//
// StringPrototype.cs:
//
// Author:
//	Cesar Lopez Nataren (cesar@ciencias.unam.mx)
//
// (C) 2003, Cesar Lopez Nataren
//

//
// 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.
//

using System;
using Microsoft.JScript.Vsa;
using System.Globalization;
using System.Text.RegularExpressions;
using System.Collections;

namespace Microsoft.JScript {
	
	public class StringPrototype : StringObject {

		internal static StringPrototype Proto = new StringPrototype ();

		/* Note that the implementation of this HTML tag stuff is pretty dumb.
		 * It does not do any escaping of HTML characters like '<', '>' or '"' which means that you can do
		 * HTML injection via for example "foo".anchor("NAME\" style=\"font-size: 500pt;") which will result
		 * in <A NAME="NAME" style="font-size: 500pt;">, however Mozilla, Internet Explorer and Opera all do
		 * the same thing and I could not find any standard against this behavior. */

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_anchor)]
		public static string anchor (object thisObj, object anchorName)
		{
			return "<A NAME=\"" + Convert.ToString (anchorName) + "\">" + Convert.ToString (thisObj) + "</A>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_big)]
		public static string big (object thisObj)
		{
			return "<BIG>" + Convert.ToString (thisObj) + "</BIG>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_blink)]
		public static string blink (object thisObj)
		{
			return "<BLINK>" + Convert.ToString (thisObj) + "</BLINK>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_bold)]
		public static string bold (object thisObj)
		{
			return "<B>" + Convert.ToString (thisObj) + "</B>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_charAt)]
		public static string charAt (object thisObj, double pos)
		{
			int _pos = Convert.ToInt32 (pos);
			string string_obj = Convert.ToString (thisObj);

			if (_pos < 0 || _pos >= string_obj.Length)
				return "";

			return string_obj.Substring (_pos, 1);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_charCodeAt)]
		public static object charCodeAt (object thisObj, double arg)
		{
			string string_obj = Convert.ToString (thisObj);
			int pos = Convert.ToInt32 (arg);

			if (pos < 0 || pos >= string_obj.Length)
				return Double.NaN;

			return string_obj [pos];
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject | JSFunctionAttributeEnum.HasVarArgs, JSBuiltin.String_concat)]
		public static string concat (object thisObj, params object [] args)
		{
			string result = Convert.ToString (thisObj);

			foreach (object arg in args)
				result += Convert.ToString (arg);

			return result;
		}


		public static StringConstructor constructor {
			get { return StringConstructor.Ctr; }
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_fixed)]
		public static string @fixed (object thisObj)
		{
			return "<TT>" + Convert.ToString (thisObj) + "</TT>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_fontcolor)]
		public static string fontcolor (object thisObj, object colorName)
		{
			return "<FONT COLOR=\"" + Convert.ToString (colorName) + "\">" + Convert.ToString (thisObj) + "</FONT>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_fontsize)]
		public static string fontsize (object thisObj, object fontsize)
		{
			return "<FONT SIZE=\"" + Convert.ToString (fontsize) + "\">" + Convert.ToString (thisObj) + "</FONT>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_indexOf)]
		public static int indexOf (object thisObj, object searchString, double position)
		{
			string string_obj = Convert.ToString (thisObj);
			string search_obj = Convert.ToString (searchString);
			int pos = (int) position;
			if (pos < 0)
				pos = 0;
			else if (pos > string_obj.Length)
				pos = string_obj.Length;
			return string_obj.IndexOf (search_obj, pos);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_italics)]
		public static string italics (object thisObj)
		{
			return "<I>" + Convert.ToString (thisObj) + "</I>";
		}
		
