#region Using declarations
using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Globalization;
using System.Windows.Media;
using NinjaTrader.Data;
using NinjaTrader.Gui.Tools;
using NinjaTrader.NinjaScript;
using NinjaTrader.NinjaScript.DrawingTools;
#endregion

// Jason Opening Range 是只显示市场结构的图表指标。
// 它不生成交易信号，也不执行任何交易操作。
namespace NinjaTrader.NinjaScript.Indicators
{
    public class JasonOpeningRange : Indicator
    {
        private SessionIterator sessionIterator;
        private DateTime sessionBegin;
        private DateTime sessionEnd;
        private DateTime rangeBegin;
        private DateTime rangeEnd;
        private string sessionTag;
        private int rangeStartBar;
        private double rangeHigh;
        private double rangeLow;
        private bool hasRangeData;
        private bool sessionInitialized;
        private bool rangeWindowAvailable;
        private bool hasReportedSessionError;

        protected override void OnStateChange()
        {
            if (State == State.SetDefaults)
            {
                Description = "显示每个 Trading Hours Session 的 Opening Range High、Low 和 Mid。";
                Name = "JasonOpeningRange";
                Calculate = Calculate.OnBarClose;
                IsOverlay = true;
                DisplayInDataBox = false;
                PaintPriceMarkers = false;

                StartTime = 93000;
                EndTime = 100000;
                ShowHigh = true;
                ShowLow = true;
                ShowMid = true;
                ShowLabels = true;
                LineWidth = 2;
                LineStyle = DashStyleHelper.Solid;
            }
            else if (State == State.DataLoaded)
            {
                // SessionIterator 只在 Bars 数据可用后创建。
                try
                {
                    sessionIterator = new SessionIterator(Bars);
                }
                catch (Exception exception)
                {
                    sessionIterator = null;
                    Print(Name + ": 无法初始化 SessionIterator: " + exception.Message);
                }
            }
        }

        protected override void OnBarUpdate()
        {
            try
            {
                DateTime barTime = Time[0];

                // NinjaTrader 会在每个 Trading Hours Session 的首根 Bar 标记此属性。
                // 对首次加载的历史 Bar 也会重置，因此历史图表可从数据序列起点计算。
                if (Bars.IsFirstBarOfSession || !sessionInitialized)
                    ResetSession(barTime);

                if (!rangeWindowAvailable)
                    return;

                // 时间范围使用图表 Bar 的时间戳，左闭右开。
                // 例如 09:30–10:00 会纳入时间戳从 09:30 到 09:59:59 的 Bar。
                if (barTime >= rangeBegin && barTime < rangeEnd)
                {
                    if (!hasRangeData)
                    {
                        rangeHigh = High[0];
                        rangeLow = Low[0];
                        rangeStartBar = CurrentBar;
                        hasRangeData = true;
                    }
                    else
                    {
                        rangeHigh = Math.Max(rangeHigh, High[0]);
                        rangeLow = Math.Min(rangeLow, Low[0]);
                    }
                }

                // 等到窗口结束才绘制完整区间；同一 Session 复用相同 Tag，
                // 每根新 Bar 只更新已有对象，不创建重复绘图对象。
                if (!hasRangeData || barTime < rangeEnd)
                    return;

                double rangeMid = (rangeHigh + rangeLow) / 2.0;
                DrawLevel("High", "ORH", rangeHigh, Brushes.SteelBlue, ShowHigh);
                DrawLevel("Low", "ORL", rangeLow, Brushes.IndianRed, ShowLow);
                DrawLevel("Mid", "ORM", rangeMid, Brushes.DarkGray, ShowMid);
            }
            catch (Exception exception)
            {
                ReportSessionError("Opening Range 计算或绘图失败", exception);
            }
        }

        /// <summary>
        /// 清空上一 Session 的状态，并从 Trading Hours 模板解析本 Session 的
        /// 实际起止时间以及其中第一个完整的每日 Opening Range 时间窗口。
        /// </summary>
        private void ResetSession(DateTime barTime)
        {
            sessionInitialized = true;
            rangeWindowAvailable = false;
            hasRangeData = false;
            rangeStartBar = -1;
            rangeHigh = double.MinValue;
            rangeLow = double.MaxValue;
            hasReportedSessionError = false;
            sessionBegin = DateTime.MinValue;
            sessionEnd = DateTime.MinValue;
            rangeBegin = DateTime.MinValue;
            rangeEnd = DateTime.MinValue;
            sessionTag = barTime.ToString("yyyyMMdd_HHmmss", CultureInfo.InvariantCulture);

            try
            {
                if (sessionIterator == null)
                {
                    ReportSessionError("SessionIterator 不可用，当前 Session 已跳过", null);
                    return;
                }

                if (!TryConvertTime(StartTime, out TimeSpan startOffset)
                    || !TryConvertTime(EndTime, out TimeSpan endOffset)
                    || startOffset == endOffset)
                {
                    ReportSessionError("开始和结束时间必须是不同的有效 HHmmss 时间", null);
                    return;
                }

                if (!sessionIterator.GetNextSession(barTime, true))
                {
                    ReportSessionError("无法读取当前 Trading Hours Session", null);
                    return;
                }

                sessionBegin = sessionIterator.ActualSessionBegin;
                sessionEnd = sessionIterator.ActualSessionEnd;

                if (sessionEnd <= sessionBegin)
                {
                    ReportSessionError("Trading Hours Session 的起止时间无效", null);
                    return;
                }

