FXN-ASIAN SESSION RANGE

//@version=5
indicator("FXN - Asian Session Range (Clone)", overlay=true, max_boxes_count=500, max_lines_count=500)

// --- Inputs ---
string i_session = input.session("2000-0200:23456", title="Asian Session Time (EST)", tooltip="Format: HHMM-HHMM followed by days (2=Mon, 3=Tue...)")
string i_timezone = input.string("America/New_York", title="Session Timezone")

// Color Customizations
color c_box_bg = input.color(color.new(#2196F3, 90), title="Session Box Background")
color c_high_line = input.color(#2196F3, title="Asian High Line Color")
color c_mid_line = input.color(#FF9800, title="Asian Midline Color")
color c_low_line = input.color(#F44336, title="Asian Low Line Color")

// Style Options
int i_line_width = input.int(1, minval=1, title="Line Width")
string i_line_style = input.string("Dashed", title="Line Style", options=["Solid", "Dashed", "Dotted"])

// --- Helper function for line style ---
get_line_style(style_str) =>
style_str == "Solid" ? line.style_solid : style_str == "Dashed" ? line.style_dashed : line.style_dotted

// --- Logic to check if we are inside the session ---
in_session = not na(time(timeframe.period, i_session, i_timezone))
session_changed = in_session and not in_session[1]

// --- Persistent variables across bars ---
var int start_bar_index = na
var float session_high = na
var float session_low = na

var box session_box = na
var line high_ext_line = na
var line mid_ext_line = na
var line low_ext_line = na

// --- Script Execution ---
if session_changed
// Triggered on the very first bar of a new Asian session
start_bar_index := bar_index
session_high := high
session_low := low

// Create new visual components for the day
session_box := box.new(left=bar_index, top=session_high, right=bar_index, bottom=session_low, bgcolor=c_box_bg, border_color=color.new(c_high_line, 50))
high_ext_line := line.new(x1=bar_index, y1=session_high, x2=bar_index, y2=session_high, color=c_high_line, width=i_line_width, style=get_line_style(i_line_style))
mid_ext_line := line.new(x1=bar_index, y1=(session_high + session_low) / 2, x2=bar_index, y2=(session_high + session_low) / 2, color=c_mid_line, width=i_line_width, style=get_line_style(i_line_style))
low_ext_line := line.new(x1=bar_index, y1=session_low, x2=bar_index, y2=session_low, color=c_low_line, width=i_line_width, style=get_line_style(i_line_style))

else if in_session
// Continuous updating while the Asian session is active
session_high := math.max(high, session_high)
session_low := math.min(low, session_low)
float session_mid = (session_high + session_low) / 2

// Update the box boundaries and lines dynamically
box.set_top(session_box, session_high)
box.set_bottom(session_box, session_low)
box.set_right(session_box, bar_index)

line.set_xy1(high_ext_line, start_bar_index, session_high)
line.set_xy2(high_ext_line, bar_index, session_high)

line.set_xy1(mid_ext_line, start_bar_index, session_mid)
line.set_xy2(mid_ext_line, bar_index, session_mid)

line.set_xy1(low_ext_line, start_bar_index, session_low)
line.set_xy2(low_ext_line, bar_index, session_low)

else if not na(start_bar_index)
// When the session ends, keep extending lines to the right (into London/NY sessions)
box.set_right(session_box, bar_index)
line.set_x2(high_ext_line, bar_index)
line.set_x2(mid_ext_line, bar_index)
line.set_x2(low_ext_line, bar_index)