		//
		// Note: I think the signature Microsoft uses makes
		// standards-compliant behavior impossible. If
		// position is not supplied the standard says to
		// default to the string's length. We can not do this
		// with their signature, because position will
		// automatically be forced to 0 in that case. Because
		// of that we currently use 'object position' instead
		// of their 'double position' in lastIndexOfGood
		// (which we use from our own compiler) and a wrapper
		// around that for when we run MS IL.
		//
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject)]
		public static int lastIndexOfGood (object thisObj, object searchString, object position)
		{
			string string_obj = Convert.ToString (thisObj);
			string search_obj = Convert.ToString (searchString);
			int pos;
			if (position == null)
				pos = string_obj.Length;
			else {
				pos = Convert.ToInt32 (position);
				if (pos < 0)
					pos = 0;
				else if (pos > string_obj.Length)
					pos = string_obj.Length;
			}
			int result = string_obj.LastIndexOf (search_obj, pos);
			// string:LastIndexOf ignores matches at string start if pos is 0
			if (result == -1 && pos == 0 && string_obj.StartsWith (search_obj))
				return 0;
			return result;
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_lastIndexOf)]
		public static int lastIndexOf (object thisObj, object searchString, object position)
		{
			return lastIndexOfGood (thisObj, searchString, position);
		}

		public static int lastIndexOf (object thisObj, object searchString, double position)
		{
			return lastIndexOfGood (thisObj, searchString, position);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_link)]
		public static string link (object thisObj, object linkRef)
		{
			return "<A HREF=\"" + Convert.ToString (linkRef) + "\">" + Convert.ToString (thisObj) + "</A>";
		}

		[MonoTODO ("I18N Needs checking -- contact flgr@ccan.de for details")]
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_localeCompare)]
		public static int localeCompare (object thisObj, object thatObj)
		{
			// TODO FIXME I18N: Verify that we do the right thing even in border cases.
			string string_a = Convert.ToString (thisObj);
			string string_b = Convert.ToString (thatObj);
			int caseless_result = String.Compare (string_a, string_b, true);
			/* I have no idea if this is enough to fix the behavior in all cases, but it at least makes
			 * localeCompare("abc", "ABC") work as in MS JS.NET -- this will likely be revised after
			 * more testing.
			 * 
			 * Related to http://bugzilla.ximian.com/show_bug.cgi?id=70478?
			 */
			if (caseless_result == 0)
				return -String.Compare (string_a, string_b, false);
			else
				return String.Compare (string_a, string_b, false);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject | JSFunctionAttributeEnum.HasEngine, JSBuiltin.String_match)]
		public static object match (object thisObj, VsaEngine engine, object regExp)
		{
			string string_obj = Convert.ToString (thisObj);
			RegExpObject regex_obj = Convert.ToRegExp (regExp);
			bool global = regex_obj.global;

			if (!global)
				return RegExpPrototype.exec (regex_obj, string_obj);

			MatchCollection md = regex_obj.regex.Matches (string_obj);
			uint n = (uint) md.Count;
			Match lastMatch = md [(int) (n - 1)];
			regex_obj.lastIndex = lastMatch.Index + 1;
			RegExpConstructor.UpdateLastMatch (lastMatch, string_obj);

			ArrayObject result = new ArrayObject ();
			result.length = n;
			for (uint i = 0; i < n; i++)
				result.elems [i] = md [(int) i].Value;

			return result;
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_replace)]
		public static string replace (object thisObj, object regExp, object replacement)
		{
			string string_obj = Convert.ToString (thisObj);

			if (!(regExp is RegExpObject)) {
				string match_str = Convert.ToString (regExp);
				string replace_str = Convert.ToString (replacement);
				int match_pos = string_obj.IndexOf (match_str);

				if (match_pos == -1)
					return string_obj;

				return String.Concat (string_obj.Substring (0, match_pos), replace_str,
					string_obj.Substring (match_pos + match_str.Length));
			}

			RegExpObject regex_obj = (RegExpObject) regExp;
			int count = regex_obj.global ? -1 : 1;

			if (!(replacement is ScriptFunction))
				return regex_obj.regex.Replace (string_obj, Convert.ToString (replacement), count);

