/*
 * Copyright (C)2005-2019 Haxe Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

import cs.system.text.regularexpressions.Regex;
import cs.system.text.regularexpressions.Match;
import cs.system.text.regularexpressions.RegexOptions;
import cs.system.text.regularexpressions.*;

@:coreApi final class EReg {
	private var regex:Regex;
	private var m:Match;
	private var isGlobal:Bool;
	private var cur:String;

	public function new(r:String, opt:String):Void {
		var opts:Int = cast CultureInvariant;
		for (i in 0...opt.length)
			untyped {
				switch (cast(opt[i], Int)) {
					case 'i'.code:
						opts |= cast(IgnoreCase, Int);
					case 'g'.code:
						isGlobal = true;
					case 'm'.code:
						opts |= cast(Multiline, Int);
					#if (!unity && !unity_std_target)
					case 'c'.code:
						opts |= cast(Compiled, Int);
					#end
				}
			}

		this.regex = new Regex(r, cast(opts, RegexOptions));
	}

	public function match(s:String):Bool {
		m = regex.Match(s);
		cur = s;
		return m.Success;
	}

	public function matched(n:Int):String {
		if (m == null || cast(n, UInt) > m.Groups.Count)
			throw "EReg::matched";
		if (!m.Groups[n].Success)
			return null;
		return m.Groups[n].Value;
	}

	public function matchedLeft():String {
		return untyped cur.Substring(0, m.Index);
	}

	public function matchedRight():String {
		return untyped cur.Substring(m.Index + m.Length);
	}

	public function matchedPos():{pos:Int, len:Int} {
		return {pos: m.Index, len: m.Length};
	}

	public function matchSub(s:String, pos:Int, len:Int = -1):Bool {
		m = if (len < 0) regex.Match(s, pos) else regex.Match(s, pos, len);
		cur = s;
		return m.Success;
	}

	public function split(s:String):Array<String> {
		if (isGlobal)
			return cs.Lib.array(regex.Split(s));
		var m = regex.Match(s);
		if (!m.Success)
			return [s];
		return untyped [s.Substring(0, m.Index), s.Substring(m.Index + m.Length)];
	}

	inline function start(group:Int):Int {
		return m.Groups[group].Index;
	}

	inline function len(group:Int):Int {
		return m.Groups[group].Length;
	}

	public function replace(s:String, by:String):String {
		return (isGlobal) ? regex.Replace(s, by) : regex.Replace(s, by, 1);
	}

	public function map(s:String, f:EReg->String):String {
		var offset = 0;
		var buf = new StringBuf();
		do {
			if (offset >= s.length)
				break;
			else if (!matchSub(s, offset)) {
				buf.add(s.substr(offset));
				break;
			}
			var p = matchedPos();
			buf.add(s.substr(offset, p.pos - offset));
			buf.add(f(this));
			if (p.len == 0) {
				buf.add(s.substr(p.pos, 1));
				offset = p.pos + 1;
			} else
				offset = p.pos + p.len;
		} while (isGlobal);
		if (!isGlobal && offset > 0 && offset < s.length)
			buf.add(s.substr(offset));
		return buf.toString();
	}

	public static inline function escape(s:String):String {
		return Regex.Escape(s);
	}
}