using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.IO;

namespace Cosmos.Compiler.Assembler {
  public class DataMember : BaseAssemblerElement, IComparable<DataMember> {
    public const string IllegalIdentifierChars = "&.,+$<>{}-`\'/\\ ()[]*!=";
    public static string GetStaticFieldName(FieldInfo aField) {
      return FilterStringForIncorrectChars("static_field__" + MethodInfoLabelGenerator.GetFullName(aField.DeclaringType) + "." + aField.Name);
    }

    public static string FilterStringForIncorrectChars(string aName) {
      string xTempResult = aName;
      foreach (char c in IllegalIdentifierChars) {
        xTempResult = xTempResult.Replace(c, '_');
      }
      return String.Intern(xTempResult);
    }

    public DataMember(string aName, Stream aData) {
      Name = aName;
      RawDefaultValue = new byte[aData.Length];
      aData.Read(RawDefaultValue, 0, RawDefaultValue.Length);
    }

    public string Name { get; private set; }
    public bool IsComment { get; set; }
    public byte[] RawDefaultValue { get; set; }
    public uint Alignment { get; set; }
    protected object[] UntypedDefaultValue;

    protected DataMember(string aName) {
      Name = aName;
    }

    public DataMember(string aName, params object[] aDefaultValue) {
      Name = aName;
      UntypedDefaultValue = aDefaultValue;
    }

    public DataMember(string aName, string aValue) {
      Name = aName;
      var xBytes = ASCIIEncoding.ASCII.GetBytes(aValue);
      var xBytes2 = new byte[xBytes.Length + 1];
      xBytes.CopyTo(xBytes2, 0);
      xBytes2[xBytes2.Length - 1] = 0;
      RawDefaultValue = xBytes2;
    }

    public DataMember(string aName, byte[] aDefaultValue) {
      Name = aName;
      RawDefaultValue = aDefaultValue;
      //UntypedDefaultValue = aDefaultValue;
    }

    public DataMember(string aName, short[] aDefaultValue) {
      Name = aName;
      RawDefaultValue = new byte[aDefaultValue.Length * 2];
      for (int i = 0; i < aDefaultValue.Length; i++) {
        Array.Copy(BitConverter.GetBytes(aDefaultValue[i]), 0,
                    RawDefaultValue, i * 2, 2);
      }
      //UntypedDefaultValue = aDefaultValue;
    }

    public DataMember(string aName, params ushort[] aDefaultValue) {
      Name = aName;
      RawDefaultValue = new byte[aDefaultValue.Length * 2];
      for (int i = 0; i < aDefaultValue.Length; i++) {
        Array.Copy(BitConverter.GetBytes(aDefaultValue[i]), 0,
                    RawDefaultValue, i * 2, 2);
      }
      //UntypedDefaultValue = aDefaultValue;
    }

    public DataMember(string aName, params uint[] aDefaultValue) {
      Name = aName;
      //RawDefaultValue = new byte[aDefaultValue.Length * 4];
      //for (int i = 0; i < aDefaultValue.Length; i++) {
      //    Array.Copy(BitConverter.GetBytes(aDefaultValue[i]), 0,
      //                RawDefaultValue, i * 4, 4);
      //}
      UntypedDefaultValue = aDefaultValue.Cast<object>().ToArray();
    }

    public DataMember(string aName, params int[] aDefaultValue) {
      Name = aName;
      //RawDefaultValue = new byte[aDefaultValue.Length * 4];
      //for (int i = 0; i < aDefaultValue.Length; i++) {
      //    Array.Copy(BitConverter.GetBytes(aDefaultValue[i]), 0,
      //                RawDefaultValue, i * 4, 4);
      //}
      UntypedDefaultValue = aDefaultValue.Cast<object>().ToArray();
    }

    public override void WriteText(Assembler aAssembler, TextWriter aOutput) {
      if (RawDefaultValue != null) {
        if (RawDefaultValue.Length == 0) {
          aOutput.Write(Name);
          aOutput.Write(":");
          return;
        }
        if ((from item in RawDefaultValue
             group item by item
               into i
               select i).Count() > 1 || RawDefaultValue.Length < 250) {
          if (IsGlobal) {
            aOutput.Write("global ");
            aOutput.WriteLine(Name);
          }
          aOutput.Write(Name);
          aOutput.Write(" db ");
          for (int i = 0; i < (RawDefaultValue.Length - 1); i++) {
            aOutput.Write(RawDefaultValue[i]);
            aOutput.Write(", ");
          }
          aOutput.Write(RawDefaultValue.Last());
        } else {
          //aOutputWriter.WriteLine("TIMES 0x50000 db 0");
          aOutput.Write("global ");
          aOutput.WriteLine(Name);
          aOutput.Write(Name);
          aOutput.Write(": TIMES ");
          aOutput.Write(RawDefaultValue.Length);
          aOutput.Write(" db ");
          aOutput.Write(RawDefaultValue[0]);
        }
        return;
      }
      if (UntypedDefaultValue != null) {
        StringBuilder xSB = new StringBuilder();
        if (IsGlobal) {
          aOutput.Write("global ");
          aOutput.WriteLine(Name);
        }
        aOutput.Write(Name);
        aOutput.Write(" dd ");
        Func<object, string> xGetTextForItem = delegate(object aItem) {
                                                     var xElementRef = aItem as ElementReference;
                                                     if (xElementRef == null) {
                                                       return (aItem ?? 0).ToString();
                                                     } else {
                                                       if (xElementRef.Offset == 0) {
                                                         return xElementRef.Name;
                                                       }
                                                       return xElementRef.Name + " + " + xElementRef.Offset;
                                                     }
                                                   };
        for (int i = 0; i < (UntypedDefaultValue.Length - 1); i++) {
          aOutput.Write(xGetTextForItem(UntypedDefaultValue[i]));
          aOutput.Write(", ");
        }
        aOutput.Write(xGetTextForItem(UntypedDefaultValue.Last()));
        return;
      }
      throw new Exception("Situation unsupported!");
    }

