using System;
using System.Collections.Generic;
using Microsoft.Extensions.Options;
using MySql.Data.MySqlClient;
using Dapper;
using System.Threading.Tasks;
using System.Threading;

namespace JetHerald
{
    public class Db
    {
        public class Topic
        {
            public uint TopicId { get; set; }
            public NamespacedId Creator { get; set; }
            public string Name { get; set; }
            public string Description { get; set; }
            public string ReadToken { get; set; }
            public string WriteToken { get; set; }
            public string AdminToken { get; set; }
            public DateTime? ExpiryTime { get; set; }
            public bool ExpiryMessageSent { get; set; }

            public NamespacedId? Chat { get; set; }

            public override string ToString()
                => Name == Description ? Name : $"{Name}: {Description}";
        }

        public class HeartAttack
        {
            public ulong HeartattackId { get; set; }
            public uint TopicId { get; set; }
            public string Heart { get; set; }
            public DateTime ExpiryTime { get; set; }

            public string Description { get; set; }
        }

        public async Task<int> DeleteTopic(string name, string adminToken)
        {
            using var c = GetConnection();
            return await c.ExecuteAsync(
                " DELETE" +
                " FROM topic" +
                " WHERE Name = @name AND AdminToken = @adminToken",
                new { name, adminToken });
        }

        public async Task<Topic> GetTopic(string name)
        {
            using var c = GetConnection();
            return await c.QuerySingleOrDefaultAsync<Topic>(
                "SELECT *" +
                " FROM topic" +
                " WHERE Name = @name",
                new { name });
        }

        public async Task<Topic> GetTopicForSub(string token, NamespacedId chat)
        {
            using var c = GetConnection();
            return await c.QuerySingleOrDefaultAsync<Topic>(
                " SELECT t.*, tc.Chat " +
                " FROM topic t " +
                " LEFT JOIN topic_chat tc ON t.TopicId = tc.TopicId AND tc.Chat = @chat " +
                " WHERE ReadToken = @token",
                new { token, chat });
        }

        public async Task<Topic> CreateTopic(NamespacedId user, string name, string descr)
        {
            var t = new Topic
            {
                Creator = user,
                Name = name,
                Description = descr,
                ReadToken = TokenHelper.GetToken(),
                WriteToken = TokenHelper.GetToken(),
                AdminToken = TokenHelper.GetToken()
            };
            using var c = GetConnection();
            return await c.QuerySingleOrDefaultAsync<Topic>(
                " INSERT INTO herald.topic " +
                " ( Creator,  Name,  Description,  ReadToken,  WriteToken,  AdminToken) " +
                " VALUES " +
                " (@Creator, @Name, @Description, @ReadToken, @WriteToken, @AdminToken); " +
                " SELECT * FROM topic WHERE TopicId = LAST_INSERT_ID(); ",
                t);
        }
        public async Task<IEnumerable<NamespacedId>> GetChatsForTopic(uint topicid)
        {
            using var c = GetConnection();
            return await c.QueryAsync<NamespacedId>(
                " SELECT Chat " +
                " FROM topic_chat " +
                " WHERE TopicId = @topicid",
                new { topicid });
        }

        public async Task<IEnumerable<Topic>> GetTopicsForChat(NamespacedId chat)
        {
            using var c = GetConnection();
            return await c.QueryAsync<Topic>(
                " SELECT t.*" +
                " FROM topic_chat ct" +
                " JOIN topic t on t.TopicId = ct.TopicId" +
                " WHERE ct.Chat = @chat",
                new { chat });
        }

        public async Task CreateSubscription(uint topicId, NamespacedId chat)
        {
            using var c = GetConnection();
            await c.ExecuteAsync(
                " INSERT INTO topic_chat" +
                " (Chat, TopicId)" +
                " VALUES" +
                " (@chat, @topicId)",
                new { topicId, chat });
        }

        public async Task<int> RemoveSubscription(string topicName, NamespacedId chat)
        {
            using var c = GetConnection();
            return await c.ExecuteAsync(
                " DELETE tc " +
                " FROM topic_chat tc" +
                " JOIN topic t ON tc.TopicId = t.TopicId " +
                " WHERE t.Name = @topicName AND tc.Chat = @chat;",
                new { topicName, chat });
        }


        public async Task<int> ReportHeartbeat(uint topicId, string heart, int timeoutSeconds)
        {
            using var c = GetConnection();
            return await c.ExecuteAsync(
                @"
                    INSERT INTO heartbeat
	                    (TopicId, Heart, ExpiryTime)
	                    VALUES
	                    (@topicId, @heart, CURRENT_TIMESTAMP() + INTERVAL @timeoutSeconds SECOND)
                        ON DUPLICATE KEY UPDATE
                        ExpiryTime = CURRENT_TIMESTAMP() + INTERVAL @timeoutSeconds SECOND;
                ",
                new { topicId, heart, @timeoutSeconds });
        }

        public async Task<IEnumerable<HeartAttack>> ProcessHeartAttacks()
        {
            using var c = GetConnection();
            return await c.QueryAsync<HeartAttack>("CALL process_heartattacks();");
        }

        public async Task MarkHeartAttackReported(ulong id, byte status = 1)
        {
            using var c = GetConnection();
            await c.ExecuteAsync("UPDATE heartattack SET Status = @status WHERE HeartattackId = @id", new { id, status });
        }




        public Db(IOptions<Options.ConnectionStrings> cfg)
        {
            Config = cfg.Value;
        }

        Options.ConnectionStrings Config { get; }
        MySqlConnection GetConnection() => new(Config.DefaultConnection);
    }
}