Laborejo/engine/api.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2022, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),

Laborejo2 is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import logging; logger = logging.getLogger(__name__); logger.info("import")

#Python Standard Library
import sys
import random
random.seed()
from typing import Iterable, Callable, Tuple

#Template Modules
from template.calfbox import cbox
import template.engine.api #we need direct access to the module to inject data in the provided structures. but we also need the functions directly. next line:
from template.engine.api import *
from template.engine.duration import DM, DB, DL, D1, D2, D4, D8, D16, D32, D64, D128, D256, D512, D1024, D_DEFAULT, D_STACCATO, D_TENUTO, D_TIE
import template.engine.pitch as pitchmath
from template.helper import flatList, EndlessGenerator

#Our Modules
from . import items
from . import lilypond
from .tempotrack import TempoItem, TempoTrack
from .ccsubtrack import GraphItem, GraphTrackCC
from .track import Track

apiModuleSelfReference = sys.modules[__name__]

#New callbacks
class ClientCallbacks(Callbacks): #inherits from the templates api callbacks
    def __init__(self):
        super().__init__()

        self.setCursor = []
        self.setSelection = []

        self.tracksChanged = []
        self.tracksChangedIncludingHidden = []
        self.updateTrack = []
        self.updateBlockTrack = []

        #self.playbackStart = []
        #self.playbackStop = []
        self._cachedTickIndex = -1

        self.updateGraphTrackCC = []
        self.graphCCTracksChanged = []
        self.updateGraphBlockTrack = []

        self.updateTempoTrack = []
        self.updateTempoTrackBlocks = []
        self.updateTempoTrackMeta = []
        self.tempoScalingChanged = []

        self.prevailingBaseDurationChanged = []

        #self.recordingStreamNoteOn = []
        #self.recordingStreamNoteOff = []
        #self.recordingStreamClear = []

    def _dataChanged(self):
        """Only called from within the callbacks.
        This is about data the user cares about. In other words this is the indicator if you need
        to save again.

        The data changed when notes are inserted, track names are changed, a CC value is added etc.
        but not when the cursor moves, the metronome is generated or the playback tick advances.
        """
        session.nsmClient.announceSaveStatus(False)
        self._historyChanged()

    def _setCursor(self, destroySelection = True):
        """set a new cursor position.
        Only do destroySelection = False if you really modify the
        selection. If in doubt: destroy it. """
        if destroySelection or session.history.doNotRegisterRightNow or session.history.duringRedo:
            session.data.cursorWhenSelectionStarted = None

        if self.setCursor:
            ex = session.data.cursorExport()
            for func in self.setCursor:
                func(ex)

        """Exports a tuple of cursors. This is to indicate a GUI to
        draw a selection rectangle or so. Not for processing. Because:
        The exported top left item is included in the selection.
        The exported bottom right item is NOT in the selection.
        But for a GUI it looks like the rectangle goes to the current
        cursor position, which appears to be left of the current item."""
        ex = session.data.selectionExport()
        for func in self.setSelection:
            func(ex)

    def _updateChangedTracks(self):
        """Determines which tracks have changed in the step before
        this callback and calls an update for those"""
        changedTracks, currentItem = session.data.currentContentLinkAndItsBlocksInAllTracks()
        for track in changedTracks:
            self._updateTrack(id(track))
            if session.data.currentMetronomeTrack is track:
                setMetronome(track.asMetronomeData, label=track.name) #template api

    def _updateTrack(self, trId):
        """The most important function. Create a static representation of the music data which
        can be used by a GUI to draw notes.
        track.staticRepresentation also creates the internal midi representation for cbox. """
        if self.updateTrack:
            ex = session.data.trackById(trId).staticRepresentation()
            for func in self.updateTrack:
                func(trId, ex)
            self._updateBlockTrack(trId)

    def _updateBlockTrack(self, trId):
        if self.updateBlockTrack:
            ex = session.data.trackById(trId).staticBlocksRepresentation()
            for func in self.updateBlockTrack:
                func(trId, ex)

        self._updateTempoTrack() #The last Tempo Block reacts to changing score sizes.
        self._dataChanged()

    def _updateGraphTrackCC(self, trId, cc):
        """No cursor, so it always needs a graphTrack Id.
        Also handles a GraphBlock overview callback,
        for extra block view or background colors."""
        track = session.data.trackById(trId)
        if cc in track.ccGraphTracks:
            graphTracksThatNeedUpdate = track.ccGraphTracks[cc].otherTracksWithOurLinkedContent()

            for gTr in graphTracksThatNeedUpdate:
                trId = id(gTr.parentTrack)
                ex = gTr.staticRepresentation()

                for func in self.updateGraphTrackCC:
                    func(trId, cc, ex)

                ex = gTr.staticGraphBlocksRepresentation()
                for func in self.updateGraphBlockTrack:
                    func(trId, cc, ex)

