using FastReport.Code;
using FastReport.Data;
using FastReport.Utils;
using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace FastReport
{
    public partial class Report
    {

#if REFLECTION_EMIT_COMPILER
        private readonly Dictionary<string, string> _cachedParsedExpressions = new Dictionary<string, string>();
        private Code.Expressions.ILParser _ilParser;


        private bool IsCompileNeeded { get; set; }
#endif

        #region Script related

#if REFLECTION_EMIT_COMPILER
        private void SetIsCompileNeeded()
        {
            // we check report object to AdvMatrix, because this object doesn't work without compilation
            if (!scriptChanged)
            {
                foreach (var reportObject in AllObjects)
                {
                    if (reportObject is ReportComponentBase reportObj)
                        if (reportObj.IsCompilationNeeded)
                        {
                            IsCompileNeeded = true;
                            break;
                        }
                }
            }
            else
                IsCompileNeeded = scriptChanged;

            if (!IsCompileNeeded)
                _ilParser = Code.Expressions.ILParser.Create(this);
        }

        private bool TryReflectionEmit(string expression, Variant value, out object returnValue)
        {
            returnValue = null;
            if (IsCompileNeeded) return false;

            try
            {
                if (!_cachedParsedExpressions.TryGetValue(expression, out var result))
                {
                    result = expression;
                    // TODO: optimize
                    if (DataHelper.IsValidColumn(Report.Dictionary, expression))
                        result = "[" + expression + "]";

                    result = AssemblyDescriptor.ReplaceDataItems(this, result);
                    _cachedParsedExpressions.Add(expression, result);
                }

                returnValue = _ilParser.StartDynamic(result, this, value);
                return true;
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"ERROR in compilation expression {expression}, message: {ex.Message}");
                Config.WriteLogString(ex.Message);
                return false;
            }
        }
#endif

        #endregion Script related

    }
}