                // Trading Hours 可以跨越午夜。逐日查找本 Session 内完整的时间窗口，
                // 因此晚间开始的 Session 也可以在次日早晨形成 Opening Range。
                for (DateTime candidateDate = sessionBegin.Date.AddDays(-1);
                    candidateDate <= sessionEnd.Date;
                    candidateDate = candidateDate.AddDays(1))
                {
                    DateTime candidateBegin = candidateDate.Date + startOffset;
                    DateTime candidateEnd = candidateDate.Date + endOffset;

                    // 结束时间小于开始时间时，窗口跨午夜；相等输入已在上方拒绝。
                    if (endOffset < startOffset)
                        candidateEnd = candidateEnd.AddDays(1);

                    bool isInsideSession =
                        candidateBegin >= sessionBegin
                        && candidateBegin < sessionEnd
                        && candidateEnd <= sessionEnd;

                    if (!isInsideSession)
                        continue;

                    rangeBegin = candidateBegin;
                    rangeEnd = candidateEnd;
                    sessionTag = sessionBegin.ToString(
                        "yyyyMMdd_HHmmss",
                        CultureInfo.InvariantCulture);
                    rangeWindowAvailable = true;
                    return;
                }

                // 若 Trading Hours 模板不覆盖所设窗口，保持安静且不绘图。
                rangeWindowAvailable = false;
            }
            catch (Exception exception)
            {
                ReportSessionError("读取 Session 时间失败，当前 Session 已跳过", exception);
            }
        }

        /// <summary>
        /// 将 NinjaTrader 常用 HHmmss 整数解析为一天内的时间。
        /// </summary>
        private bool TryConvertTime(int timeValue, out TimeSpan timeOffset)
        {
            timeOffset = TimeSpan.Zero;

            if (timeValue < 0 || timeValue > 235959)
                return false;

            int hours = timeValue / 10000;
            int minutes = (timeValue / 100) % 100;
            int seconds = timeValue % 100;

            if (hours > 23 || minutes > 59 || seconds > 59)
                return false;

            timeOffset = new TimeSpan(hours, minutes, seconds);
            return true;
        }

        /// <summary>
        /// 绘制或更新一条价格线及可选标签。Tag 按 Session 和水平名称固定。
        /// </summary>
        private void DrawLevel(
            string levelName,
            string label,
            double price,
            Brush brush,
            bool isVisible)
        {
            string lineTag = "JasonOpeningRange." + sessionTag + "." + levelName;
            string labelTag = lineTag + ".Label";

            if (!isVisible)
            {
                RemoveDrawObject(lineTag);
                RemoveDrawObject(labelTag);
                return;
            }

            int startBarsAgo = CurrentBar - rangeStartBar;

            Draw.Line(
                this,
                lineTag,
                false,
                startBarsAgo,
                price,
                0,
                price,
                brush,
                LineStyle,
                LineWidth);

            if (ShowLabels)
                Draw.Text(this, labelTag, label, 0, price, brush);
            else
                RemoveDrawObject(labelTag);
        }

        /// <summary>
        /// 限制每个 Session 的错误输出次数，避免异常情况下重复刷屏。
        /// </summary>
        private void ReportSessionError(string message, Exception exception)
        {
            if (hasReportedSessionError)
                return;

            hasReportedSessionError = true;

            string detail = exception == null ? string.Empty : ": " + exception.Message;
            Print(Name + ": " + message + detail);
        }

        #region User parameters

        [NinjaScriptProperty]
        [Range(0, 235959)]
        [Display(Name = "Start Time (HHmmss)", Description = "图表时间戳中的 Opening Range 开始时间。", Order = 1, GroupName = "Opening Range")]
        public int StartTime { get; set; }

        [NinjaScriptProperty]
        [Range(0, 235959)]
        [Display(Name = "End Time (HHmmss)", Description = "图表时间戳中的 Opening Range 结束时间，不包含结束时间戳。", Order = 2, GroupName = "Opening Range")]
        public int EndTime { get; set; }

        [NinjaScriptProperty]
        [Display(Name = "Show High", Order = 1, GroupName = "Display")]
        public bool ShowHigh { get; set; }

        [NinjaScriptProperty]
        [Display(Name = "Show Low", Order = 2, GroupName = "Display")]
        public bool ShowLow { get; set; }

        [NinjaScriptProperty]
        [Display(Name = "Show Mid", Order = 3, GroupName = "Display")]
        public bool ShowMid { get; set; }

        [NinjaScriptProperty]
        [Display(Name = "Show Labels", Order = 4, GroupName = "Display")]
        public bool ShowLabels { get; set; }

        [NinjaScriptProperty]
        [Range(1, 5)]
        [Display(Name = "Line Width", Order = 5, GroupName = "Display")]
        public int LineWidth { get; set; }

        [NinjaScriptProperty]
        [Display(Name = "Line Style", Order = 6, GroupName = "Display")]
        public DashStyleHelper LineStyle { get; set; }

        #endregion
    }
}