    def _updateSingleTrackAllCC(self, trId):
        """Used on CC-Channels change. No own callback list."""
        for cc, graphTrackCC in session.data.trackById(trId).ccGraphTracks.items():
            ex = graphTrackCC.staticRepresentation()
            for func in self.updateGraphTrackCC:
                func(trId, cc, ex)

    def _graphCCTracksChanged(self, trId):
        """CC graphs of a track deleted or added.
        Does not need to react to block or item changes, even (not) block duration changes
        which change the tracks overall duration!"""
        #TODO: moved?
        if self.graphCCTracksChanged:
            ex = list(session.data.trackById(trId).ccGraphTracks.keys())  # list of ints from 0 to 127
            for func in self.graphCCTracksChanged:
                func(trId, ex)
        self._dataChanged()

    def _tracksChanged(self):
        """Track deleted, added or moved. Or toggled double/non-double, visible, eudible etc.
        This callback is relatively cheap because it does not generate
        any item data."""
        #TODO: does NOT call template.api._numberOfTracksChanged
        session.data.updateJackMetadataSorting()
        ex = session.data.listOfStaticTrackRepresentations()

        if self.tracksChanged:
            for func in self.tracksChanged:
                func(ex)

        if self.tracksChangedIncludingHidden:
            exHidden  = session.data.listOfStaticHiddenTrackRepresentations()
            for func in reversed(self.tracksChangedIncludingHidden):
                func(ex + exHidden)
        self._dataChanged()

        session.data.metronome.label = session.data.currentMetronomeTrack.name #not the expensive redundant data generation
        self._metronomeChanged() #because the track name is sent here.

    def _updateTempoTrack(self):
        """Sends the block update as well.
        staticRepresentations also updates midi.

        Of course the order is: track meta, then blocks first, then items.
        This must not change! The GUI depends on it."""

        if self.updateTempoTrackMeta:
            ex = session.data.tempoTrack.staticTrackRepresentation() #only track metadata, no block information. parses all items.
            for func in self.updateTempoTrackMeta:
                func(ex)

        if self.updateTempoTrackBlocks:
            ex = session.data.tempoTrack.staticGraphBlocksRepresentation() #block boundaries and meta data. Does not parse items therefore cheap to call.
            for func in self.updateTempoTrackBlocks:
                func(ex)

        if self.updateTempoTrack:
            ex = session.data.tempoTrack.staticRepresentation() #export all items. performance-expensive.
            for func in self.updateTempoTrack:
                func(ex)

        #TODO: We need blocks before items, but also blocks after items. This is a cheap call though.
        if self.updateTempoTrackBlocks:
            ex = session.data.tempoTrack.staticGraphBlocksRepresentation() #yes, we need to regenerate that. That is the problem. #TODO.
            for func in self.updateTempoTrackBlocks:
                func(ex)

        self._dataChanged()
        #since the exported cursor also has a tempo entry it needs updating as well
        #TODO: but this also leads to centerOn cursor in the gui after every mouse click in the conductor.
        #self._setCursor(destroySelection = False)

    def _tempoScalingChanged(self, newValue):
        for func in self.tempoScalingChanged:
            func(newValue)

    def _playbackStart(self):
        for func in self.playbackStart:
            func()

    def _playbackStop(self):
        for func in self.playbackStop:
            func()


    def _prevailingBaseDurationChanged(self, newPrevailingBaseDuration):
        for func in self.prevailingBaseDurationChanged:
            func(newPrevailingBaseDuration)

    def _historyChanged(self):
        """sends two lists of strings.
        the first is the undoHistory, the last added item is [-1]. We can show that to a user to
        indicate what the next undo will do.

        the second is redoHistory, same as undo: [-1] shows the next redo action."""
        undoHistory, redoHistory = session.history.asList()
        for func in self.historyChanged:
            func(undoHistory, redoHistory)

    def _recordingStreamNoteOn(self, liveChord):
        """One dict at a time"""
        trId = id(session.data.currentTrack())
        for func in self.recordingStreamNoteOn:
            func(trId, liveChord)

    def _recordingStreamNoteOff(self, liveChord):
        """One dict at a time"""
        trId = id(session.data.currentTrack())
        for func in self.recordingStreamNoteOff:
            func(trId, liveChord)

    def _recordingStreamClear(self):
        for func in self.recordingStreamClear:
            func()

#Inject our derived Callbacks into the parent module
template.engine.api.callbacks = ClientCallbacks()
from template.engine.api import callbacks


_templateStartEngine = startEngine
def startEngine(nsmClient, additionalData:dict={}):
    _templateStartEngine(nsmClient)

    #Send initial Data etc.
    session.data.tempoMap.isTransportMaster = True #always true for Laborejo.
    callbacks._tracksChanged()  # This creates the frontend/GUI tracks with access through track ids. From now on we can send the GUI a trId and it knows which track needs change.

    for track in session.data.hiddenTracks: #After loading a file some tracks could be hidden. We want midi for them as well.
        track.staticRepresentation()  #that generates the calfbox data as a side effect. discard the other data.


