//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="RegexInterpreter.IRGenerate"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//     
// 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 StgSharp.RegularAnalysis.Abstraction;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace StgSharp.RegularAnalysis.TextRegex
{
    public partial class RegexInterpreter
    {

        private List<RegexIR> EmptyIR { get; } = [];

        internal List<RegexIR> GenerateIR(
                               AbstractSyntaxTree<RegexAstNode, RegexElementLabel> tree
        )
        {
            return GenerateIRRecursion(tree.Root, 0);
        }

        private List<RegexIR> GenerateIRRecursion(
                              RegexAstNode node,
                              int depth
        )
        {
            if (depth > 1024) {
                throw new OverflowException("Regex parse exceeds maximum recursion depth");
            }
            int curDepth = depth;
            RegexAstNode left = node.Left;
            RegexAstNode right = node.Right;
            List<RegexIR> leftIR = EmptyIR;
            List<RegexIR> rightIR = EmptyIR;

            bool isLeftOperator = !RegexAstNode.IsNullOrEmpty(left) &&
                                  (left.Source.Flag & RegexElementLabel.OPERATOR) != 0;
            bool isRightOperator = !RegexAstNode.IsNullOrEmpty(right) &&
                                   (right.Source.Flag & RegexElementLabel.OPERATOR) != 0;

            Token<RegexElementLabel> token = node.Source;

            switch (node.Source.Flag)
            {
                case RegexElementLabel.GROUP_BEGIN:
                    string group_source = token.Value;
                    bool is_group = group_source.Length == 1;
                    string group_name = group_source.StartsWith(@"(?<", StringComparison.Ordinal) ?
                                        group_source[3..^2] :
                                        string.Empty;

                    List<RegexIR> groupIR = [];
                    rightIR = GenerateIRRecursion(right, curDepth + 1);
                    groupIR.Add(RegexIR.Try(rightIR.Count));
                    groupIR.AddRange(rightIR);
                    groupIR.Add(RegexIR.Condition(2, 1));
                    groupIR.Add(RegexIR.PopLevel(false));
                    groupIR.Add(RegexIR.PopLevel(true));
                    break;
                case RegexElementLabel.COUNT:
                    break;
                case RegexElementLabel.CONCAT:
                    break;
                case RegexElementLabel.ALT:
                    break;
                default:
                    break;
            }

            return [];
        }

    }
}