module term

import os

const (
	default_columns_size = 80
	default_rows_size = 25
)

// can_show_color_on_stdout returns true if colors are allowed in stdout;
// returns false otherwise.
pub fn can_show_color_on_stdout() bool {
	return supports_escape_sequences(1)
}

// can_show_color_on_stderr returns true if colors are allowed in stderr;
// returns false otherwise.
pub fn can_show_color_on_stderr() bool {
	return supports_escape_sequences(2)
}

// ok_message returns a colored string with green color.
// If colors are not allowed, returns a given string.
pub fn ok_message(s string) string {
	return if can_show_color_on_stdout() { green(s) } else { s }
}

// fail_message returns a colored string with red color.
// If colors are not allowed, returns a given string.
pub fn fail_message(s string) string {
	return if can_show_color_on_stdout() { red(s) } else { s }
}

// h_divider returns a horizontal divider line with a dynamic width,
// that depends on the current terminal settings.
pub fn h_divider(divider string) string {
	cols, _ := get_terminal_size()
	result := divider.repeat(1 + (cols / divider.len))
	return result[0..cols]
}

fn supports_escape_sequences(fd int) bool {
	$if windows {
		return (is_atty(fd) & 0x0004) > 0 && os.getenv('TERM') != 'dumb' // ENABLE_VIRTUAL_TERMINAL_PROCESSING
	} $else {
		return is_atty(fd) > 0 && os.getenv('TERM') != 'dumb'
	}
}