//+------------------------------------------------------------------+
//|                                 ForexSessionDetector.mq5          |
//|                        Copyright 2023, MetaQuotes Software Corp.  |
//|                                             https://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright 2023, MetaQuotes Software Corp."
#property link "https://www.metaquotes.net/"
#property version "1.00"
#property indicator_chart_window
#property indicator_buffers 0
#property indicator_plots 0

//+------------------------------------------------------------------+
//| Session Times                                                    |
//+------------------------------------------------------------------+
input color SydneyColor = clrRoyalBlue;   // Sydney session color
input color TokyoColor = clrGreen;        // Tokyo session color
input color LondonColor = clrRed;         // London session color
input color NewYorkColor = clrDodgerBlue; // New York session color
input int TextSize = 8;                   // Font size
input bool ShowHighLow = true;            // Show High/Low prices
input bool ShowSessionTimes = true;       // Show Session Times

//+------------------------------------------------------------------+
//| Global Variables                                                 |
//+------------------------------------------------------------------+
struct SessionInfo
{
    string name;
    int startHour;
    int startMinute;
    int endHour;
    int endMinute;
    color clr;
    datetime sessionStart;
    datetime sessionEnd;
    double high;
    double low;
    bool active;
};

SessionInfo sessions[4];
string fontFace = "Arial";

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
{
    // Initialize session information
    sessions[0].name = "Sydney";
    sessions[0].startHour = 22;
    sessions[0].startMinute = 0;
    sessions[0].endHour = 6;
    sessions[0].endMinute = 0;
    sessions[0].clr = SydneyColor;

    sessions[1].name = "Tokyo";
    sessions[1].startHour = 0;
    sessions[1].startMinute = 0;
    sessions[1].endHour = 9;
    sessions[1].endMinute = 0;
    sessions[1].clr = TokyoColor;

    sessions[2].name = "London";
    sessions[2].startHour = 8;
    sessions[2].startMinute = 0;
    sessions[2].endHour = 17;
    sessions[2].endMinute = 0;
    sessions[2].clr = LondonColor;

    sessions[3].name = "New York";
    sessions[3].startHour = 13;
    sessions[3].startMinute = 0;
    sessions[3].endHour = 22;
    sessions[3].endMinute = 0;
    sessions[3].clr = NewYorkColor;

    return (INIT_SUCCEEDED);
}

//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
{
    // Clear previous objects
    ObjectsDeleteAll(0, "Session_");

    // Process each session
    for (int i = 0; i < 4; i++)
    {
        ProcessSession(i, time, high, low, rates_total);
    }

    return (rates_total);
}

//+------------------------------------------------------------------+
//| Process a single session                                         |
//+------------------------------------------------------------------+
void ProcessSession(int sessionIndex, const datetime &time[], const double &high[], const double &low[], int rates_total)
{
    SessionInfo session = sessions[sessionIndex];

    // Find current session start and end times
    datetime currentTime = TimeCurrent();
    MqlDateTime currentTimeStruct;
    TimeToStruct(currentTime, currentTimeStruct);

    datetime sessionStart, sessionEnd;

    // Handle sessions that span midnight
    if (session.startHour > session.endHour)
    {
        // Session spans midnight (e.g., Sydney 22:00-6:00)
        if (currentTimeStruct.hour >= session.startHour || currentTimeStruct.hour < session.endHour)
        {
            sessionStart = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.startHour, session.startMinute, 0);
            if (currentTimeStruct.hour < session.startHour)
                sessionStart -= 86400; // Previous day
            sessionEnd = sessionStart + (session.endHour - session.startHour) * 3600 + (session.endMinute - session.startMinute) * 60;
            if (sessionEnd <= sessionStart)
                sessionEnd += 86400;
            session.active = true;
        }
        else
        {
            sessionStart = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.startHour, session.startMinute, 0);
            sessionEnd = sessionStart + (session.endHour - session.startHour) * 3600 + (session.endMinute - session.startMinute) * 60;
            if (sessionEnd <= sessionStart)
                sessionEnd += 86400;
            session.active = false;
        }
    }
    else
    {
        // Normal session (doesn't span midnight)
        if (currentTimeStruct.hour >= session.startHour && currentTimeStruct.hour < session.endHour)
        {
            sessionStart = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.startHour, session.startMinute, 0);
            sessionEnd = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.endHour, session.endMinute, 0);
            session.active = true;
        }
        else
        {
            sessionStart = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.startHour, session.startMinute, 0);
            sessionEnd = StructToTime(currentTimeStruct.year, currentTimeStruct.mon, currentTimeStruct.day, session.endHour, session.endMinute, 0);
            session.active = false;
        }
    }

    session.sessionStart = sessionStart;
    session.sessionEnd = sessionEnd;

    // Find high/low for the session
    int startIndex = iBarShift(NULL, 0, sessionStart);
    int endIndex = iBarShift(NULL, 0, sessionEnd);

    if (startIndex == -1 || endIndex == -1)
        return;

    session.high = high[ArrayMaximum(high, endIndex, startIndex - endIndex + 1)];
    session.low = low[ArrayMinimum(low, endIndex, startIndex - endIndex + 1)];

    // Draw session information on chart
    DrawSessionInfo(session, startIndex, endIndex, sessionIndex);
}

//+------------------------------------------------------------------+
//| Get chart window price max                                       |
//+------------------------------------------------------------------+
double GetWindowPriceMax()
{
    double maxPrice;
    ChartGetDouble(0, CHART_PRICE_MAX, 0, maxPrice);
    return maxPrice;
}

