-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=27807
-- Id:  

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function Init()
    indicator:name("Week of week lables indicator")
    indicator:description("Week of week lables indicator")
    indicator:requiredSource(core.Bar)
    indicator:type(core.Indicator)

    indicator.parameters:addGroup("Calculation")
    indicator.parameters:addInteger("start_day", "Start day", "", 1);
    indicator.parameters:addIntegerAlternative("start_day", "Sunday", "", 1);
    indicator.parameters:addIntegerAlternative("start_day", "Monday", "", 2);
    indicator.parameters:addIntegerAlternative("start_day", "Tuesday", "", 3);
    indicator.parameters:addIntegerAlternative("start_day", "Wednesday", "", 4);
    indicator.parameters:addIntegerAlternative("start_day", "Thursday", "", 5);
    indicator.parameters:addIntegerAlternative("start_day", "Friday", "", 6);
    indicator.parameters:addIntegerAlternative("start_day", "Saturday", "", 7);
    indicator.parameters:addString("BeginTime", "Begin time of the day", "", "00:00:00")

    indicator.parameters:addGroup("Style")
    indicator.parameters:addColor("HL_LineClr", "High/Low lines color", "High/Low lines color", core.rgb(0, 255, 0))
    indicator.parameters:addInteger("HL_Width", "High/Low lines width", "High/Low lines width", 3, 1, 5)
    indicator.parameters:addInteger("HL_Style", "High/Low lines style", "High/Low lines style", core.LINE_SOLID)
    indicator.parameters:setFlag("HL_Style", core.FLAG_LINE_STYLE)
    indicator.parameters:addColor("Central_LineClr", "Central line color", "Central line color", core.rgb(0, 255, 0))
    indicator.parameters:addInteger("Central_Width", "Central line width", "Central line width", 2, 1, 5)
    indicator.parameters:addInteger("Central_Style", "Central line style", "Central line style", core.LINE_DASHDOT)
    indicator.parameters:setFlag("Central_Style", core.FLAG_LINE_STYLE)
    indicator.parameters:addColor("Fibo_LineClr", "Fibo lines color", "Fibo lines color", core.rgb(0, 255, 0))
    indicator.parameters:addInteger("Fibo_Width", "Fibo lines width", "Fibo lines width", 1, 1, 5)
    indicator.parameters:addInteger("Fibo_Style", "Fibo lines style", "Fibo lines style", core.LINE_DOT)
    indicator.parameters:setFlag("Fibo_Style", core.FLAG_LINE_STYLE)
    indicator.parameters:addColor("LableClr", "Lable Color", "Lable Color", core.rgb(255, 255, 0))
    indicator.parameters:addInteger("FontSize", "Label font size", "Label font size", 10)
end

local first
local source = nil
local start_day;
local BeginT
local font
local H, L = nil, nil
local F1, F2, F3, F4, F5 = nil, nil, nil, nil, nil

function ParseTime(time)
    local pos = string.find(time, ":");
    if pos == nil then
        return nil, false;
    end
    local h = tonumber(string.sub(time, 1, pos - 1));
    time = string.sub(time, pos + 1);
    pos = string.find(time, ":");
    if pos == nil then
        return nil, false;
    end
    local m = tonumber(string.sub(time, 1, pos - 1));
    local s = tonumber(string.sub(time, pos + 1));
    return (h / 24.0 +  m / 1440.0 + s / 86400.0),                          -- time in ole format
           ((h >= 0 and h < 24 and m >= 0 and m < 60 and s >= 0 and s < 60) or (h == 24 and m == 0 and s == 0)); -- validity flag
end

function Prepare(nameOnly)
    source = instance.source
    first = source:first() + 2
    local name = profile:id() .. "(" .. source:name() .. ")"
    instance:name(name)
    if nameOnly then
        return
    end
    start_day = instance.parameters.start_day;
    BeginT, valid = ParseTime(instance.parameters.BeginTime);
    assert(valid, "Time " .. instance.parameters.BeginTime .. " is invalid");

    font = core.host:execute("createFont", "Arial", instance.parameters.FontSize, true, false)
    H = instance:addStream("H", core.Line, name .. ".H", "H", instance.parameters.HL_LineClr, first)
    H:setWidth(instance.parameters.HL_Width)
    H:setStyle(instance.parameters.HL_Style)
    L = instance:addStream("L", core.Line, name .. ".L", "L", instance.parameters.HL_LineClr, first)
    L:setWidth(instance.parameters.HL_Width)
    L:setStyle(instance.parameters.HL_Style)
    F1 = instance:addStream("F1", core.Line, name .. ".F1", "F1", instance.parameters.Fibo_LineClr, first)
    F1:setWidth(instance.parameters.Fibo_Width)
    F1:setStyle(instance.parameters.Fibo_Style)
    F2 = instance:addStream("F2", core.Line, name .. ".F2", "F2", instance.parameters.Fibo_LineClr, first)
    F2:setWidth(instance.parameters.Fibo_Width)
    F2:setStyle(instance.parameters.Fibo_Style)
    F3 = instance:addStream("F3", core.Line, name .. ".F3", "F3", instance.parameters.Central_LineClr, first)
    F3:setWidth(instance.parameters.Central_Width)
    F3:setStyle(instance.parameters.Central_Style)
    F4 = instance:addStream("F4", core.Line, name .. ".F4", "F4", instance.parameters.Fibo_LineClr, first)
    F4:setWidth(instance.parameters.Fibo_Width)
    F4:setStyle(instance.parameters.Fibo_Style)
    F5 = instance:addStream("F5", core.Line, name .. ".F5", "F5", instance.parameters.Fibo_LineClr, first)
    F5:setWidth(instance.parameters.Fibo_Width)
    F5:setStyle(instance.parameters.Fibo_Style)
end

function DayNumber(period)
    local D = source:date(period)
    local T = core.dateToTable(D - (1.0 / 17) + BeginT)
    return T.wday;
end

function Update(period, mode)
    if period > first then
        local DN = DayNumber(period)
        local DN2 = DayNumber(period - 1)
        if DN == start_day and DN2 ~= start_day then
            H[period] = source.high[period]
            L[period] = source.low[period]
        else
            H[period] = math.max(H[period - 1], source.high[period])
            L[period] = math.min(L[period - 1], source.low[period])
        end
        F1[period] = 0.236 * (H[period] - L[period]) + L[period]
        F2[period] = 0.382 * (H[period] - L[period]) + L[period]
        F3[period] = 0.5 * (H[period] - L[period]) + L[period]
        F4[period] = 0.618 * (H[period] - L[period]) + L[period]
        F5[period] = 0.764 * (H[period] - L[period]) + L[period]
    elseif period == first then
        H[period] = source.high[period]
        L[period] = source.low[period]
    end
end