    #because we do a simplicifaction in _updateGraphTrackCC that calls all tracks for one CC (for content links) we need to build the structure first, only during file load.
    for trId in session.data.listOfTrackIds():
        callbacks._graphCCTracksChanged(trId) #create structure: all CC graphs, accessed by CC number (0-127)

    for trId in session.data.listOfTrackIds():
        callbacks._updateTrack(trId) #create content: music items
        callbacks._updateTempoTrack() # does everything at once
        #done above. Special situation at file load. callbacks._graphCCTracksChanged(trId) #create structure: all CC graphs, accessed by CC number (0-127)
        for cc in session.data.trackById(trId).listOfCCsInThisTrack():
            callbacks._updateGraphTrackCC(trId, cc) #create content: CC points. user points and interpolated points.

    if session.data.currentMetronomeTrack.asMetronomeData:
        setMetronome(session.data.currentMetronomeTrack.asMetronomeData, label=session.data.currentMetronomeTrack.name) #track.asMetronomeData is generated in staticRepresentation  #template api. has callbacks
    callbacks._setCursor()

    if session.data.metaData["title"]:
        cbox.JackIO.Metadata.client_set_property("http://jackaudio.org/metadata/pretty-name", session.data.metaData["title"])

    global laborejoEngineStarted #makes for a convenient check. stepMidiInput uses it, which needs to know that the gui already started the api.
    laborejoEngineStarted = True

#General and abstract Commands

def getMetadata():
    """Do not confuse with template/config METADATA. This is Lilypond title, composer etc."""
    return session.data.metaData

def setMetadata(data):
    titleBefore = bool(session.data.metaData["title"])
    session.data.metaData = data
    if session.data.metaData["title"]:
        cbox.JackIO.Metadata.client_set_property("http://jackaudio.org/metadata/pretty-name", session.data.metaData["title"])
    elif titleBefore:
        cbox.JackIO.Metadata.client_remove_property("http://jackaudio.org/metadata/pretty-name")


def playFromCursor():
    playFrom(ticks=session.data.cursorExport()["tickindex"])

def playFromBlockStart():
    tr = session.data.currentTrack()
    ticks = 0
    for idx, bl in enumerate(tr.blocks):
        if idx == tr.state.blockindex:
            playFrom(ticks)
            return
        else:
            ticks += bl.duration()
    else:
        raise RuntimeError("reached end of blocks without matchin  current block index")


def getMidiInputNameAndUuid()->(str, int): #tuple name:str, uuid
    """Override template function. We access the stepMidi directly.
    Used by the quick midi input widget

    Return name and cboxMidiPortUid.
    name is Client:Port JACK format

    If not return None, None
    """
    from engine.midiinput.stepmidiinput import stepMidiInput  #singleton instance #avoid circular dependency. stepMidiInput import api
    if stepMidiInput.ready: #startup delay
        return stepMidiInput.fullName(), stepMidiInput.cboxMidiPortUid
    else:
        return None, None

topLevelFunction = None
def simpleCommand(function, autoStepLeft = True, forceReturnToItem = None):
    """
    simpleCommand demands that the cursor is on the item you want to
    change. That means for scripting and working with selections
    that you can't simply iterate over block.data, which is a list.
    Well you can, but then you don't get the context data which is in
    track.state.

    Recursive commands are not allowed"""
    global topLevelFunction  #todo: replace with a python-context
    if not topLevelFunction:
        topLevelFunction = function

    if autoStepLeft and session.data.currentTrack().state.isAppending():
        session.data.currentTrack().left()
        function() #<-------- The action
        session.data.currentTrack().right()
    else:
        function() #<-------- The action

    if forceReturnToItem:
        curBlock, curItem = forceReturnToItem
        session.data.currentTrack().toItemInBlock(curItem, curBlock) #even works with appending positions (None)

    if function == topLevelFunction:
        callbacks._updateChangedTracks() #works with the current item @ cursor.
        callbacks._setCursor()
        topLevelFunction = None

def insertItem(item):
    orderBeforeInsert = session.data.getBlockAndItemOrder()
    moveFunction = _createLambdaMoveToForCurrentPosition()
    if session.data.currentTrack().insert(item):
        def registeredUndoFunction():
            moveFunction()
            _changeBlockAndItemOrder(orderBeforeInsert)
        session.history.register(registeredUndoFunction, descriptionString=f"Insert {item}")
        simpleCommand(nothing, autoStepLeft = False) #for callbacks
        callbacks._historyChanged()

def insertItemAtTickindex(item, tickindex):
    #session.data.currentTrack().goToTickindex

