using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CSS_Solution.Request
{
    class Task_handler
    {
        public static Index_Task_handler index_Task_Handler = new Index_Task_handler();
        public static Login_Task_handler login_Task_Handler = new Login_Task_handler();
        public static ToCourse_Task_Handler toCourse_Task_Handler = new ToCourse_Task_Handler();
        public bool Code_Test()
        {
            try
            {
                return true;
            }
            catch(Exception)
            {
                return false;
            }
        }
    }
    class Index_Task_handler
    {
        int current_id = 0;
        public LinkedList<Get_Index_Result> results = new LinkedList<Get_Index_Result>();
        Dictionary<int, (Get_Index, Action<Get_Index_Result>)> tasks = new Dictionary<int, (Get_Index, Action<Get_Index_Result>)>();
        public void Make_request(Action<Get_Index_Result> result_handler)
        {
            current_id++;
            Get_Index get_Index = new Get_Index(current_id, GetIndex_success, GetIndex_failed);
            get_Index.Run();
            tasks.Add(current_id, (get_Index, result_handler));
        }
        public void GetIndex_success(int id)
        {
            Action<Get_Index_Result> result_handler;
            Get_Index_Result result;
            if (tasks.TryGetValue(id, out (Get_Index, Action<Get_Index_Result>) value))
            {
                Get_Index task = value.Item1;
                result_handler = value.Item2;
                result = new Get_Index_Result(task);
                if (result.Wrong_Result())
                {
                    GetIndex_failed(id, new HttpRequestException("Get_Index Result info error, Check it out!"), result);
                    return;
                }
                results.AddFirst(result);
            }
            else
            {
                GetIndex_failed(id, new KeyNotFoundException($"Get_Index: who called me? I even don't have ID {id}"));
                return;
            }
            tasks.Remove(id);
            result_handler(result);
        }
        public void GetIndex_failed(int id, Exception e, Get_Index_Result? result = null)
        {
            if (e.GetType() == typeof(KeyNotFoundException))
            {
                Initialize.default_logger.LogWarning($"[{DateTime.Now}] ToIndex: {e.Message}");
                return;
            }
            if (result == null)
                result = new Get_Index_Result(e.Message);
            else
                result.Error_info = e.Message;
            tasks[id].Item2(result);
            tasks.Remove(id);
        }
        public Get_Index_Result Newest_Result() => results.First();
    }
    class Login_Task_handler
    {
        int current_id = 0;
        public LinkedList<Login_Result> results = new LinkedList<Login_Result>();
        Dictionary<int, (Login, Action<Login_Result>)> tasks = new Dictionary<int, (Login, Action<Login_Result>)>();
        public void Make_request(Action<Login_Result> result_handler, Get_Index_Result? last_result)
        {
            current_id++;
            last_result ??= Task_handler.index_Task_Handler.Newest_Result();
            if (last_result == null)
                throw new InvalidOperationException("No usable Get_Index_Result for Login");
            Login login = new Login(current_id, last_result, Login_success, Login_failed);
            login.Run();
            tasks.Add(current_id, (login, result_handler));
        }
        public void Login_success(int id)
        {
            Action<Login_Result> result_handler;
            Login_Result result;
            if (tasks.TryGetValue(id, out (Login, Action<Login_Result>) value))
            {
                Login task = value.Item1;
                result_handler = value.Item2;
                result = new Login_Result(task);
                if (result.Wrong_Result())
                {
                    Login_failed(id, new HttpRequestException("Login Result info error, Check it out!"), result);
                    return;
                }
                results.AddFirst(result);
            }
            else
            {
                Login_failed(id, new KeyNotFoundException($"Login: who called me? I even don't have ID {id}"));
                return;
            }
            tasks.Remove(id);
            Initialize.default_logger.LogInformation($"[{DateTime.Now}] login success");
            result_handler(result);
        }
        public void Login_failed(int id, Exception e, Login_Result? result = null)
        {
            if (e.GetType() == typeof(KeyNotFoundException))
            {
                Initialize.default_logger.LogWarning($"[{DateTime.Now}] Login: {e.Message}");
                return;
            }
            if (result == null)
                result = new Login_Result(e.Message);
            else if (result.Error_info.Length == 0)
                result.Error_info = "Login:" + e.Message;
            else
                result.Error_info = "Login:" + e.Message + "error_info:" + result.Error_info;
            Initialize.default_logger.LogWarning($"[{DateTime.Now}] {result.Error_info}");
            tasks[id].Item2(result);
            tasks.Remove(id);
        }
        public List<KeyValuePair<string,string>>? Newest_cookie() => results.First()?.cookie;
        public Login_Result Newest_result() => results.First();
    }
    class ToCourse_Task_Handler
    {
        int current_id = 0;
        public LinkedList<To_Course_Result>results = new LinkedList<To_Course_Result>();
        Dictionary<int, (To_Course, Action<To_Course_Result>)> tasks = new Dictionary<int, (To_Course, Action<To_Course_Result>)>();
        public void Make_request(Action<To_Course_Result> result_handler,Login_Result? last_result) 
        {
            current_id++;
            last_result ??=Task_handler.login_Task_Handler.Newest_result();
            if(last_result == null)
                throw new InvalidOperationException("No usable Login_Result for Login");
            To_Course to_Course = new To_Course(current_id, last_result,To_Course_success,To_Course_failed);
            to_Course.Run();
            tasks.Add(current_id, (to_Course, result_handler));
        }
        public void To_Course_success(int id)
        {
            Action<To_Course_Result> result_handler;
            To_Course_Result result;
            if(tasks.TryGetValue(id,out (To_Course,Action<To_Course_Result>) value))
            {
                To_Course task = value.Item1;
                result_handler = value.Item2;
                result = new To_Course_Result(task);
                if(result.Wrong_Result())
                {
                    To_Course_failed(id, new HttpRequestException("To_Course Result info error, Check it out!"), result);
                    return;
                }
                results.AddLast(result);
            }
            else
            {
                To_Course_failed(id, new KeyNotFoundException($"To_Course: who called me? I even don't have ID {id}"));
                return;
            }
            tasks.Remove(id);
            result_handler(result);
        }

        public void To_Course_failed(int id,Exception e,To_Course_Result? result = null) 
        {
            if (e.GetType() == typeof(KeyNotFoundException))
            {
                Initialize.default_logger.LogWarning($"[{DateTime.Now}] Login: {e.Message}");
                return;
            }
            if(result==null)
                result = new To_Course_Result(e.Message);
            else
                result.Error_info = e.Message;
            tasks[id].Item2(result);
            tasks.Remove(id);

        }

    }
}