using Aurora;
using Aurora.Api;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reactive.Linq;
using System.Text;
using System.Threading.Tasks;
using WeldingCommon.Data;
using WeldingCommon.Devices;
using WeldingCommon.Settings;
using WeldingCommon.Utils;
using WeldingCommon.Utils.Diff;

namespace WeldingCommon.Recipes
{
    public class RecipeChangeHistoryHandler
    {
        protected Logger Log = new Logger("RchHandler", "RecipeChangeHistory_Evnet");
        protected IAuroraEnvironment _aurora;
        protected IRecipeEntry _recipeEntry;
        protected SystemParameter _settingParameter;

        protected readonly object _historyLock = new object();

        public ObservableCollection<RecipeHistory> HistoryDatas { get; set; } = new ObservableCollection<RecipeHistory>();

        private string _currentDateKey; // yyyyMMdd

        private string GetDateKey(DateTime t) => t.ToString("yyyyMMdd", CultureInfo.InvariantCulture);

        private string GetDailyFilePath(string dateKey)
        {
            var dir = _settingParameter.RecipeHistoryFolderPath;
            if (!string.IsNullOrEmpty(dir))
                Directory.CreateDirectory(dir);

            return Path.Combine(dir, $"RecipeInfo_{dateKey}.ndjson");
        }

        public void RegistryDeviceHandler(IAuroraEnvironment aurora)
        {
            _aurora = aurora;
            _recipeEntry = aurora.RecipeManager;
            _settingParameter = _aurora.SettingEntry[CommonSettingIds.SystemParameter] as SystemParameter;

            EnsureDailyContext(DateTime.Now);
        }

        public void AppendChangedItem(string recipeName, ObservableCollection<PropertyDiff> diffs)
        {
            lock (_historyLock) {
                var now = DateTime.Now;
                EnsureDailyContext(now);

                var item = new RecipeHistory {
                    Timestamp = now,
                    RecipeName = recipeName,
                    Changes = diffs.Select(d => d.ToString()).ToList()
                };

                HistoryDatas.Add(item);

                AppendNdjsonLine(GetDailyFilePath(_currentDateKey), item);
            }
        }


        private void EnsureDailyContext(DateTime today)
        {
            var key = GetDateKey(today);
            if (_currentDateKey == key)
                return;

            _currentDateKey = key;

            HistoryDatas.Clear();

            var path = GetDailyFilePath(key);
            LoadNdjson(path, HistoryDatas);
        }

        private void AppendNdjsonLine(string path, RecipeHistory item)
        {
            var json = JsonConvert.SerializeObject(item);

            using (var fs = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite)) {
                using (var sw = new StreamWriter(fs, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true))) {
                    sw.WriteLine(json);
                }
            }
        }

        private void LoadNdjson(string path, ObservableCollection<RecipeHistory> target)
        {
            if (!File.Exists(path))
                return;

            using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)) {
                using (var sr = new StreamReader(fs, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true))) {
                    string line;
                    while ((line = sr.ReadLine()) != null) {
                        if (string.IsNullOrWhiteSpace(line))
                            continue;

                        try {
                            var item = JsonConvert.DeserializeObject<RecipeHistory>(line);
                            if (item != null)
                                target.Add(item);
                        } catch {
                        }
                    }
                }
            }
        }

        public ObservableCollection<RecipeHistory> FromStartToEndHistory(DateTime start, DateTime end)
        {
            if (end < start) {
                var tmp = start;
                start = end;
                end = tmp;
            }

            var result = new List<RecipeHistory>();
            var day = start.Date;
            var lastDay = end.Date;

            lock (_historyLock) {
                while (day <= lastDay) {
                    var key = GetDateKey(day);
                    var path = GetDailyFilePath(key);

                    if (File.Exists(path)) {
                        using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
                        using (var sr = new StreamReader(fs, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true))) {
                            string line;
                            while ((line = sr.ReadLine()) != null) {
                                if (string.IsNullOrWhiteSpace(line))
                                    continue;

                                try {
                                    var item = JsonConvert.DeserializeObject<RecipeHistory>(line);
                                    if (item == null)
                                        continue;

                                    //if (item.Timestamp >= start && item.Timestamp <= end)
                                        result.Add(item);
                                } catch {
                                }
                            }
                        }
                    }

                    day = day.AddDays(1);
                }

                var ordered = result.OrderByDescending(x => x.Timestamp);

                return new ObservableCollection<RecipeHistory>(ordered);
            }
        }
    }
}