    public int CompareTo(DataMember other) {
      return String.Compare(Name, other.Name);
    }

    public bool IsGlobal {
      get;
      set;
    }

    public override ulong? ActualAddress {
      get {
        // TODO: for now, we dont have any data alignment
        return StartAddress;
      }
    }

    public override void UpdateAddress(Assembler aAssembler, ref ulong xAddress) {
      if (Alignment > 0) {
        if (xAddress % Alignment != 0) {
          xAddress += Alignment - (xAddress % Alignment);
        }
      }
      base.UpdateAddress(aAssembler, ref xAddress);
      if (RawDefaultValue != null) {
        xAddress += (ulong)RawDefaultValue.LongLength;
      }
      if (UntypedDefaultValue != null) {
        // TODO: what to do with 64bit target platforms? right now we only support 32bit
        xAddress += (ulong)(UntypedDefaultValue.LongLength * 4);
      }
    }

    public override bool IsComplete(Assembler aAssembler) {
      if (UntypedDefaultValue != null &&
          UntypedDefaultValue.LongLength > 0) {
        foreach (var xReference in (from item in UntypedDefaultValue
                                    let xRef = item as ElementReference
                                    where xRef != null
                                    select xRef)) {
          var xRef = aAssembler.TryResolveReference(xReference);
          if (xRef == null) {
            return false;
          } else if (!xRef.IsComplete(aAssembler)) {
            return false;
          }
        }
      }
      return true;
    }

    public override byte[] GetData(Assembler aAssembler) {
      if (UntypedDefaultValue != null &&
          UntypedDefaultValue.LongLength > 0) {
        var xBuff = (byte[])Array.CreateInstance(typeof(byte), UntypedDefaultValue.LongLength * 4);
        for (int i = 0; i < UntypedDefaultValue.Length; i++) {
          var xRef = UntypedDefaultValue[i] as ElementReference;
          byte[] xTemp;
          if (xRef != null) {
            var xTheRef = aAssembler.TryResolveReference(xRef);
            if (xTheRef == null) {
              throw new Exception("Reference not found!");
            }
            if (!xTheRef.ActualAddress.HasValue) {
              Console.Write("");
            }
            xTemp = BitConverter.GetBytes(xTheRef.ActualAddress.Value);
          } else {
            if (UntypedDefaultValue[i] is int) {
              xTemp = BitConverter.GetBytes((int)UntypedDefaultValue[i]);
            } else {
              if (UntypedDefaultValue[i] is uint) {
                xTemp = BitConverter.GetBytes((uint)UntypedDefaultValue[i]);
              } else {
                throw new Exception("Invalid value inside UntypedDefaultValue");
              }
            }
          }
          Array.Copy(xTemp, 0, xBuff, i * 4, 4);
        }
        return xBuff;
      }
      return RawDefaultValue;
    }

    public override void WriteData(Assembler aAssembler, Stream aOutput) {
      if (UntypedDefaultValue != null &&
          UntypedDefaultValue.LongLength > 0) {
        //var xBuff = (byte[])Array.CreateInstance(typeof(byte), UntypedDefaultValue.LongLength * 4);
        for (int i = 0; i < UntypedDefaultValue.Length; i++) {
          var xRef = UntypedDefaultValue[i] as ElementReference;
          //byte[] xTemp;
          if (xRef != null) {
            var xTheRef = aAssembler.TryResolveReference(xRef);
            if (xTheRef == null) {
              throw new Exception("Reference not found!");
            }
            if (!xTheRef.ActualAddress.HasValue) {
              Console.Write("");
            }
            aOutput.Write(BitConverter.GetBytes(xTheRef.ActualAddress.Value), 0, 4);
            //xTemp = BitConverter.GetBytes();
          } else {
            if (UntypedDefaultValue[i] is int) {
              aOutput.Write(BitConverter.GetBytes((int)UntypedDefaultValue[i]), 0, 4);
              //xTemp = BitConverter.GetBytes((int)UntypedDefaultValue[i]);
            } else {
              if (UntypedDefaultValue[i] is uint) {
                aOutput.Write(BitConverter.GetBytes((uint)UntypedDefaultValue[i]), 0, 4);

                //xTemp = BitConverter.GetBytes((uint)UntypedDefaultValue[i]);
              } else {
                throw new Exception("Invalid value inside UntypedDefaultValue");
              }
            }
          }
          //Array.Copy(xTemp, 0, xBuff, i * 4, 4);
        }
      } else {
        aOutput.Write(RawDefaultValue, 0, RawDefaultValue.Length);
      }
    }
  }
}