/*
 *                     GNU AFFERO GENERAL PUBLIC LICENSE
 *                       Version 3, 19 November 2007
 *  Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 *  Everyone is permitted to copy and distribute verbatim copies
 *  of this license document, but changing it is not allowed.
 */

using System;
using System.IO;
using System.Text.RegularExpressions;

namespace UVtools.Core.Scripting
{
    public static class ScriptParser
    {
        public static string ParseScriptFromFile(string path)
        {
            return ParseScriptFromText(File.ReadAllText(path));
        }

        /// <summary>
        /// Parse the script and clean forbidden keywords
        /// </summary>
        /// <param name="text">Text to parse</param>
        /// <returns>The parsed text</returns>
        public static string ParseScriptFromText(string text)
        {
            if(!Regex.Match(text, @"(void\s*ScriptInit\s*\(\s*\))").Success)
            {
                throw new ArgumentException("The method \"void ScriptInit()\" was not found on script, please verify the script.");
            }
            if (!Regex.Match(text, @"(string\s*ScriptValidate\s*\(\s*\))").Success)
            {
                throw new ArgumentException("The method \"string ScriptValidate()\" was not found on script, please verify the script.");
            }
            if (!Regex.Match(text, @"(bool\s*ScriptExecute\s*\(\s*\))").Success)
            {
                throw new ArgumentException("The method \"bool ScriptExecute()\" was not found on script, please verify the script.");
            }

            var textLength = text.Length;
            sbyte bracketsToRemove = 0;
            text = Regex.Replace(text, @"(namespace .*\n*.*{)", string.Empty);
            if (textLength != text.Length) bracketsToRemove++;
            textLength = text.Length;
            text = Regex.Replace(text, "(.*class .*\n*.*{)", string.Empty);
            if (textLength != text.Length) bracketsToRemove++;

            if (bracketsToRemove <= 0) return text;

            for (textLength = text.Length - 1; textLength >= 0 && bracketsToRemove > 0; textLength--)
            {
                if (text[textLength] == '}') bracketsToRemove--;
            }

            return text.Substring(0, textLength);
        }
    }
}