using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace ET.Server
{
    [EntitySystemOf(typeof(DBComponent))]
    [FriendOf(typeof(DBComponent))]
    public static partial class DBComponentSystem
    {
        [EntitySystem]
        private static void Awake(this DBComponent self, string dbConnection, string dbName)
        {
            if (string.Equals(dbConnection, "memory", StringComparison.OrdinalIgnoreCase))
            {
                self.Inner = new MemoryDBComponent();
                return;
            }

#if DOTNET || UNITY_EDITOR || UNITY_STANDALONE_WIN || UNITY_STANDALONE_LINUX || UNITY_STANDALONE_OSX
            self.Inner = new MongoDBComponent(dbConnection, dbName);
#else
            self.Inner = new MemoryDBComponent();
#endif
        }

        [EntitySystem]
        private static void Awake(this DBComponent self, IDBComponent component)
        {
            self.Inner = component;
        }

        [EntitySystem]
        private static void Destroy(this DBComponent self)
        {
            self.Inner = null;
        }

        public static ETTask Save<T>(this DBComponent self, long entityId, T entity) where T : class
        {
            if (self.Inner == null)
            {
                throw new Exception("DBComponent not initialized.");
            }
            return SaveInternal(self, entityId, entity);
        }

        public static ETTask<T> QueryByEntityId<T>(this DBComponent self, long entityId) where T : class
        {
            if (self.Inner == null)
            {
                throw new Exception("DBComponent not initialized.");
            }

            return QueryByEntityIdInternal<T>(self, entityId);
        }

        public static ETTask<List<T>> Query<T>(this DBComponent self, Func<T, bool> predicate = null) where T : class
        {
            if (self.Inner == null)
            {
                throw new Exception("DBComponent not initialized.");
            }

            return QueryInternal(self, predicate);
        }

        public static ETTask Update<T>(this DBComponent self, long entityId, T entity) where T : class
        {
            if (self.Inner == null)
            {
                throw new Exception("DBComponent not initialized.");
            }

            return UpdateInternal(self, entityId, entity);
        }

        public static ETTask Delete<T>(this DBComponent self, long entityId) where T : class
        {
            if (self.Inner == null)
            {
                throw new Exception("DBComponent not initialized.");
            }

            return DeleteInternal<T>(self, entityId);
        }

        private static async ETTask SaveInternal<T>(DBComponent self, long entityId, T entity) where T : class
        {
            Stopwatch sw = Stopwatch.StartNew();
            await self.Inner.Save(entityId, entity);
            sw.Stop();
            if (sw.ElapsedMilliseconds > 200)
            {
                LogExtensions.Slow("DB", $"Save<{typeof(T).Name}>", sw.ElapsedMilliseconds, $"id={entityId}");
            }
        }

        private static async ETTask<T> QueryByEntityIdInternal<T>(DBComponent self, long entityId) where T : class
        {
            Stopwatch sw = Stopwatch.StartNew();
            T result = await self.Inner.QueryByEntityId<T>(entityId);
            sw.Stop();
            if (sw.ElapsedMilliseconds > 100)
            {
                LogExtensions.Slow("DB", $"QueryByEntityId<{typeof(T).Name}>", sw.ElapsedMilliseconds, $"id={entityId}");
            }

            return result;
        }

        private static async ETTask<List<T>> QueryInternal<T>(DBComponent self, Func<T, bool> predicate = null) where T : class
        {
            Stopwatch sw = Stopwatch.StartNew();
            List<T> result = await self.Inner.Query(predicate);
            sw.Stop();
            if (sw.ElapsedMilliseconds > 100)
            {
                LogExtensions.Slow("DB", $"Query<{typeof(T).Name}>", sw.ElapsedMilliseconds);
            }

            return result;
        }

        private static async ETTask UpdateInternal<T>(DBComponent self, long entityId, T entity) where T : class
        {
            Stopwatch sw = Stopwatch.StartNew();
            await self.Inner.Update(entityId, entity);
            sw.Stop();
            if (sw.ElapsedMilliseconds > 200)
            {
                LogExtensions.Slow("DB", $"Update<{typeof(T).Name}>", sw.ElapsedMilliseconds, $"id={entityId}");
            }
        }

        private static async ETTask DeleteInternal<T>(DBComponent self, long entityId) where T : class
        {
            Stopwatch sw = Stopwatch.StartNew();
            await self.Inner.Delete<T>(entityId);
            sw.Stop();
            if (sw.ElapsedMilliseconds > 200)
            {
                LogExtensions.Slow("DB", $"Delete<{typeof(T).Name}>", sw.ElapsedMilliseconds, $"id={entityId}");
            }
        }
    }
}