    """
    Das ist eine conversion in der session. keine api befehle benutzen.
    hier weiter machen. Der Cursor muss in Ruhe gelassen werden. Oder aber ich resette ohne callback? das erscheint mir erstmal simpler.
    Ich brauch aber eine Funktion goToTickindex im Track die Pausen erstellt wenn man da nicht hinkommt.  Jetzt wünsch ich mir ich hätte die Noten nicht in ner liste sondern in einem dict mit tickindex. welp...
    vielleicht brauch ich eine komplette parallelwelt. das midi modul sollte auf jeden fall nicht die keysig suchen müssen. kontext wird in der api hergestellt, nicht im midi
    """

def _createLambdaMoveToForCurrentPosition():
    """for undo only"""
    def moveTo(trackIndex, blockIndex, localCursorIndexInBlock, pitchindex):
        try:
            session.data.goTo(trackIndex, blockIndex, localCursorIndexInBlock)
            session.data.cursor.pitchindex = pitchindex
        except: #the worst that can happen is wrong movement.
            pass
    trackIndex, blockIndex, localCursorIndexInBlock = session.data.where()
    moveFunction = lambda trIdx=trackIndex, blIdx=blockIndex, curIdx=localCursorIndexInBlock, pitchIdx=session.data.cursor.pitchindex: moveTo(trIdx, blIdx, curIdx, pitchIdx)
    return moveFunction


def _createLambdaRecreateSelection():
    """Not for undo.
    Call it when you still have a selection, right after you do the
    processing.

    This is to keep a selection that changed the item positions but you want to support a new
    call to the function immediately. For example the reorder notes by shuffling function.
    The user will most likely hit that several times in a row to find something nice.

    A valid selection implies that the cursor is on one end
    of the selection. It doesn't matter which one but for the
    sake of consistency and convenience we make sure that we end up with
    the cursor on the bottomRight position.
    It is entirely possible that the selection changed
    the duration and the dimensions. The bottom right item might not
    be on the same tickindex nor does it need to exist anymore.
    Only the topLeft position is guaranteed to exist and have the same
    tickindex. The item on that position however may not be there
    anymore.
    """
    def recreateSelection(moveToFunction, topLeftCursor, bottomRightCursor):
        session.data.cursorWhenSelectionStarted = None #take care of the current selection
        moveToFunction()
        session.data.goTo(topLeftCursor["trackIndex"], topLeftCursor["blockindex"], topLeftCursor["localCursorIndex"])
        session.data.setSelectionBeginning()
        session.data.goTo(bottomRightCursor["trackIndex"], bottomRightCursor["blockindex"], bottomRightCursor["localCursorIndex"])

    assert session.data.cursorWhenSelectionStarted #only call this when you still have a selection
    createSelectionFunction = lambda moveTo=_createLambdaMoveToForCurrentPosition(), tL=session.data.cursor.exportObject(session.data.currentTrack().state), bR=session.data.cursorWhenSelectionStarted, : recreateSelection(moveTo, tL, bR)
    return createSelectionFunction #When this function gets called we are back in the position that the newly generated data is selected, ready to to the complementary processing.


def _updateCallbackForListOfTrackIDs(listOfChangedTrackIds):
    for trackId in listOfChangedTrackIds:
        callbacks._updateTrack(trackId)

def _updateCallbackAllTracks():
    _updateCallbackForListOfTrackIDs(session.data.listOfTrackIds())

updateCallbackAllTracks = _updateCallbackAllTracks

def _changeBlockAndItemOrder(dictWithTrackIDsAndDataLists):
    """A helper function for deleteSelection, paste and other...
    This makes it possible to undo/redo properly. It registers
    itself with complementary data as undo/redo."""
    orderBeforeInsert = session.data.getBlockAndItemOrder() #save the current version as old version. as long as we keep this data around, e.g. in the undo stack, the items will not be truly deleted
    moveFunction = _createLambdaMoveToForCurrentPosition() #the goTo function for the cursor is not exactly in the right place. It may end up on the "other" side of a selection. Which is close enough.
    def registeredUndoFunction():
        moveFunction()
        _changeBlockAndItemOrder(orderBeforeInsert)
    session.history.register(registeredUndoFunction, descriptionString="change order")

    #Replace old data with new parameter-data.
    listOfTrackIDs = session.data.putBlockAndItemOrder(dictWithTrackIDsAndDataLists)

    #Make changes visible in the GUI
    _updateCallbackForListOfTrackIDs(listOfTrackIDs)
    callbacks._setCursor()

def cutObjects():
    copyObjects()
    _deleteSelection()

def _deleteSelection(backspaceParamForCompatibilityIgnoreThis = None): #this is so special it gets its own command and is not part of the single delete() command.
    orderBeforeDelete = session.data.getBlockAndItemOrder()
    moveFunction = _createLambdaMoveToForCurrentPosition()

    listOfChangedTrackIDs = session.data.deleteSelection()

    if listOfChangedTrackIDs: #delete succeeded.
        def registeredUndoFunction():
            moveFunction()
            _changeBlockAndItemOrder(orderBeforeDelete)
        session.history.register(registeredUndoFunction, descriptionString="delete selection")

        #Make changes visible in the GUI and midi
        for trackId in listOfChangedTrackIDs:
            callbacks._updateTrack(trackId)
        callbacks._setCursor()

def copyObjects(): #ctrl+c
    session.data.copyObjects()
    #The score doesn't change at all. No callback.
    #no undo.

