// These classes use a generic enumerator implementation to create the various enumerators required by the engine.
// They allow the enumeration of everything from programs to breakpoints.

using Microsoft.VisualStudio;
using Microsoft.VisualStudio.Debugger.Interop;

namespace Cosmos.VS.DebugEngine.AD7.Impl {
  #region Base Class
  class AD7Enum<T, I> where I : class {
    readonly T[] m_data;
    uint m_position;

    public AD7Enum(T[] data) {
      m_data = data;
      m_position = 0;
    }

    public int Clone(out I ppEnum) {
      ppEnum = null;
      return VSConstants.E_NOTIMPL;
    }

    public int GetCount(out uint pcelt) {
      pcelt = (uint)m_data.Length;
      return VSConstants.S_OK;
    }

    public int Next(uint celt, T[] rgelt, out uint celtFetched) {
      return Move(celt, rgelt, out celtFetched);
    }

    public int Reset() {
      lock (this) {
        m_position = 0;

        return VSConstants.S_OK;
      }
    }

    public int Skip(uint celt) {
      uint celtFetched;

      return Move(celt, null, out celtFetched);
    }

    private int Move(uint celt, T[] rgelt, out uint celtFetched) {
      lock (this) {
        int hr = VSConstants.S_OK;
        celtFetched = (uint)m_data.Length - m_position;

        if (celt > celtFetched) {
          hr = VSConstants.S_FALSE;
        } else if (celt < celtFetched) {
          celtFetched = celt;
        }

        if (rgelt != null) {
          for (int c = 0; c < celtFetched; c++) {
            rgelt[c] = m_data[m_position + c];
          }
        }

        m_position += celtFetched;

        return hr;
      }
    }
  }
  #endregion Base Class

  class AD7ProgramEnum : AD7Enum<IDebugProgram2, IEnumDebugPrograms2>, IEnumDebugPrograms2 {
    public AD7ProgramEnum(IDebugProgram2[] data)
      : base(data) {
    }

    public int Next(uint celt, IDebugProgram2[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

  class AD7FrameInfoEnum : AD7Enum<FRAMEINFO, IEnumDebugFrameInfo2>, IEnumDebugFrameInfo2 {
    public AD7FrameInfoEnum(FRAMEINFO[] data)
      : base(data) {
    }

    public int Next(uint celt, FRAMEINFO[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

  class AD7PropertyInfoEnum : AD7Enum<DEBUG_PROPERTY_INFO, IEnumDebugPropertyInfo2>, IEnumDebugPropertyInfo2 {
    public AD7PropertyInfoEnum(DEBUG_PROPERTY_INFO[] data)
      : base(data) {
    }
  }

  class AD7ThreadEnum : AD7Enum<IDebugThread2, IEnumDebugThreads2>, IEnumDebugThreads2 {
    public AD7ThreadEnum(IDebugThread2[] threads)
      : base(threads) {

    }

    public int Next(uint celt, IDebugThread2[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

  class AD7ModuleEnum : AD7Enum<IDebugModule2, IEnumDebugModules2>, IEnumDebugModules2 {
    public AD7ModuleEnum(IDebugModule2[] modules)
      : base(modules) {

    }

    public int Next(uint celt, IDebugModule2[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

  class AD7PropertyEnum : AD7Enum<DEBUG_PROPERTY_INFO, IEnumDebugPropertyInfo2>, IEnumDebugPropertyInfo2 {
    public AD7PropertyEnum(DEBUG_PROPERTY_INFO[] properties)
      : base(properties) {

    }
  }

  class AD7CodeContextEnum : AD7Enum<IDebugCodeContext2, IEnumDebugCodeContexts2>, IEnumDebugCodeContexts2 {
    public AD7CodeContextEnum(IDebugCodeContext2[] codeContexts)
      : base(codeContexts) {

    }

    public int Next(uint celt, IDebugCodeContext2[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

  class AD7BoundBreakpointsEnum : AD7Enum<IDebugBoundBreakpoint2, IEnumDebugBoundBreakpoints2>, IEnumDebugBoundBreakpoints2 {
    public AD7BoundBreakpointsEnum(IDebugBoundBreakpoint2[] breakpoints)
      : base(breakpoints) {

    }

    public int Next(uint celt, IDebugBoundBreakpoint2[] rgelt, ref uint celtFetched) {
      return Next(celt, rgelt, out celtFetched);
    }
  }

}