//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="ExpSwitchNode.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. 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 System;
using System.Collections.Frozen;
using System.Collections.Generic;
using System.Text;

namespace StgSharp.Script.Express
{
    public class ExpSwitchNode : ExpSyntaxNode
    {

        private ExpSyntaxNode _default;
        private ExpSyntaxNode _target;

        private FrozenDictionary<ExpSyntaxNode, ExpSyntaxNode> _cases;

        public ExpSwitchNode(
               Token source,
               ExpSyntaxNode target,
               ExpSyntaxNode defaultCase,
               params (ExpSyntaxNode label, ExpSyntaxNode op)[] cases )
            : base( source )
        {
            _target = target;
            _default = defaultCase;
            Dictionary<ExpSyntaxNode, ExpSyntaxNode> casesDic = new Dictionary<ExpSyntaxNode, ExpSyntaxNode>(
                );
            foreach( (ExpSyntaxNode label, ExpSyntaxNode op ) item in cases )
            {
                if( item.op == null )
                {
                    casesDic.Add( item.label, null! );
                } else
                {
                    casesDic.Add( item.label, item.op );
                }
            }
            _cases = casesDic.ToFrozenDictionary();


            string str = @"switch( {0} ){";
            StringBuilder codeFormatBuilder = new StringBuilder();
            codeFormatBuilder.AppendLine( str );
            for( int i = 0; i < casesDic.Count; i++ )
            {
                int index = i * 2 + 1;
                codeFormatBuilder.AppendLine(
                    $$"""
                        case {{{index}}}:
                            {{{index + 1}}}
                            break;
                    """ );
            }
            CodeConvertTemplate = codeFormatBuilder.ToString();
        }

        public ExpSwitchNode(
               Token source,
               ExpSyntaxNode target,
               ExpSyntaxNode defaultCase,
               IDictionary<ExpSyntaxNode, ExpSyntaxNode> cases )
            : base( source )
        {
            _target = target;
            _default = defaultCase;
            _cases = cases.ToFrozenDictionary();

            string str = @"switch( {0} ){";
            StringBuilder codeFormatBuilder = new StringBuilder();
            codeFormatBuilder.AppendLine( str );
            for( int i = 0; i < cases.Count; i++ )
            {
                int index = i * 2 + 1;
                codeFormatBuilder.AppendLine(
                    $$"""
                        case {{{index}}}:
                            {{{index + 1}}}
                            break;
                    """ );
            }
            CodeConvertTemplate = codeFormatBuilder.ToString();
        }

        public ExpSyntaxNode this[ ExpSyntaxNode index ]
        {
            get
            {
                if( _cases.TryGetValue( index, out ExpSyntaxNode? ret ) ) {
                    return ret;
                }
                return _default;
            }
        }

        public override ExpSyntaxNode Left => Empty;

        public override ExpSyntaxNode Right => Empty;

        public override IExpElementSource EqualityTypeConvert => null!;

        public bool ContainsCase( ExpSyntaxNode token )
        {
            return _cases.ContainsKey( token );
        }

    }
}