def pasteObjects(customBuffer=None, updateCursor=True, overwriteSelection=True): #ctrl+v
    """api.duplicate overrides default paste behaviour by providing its own copyBuffer
    and not destroying the selection/keep the cursor at its origin position
    """
    dataBefore = session.data.getBlockAndItemOrder()
    moveFunction = _createLambdaMoveToForCurrentPosition()
    listOfChangedTrackIDs = session.data.pasteObjects(customBuffer, overwriteSelection)
    if listOfChangedTrackIDs: #paste succeeded.
        def registeredUndoFunction():
            moveFunction()
            _changeBlockAndItemOrder(dataBefore)
        session.history.register(registeredUndoFunction, descriptionString="paste")

        #Make changes visible in the GUI
        for trackId in listOfChangedTrackIDs:
            callbacks._updateTrack(trackId)

        if updateCursor:
            callbacks._setCursor()

def pasteObjectsTransposedReal(root:int=None, toPitch:int=None, adjustToKeySignature=False):
    """Uses the global/session clipboard buffer but pastes a transposed version, starting on the
    pitch cursor position, that is adjusted to the current keysignature.

    The notes are transformed into a custom buffer. We use standard paste for everything else.

    If root or toPitch for the transposition interval are None they will derive their pitch from
    the first pitch in the copy buffer and the cursor position, respectively.
    """

    if not session.data.copyObjectsBuffer:
        return #guard


    copyBuffer = session.data.getIndenpendetCopyObjectsBuffer()
    #Determine the first of the two pitches for our transposition interval
    if root is None or not type(root) is int:
        #First iteration only until the very first note, which we use to calculate the interval
        for track in copyBuffer:
            for item in track:
                if type(item) is items.Chord:
                    root = item.notelist[0].pitch #ordered by ascending pitch
                    break
                else: #inner loop finished without break. No chord? in the first track.
                    logging.warning("Found copy buffer without note in the first track. This is worth an investigation.")
                    continue #jump to the start and don't execute the outer loop break
            break #outer loop. We only get here if the inner loop did break as well.

        #Final Sanity Check. I don't think selections without chords are even allowed...
        if root is None:
            logging.error("pasteObjectsTransposedModal without notes in the copy buffer! (but not empty)")
            return

    if toPitch is None:
        toPitch = getCursorPitch()

    keysig = session.data.currentTrack().state.keySignature()
    #Edit the copy buffer in place. We don't modify the list, just the contents.
    for track in copyBuffer:
        for item in track:
            if type(item) is items.Chord:
                item.intervalAutomatic(root, toPitch)
                if adjustToKeySignature:
                    item.adjustToKeySignature([keysig,]) #keysig must be in a list because it is a chord. If it is just len==1 the transpose function will deal with it correctly.

    pasteObjects(customBuffer=copyBuffer) #normal paste except our special buffer


def pasteObjectsTransposedModal(root:int=None, toPitch:int=None):
    pasteObjectsTransposedReal(root, toPitch, adjustToKeySignature=True)


def duplicate(howOften:int): #ctrl+d
    """Duplicate a single object and put it right of the original. The cursor moves with it
    to enable follow up insertion.

    Duplicate the entire selection and put the copy right of the last selected note.
    The cursor moves to selection start. deal with it.

    Basically a special case of copy and paste that does not touch the clipboard."""
    if session.data.cursorWhenSelectionStarted:
        customBuffer = session.data.copyObjects(writeInSessionBuffer = False)
        if customBuffer: #success
            session.data.goToSelectionStart()
            pos = session.data.where() #where even keeps the local position if a content linked block inserts items before our position
            with session.history.sequence("duplicate selection"):
                for i in range(howOften):
                    pasteObjects(customBuffer = customBuffer, updateCursor = False, overwriteSelection = False) #handles undo
                    session.data.goTo(*pos)
            callbacks._setCursor(destroySelection=False)
    else:
        item = session.data.currentItem()
        if item:
            with session.history.sequence("duplicate item"):
                for i in range(howOften):
                    insertItem(item.copy())
        callbacks._setCursor()


#Score
def transposeScore(rootPitch, targetPitch):
    """Based on automatic transpose. The interval is caculated from two pitches.
    There is also tranpose. But no transposeTrack, this is just select track and transpose."""
    session.data.transposeScore(rootPitch, targetPitch)
    session.history.register(lambda r=rootPitch,t=targetPitch: transposeScore(t,r), descriptionString="transpose score")
    callbacks._historyChanged()
    _updateCallbackAllTracks()

def useCurrentTrackAsMetronome():
    """This is called once after loading/creating a session in startEngine"""
    session.data.currentMetronomeTrack = session.data.currentTrack()
    setMetronome(session.data.currentMetronomeTrack.asMetronomeData, label=session.data.currentMetronomeTrack.name) #template api. has callbacks

