using MediatR;
using Microsoft.Extensions.Configuration;
using ReC.Application.Common;
using ReC.Application.Common.Constants;
using ReC.Application.Common.Dto;
using ReC.Application.Common.Exceptions;
using ReC.Application.Common.Procedures.InsertProcedure;
using ReC.Application.Results.Commands;
using ReC.Domain.Constants;
using System.Net;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;

namespace ReC.Application.RecActions.Commands;

public record InvokeRecActionViewCommand : IRequest<bool>
{
    public RecActionViewDto Action { get; set; } = null!;
}

public static class InvokeRecActionViewCommandExtensions
{
    public static InvokeRecActionViewCommand ToInvokeCommand(this RecActionViewDto dto) => new() { Action = dto };
}

public class InvokeRecActionViewCommandHandler(
    ISender sender,
    IHttpClientFactory clientFactory,
    IConfiguration? config = null
    ) : IRequestHandler<InvokeRecActionViewCommand, bool>
{
    public async Task<bool> Handle(InvokeRecActionViewCommand request, CancellationToken cancel)
    {
        var action = request.Action;

        using var http = clientFactory.CreateClient(Http.ClientName);

        if (action.RestType is not RestType restType)
            throw new DataIntegrityException(
                $"Rec action could not be invoked because the RestType value is null. " +
                $"ProfileId: {action.ProfileId}, " +
                $"Id: {action.Id}"
            );

        using var httpReq = restType
            .ToHttpMethod()
            .ToHttpRequestMessage(action.EndpointUri);

        if (action.Body is not null)
        {
            using var reqBody = new StringContent(action.Body);
            httpReq.Content = reqBody;
        }

        if (action.Headers is not null)
            foreach (var header in action.Headers)
                httpReq.Headers.Add(header.Key, header.Value);

        switch (action.EndpointAuthType)
        {
            case EndpointAuthType.NoAuth:
                break;

            case EndpointAuthType.ApiKey:
                if (action.EndpointAuthApiKey is string apiKey && action.EndpointAuthApiValue is string apiValue)
                {
                    switch (action.EndpointAuthApiKeyAddTo)
                    {
                        case ApiKeyLocation.Header:
                            httpReq.Headers.Add(apiKey, apiValue);
                            break;                        
                        case ApiKeyLocation.Query:                        
                            var uriBuilder = new UriBuilder(httpReq.RequestUri!);
                            var query = System.Web.HttpUtility.ParseQueryString(uriBuilder.Query);
                            query[apiKey] = apiValue;
                            uriBuilder.Query = query.ToString();
                            httpReq.RequestUri = uriBuilder.Uri;
                            break;
                        default:
                            throw new DataIntegrityException(
                                $"The API key location '{action.EndpointAuthApiKeyAddTo}' is not supported. " +
                                $"ProfileId: {action.ProfileId}, " +
                                $"Id: {action.Id}"
                            );
                    }
                }
                break;

            case EndpointAuthType.BearerToken:
            case EndpointAuthType.JwtBearer:
            case EndpointAuthType.OAuth2:
                if (action.EndpointAuthToken is string authToken)
                    httpReq.Headers.Authorization = new AuthenticationHeaderValue("Bearer", authToken);
                break;

            case EndpointAuthType.BasicAuth:
                if (action.EndpointAuthUsername is string authUsername && action.EndpointAuthPassword is string authPassword)
                {
                    var basicAuth = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{authUsername}:{authPassword}"));
                    httpReq.Headers.Authorization = new AuthenticationHeaderValue("Basic", basicAuth);
                }
                break;

            case EndpointAuthType.NtlmAuth:
                if (!string.IsNullOrWhiteSpace(action.EndpointAuthUsername))
                {
                    var credentials = new NetworkCredential(
                        action.EndpointAuthUsername,
                        action.EndpointAuthPassword,
                        action.EndpointAuthDomain);
                    var credentialCache = new CredentialCache { { httpReq.RequestUri!, "NTLM", credentials } };
                    httpReq.Options.Set(new HttpRequestOptionsKey<CredentialCache>("Credentials"), credentialCache);
                }
                break;

            case EndpointAuthType.DigestAuth:
            case EndpointAuthType.OAuth1:
            case EndpointAuthType.AwsSignature:
            // These authentication methods require more complex implementations,
            // often involving multi-step handshakes or specialized libraries.
            // They are left as placeholders for future implementation.
            default:
                throw new NotImplementedException(
                    $"The authentication type '{action.EndpointAuthType}' is not supported yet. " +
                    $"ProfileId: {action.ProfileId}, " +
                    $"Id: {action.Id}"
                );
        }

        using var response = await http.SendAsync(httpReq, cancel);
        var resBody = await response.Content.ReadAsStringAsync(cancel);
        var resHeaders = response.Headers.ToDictionary();

        var statusCode = (short)response.StatusCode;

        await sender.ExecuteInsertProcedure(new InsertResultProcedure()
        {
            StatusId = statusCode,
            ActionId = action.Id,
            Header = JsonSerializer.Serialize(resHeaders, options: new() { WriteIndented = false }),
            Body = resBody
        }, config?["AddedWho"], cancel);

        return response.IsSuccessStatusCode;
    }
}