/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

Part of Core Audio AUInstrument Base Classes

*/

#ifndef __SynthNoteList__

#define __SynthNoteList__

#include "SynthNote.h"

#if DEBUG

#ifndef DEBUG_PRINT

    #define DEBUG_PRINT 0

#endif

    #define USE_SANITY_CHECK 0

#endif

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

struct SynthNoteList

{

    SynthNoteList() : mState(kNoteState_Unset), mHead(0), mTail(0) {}

    bool NotEmpty() const { return mHead != NULL; }

    bool IsEmpty() const { return mHead == NULL; }

    void Empty() { 

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        mHead = mTail = NULL; 

    }

    UInt32 Length() const {

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        UInt32 length = 0;

        for (SynthNote* note = mHead; note; note = note->mNext) 

            length++;

        return length;

    };

    void AddNote(SynthNote *inNote)

    {

#if DEBUG_PRINT

        printf("AddNote(inNote=%p) to state: %lu\n", inNote, mState);

#endif

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        inNote->SetState(mState);

        inNote->mNext = mHead;

        inNote->mPrev = NULL;

        if (mHead) { mHead->mPrev = inNote; mHead = inNote; }

        else mHead = mTail = inNote;

#if USE_SANITY_CHECK

        SanityCheck();

#endif

    }

    void RemoveNote(SynthNote *inNote)

    {

#if DEBUG_PRINT

        printf("RemoveNote(inNote=%p) from state: %lu\n", inNote, mState);

#endif

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        if (inNote->mPrev) inNote->mPrev->mNext = inNote->mNext;

        else mHead = inNote->mNext;

        if (inNote->mNext) inNote->mNext->mPrev = inNote->mPrev;

        else mTail = inNote->mPrev;

        inNote->mPrev = 0;

        inNote->mNext = 0;

#if USE_SANITY_CHECK

        SanityCheck();

#endif

    }

    void TransferAllFrom(SynthNoteList *inNoteList, UInt32 inFrame)

    {

#if DEBUG_PRINT

        printf("TransferAllFrom: from state %lu into state %lu\n", inNoteList->mState, mState);

#endif

#if USE_SANITY_CHECK

        SanityCheck();

        inNoteList->SanityCheck();

#endif

        if (!inNoteList->mTail) return;

        if (mState == kNoteState_Released)

        {

            for (SynthNote* note = inNoteList->mHead; note; note = note->mNext)

            {

#if DEBUG_PRINT

                printf("TransferAllFrom: releasing note %p\n", note);

#endif

                note->Release(inFrame);

                note->SetState(mState);

            }

        }

        else

        {

            for (SynthNote* note = inNoteList->mHead; note; note = note->mNext)

            {

                note->SetState(mState);

            }

        }

        inNoteList->mTail->mNext = mHead;

        if (mHead) mHead->mPrev = inNoteList->mTail;

        else mTail = inNoteList->mTail;

        mHead = inNoteList->mHead;

        inNoteList->mHead = NULL;

        inNoteList->mTail = NULL;

#if USE_SANITY_CHECK

        SanityCheck();

        inNoteList->SanityCheck();

#endif

    }

    SynthNote* FindOldestNote()

    {

#if DEBUG_PRINT

        printf("FindOldestNote\n");

#endif

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        UInt64 minStartFrame = -1;

        SynthNote* oldestNote = NULL;

        for (SynthNote* note = mHead; note; note = note->mNext)

        {

            if (note->mAbsoluteStartFrame < minStartFrame)

            {

                oldestNote = note;

                minStartFrame = note->mAbsoluteStartFrame;

            }

        }

        return oldestNote;

    }

    SynthNote* FindMostQuietNote()

    {

#if DEBUG_PRINT

        printf("FindMostQuietNote\n");

#endif

        Float32 minAmplitude = 1e9f;

        UInt64 minStartFrame = -1;

        SynthNote* mostQuietNote = NULL;

        for (SynthNote* note = mHead; note; note = note->mNext)

        {

            Float32 amp = note->Amplitude();

#if DEBUG_PRINT

            printf("   amp %g   minAmplitude %g\n", amp, minAmplitude);

#endif

            if (amp < minAmplitude)

            {

                mostQuietNote = note;

                minAmplitude = amp;

                minStartFrame = note->mAbsoluteStartFrame;

            }

            else if (amp == minAmplitude && note->mAbsoluteStartFrame < minStartFrame)

            {

                // use earliest start time as a tie breaker

                mostQuietNote = note;

                minStartFrame = note->mAbsoluteStartFrame;

            }

        }

#if USE_SANITY_CHECK

        SanityCheck();

#endif

        return mostQuietNote;

    }

    void SanityCheck() const;

    SynthNoteState  mState;

    SynthNote *     mHead;

    SynthNote *     mTail;

};

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

#endif