using System;
using OpenAI;
using System.Linq;
using OllamaSharp;
using System.Net.Http;
using xAiApi.Constants;
using xAiModels.Models;
using System.Threading;
using System.ClientModel;
using xCommons.Extensions;
using xAiModels.Constants;
using xAiModels.Extensions;
using xAiApi.Configurations;
using xExceptions.Constants;
using Microsoft.Extensions.AI;
using System.Collections.Generic;
using System.ClientModel.Primitives;

namespace xAiApi.Extensions
{
    public static class XModelsExtensions
    {
        /// <summary>
        /// Validate Configurations ...
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static bool IsValid(this XAiApiConfiguration source)
        {
            //
            var result =
                !source.IsNullOrDefault() &&
                source.Models.HasChild() &&
                source.Models.All(m => m.IsValid()) &&
                source.Prompts.All(m => m.IsValid()) &&
                source.Prompts.Any(p => p.Name
                    .Equals(
                        XAiApiConstants.XAiApiIntroductionPromptName,
                        System.StringComparison.InvariantCultureIgnoreCase));

            //
            return result;
        }

        /// <summary>
        /// Extract Default Model Descriptor ...
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static XAiModelDescriptor GetDefaultModel(this XAiApiConfiguration source)
        {
            //
            XAiModelDescriptor result = null;

            //
            if (source.IsValid())
            {
                result = source.Models[0];
            }

            //
            return result;
        }

        /// <summary>
        /// Retrieve Specified Model from Config ...
        /// </summary>
        /// <param name="source"></param>
        /// <param name="name"></param>
        /// <returns></returns>
        public static XAiModelDescriptor GetModel(
            this XAiApiConfiguration source,
            string name
        )
        {
            //
            XAiModelDescriptor result = null;

            //
            if (source.IsValid())
            {
                //
                if (name.IsNullOrEmpty())
                {
                    result = source.GetDefaultModel();
                }
                else
                {
                    result = source.Models
                        .FirstOrDefault(m => m.Name
                            .Equals(name, System.StringComparison.InvariantCultureIgnoreCase));
                }
            }

            //
            return result;
        }

        /// <summary>
        /// Retrieve Introduction Prompt ...
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static XAiPromptDescriptor GetIntroductionPrompt(this XAiApiConfiguration source)
        {
            //
            XAiPromptDescriptor result = null;

            //
            if (source.IsValid())
            {
                //
                result = source.Prompts
                    .FirstOrDefault(p => p.Name
                        .Equals(
                            XAiApiConstants.XAiApiIntroductionPromptName,
                            System.StringComparison.InvariantCultureIgnoreCase));
            }

            //
            return result;
        }

        /// <summary>
        /// Select Specified Prompts and Parse it's Template
        /// and Generate Message ...
        /// </summary>
        /// <param name="source"></param>
        /// <param name="name"></param>
        /// <param name="params"></param>
        /// <returns></returns>
        public static string GetPrompt(
            this XAiApiConfiguration source,
            string name = null,
            IDictionary<string, string> @params = null
        )
        {
            //
            var result = string.Empty;

            //
            // Normalize ...
            if (name.IsNullOrEmpty())
            {
                name = XAiApiConstants.XAiApiIntroductionPromptName;
            }

            //
            if (source.IsValid())
            {
                //
                var prompt = source.Prompts
                    .FirstOrDefault(p => p.Name
                        .Equals(
                            name,
                            System.StringComparison.InvariantCultureIgnoreCase
                        )
                    );
                if (!prompt.IsNullOrDefault())
                {
                    //
                    result = prompt.Template;

                    //
                    // Handle Params ...
                    if (!@params.IsNullOrDefault() && @params.HasChild())
                    {
                        //
                        // Select Params ...
                        var existsParams = prompt.Params
                            .Where(p => @params.Any(pr => pr.Key == p.Name))
                            .Distinct()
                            .ToList();

                        //
                        // Replace Selected Params ...
                        existsParams
                            .ForEach(pk =>
                            {
                                result = result.Replace(pk.Param, @params[pk.Name]);
                            });
                    }
                }
            }

            //
            return result;
        }

        /// <summary>
        /// Provide HttpClient for Common Usages ...
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static HttpClient GetHttpClient(this string source)
        {
            //
            var result = new HttpClient
            {
                //
                // Disable timeout completely (not recommended for production)
                Timeout = Timeout.InfiniteTimeSpan,

                //
                BaseAddress = source.IsNullOrEmpty()
                    ? null
                    : new Uri(source),

                //
                // OR set a very long timeout (e.g., 30 minutes for large file uploads)
                // Timeout = TimeSpan.FromMinutes(30)
            };

            //
            return result;
        }

        /// <summary>
        /// Instance and Retrieve Chat Client ...
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static IChatClient GetClient(this XAiModelDescriptor source)
        {
            //
            // Try to Initialize LLm ...
            var model = source.LLM;
            var apiKey = source.ApiKey;
            var url = new Uri(source.Url);
            var httpClient = source.Url.GetHttpClient();

            //
            IChatClient result = null;
            switch (source.Provider)
            {
                //
                case XAiModelProviderType.Ollama:
                    //
                    // Instance Ollama Client using Custom HttpCLient ...
                    var ollamaClient = new OllamaApiClient(httpClient, model);
                    result =
                        new ChatClientBuilder(ollamaClient)
                        .UseFunctionInvocation()
                        .Build();
                    break;

                //
                case XAiModelProviderType.OpenAI:
                    //
                    // Instance Ollama Client using Custom HttpCLient ...
                    var openAiClient = new OpenAIClient(
                        new ApiKeyCredential(apiKey.IsNullOrEmpty() ? XAiApiConstants.XOpenAINoKey : apiKey),
                        new OpenAIClientOptions
                        {
                            Endpoint = url,
                            Transport = new HttpClientPipelineTransport(httpClient)
                        }
                    );
                    result =
                        new ChatClientBuilder(
                            openAiClient
                            .GetChatClient(model)
                        .AsIChatClient())
                        .UseFunctionInvocation()
                        .Build();
                    break;

                //
                case XAiModelProviderType.DeepSeek:
                    break;

                //
                case XAiModelProviderType.HuggingFace:
                    break;

                //
                default:
                    break;
            }

            //
            if (result.IsNullOrDefault())
            {
                XException.InvalidData.Throw();
            }

            //
            return result;
        }

    }
}