			ScriptFunction fun = (ScriptFunction) replacement;
			MatchEvaluator wrap_fun = new MatchEvaluator (new ReplaceDelegate (fun, string_obj).Replace);
			return regex_obj.regex.Replace (string_obj, wrap_fun, count);
		}

		private class ReplaceDelegate {
			private ScriptFunction fun;
			private string string_obj;

			internal ReplaceDelegate (ScriptFunction fun, string string_obj)
			{
				this.fun = fun;
				this.string_obj = string_obj;
			}

			internal string Replace (Match md)
			{
				ArrayList arg_list = new ArrayList ();

				foreach (Group cap in md.Groups)
					arg_list.Add (cap.Value);

				arg_list.Add (md.Index);
				arg_list.Add (string_obj);

				return Convert.ToString (fun.Invoke (null, arg_list.ToArray ()));
			}
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject | JSFunctionAttributeEnum.HasEngine, JSBuiltin.String_search)]
		public static int search (object thisObj, VsaEngine engine, object regExp)
		{
			string string_obj = Convert.ToString (thisObj);
			RegExpObject regex_obj = Convert.ToRegExp (regExp);
			Match md = regex_obj.regex.Match (string_obj);
			/* Note: Microsoft's implementation updates the lastIndex property of regex_obj here, but
			 * ECMA-262, 15.5.4.12, NOTE 1 explicitely says not to do so. We do the ECMA-262 behavior. */
			if (md.Success)
				return md.Index;
			else
				return -1;
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_slice)]
		public static string slice (object thisObj, double start, object end)
		{
			string string_obj = Convert.ToString (thisObj);
			int string_len = string_obj.Length;
			int _start, _end;

			if (start > string_len)
				_start = string_len;
			else {
				_start = (int) start;
				if (_start < 0)
					_start += string_len;
			}

			if (end == null)
				_end = string_len;
			else {
				_end = Convert.ToInt32 (end);

				if (_end < 0)
					_end += string_len;
				else if (_end > string_len)
					_end = string_len;
			}

			if (_end < _start)
				_end = _start;

			return string_obj.Substring (_start, _end - _start);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_small)]
		public static string small (object thisObj)
		{
			return "<SMALL>" + Convert.ToString (thisObj) + "</SMALL>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject | JSFunctionAttributeEnum.HasEngine, JSBuiltin.String_split)]
		public static ArrayObject split (object thisObj, VsaEngine engine,
						 object separator, object limit)
		{
			string string_obj = Convert.ToString (thisObj);
			int length = string_obj.Length;
			int max_count = (limit != null) ? Convert.ToInt32 (limit) : -1;
			ArrayObject result = new ArrayObject ();

			if (separator == null) {
				result.length = (uint) 1;
				result.elems [(uint) 0] = string_obj;
				return result;
			}

			int start_pos = 0;
			int end_pos = -1;
			int match_len = 0;
			uint count = 0;
			int sep_len = 0;

			if (!(separator is RegExpObject)) {
				string sep_str = Convert.ToString (separator);
				sep_len = sep_str.Length;

				if (string_obj.Length == 0) {
					if (sep_len > 0) {
						result.length = (uint) 1;
						result.elems [(uint) 0] = string_obj;
					}

					return result;
				}

				while (end_pos != length && (max_count == -1 || count < max_count)) {
					end_pos = (length != 0) ? string_obj.IndexOf (sep_str, start_pos) : length;
					if (end_pos == -1)
						end_pos = length;
					else if (sep_len == 0)
						end_pos++;

					match_len = end_pos - start_pos;
					result.elems [count] = string_obj.Substring (start_pos, match_len);

					start_pos += match_len + sep_len;
					count++;
				}

				result.length = count;
				return result;
			}

			RegExpObject sep_re = (RegExpObject) separator;
			MatchCollection md = sep_re.regex.Matches (string_obj);
			uint n = (uint) md.Count;

			Match match = null;
			for (int i = 0; i < n; i++) {
				if (max_count != -1 && count >= max_count)
					break;

				match = md [i];
				sep_len = match.Length;
				end_pos = match.Index;
				match_len = end_pos - start_pos;

