentNullException(nameof(relativeUrl));
        }
    }
}