/*
 * 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.
 */
@:coreApi final class EReg {
	var r:Dynamic;
	var last:String;
	var global:Bool;

	public function new(r:String, opt:String):Void {
		var a = opt.split("g");
		global = a.length > 1;
		if (global)
			opt = a.join("");
		this.r = regexp_new_options(untyped r.__s, untyped opt.__s);
	}

	public function match(s:String):Bool {
		var p = regexp_match(r, untyped s.__s, 0, s.length);
		if (p)
			last = s;
		else
			last = null;
		return p;
	}

	public function matched(n:Int):String {
		var m = regexp_matched(r, n);
		return (m == null) ? null : new String(m);
	}

	public function matchedLeft():String {
		var p = regexp_matched_pos(r, 0);
		return last.substr(0, p.pos);
	}

	public function matchedRight():String {
		var p = regexp_matched_pos(r, 0);
		var sz = p.pos + p.len;
		return last.substr(sz, last.length - sz);
	}

	public function matchedPos():{pos:Int, len:Int} {
		return regexp_matched_pos(r, 0);
	}

	public function matchSub(s:String, pos:Int, len:Int = -1):Bool {
		var p = regexp_match(r, untyped s.__s, pos, len < 0 ? s.length - pos : len);
		if (p)
			last = s;
		else
			last = null;
		return p;
	}

	public function matchedNum():Int {
		var num = regexp_matched_num(r);
		if(last == null || num == -1) return 0;
		return num;
	}

	public function split(s:String):Array<String> {
		var pos = 0;
		var len = s.length;
		var a = new Array();
		var first = true;
		do {
			if (!regexp_match(r, untyped s.__s, pos, len))
				break;
			var p = regexp_matched_pos(r, 0);
			if (p.len == 0 && !first) {
				if (p.pos == s.length)
					break;
				p.pos += 1;
			}
			a.push(s.substr(pos, p.pos - pos));
			var tot = p.pos + p.len - pos;
			pos += tot;
			len -= tot;
			first = false;
		} while (global);
		a.push(s.substr(pos, len));
		return a;
	}

	public function replace(s:String, by:String):String {
		var b = new StringBuf();
		var pos = 0;
		var len = s.length;
		var a = by.split("$");
		var first = true;
		do {
			if (!regexp_match(r, untyped s.__s, pos, len))
				break;
			var p = regexp_matched_pos(r, 0);
			if (p.len == 0 && !first) {
				if (p.pos == s.length)
					break;
				p.pos += 1;
			}
			b.addSub(s, pos, p.pos - pos);
			if (a.length > 0)
				b.add(a[0]);
			var i = 1;
			while (i < a.length) {
				var k = a[i];
				var c = k.charCodeAt(0);
				// 1...9
				if (c >= 49 && c <= 57) {
					var p = try regexp_matched_pos(r, Std.int(c) - 48) catch (e:String) null;
					if (p == null) {
						b.add("$");
						b.add(k);
					} else {
						if (p.pos >= 0)
							b.addSub(s, p.pos, p.len);
						b.addSub(k, 1, k.length - 1);
					}
				} else if (c == null) {
					b.add("$");
					i++;
					var k2 = a[i];
					if (k2 != null && k2.length > 0)
						b.add(k2);
				} else
					b.add("$" + k);
				i++;
			}
			var tot = p.pos + p.len - pos;
			pos += tot;
			len -= tot;
			first = false;
		} while (global);
		b.addSub(s, pos, len);
		return b.toString();
	}

	// public function map( s : String, f : EReg -> String ) : String {
	// var b = new StringBuf();
	// var pos = 0;
	// var len = s.length;
	// var first = true;
	// last = s;
	// do {
	// if( !regexp_match(r,untyped s.__s,pos,len) )
	// break;
	// var p = regexp_matched_pos(r,0);
	// if( p.len == 0 && !first ) {
	// if( p.pos == s.length )
	// break;
	// p.pos += 1;
	// }
	// b.addSub(s,pos,p.pos-pos);
	// b.add(f(this));
	// var tot = p.pos + p.len - pos;
	// pos += tot;
	// len -= tot;
	// first = false;
	// } while( global );
	// b.addSub(s,pos,len);
	// return b.toString();
	// }

	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 = regexp_matched_pos(r, 0);
			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 (global);
		if (!global && offset > 0 && offset < s.length)
			buf.add(s.substr(offset));
		return buf.toString();
	}

	public static function escape(s:String):String {
		return escapeRegExpRe.map(s, function(r) return "\\" + r.matched(0));
	}

	static var escapeRegExpRe = ~/[\[\]{}()*+?.\\\^$|]/g;

	static var regexp_new_options = neko.Lib.load("regexp", "regexp_new_options", 2);
	static var regexp_match = neko.Lib.load("regexp", "regexp_match", 4);
	static var regexp_matched = neko.Lib.load("regexp", "regexp_matched", 2);
	static var regexp_matched_pos:Dynamic->Int->{pos: Int, len: Int} = neko.Lib.load("regexp", "regexp_matched_pos", 2);
	static var regexp_matched_num = try neko.Lib.load("regexp", "regexp_matched_num", 1) catch (_:Dynamic) fallback_matched_num;

	private static function fallback_matched_num(r:Dynamic):Int {
		var i = 0;
		var num = 0;
		try {
			while (true) {
				if (regexp_matched(r, i) != null) num++;
				i++;
			}
		} catch (_:Dynamic) {}
		return num;
	}
}
