Get Rsi indicator calculation Code That Actually Works

//@version=5
indicator(title="RSI Indicator Calculation", shorttitle="RSI Calc", overlay=false, timeframe="")

// Input parameters for customization
rsiLength = input.int(14, minval=1, title="RSI Length", tooltip="Period for RSI calculation")
rsiSource = input.source(close, title="Source", tooltip="Price source for RSI")
overbought = input.int(70, minval=50, maxval=100, title="Overbought Level")
oversold = input.int(30, minval=0, maxval=50, title="Oversold Level")
showMiddle = input.bool(true, title="Show 50 Level")

// RSI Calculation Logic
// Step 1: Calculate changes in source
change = ta.change(rsiSource)

// Step 2: Separate gains and losses
gain = math.max(change, 0)
loss = math.max(-change, 0)

// Step 3: Exponential Moving Averages (RMA) for smoothed gains/losses
// RMA is used in Pine Script for Wilder's smoothing (alpha = 1/length)
avgGain = ta.rma(gain, rsiLength)
avgLoss = ta.rma(loss, rsiLength)

// Step 4: Relative Strength (RS) = avgGain / avgLoss
rs = avgLoss == 0 ? 0 : avgGain / avgLoss

// Step 5: RSI = 100 - (100 / (1 + RS))
rsi = rs == 0 ? 100 : 100 - (100 / (1 + rs))

// Visual Plots
plot(rsi, title="RSI", color=color.new(color.purple, 0), linewidth=2)

// Horizontal lines for levels
hline(overbought, "Overbought", color=color.new(color.red, 0), linestyle=hline.style_dashed)
hline(oversold, "Oversold", color=color.new(color.green, 0), linestyle=hline.style_dashed)
if showMiddle
    hline(50, "Middle", color=color.new(color.gray, 50), linestyle=hline.style_dotted)

// Background coloring for zones
bgcolor(rsi > overbought ? color.new(color.red, 90) : rsi < oversold ? color.new(color.green, 90) : na)

// Alerts
alertcondition(ta.crossover(rsi, oversold), title="RSI Oversold Cross Up", message="RSI crossed above oversold level: {{ticker}} RSI={{plot_0}}")
alertcondition(ta.crossunder(rsi, overbought), title="RSI Overbought Cross Down", message="RSI crossed below overbought level: {{ticker}} RSI={{plot_0}}")
alertcondition(ta.crossover(rsi, 50), title="RSI Midline Cross Up", message="RSI crossed above 50: {{ticker}} RSI={{plot_0}}")

// Table for current values (optional display)
var table infoTable = table.new(position.top_right, 2, 4, bgcolor=color.white, border_width=1)
if barstate.islast
    table.cell(infoTable, 0, 0, "RSI", text_color=color.black, bgcolor=color.gray)
    table.cell(infoTable, 1, 0, str.tostring(rsi, "#.##"), text_color=color.black)
    table.cell(infoTable, 0, 1, "Avg Gain", text_color=color.black, bgcolor=color.gray)
    table.cell(infoTable, 1, 1, str.tostring(avgGain, "#.####"), text_color=color.black)
    table.cell(infoTable, 0, 2, "Avg Loss", text_color=color.black, bgcolor=color.gray)
    table.cell(infoTable, 1, 2, str.tostring(avgLoss, "#.####"), text_color=color.black)
    table.cell(infoTable, 0, 3, "RS", text_color=color.black, bgcolor=color.gray)
    table.cell(infoTable, 1, 3, str.tostring(rs, "#.####"), text_color=color.black)