//+------------------------------------------------------------------+
//| Get chart window price min                                       |
//+------------------------------------------------------------------+
double GetWindowPriceMin()
{
    double minPrice;
    ChartGetDouble(0, CHART_PRICE_MIN, 0, minPrice);
    return minPrice;
}

//+------------------------------------------------------------------+
//| Draw session information on chart                                |
//+------------------------------------------------------------------+
void DrawSessionInfo(SessionInfo &session, int startIndex, int endIndex, int sessionIndex)
{
    string objName;
    color textColor = session.clr;
    double priceMax = GetWindowPriceMax();
    double priceMin = GetWindowPriceMin();

    // Draw vertical lines for session start/end
    objName = "Session_" + session.name + "_Start";
    ObjectCreate(0, objName, OBJ_VLINE, 0, session.sessionStart, 0);
    ObjectSetInteger(0, objName, OBJPROP_COLOR, session.clr);
    ObjectSetInteger(0, objName, OBJPROP_STYLE, STYLE_DOT);
    ObjectSetInteger(0, objName, OBJPROP_WIDTH, 1);
    ObjectSetInteger(0, objName, OBJPROP_BACK, true);

    objName = "Session_" + session.name + "_End";
    ObjectCreate(0, objName, OBJ_VLINE, 0, session.sessionEnd, 0);
    ObjectSetInteger(0, objName, OBJPROP_COLOR, session.clr);
    ObjectSetInteger(0, objName, OBJPROP_STYLE, STYLE_DOT);
    ObjectSetInteger(0, objName, OBJPROP_WIDTH, 1);
    ObjectSetInteger(0, objName, OBJPROP_BACK, true);

    // Draw session name label
    if (ShowSessionTimes)
    {
        objName = "Session_" + session.name + "_Label";
        ObjectCreate(0, objName, OBJ_TEXT, 0, session.sessionStart, priceMax - (priceMax - priceMin) * 0.1 * (sessionIndex + 1));
        ObjectSetString(0, objName, OBJPROP_TEXT, session.name + " " + TimeToString(session.sessionStart, TIME_MINUTES) + " - " + TimeToString(session.sessionEnd, TIME_MINUTES));
        ObjectSetInteger(0, objName, OBJPROP_COLOR, textColor);
        ObjectSetInteger(0, objName, OBJPROP_FONTSIZE, TextSize);
        ObjectSetString(0, objName, OBJPROP_FONT, fontFace);
        ObjectSetInteger(0, objName, OBJPROP_ANCHOR, ANCHOR_LEFT_UPPER);
        ObjectSetInteger(0, objName, OBJPROP_BACK, false);
    }

    // Draw high/low prices if enabled
    if (ShowHighLow)
    {
        objName = "Session_" + session.name + "_High";
        ObjectCreate(0, objName, OBJ_TEXT, 0, session.sessionStart + (session.sessionEnd - session.sessionStart) / 2, session.high);
        ObjectSetString(0, objName, OBJPROP_TEXT, "H: " + DoubleToString(session.high, _Digits));
        ObjectSetInteger(0, objName, OBJPROP_COLOR, textColor);
        ObjectSetInteger(0, objName, OBJPROP_FONTSIZE, TextSize);
        ObjectSetString(0, objName, OBJPROP_FONT, fontFace);
        ObjectSetInteger(0, objName, OBJPROP_ANCHOR, ANCHOR_LOWER);
        ObjectSetInteger(0, objName, OBJPROP_BACK, false);

        objName = "Session_" + session.name + "_Low";
        ObjectCreate(0, objName, OBJ_TEXT, 0, session.sessionStart + (session.sessionEnd - session.sessionStart) / 2, session.low);
        ObjectSetString(0, objName, OBJPROP_TEXT, "L: " + DoubleToString(session.low, _Digits));
        ObjectSetInteger(0, objName, OBJPROP_COLOR, textColor);
        ObjectSetInteger(0, objName, OBJPROP_FONTSIZE, TextSize);
        ObjectSetString(0, objName, OBJPROP_FONT, fontFace);
        ObjectSetInteger(0, objName, OBJPROP_ANCHOR, ANCHOR_UPPER);
        ObjectSetInteger(0, objName, OBJPROP_BACK, false);
    }

    // Highlight active session
    if (session.active)
    {
        objName = "Session_" + session.name + "_Background";
        ObjectCreate(0, objName, OBJ_RECTANGLE, 0, session.sessionStart, priceMax, session.sessionEnd, priceMin);
        ObjectSetInteger(0, objName, OBJPROP_COLOR, session.clr);
        ObjectSetInteger(0, objName, OBJPROP_BGCOLOR, session.clr);
        ObjectSetInteger(0, objName, OBJPROP_BACK, true);
        ObjectSetInteger(0, objName, OBJPROP_FILL, true);
        ObjectSetInteger(0, objName, OBJPROP_WIDTH, 1);
    }
}

//+------------------------------------------------------------------+
//| Create datetime from components                                  |
//+------------------------------------------------------------------+
datetime StructToTime(int year, int month, int day, int hour, int minute, int second)
{
    MqlDateTime mdt;
    mdt.year = year;
    mdt.mon = month;
    mdt.day = day;
    mdt.hour = hour;
    mdt.min = minute;
    mdt.sec = second;
    return StructToTime(mdt);
}
//+------------------------------------------------------------------+