//@version=5
strategy("BTST and STBT Gap Momentum Strategy", overlay=true, initial_capital=100000, default_qty_type=strategy.fixed, default_qty_value=1)

// --- Input Parameters ---
trend_ema_len = input.int(20, title="Trend Filter EMA Length")
entry_hour    = input.int(15, title="Entry Hour (24h format)", minval=0, maxval=23)
entry_minute  = input.int(15, title="Entry Minute", minval=0, maxval=59)
exit_hour     = input.int(9, title="Exit Hour (24h format)", minval=0, maxval=23)
exit_minute   = input.int(15, title="Exit Minute", minval=0, maxval=59)

// --- Indicator Setup ---
ema_val = ta.ema(close, trend_ema_len)
plot(ema_val, color=color.blue, title="Trend Filter EMA", linewidth=2)

// --- Session Verification ---
is_entry_time = (hour == entry_hour and minute == entry_minute)
is_exit_time  = (hour == exit_hour and minute == exit_minute)

// --- Strategy Entry Conditions ---
// BTST (Buy Today, Sell Tomorrow) - Long setup if price is above EMA at entry time
btst_long_cond = is_entry_time and (close > ema_val)

// STBT (Sell Today, Buy Tomorrow) - Short setup if price is below EMA at entry time
stbt_short_cond = is_entry_time and (close < ema_val)

// --- Execution ---
if (btst_long_cond)
    strategy.entry("BTST_Long", strategy.long, comment="BTST Entry")

if (stbt_short_cond)
    strategy.entry("STBT_Short", strategy.short, comment="STBT Entry")

// Clear positions on market open (Gap realization target)
if (is_exit_time)
    strategy.close("BTST_Long", comment="BTST Open Exit")
    strategy.close("STBT_Short", comment="STBT Open Exit")