Decode.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Waher.Content;
using Waher.Content.Xml;
using Waher.Runtime.Collections;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Content.Functions.Encoding
{
    public class Decode : FunctionTwoScalarVariables
    {
        public Decode(ScriptNode Content, ScriptNode ContentType, int Start, int Length, Expression Expression)
            : base(Content, ContentType, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(Decode);
 
        public override bool IsAsynchronous => true;
 
        public override bool UpgradeScalarsToSameSet => false;
 
        public override IElement EvaluateScalar(IElement Argument1, IElement Argument2, Variables Variables)
        {
            return this.EvaluateScalarAsync(Argument1, Argument2, Variables).Result;
        }
 
        public override Task<IElement> EvaluateScalarAsync(IElement Argument1, IElement Argument2, Variables Variables)
        {
            if (!(Argument1.AssociatedObjectValue is byte[] Bin))
                throw new BinaryDataExpectedScriptException(this);
 
            string ContentType = Argument2.AssociatedObjectValue is string s2 ? s2 : Expression.ToExpressionString(Argument2.AssociatedObjectValue);
 
            return this.DoDecodeAsync(Bin, ContentType, null);
        }
 
        private async Task<IElement> DoDecodeAsync(byte[] Data, string ContentType, System.Text.Encoding Encoding)
        {
            ContentResponse Content;
 
            if (Encoding is null)
                Content = await InternetContent.DecodeAsync(ContentType, Data, null);
            else
                Content = await InternetContent.DecodeAsync(ContentType, Data, Encoding, Array.Empty<KeyValuePair<string, string>>(), null);
 
            if (Content.HasError)
                throw new ScriptRuntimeException(Content.Error.Message, this, Content.Error);
 
            if (Content.Decoded is string[][] Records)
            {
                int Rows = Records.Length;
                int MaxCols = 0;
                int i, c;
 
                foreach (string[] Rec in Records)
                {
                    if (Rec is null)
                        continue;
 
                    c = Rec.Length;
                    if (c > MaxCols)
                        MaxCols = c;
                }
 
                ChunkedList<IElement> Elements = new ChunkedList<IElement>();
 
                foreach (string[] Rec in Records)
                {
                    i = 0;
 
                    if (!(Rec is null))
                    {
                        foreach (string s in Rec)
                        {
                            if (s is null || string.IsNullOrEmpty(s))
                                Elements.Add(ObjectValue.Null);
                            else if (CommonTypes.TryParse(s, out double dbl))
                                Elements.Add(new DoubleNumber(dbl));
                            else if (CommonTypes.TryParse(s, out bool b))
                                Elements.Add(new BooleanValue(b));
                            else if (XML.TryParse(s, out DateTime TP))
                                Elements.Add(new DateTimeValue(TP));
                            else if (TimeSpan.TryParse(s, out TimeSpan TS))
                                Elements.Add(new ObjectValue(TS));
                            else
                                Elements.Add(new StringValue(s));
 
                            i++;
                        }
                    }
 
                    while (i++ < MaxCols)
                        Elements.Add(new StringValue(string.Empty));
                }
 
                return Operators.Matrices.MatrixDefinition.Encapsulate(Elements, Rows, MaxCols, this);
            }
            else
                return Expression.Encapsulate(Content.Decoded);
        }
 
        public override IElement EvaluateScalar(string Argument1, string Argument2, Variables Variables)
        {
            return this.EvaluateScalarAsync(Argument1, Argument2, Variables).Result;
        }
 
        public override Task<IElement> EvaluateScalarAsync(string Argument1, string Argument2, Variables Variables)
        {
            System.Text.Encoding Encoding = System.Text.Encoding.UTF8;
            byte[] Bin = Encoding.GetBytes(Argument1);
 
            return this.DoDecodeAsync(Bin, Argument2, Encoding);
        }
    }
}