#Tracks
def insertTrack(atIndex, trackObject):
    moveFunction = _createLambdaMoveToForCurrentPosition()
    newTrackId = id(trackObject)
    session.data.insertTrack(atIndex, trackObject) #side-effect: changes the active track to the new track which can be used in the next step:
    def registeredUndoFunction():
        moveFunction()
        deleteTrack(newTrackId)
    session.history.register(registeredUndoFunction, descriptionString = "insert track")
    session.data.calculateAudibleSoloForCbox()
    callbacks._tracksChanged()
    callbacks._updateTrack(newTrackId)
    callbacks._setCursor()

#search tags: newTrack addTrack
def newEmptyTrack():
    """Append an empty track and switch to the new track"""
    newIndex = len(session.data.tracks)
    newTrack = Track(session.data)

    if newIndex > 0:
        newTrack.initialKeySignature = session.data.tracks[0].initialKeySignature.copy()
        newTrack.initialMetricalInstruction = session.data.tracks[0].initialMetricalInstruction.copy()
        newTrack.upbeatInTicks = session.data.tracks[0].upbeatInTicks #just an int

    insertTrack(newIndex, newTrack) #handles callbacks and undo
    return (id(newTrack))

def deleteTrack(trId):
    """Can not delete hidden tracks because these don't implement undo.
    A hidden track is already considered "deleted" by the program.
    Therefore you can only delete visible tracks."""
    trackObject = session.data.trackById(trId)
    assert trackObject not in session.data.hiddenTracks #enforce docstring.
    trackIndex = session.data.tracks.index(trackObject)
    didDelete = session.data.deleteTrack(trackObject) #may or may not change the trackindex. In any case, logically the cursor is now in a different track.
    if didDelete: #score.deleteTrack does not delete the last remaining track
        def registeredUndoFunction():
            trackObject.sequencerInterface.recreateThroughUndo()
            insertTrack(trackIndex, trackObject)
        session.history.register(registeredUndoFunction, descriptionString = "delete track")
        callbacks._tracksChanged()
        callbacks._setCursor()
        if trackObject is session.data.currentMetronomeTrack:
            useCurrentTrackAsMetronome() #we already have a new current one
    session.data.calculateAudibleSoloForCbox()

def deleteCurrentTrack():
    deleteTrack(id(session.data.currentTrack()))

def hideTrack(trId):
    """For the callbacks this looks like a delete. But there is no undo.
    The track still emits playback.

    hide and unhide track register in the history. deleteItem depends on the item to be in a visible
    track so it may possible to insert an item, hide the track and then undo which would try to
    delete an item in a hidden track. Therefore hide and unhide register.
     """
    trackObject = session.data.trackById(trId)
    result = session.data.hideTrack(trackObject)
    if result: #not the only track
        session.history.register(lambda trId=trId: unhideTrack(trId), descriptionString = "hide track")
    callbacks._tracksChanged() #even if there is no change the GUI needs to be notified to redraw its checkboxes that may have been enabled GUI-side.
    callbacks._setCursor()

def unhideTrack(trId):
    trackObject = session.data.trackById(trId)
    session.data.unhideTrack(trackObject) #always succeeds, or throws error.
    session.history.register(lambda trId=trId: hideTrack(trId), descriptionString = "unhide track")
    callbacks._tracksChanged()
    callbacks._updateTrack(trId)
    #the cursor is uneffected

def trackAudible(trId, state:bool):
    """
    Aka. mute, but we don't call it like this because:
    Send midi notes or not.  CCs and instrument changes are unaffected.
    Not managed by undo/redo.
    Does not need updateTrack. There is no new midi data to generate. cbox handles mute on its own

    Audible will shut off any output, no matter if solo or not.
    Solo will determine which of the audible tracks are played.
    Like in any DAW. Inverted Solo logic etc.
    """
    session.data.trackById(trId).audible = state
    session.data.calculateAudibleSoloForCbox()
    callbacks._tracksChanged() #even if there is no change the GUI needs to be notified to redraw its checkboxes that may have been enabled GUI-side.


def trackSolo(trId, state:bool):
    """
    Another layer like audible tracks.
    This is the classic solo/mute duality.

    Audible will shut off any output, no matter if solo or not.
    Solo will determine which of the audible tracks are played.
    Like in any DAW. Inverted Solo logic etc.