				//
				// The specification says that "ab".split(/a*/) is ["", "b"], but would
				// that would also mean that "abcdef".split(/./).length would not be 6.
				// I'm currently going with the Rhino behavior that seems to make more
				// sense.
				//
				if (!(end_pos == 0 && sep_len == 0)) {
					result.elems [count] = string_obj.Substring (start_pos, match_len);
					count++;
				}

				bool first_cap = true;
				foreach (Capture cap in match.Groups) {
					if (max_count != -1 && count >= max_count)
						break;

					if (first_cap) {
						first_cap = false;
						continue;
					}

					result.elems [count] = cap.Value;
					count++;
				}

				start_pos += match_len + sep_len;
			}

			if (n > 0 && (max_count == -1 || count < max_count)) {
				sep_re.lastIndex = match.Index + match.Length;
				RegExpConstructor.UpdateLastMatch (match, string_obj);

				if (start_pos < length) {
					result.elems [count] = string_obj.Substring (start_pos);
					count++;
				}
			} else if (n == 0) {
				result.elems [(uint) 0] = string_obj;
				count++;
			}

			result.length = count;
			return result;
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_strike)]
		public static string strike (object thisObj)
		{
			return "<STRIKE>" + Convert.ToString (thisObj) + "</STRIKE>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_sub)]
		public static string sub (object thisObj)
		{
			return "<SUB>" + Convert.ToString (thisObj) + "</SUB>";
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_substr)]
		public static string substr (object thisObj, double start, object count)
		{
			string string_obj = Convert.ToString (thisObj);
			int string_len = string_obj.Length;
			int _start, _end;

			if (start > string_len)
				_start = string_len;
			else {
				_start = (int) start;
				if (_start < 0)
					_start += string_len;
			}

			if (count == null)
				_end = string_len;
			else {
				int _count = Convert.ToInt32 (count);
				_end = _start + _count;

				if (_end < 0)
					return "";
				else if (_end > string_len)
					_end = string_len;
			}
			return string_obj.Substring (_start, _end - _start);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_substring)]
		public static string substring (object thisObj, double start, object end)
		{
			string string_obj = Convert.ToString (thisObj);
			int string_len = string_obj.Length;
			int _start, _end;

			if (start == Double.NaN || start < 0)
				_start = 0;
			else if (start > string_len)
				_start = string_len;
			else
				_start = (int) start;

			if (end == null)
				_end = string_len;
			else {
				_end = Convert.ToInt32 (end);

				if (_end == Double.NaN || _end < 0)
					_end = 0;
				else if (_end > string_len)
					_end = string_len;
			}

			if (_end < _start) {
				int temp = _start;
				_start = _end;
				_end = temp;
			}
			return string_obj.Substring (_start, _end - _start);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_sup)]
		public static string sup (object thisObj)
		{
			return "<SUP>" + Convert.ToString (thisObj) + "</SUP>";
		}

		/* TODO FIXME I18N: Somebody who is familar with locales should check if the definition of these really is
		 * this simple. */

		[MonoTODO ("I18N Needs checking -- contact flgr@ccan.de for details")]
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_toLocaleLowerCase)]
		public static string toLocaleLowerCase (object thisObj)
		{
			string string_obj = Convert.ToString (thisObj);
			return string_obj.ToLower ();
		}

		[MonoTODO ("I18N Needs checking -- contact flgr@ccan.de for details")]
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_toLocaleUpperCase)]
		public static string toLocaleUpperCase (object thisObj)
		{
			string string_obj = Convert.ToString (thisObj);
			return string_obj.ToUpper ();
		}

		[MonoTODO ("I18N Needs checking -- contact flgr@ccan.de for details")]
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_toLowerCase)]
		public static string toLowerCase (object thisObj)
		{
			string string_obj = Convert.ToString (thisObj);
			return string_obj.ToLower (CultureInfo.InvariantCulture);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_toString)]
		public static string toString (object thisObj)
		{
			if (!Convert.IsString (thisObj))
				throw new JScriptException (JSError.StringExpected);
			else
				return Convert.ToString (thisObj);
		}

		[MonoTODO ("I18N Needs checking -- contact flgr@ccan.de for details")]
		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_toUpperCase)]
		public static string toUpperCase (object thisObj)
		{
			string string_obj = Convert.ToString (thisObj);
			return string_obj.ToUpper (CultureInfo.InvariantCulture);
		}

		[JSFunctionAttribute (JSFunctionAttributeEnum.HasThisObject, JSBuiltin.String_valueOf)]
		public static object valueOf (object thisObj)
		{
			return toString (thisObj);
		}
	}
}