// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("TTM Trend", "TTM_TREND", overlay=true)

//@function Calculates TTM Trend using 6-period moving average with color-coded trend
//@param source Series to calculate TTM Trend from
//@param period Lookback period for moving average
//@returns Tuple [ttm_line, trend, strength] where trend is -1/0/1 and strength is percentage change
ttm_trend(series float source, simple int period = 6) =>
    if period <= 0
        runtime.error("Period must be greater than 0")
    
    float alpha = 2.0 / (period + 1)
    var float ema = source
    var float ema_prev = source
    
    ema := alpha * (source - ema) + ema
    
    float trend = math.sign(ema - ema_prev)
    float strength = math.abs(ema - ema_prev) / math.max(ema_prev, 1e-10) * 100
    
    ema_prev := ema
    
    [ema, trend, strength]

// ---------- Main loop ----------

// Inputs
i_period = input.int(6, "Period", minval=1)
i_source = input.source(hlc3, "Source")
i_show_strength = input.bool(true, "Show Trend Strength %")

// Calculation
[ttm_line, trend, strength] = ttm_trend(i_source, i_period)

// Colors
color up_color = color.new(color.green, 0)
color down_color = color.new(color.red, 0)
color neutral_color = color.new(color.gray, 50)
color line_color = trend > 0 ? up_color : trend < 0 ? down_color : neutral_color

// Plot
plot(ttm_line, "TTM Trend", color=line_color, linewidth=3, style=plot.style_line)

// Strength band (optional)
float strength_multiplier = 0.01
float upper_band = i_show_strength ? ttm_line + (ttm_line * strength * strength_multiplier) : na
float lower_band = i_show_strength ? ttm_line - (ttm_line * strength * strength_multiplier) : na

p1 = plot(upper_band, "Upper Strength", color=color.new(color.blue, 80), linewidth=1)
p2 = plot(lower_band, "Lower Strength", color=color.new(color.blue, 80), linewidth=1)
fill(p1, p2, color=color.new(color.blue, 90), title="Strength Band")

// Optional: Plot trend change signals
bool trend_change = trend != nz(trend[1], 0) and bar_index > 0
plotshape(trend_change and trend > 0, "Up", shape.triangleup, location.belowbar, color=up_color, size=size.tiny)
plotshape(trend_change and trend < 0, "Down", shape.triangledown, location.abovebar, color=down_color, size=size.tiny)