    Not managed by undo/redo.
    Does not need updateTrack. There is no new midi data to generate. cbox handles mute on its own
    """
    session.data.trackById(trId).solo = state
    session.data.calculateAudibleSoloForCbox()
    callbacks._setCursor() #the cursor includes solo export for the current track.
    callbacks._tracksChanged() #even if there is no change the GUI needs to be notified to redraw its checkboxes that may have been enabled GUI-side.


def toggleCurrentTrackSolo():
    """trackSolo, but for the cursor. And toggle"""
    track = session.data.currentTrack()
    trackSolo(id(track), not track.solo)

def resetAllSolo():
    for track in session.data.tracks + list(session.data.hiddenTracks.keys()):
        track.solo = False
    session.data.calculateAudibleSoloForCbox()
    callbacks._setCursor() #the cursor includes solo export for the current track.
    callbacks._tracksChanged() #even if there is no change the GUI needs to be notified to redraw its checkboxes that may have been enabled GUI-side.


def listOfTrackIds():
    return session.data.listOfTrackIds()

def listOfHiddenTrackIds():
    return [id(track) for track in session.data.hiddenTracks.keys()]

def rearrangeTracks(listOfTrackIds):
    if len(session.data.tracks) <= 1:
        return
    session.history.register(lambda l=session.data.asListOfTrackIds(): rearrangeTracks(l), descriptionString = "rearrange tracks")
    session.data.rearrangeTracks(listOfTrackIds)
    callbacks._tracksChanged()
    callbacks._setCursor()

def setTrackName(trId, nameString, initialInstrumentName, initialShortInstrumentName):
    trackObject = session.data.trackById(trId)
    session.history.register(lambda i=trId, n=trackObject.name, lyN=trackObject.initialInstrumentName, lySN=trackObject.initialShortInstrumentName: setTrackName(i, n, lyN, lySN), descriptionString = "change track name")
    trackObject.name = nameString # this is a setter. It changes calfbox as well.
    trackObject.initialInstrumentName = initialInstrumentName
    trackObject.initialShortInstrumentName = initialShortInstrumentName
    callbacks._tracksChanged()
    callbacks._setCursor() #cursor contains track name and thus needs updating

def setTrackUpbeat(trId, upbeatInTicks):
    trackObject = session.data.trackById(trId)
    session.history.register(lambda i=trId, u=trackObject.upbeatInTicks: setTrackUpbeat(i, u), descriptionString = "change track upbeat")
    trackObject.upbeatInTicks = upbeatInTicks
    callbacks._updateTrack(trId)

def setDoubleTrack(trId, statusBool):
    """It does not touch any important data because it is more or less
    a savefile-persistent visual convenience feature.
    So we don't need undo/redo"""
    trackObject = session.data.trackById(trId)
    trackObject.double = statusBool
    callbacks._tracksChanged()
    callbacks._updateTrack(trId)
    callbacks._setCursor()

def setTrackSettings(trId, dictionary):
    """We need to create a new playback of the track to update the midi data."""
    trackObject = session.data.trackById(trId)
    previousSettings = trackObject.staticTrackRepresentation()
    clean = True

    for key, value in dictionary.items():
        #this assumes keys are the same as track export. Will give a key error at least if not.
        if not previousSettings[key] == value:
            clean = False
            break

    if not clean:
        trackObject.initialClefKeyword = dictionary["initialClefKeyword"]

        trackObject.initialMidiChannel = dictionary["initialMidiChannel"]
        trackObject.initialMidiBankMsb = dictionary["initialMidiBankMsb"]
        trackObject.initialMidiBankLsb = dictionary["initialMidiBankLsb"]
        trackObject.initialMidiProgram = dictionary["initialMidiProgram"]
        trackObject.ccChannels = dictionary["ccChannels"]
        trackObject.midiTranspose = dictionary["midiTranspose"]

        trackObject.durationSettingsSignature.defaultOn = dictionary["duration.defaultOn"]
        trackObject.durationSettingsSignature.defaultOff = dictionary["duration.defaultOff"]
        trackObject.durationSettingsSignature.staccatoOn = dictionary["duration.staccatoOn"]
        trackObject.durationSettingsSignature.staccatoOff = dictionary["duration.staccatoOff"]
        trackObject.durationSettingsSignature.tenutoOn = dictionary["duration.tenutoOn"]
        trackObject.durationSettingsSignature.tenutoOff = dictionary["duration.tenutoOff"]
        trackObject.durationSettingsSignature.legatoOn = dictionary["duration.legatoOn"]
        trackObject.durationSettingsSignature.legatoOff = dictionary["duration.legatoOff"]

        trackObject.dynamicSettingsSignature.dynamics["ppppp"] = dictionary["dynamics.ppppp"]
        trackObject.dynamicSettingsSignature.dynamics["pppp"] = dictionary["dynamics.pppp"]
        trackObject.dynamicSettingsSignature.dynamics["ppp"] = dictionary["dynamics.ppp"]
        trackObject.dynamicSettingsSignature.dynamics["pp"] = dictionary["dynamics.pp"]
        trackObject.dynamicSettingsSignature.dynamics["p"] = dictionary["dynamics.p"]
        trackObject.dynamicSettingsSignature.dynamics["mp"] = dictionary["dynamics.mp"]
        trackObject.dynamicSettingsSignature.dynamics["mf"] = dictionary["dynamics.mf"]
        trackObject.dynamicSettingsSignature.dynamics["f"] = dictionary["dynamics.f"]
        trackObject.dynamicSettingsSignature.dynamics["ff"] = dictionary["dynamics.ff"]
        trackObject.dynamicSettingsSignature.dynamics["fff"] = dictionary["dynamics.fff"]
        trackObject.dynamicSettingsSignature.dynamics["ffff"] = dictionary["dynamics.ffff"]
        trackObject.dynamicSettingsSignature.dynamics["custom"] = dictionary["dynamics.custom"]
        trackObject.dynamicSettingsSignature.dynamics["tacet"] = dictionary["dynamics.tacet"]
        trackObject.dynamicSettingsSignature.dynamics["fp"] = dictionary["dynamics.fp"]
        trackObject.dynamicSettingsSignature.dynamics["sp"] = dictionary["dynamics.sp"]
        trackObject.dynamicSettingsSignature.dynamics["spp"] = dictionary["dynamics.spp"]
        trackObject.dynamicSettingsSignature.dynamics["sfz"] = dictionary["dynamics.sfz"]
        trackObject.dynamicSettingsSignature.dynamics["sf"] = dictionary["dynamics.sf"]
        trackObject.dynamicSettingsSignature.dynamics["sff"] = dictionary["dynamics.sff"]



