0x.FixBadShift.moon

import frame_from_ms, ms_from_frame from aegisub

export script_name = 'Fix Bad Shift'
export script_description = 'Attempt to fix misaligned timeshifted fbf subs'
export script_author = 'The0x539'
export script_version = '0.1.0'
export script_namespace = '0x.FixBadShift'

start_frame = (line) -> frame_from_ms line.start_time
end_frame = (line) -> frame_from_ms line.end_time
frame_numbers = (line) ->
	sf = start_frame line
	ef = end_frame line
	dur = ef - sf
	sf, ef, dur

main = (subs, sel, _i) ->
	for i = 1, #sel - 1
		idx1, idx2 = sel[i], sel[i + 1]
		line1, line2 = subs[idx1], subs[idx2]
		l1_start, l1_end, l1_dur = frame_numbers line1
		l2_start, l2_end, l2_dur = frame_numbers line2
		if l1_end == l2_start and l1_dur == 2 and l2_dur == 0
			new_split = ms_from_frame l1_start + 1
			line1.end_time = new_split
			line2.start_time = new_split
			subs[idx1], subs[idx2] = line1, line2

	aegisub.set_undo_point 'fix bad shift'

aegisub.register_macro script_name, script_description, main