-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=607

-- +------------------------------------------------------------------------------------------------+
-- |                                                              Copyright 2025, Gehtsoft USA LLC  | 
-- |                                                                         http://fxcodebase.com  |
-- |                                                               Paypal:  https://goo.gl/9Rj74e   |
-- +------------------------------------------------------------------------------------------------+
-- |                                                                   Developed by : Mario Jemic   |                    
-- |                                                                       mario.jemic@gmail.com    |
-- |                                                                       https://mario-jemic.com/ | 
-- |                                                             Patreon :  http://tiny.cc/1ybwxz   |   
-- |                                                      Buy Me a Coffee:  http://tiny.cc/bj7vxz   |  
-- +-----------------+----------------------+-------------------------------------------------------+
-- |  Cryptocurrency |  Network             |  Address                                              |
-- +-----------------+----------------------+-------------------------------------------------------+
-- |  BTC            |  BTC                 |  16F5k43RXibTmna4np8bPVgmXM1CzjXFJJ                   | 
-- |  SOL            |  SOL                 |  3nh5rpUKopcYLNU4zGCdUFAkM3iRQq8VVUmuzVG6VDf2         | 
-- |  ETH            |  ERC20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           |
-- |  BNB            |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- |  USDT           |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- |  XRP            |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- +-----------------+----------------------+-------------------------------------------------------+ 

function Init()
    indicator:name("High/Low Bands (Advanced)")
    indicator:description("")
    indicator:requiredSource(core.Bar)
    indicator:type(core.Indicator)

    indicator.parameters:addGroup("Calculation")
    indicator.parameters:addString("BS", "Bar Size to display High/Low", "", "D1")
    indicator.parameters:addBoolean(
        "YTD",
        "Show yesterday band",
        "Choose yes to show yesterday band and no to show today band",
        false
    )
    indicator.parameters:setFlag("BS", core.FLAG_PERIODS)
    indicator.parameters:addGroup("Display")
    indicator.parameters:addColor("clrB", "High/Low Band Color", "", core.rgb(192, 192, 192))
    indicator.parameters:addBoolean("ML", "Show middle line", "Show middle line", false)
    indicator.parameters:addBoolean("OL", "Show open line", "Show middle line", true)
    indicator.parameters:addColor("clrO", "Open line Color", "", core.rgb(255, 255, 0))
    indicator.parameters:addInteger("widthLinReg", "H/L dot size", "H/L line width", 1, 1, 5)
    indicator.parameters:addInteger("A", "High/Low Band transparency (%)", "", 90, 0, 100)
    indicator.parameters:addBoolean("show_lines", "Show as lines", "", false)
end

local source  -- the source
local hilo_data = nil -- the high/low data
local H  -- high stream
local L  -- low stream
local M = nil -- middle stream
local BS
local BSLen
local dates  -- candle dates
local host
local offset
local weekoffset
local candles  -- stream of the candle's dates
local YTD
local ML
local OL
local O = nil

function Prepare()
    source = instance.source
    host = core.host
    host = core.host
    offset = host:execute("getTradingDayOffset")
    weekoffset = host:execute("getTradingWeekOffset")
    BS = instance.parameters.BS
    ML = instance.parameters.ML
    OL = instance.parameters.OL
    YTD = instance.parameters.YTD
    local YTDn

    if YTD then
        YTDn = "prev"
    else
        YTDn = "curr"
    end

    local l1, l2
    local s, e

    s, e = core.getcandle(source:barSize(), core.now(), 0)
    l1 = e - s
    s, e = core.getcandle(BS, core.now(), 0)
    l2 = e - s
    BSLen = l2 -- remember length of the period
    assert(l1 <= l2, "The chosen time frame must be the same of longer than the chart time frame")

    local name = profile:id() .. "(" .. source:name() .. "," .. BS .. "," .. YTDn .. ")"
    show_lines = instance.parameters.show_lines;
    instance:name(name)
    H = instance:addStream("H", show_lines and core.Line or core.Dot, name .. ".H", "H", instance.parameters.clrB, 0)
    L = instance:addStream("L", show_lines and core.Line or core.Dot, name .. ".L", "L", instance.parameters.clrB, 0)
    H:setWidth(instance.parameters.widthLinReg)
    L:setWidth(instance.parameters.widthLinReg)
    if ML then
        M = instance:addStream("M", show_lines and core.Line or core.Dot, name .. ".M", "M", instance.parameters.clrB, 0)
        M:setWidth(instance.parameters.widthLinReg)
    end
    if OL then
        O = instance:addStream("O", show_lines and core.Line or core.Dot, name .. ".O", "O", instance.parameters.clrO, 0)
        O:setWidth(instance.parameters.widthLinReg)
    end
    instance:createChannelGroup("HL", "HL", H, L, instance.parameters.clrB, 100 - instance.parameters.A)
    candles = instance:addInternalStream(0, 0)
end

local loading = false
local loadingFrom, loadingTo
local pday = nil

-- the function which is called to calculate the period
function Update(period, mode)
    -- get date and time of the hi/lo candle in the reference data
    local hilo_candle
    hilo_candle = core.getcandle(BS, source:date(period), offset, weekoffset)

