//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="ExpRepeatNode.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.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Channels;

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

        private ExpElementInstance _variable;
        private ExpSyntaxNode _begin, _end, _increment, _operationBegin,_untilRule,_whileRule;

        internal ExpRepeatNode(
                 Token source,
                 ExpElementInstance variable,
                 ExpSyntaxNode begin,
                 ExpSyntaxNode end,
                 ExpSyntaxNode increment,
                 ExpSyntaxNode operationBegin,
                 ExpSyntaxNode untilRule,
                 ExpSyntaxNode whileRule)
            : base(source)
        {
            if (variable.NodeFlag != begin.NodeFlag ||
                begin.NodeFlag != end.NodeFlag ||
                (increment != null && end.NodeFlag != increment.NodeFlag)) {
                throw new InvalidCastException();
            }
            if (IsNullOrEmpty(increment))
            {
                switch ((ExpNodeFlag)variable.NodeFlag | ExpNodeFlag.BuiltinType_Any)
                {
                    case ExpNodeFlag.BuiltinType_Real:
                        increment = new ExpRealNumberNode(
                            new Token(
                                ExpressCompile.PoolString("1.0f"), source.Line, -1,
                                TokenFlag.Number),
                            1.0f, isLiteral:true);
                        break;
                    case ExpNodeFlag.BuiltinType_Int:
                        increment = new ExpIntNode(
                            new Token(
                                ExpressCompile.PoolString("1"), source.Line, -1, TokenFlag.Number),
                            1, isLiteral:true);
                        break;
                    default:
                        throw new ExpInvalidTypeException(variable, "Int or Real", "otherwise");
                }
            }
            _variable = variable;
            _begin = begin;
            _end = end;
            _increment = increment!;
            _operationBegin = operationBegin;
            _untilRule = untilRule;
            _whileRule = whileRule;
        }

        public override ExpSyntaxNode Left => throw new NotImplementedException();

        public override ExpSyntaxNode Right => _operationBegin;

        public override IExpElementSource EqualityTypeConvert => null!;

        public void AppendRepeatedOperation(ExpSyntaxNode node)
        {
            _operationBegin.AppendNode(node);
        }

        /// <summary>
        ///   Create an AST node for repeat expression in EXPRESS language. The loop does not has
        ///   WHILE and UNTIL regulation.
        /// </summary>
        /// <param name="t">
        ///   AllocatorHandle of the loop.
        /// </param>
        /// <param name="repeatVariable">
        ///   The variable recording increment by step.
        /// </param>
        /// <param name="begin">
        ///   Beginning value of the loop.
        /// </param>
        /// <param name="end">
        ///   When <see href="repeatVariable" /> reach the value, the loop ends.
        /// </param>
        /// <param name="repeatBody">
        ///   Expressions to operate multiple times.
        /// </param>
        /// <returns>
        ///   A <see cref="ExpRepeatNode" /> representing the repeat expression.
        /// </returns>
        public static ExpRepeatNode Create(
                                    Token t,
                                    ExpInstanceReferenceNode repeatVariable,
                                    ExpSyntaxNode begin,
                                    ExpSyntaxNode end,
                                    ExpSyntaxNode increment,
                                    ExpSyntaxNode whileRule,
                                    ExpSyntaxNode untilRule,
                                    ExpSyntaxNode body)
        {
            untilRule = ExpBoolNode.False(null);
            whileRule = ExpBoolNode.True(null);
            ExpRepeatNode ret = new ExpRepeatNode(
                t, repeatVariable.OriginObject, begin, end, increment, body, whileRule, untilRule)
            {
                /*
                 * 0: variable name
                 * 1: beginning value
                 * 2: ending value
                 * 3: increment
                 * 4: body
                 * 5: while
                 * 6: until
                 */

                CodeConvertTemplate = $$"""
                for( {0} = {1}; {0} <= {2}; {0} += {3})
                {
                    if(!( {5} )) break;
                    {4}
                    if( {6} ) break;
                }
                """
            };
            return ret;
        }

        public static ExpRepeatNode Create(
                                    Token t,
                                    ExpElementInstance repeatVariable,
                                    ExpSyntaxNode begin,
                                    ExpSyntaxNode end,
                                    ExpSyntaxNode increment,
                                    ExpSyntaxNode whileRule,
                                    ExpSyntaxNode untilRule,
                                    ExpSyntaxNode body)
        {
            whileRule = IsNullOrEmpty(whileRule) ? ExpBoolNode.True(t) : whileRule;
            untilRule = IsNullOrEmpty(untilRule) ? ExpBoolNode.False(t) : untilRule;
            ExpRepeatNode ret = new ExpRepeatNode(
                t, repeatVariable, begin, end, increment, body, whileRule, untilRule)
            {
                /*
                 * 0: variable name
                 * 1: beginning value
                 * 2: ending value
                 * 3: increment
                 * 4: body
                 * 5: while
                 * 6: until
                 */

                CodeConvertTemplate = $$"""
                for({{repeatVariable.TypeName}} {0} = {1}; {0} <= {2}; {0} += {3})
                {
                    if(!( {5} )) break;
                    {4}
                    if( {6} ) break;
                }
                """
            };
            return ret;
        }

    }
}