-- Id:  
-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=65645

--+------------------------------------------------------------------+
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--|                                            http://fxcodebase.com |
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--|                                      Developed by : Mario Jemic  |
--|                                          mario.jemic@gmail.com   |
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function Init()
    indicator:name("Swing Time Frame Candle View");
    indicator:description("");
    indicator:requiredSource(core.Tick);
    indicator:type(core.View);

    indicator.parameters:addGroup("Calculation");
    indicator.parameters:addString("Instrument","Instrument","", "EUR/USD");
    indicator.parameters:setFlag("Instrument", core.FLAG_INSTRUMENTS);
    indicator.parameters:addString("timeframe", "Timeframe", "", "m1");
    indicator.parameters:setFlag("timeframe", core.FLAG_BARPERIODS);
    indicator.parameters:addInteger("Step", "Number Of Bars during swing", "", 14);

    indicator.parameters:addBoolean("type", "Price Type","", true);
    indicator.parameters:setFlag("type", core.FLAG_BIDASK);

    indicator.parameters:addGroup("Range");
    indicator.parameters:addDate("from", "From","", -1000);
    indicator.parameters:addDate("to", "To","", 0);
    indicator.parameters:setFlag("to", core.FLAG_DATE_OR_NULL);
end

local Last;
local loading;
local History;
local open, high, low, close, volume;
local offer;
local offset;
local LastTime;
local Instrument;
local Count;
local FIRST;
local Step;
local LastS;
local Old;
local db;

-- initializes the instance of the indicator
function Prepare(onlyName)
    FIRST=true;
    local target_step = instance.parameters.Step;
    Instrument = instance.parameters.Instrument;

    local name = profile:id().. ", " .. Instrument .. " " .. target_step;
    instance:name(name);

    if onlyName then
        return ;
    end
    
    require("storagedb");
    db = storagedb.get_db(Instrument);
    local date1 = db:get("Date1", 0);
    local date2 = db:get("Date2", 0);
    if date1 == date2 then
        Step = target_step;
    else
        Step = math.floor(math.abs(date2 - date1) * 1440 / target_step);
        core.host:trace(Step);
    end

    -- check whether the instrument is available
    local offers = core.host:findTable("offers");
    local enum = offers:enumerator();
    local row = enum:next();
    while row ~= nil do
        if row.Instrument == Instrument then
            break;
        end
        row = enum:next();
    end

    assert(row ~= nil, "Selected instrument is not available");
    offer = row.OfferID;

    instance:initView(Instrument, row.Digits, row.PointSize, true, true);

    History = core.host:execute("getHistory", 1000, Instrument, instance.parameters.timeframe, instance.parameters.from, instance.parameters.to, instance.parameters.type);
    loading = true;
    
    if instance.parameters.to == 0 then 
        core.host:execute("subscribeTradeEvents", 2000, "offers");
    end
    core.host:execute("setStatus", "Loading");

    open = instance:addStream("open", core.Line, name .. "." .. "Open", "open", 0, 0, 0);
    high = instance:addStream("high", core.Line, name .. "." .. "High", "high", 0, 0, 0);
    low = instance:addStream("low", core.Line, name .. "." .. "Low", "low", 0, 0, 0);
    close = instance:addStream("close", core.Line, name .. "." .. "Close", "close", 0, 0, 0);
    volume = instance:addStream("volume", core.Line, name .. "." .. "Volume", "Volume", 0, 0, 0);

    instance:createCandleGroup("candle", "candle", open, high, low, close, volume , TF);
end

function Update(period)
end

function AsyncOperationFinished(cookie, success, message)
    if cookie == 1000 then
        handleHistory(); 
        core.host:execute("setStatus", "");
    elseif cookie == 2000 then
        loading = false;
        handleUpdate();
    end
end

local lastDirection;
function calcValue( Index, period)
    if period < History:first() then
        return;
    end
    if period == 1 then
        instance:addViewBar(History:date(1));
        Index=Index+1;
        Count=1;
        open[Index] = History.open[period];  
        low[Index] = History.low[period]; 
        close[Index] = History.close[period]; 
        high[Index] = History.high[period]; 
    else 
        if Last ~= History:date(period) then
            Count= Count + 1;
        end
        if Count > Step then
            Index=Index+1;
            Count = 1;
            instance:addViewBar(History:date(period));
            
            open[Index] = History.open[period];  
            low[Index] =  History.low[period];   
            close[Index]= History.close[period];  
            high[Index] = History.high[period];  
            volume[Index] = History.volume[period]; 
            Old=  History.volume[period]; 
        else
            close[Index]=History.close[period];     
            low[Index] = math.min(low[Index], History.low[period]); 
            high[Index]  = math.max(high[Index], History.high[period]); 
            if  Last ~= History:date(period) then
                Old = volume[Index]+History.volume[period];
                volume[Index] = Old ;
            else
                volume[Index] = Old + History.volume[period]; 
            end                
        end 
        
        if Last ~= History:date(period) then
            Last = History:date(period);
        end
    end
    return Index; 
end

function handleHistory()
    local s = History:size() - 1;
    local i;
    local current = open:size() - 1;
    for i = 1, s, 1 do
        current = calcValue(current, i);
    end
    loading = false;
    LastTime=History:size()-1;
     
end

function handleUpdate()
    local current = open:size() - 1;    
    local i;
    for i =   LastTime, History:size()-1, 1 do
        current = calcValue( current  ,i);
    end          
    LastTime=History:size()-1;    
end