//education purpose
//@version=5
indicator("Support, Resistance and Median with Trend", overlay=true)

// Parameters
length = input.int(22, title="Historical Length", options=[22, 44, 66])
projectionPeriods = 8 // Number of periods for projection

// Calculate support and resistance levels
highestHigh = ta.highest(high, length)
lowestLow = ta.lowest(low, length)

// Adjust levels based on sensitivity
resistanceLevel = highestHigh * 1
supportLevel = lowestLow * 1

// Calculate median
medianLevel = (resistanceLevel + supportLevel) / 2

// Trend detection
isUptrend = close > medianLevel and close[1] > medianLevel[1]
isDowntrend = close < medianLevel and close[1] < medianLevel[1]

// Plot support, resistance, and median levels for current periods
plot(resistanceLevel, title="Resistance", color=color.red, linewidth=2, style=plot.style_line)
plot(supportLevel, title="Support", color=color.green, linewidth=2, style=plot.style_line)
plot(medianLevel, title="Median", color=color.white, linewidth=1, style=plot.style_line)

// Trend box in top right corner
var table trendTable = table.new(position.top_right, 1, 1)
table.cell(trendTable, 0, 0, 
           isUptrend ? "Uptrend" : 
           isDowntrend ? "Downtrend" : "Neutral", 
           bgcolor=isUptrend ? color.green : 
                   isDowntrend ? color.red : color.gray)

// Create arrays to store projected values
var float[] resistanceArray = array.new_float(projectionPeriods, resistanceLevel)
var float[] supportArray = array.new_float(projectionPeriods, supportLevel)
var float[] medianArray = array.new_float(projectionPeriods, medianLevel)

// Update arrays with new values
for i = 0 to projectionPeriods - 1
    array.set(resistanceArray, i, resistanceLevel)
    array.set(supportArray, i, supportLevel)
    array.set(medianArray, i, medianLevel)

// Plot projections with lines to extend levels
for i = 0 to projectionPeriods - 1
    offset = i + 1
    if bar_index >= length - 1
        line.new(x1=bar_index, y1=array.get(resistanceArray, i),
                 x2=bar_index + offset, y2=array.get(resistanceArray, i),
                 color=color.red, width=2)
        line.new(x1=bar_index, y1=array.get(supportArray, i),
                 x2=bar_index + offset, y2=array.get(supportArray, i),
                 color=color.green, width=2)
        line.new(x1=bar_index, y1=array.get(medianArray, i),
                 x2=bar_index + offset, y2=array.get(medianArray, i),
                 color=color.white, width=1)