extends Node
class_name PGN


func parse(string) -> Dictionary:
	# put tags into a dictionary,
	# and the moves into a array

	var tagex = SanParse.compile('^\\[([A-Za-z0-9_]+)\\s+"([^\\r]*)"\\]\\s*$', false)
	var tagnameex = SanParse.compile("^[A-Za-z0-9_]+\\Z", false)
	var movetextex = SanParse.compile(
		"([NBKRQ]?[a-h]?[1-8]?[\\-x]?[a-h][1-8](?:=?[nbrqkNBRQK])?|[PNBRQK]?@[a-h][1-8]|--|Z0|0000|@@@@|O-O(?:-O)?|0-0(?:-0)?)|(\\{.*)|(;.*)|(\\$[0-9]+)|(\\()|(\\))|(\\*|1-0|0-1|1\\/2-1\\/2)|([\\?!]{1,2})",
		false
	)

	# get headers
	var headers := {}
	var lines = Array(string.split("\n"))
	while !lines.empty():
		var line = lines[0].strip_edges()
		if !line or line[0] in ["%", ";"]:
			lines.pop_front()
			continue

		if line[0] != "[":
			break

		lines.pop_front()
		var tag_match = tagex.search(line)
		if tag_match:
			var cap = tag_match.strings
			if tagnameex.search(cap[1]):
				headers[cap[1]] = cap[2]
			else:
				# invalid headers
				push_error("invalid headers")
				return {}
		else:
			break

	var movetext := PoolStringArray()
	while !lines.empty():
		var line = lines.pop_front().strip_edges()
		if !line:
			break
		if line[0] in ["%", ";"]:
			continue
		for found in movetextex.search_all(line):
			if found.strings[1]:
				movetext.append(found.strings[1])
	return {"headers": headers, "moves": movetext}