        session.history.register(lambda trId=trId, previousSettings=previousSettings: setTrackSettings(trId, previousSettings), descriptionString = "change track settings")
        callbacks._tracksChanged()
        callbacks._updateSingleTrackAllCC(trId)
        callbacks._updateTrack(trId)
        callbacks._setCursor() #for midi channel RT thru

def resetDynamicSettingsSignature(trId):
    trackObject = session.data.trackById(trId)
    previousSettings = trackObject.staticTrackRepresentation()
    trackObject.dynamicSettingsSignature.reset()
    session.history.register(lambda trId=trId, previousSettings=previousSettings: setTrackSettings(trId, previousSettings), descriptionString = "reset track dynamic settings")
    callbacks._tracksChanged()
    #We only need this for midi changes. callbacks._updateSingleTrackAllCC(trId)

    callbacks._updateTrack(trId)

def resetDuationSettingsSignature(trId):
    trackObject = session.data.trackById(trId)
    previousSettings = trackObject.staticTrackRepresentation()
    trackObject.durationSettingsSignature.reset()
    session.history.register(lambda trId=trId, previousSettings=previousSettings: setTrackSettings(trId, previousSettings), descriptionString = "reset track duration settings")
    callbacks._tracksChanged()
    #We only need this for midi changes. callbacks._updateSingleTrackAllCC(trId)
    callbacks._updateTrack(trId)

#Blocks
def currentBlockExport():
    """Return the static export item of the current block.
    Compatible with getDataAsDict and putDataFromDict
    such as names and minimum tick duration"""
    return session.data.currentTrack().currentBlock().getDataAsDict()

def appendBlock(trackid = None):
    """
    Has dynamic behaviour:
        If we are at the end of track appending a Block switches into
        that new block.
        On any other position it just appends a block and the cursor
        stays where it is. This gives a better typing from left-to-right
        experience."""
    if trackid:
        tr = session.data.trackById(trackid)
    else:
        tr = session.data.currentTrack()
    block = tr.appendBlock()
    if tr.state.isAppending() and len(tr.blocks)-2 == tr.state.blockindex: #end of track?
        moveFunction = _createLambdaMoveToForCurrentPosition()
        def registeredUndoFunction():
            moveFunction()
            deleteBlock(id(block))
        session.history.register(registeredUndoFunction, descriptionString = "append block")
        session.data.currentTrack().right()
    else:
        session.history.register(lambda blId = id(block): deleteBlock(blId), descriptionString = "append block")
    callbacks._updateTrack(id(tr))
    #callbacks._setCursor() #this will make the GUI jump around because it centers on the cursor

def splitBlock():
    tr = session.data.currentTrack()
    if tr.state.isAppending() and len(tr.blocks)-1 == tr.state.blockindex: #end of track? Yes len-1 here and len-2 in append() is correct. I don't know why :(
        appendBlock()
    else: #a real split
        dictOfTrackIdsWithListOfBlockIds = session.data.splitCurrentBlockAndAllContentLinks() #do the split. We get the current state as return value for undo
        if dictOfTrackIdsWithListOfBlockIds:
            rearrangeBlocksInMultipleTracks(dictOfTrackIdsWithListOfBlockIds)  #handles undo and callbacks for redrawing
        callbacks._setCursor() #cursor is still on the same item. But the item might be further to the right now when additional block boundaries have been introduced to the left through contentLinks
        right() # continue typing on the right side. This was added in 2020 to create a "split is an item" feeling

def joinBlockWithNext(blockId):
    """written for the GUI which can join blocks with the mouse"""
    track, block = session.data.blockById(blockId)
    session.data.goTo(session.data.tracks.index(track), track.blocks.index(block), 0)
    joinBlock()

def joinBlock():
    """Opposite of splitBlock (but not undo)
    Take the current block and join it with the one after it.
    Does the same automatically for all content linked blocks.
    If there is no next block this will do nothing.

    It only works on content linked blocks if ALL content linked blocks have a different
    content linked block after them. So a block A needs always to be