    -- if data for the specific candle are still loading
    -- then do nothing
    if loading and hilo_candle >= loadingFrom and (loadingTo == 0 or hilo_candle <= loadingTo) then
        return
    end

    if not (source:isAlive() and period == source:size() - 1) then
        -- replicate the previous date in case it is the same upscale candle
        if (period > source:first() and candles:hasData(period - 1) and candles[period - 1] == hilo_candle) then
            H[period] = H[period - 1]
            L[period] = L[period - 1]
            if ML then
                M[period] = M[period - 1]
            end
            if OL then
                O[period] = O[period - 1]
            end
            candles[period] = hilo_candle
        end
    end

    -- if the period is before the source start
    -- the do nothing
    if period < source:first() then
        return
    end

    -- if data is not loaded yet at all
    -- load the data
    if hilo_data == nil then
        -- there is no data at all, load initial data
        local to, t
        local from
        if (source:isAlive()) then
            -- if the source is subscribed for updates
            -- then subscribe the current collection as well
            to = 0
        else
            -- else load up to the last currently available date
            t, to = core.getcandle(BS, source:date(period), offset, weekoffset)
        end

        from = core.getcandle(BS, source:date(source:first()), offset, weekoffset) - BSLen * 5
        loading = true
        H:setBookmark(1, period)
        loadingFrom = from
        loadingTo = to
        hilo_data = host:execute("getHistory", 1, source:instrument(), BS, from, to, source:isBid())
        return
    end

    -- check whether the requested candle is before
    -- the reference collection start
    if (hilo_candle < hilo_data:date(0)) then
        H:setBookmark(1, period)
        if loading then
            return
        end
        loading = true
        loadingFrom = hilo_candle - BSLen * 5
        loadingTo = hilo_data:date(0)
        host:execute("extendHistory", 1, hilo_data, loadingFrom, loadingTo)
        return
    end

    -- check whether the requested candle is after
    -- the reference collection end
    if (not (source:isAlive()) and hilo_candle > hilo_data:date(hilo_data:size() - 1)) then
        H:setBookmark(1, period)
        if loading then
            return
        end
        loading = true
        loadingFrom = hilo_data:date(hilo_data:size() - 1)
        loadingTo = hilo_candle
        host:execute("extendHistory", 1, hilo_data, loadingFrom, loadingTo)
        return
    end

    local hilo_i = core.findDate(hilo_data, hilo_candle, false)

    -- candle is not found
    if (hilo_i == nil) then
        return
    end

    if YTD then
        if hilo_i == 0 then
            return
        end
        hilo_i = hilo_i - 1
    end

    H[period] = hilo_data.high[hilo_i]
    L[period] = hilo_data.low[hilo_i]
    if ML then
        M[period] = (H[period] + L[period]) / 2
    end
    if OL then
        O[period] = hilo_data.open[hilo_i]
    end
    candles[period] = hilo_candle

    if source:isAlive() and period > source:first() and period == source:size() - 1 then
        -- update all today's data in case today's high low is changed
        if
            candles:hasData(period - 1) and candles[period - 1] == hilo_candle and
                ((H[period - 1] ~= H[period]) or (L[period - 1] ~= L[period]))
         then
            local i = period - 1
            while i > 0 and candles:hasData(i) and candles[i] == hilo_candle do
                H[i] = hilo_data.high[hilo_i]
                L[i] = hilo_data.low[hilo_i]
                if ML then
                    M[i] = (H[i] + L[i]) / 2
                end
                if OL then
                    O[period] = hilo_data.open[hilo_i]
                end
                i = i - 1
            end
        end
    end
end

-- the function is called when the async operation is finished
function AsyncOperationFinished(cookie)
    local period

    pday = nil
    period = H:getBookmark(1)

    if (period < 0) then
        period = 0
    end
    loading = false
    instance:updateFrom(period)
end
-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=607

-- +------------------------------------------------------------------------------------------------+
-- |                                                              Copyright 2025, Gehtsoft USA LLC  | 
-- |                                                                         http://fxcodebase.com  |
-- |                                                               Paypal:  https://goo.gl/9Rj74e   |
-- +------------------------------------------------------------------------------------------------+
-- |                                                                   Developed by : Mario Jemic   |                    
-- |                                                                       mario.jemic@gmail.com    |
-- |                                                                       https://mario-jemic.com/ | 
-- |                                                             Patreon :  http://tiny.cc/1ybwxz   |   
-- |                                                      Buy Me a Coffee:  http://tiny.cc/bj7vxz   |  
-- +-----------------+----------------------+-------------------------------------------------------+
-- |  Cryptocurrency |  Network             |  Address                                              |
-- +-----------------+----------------------+-------------------------------------------------------+
-- |  BTC            |  BTC                 |  16F5k43RXibTmna4np8bPVgmXM1CzjXFJJ                   | 
-- |  SOL            |  SOL                 |  3nh5rpUKopcYLNU4zGCdUFAkM3iRQq8VVUmuzVG6VDf2         | 
-- |  ETH            |  ERC20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           |
-- |  BNB            |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- |  USDT           |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- |  XRP            |  BEP20               |  0xe53aab6bc468a963a02d1319660ee60cf80fc8e7           | 
-- +-----------------+----------------------+-------------------------------------------------------+