var TwistInstance = function(index, twist) {
	var self = this;
	this.appdata = appdata;
	this.waveform = null;
	var waveformFile;
	var waveformTab;
	this.onPlays = [];
	var sr = 44100;				
	var undoLevel;
		
	function pushOperationLog(operation) {
		var max = twist.storage.commitHistoryLevel;
		if (!max) {
			twist.storage.commitHistoryLevel = max = 16;
		}
		if (operationLog.length + 1 >= max) {
			operationLog.shift();
		}
		operationLog.push(operation);
	}
	
	this.redraw = function() {
		self.waveform.redraw();
	};
	
	this.close = function() {
		self.waveform.destroy();
		delete self.waveform;
	};

	this.show = function() {
		self.waveform.show();
	};
	
	this.movePlayhead = function() {
		
	};
	
	function removeInstance(i) {
		if (i < 0 || i > this.waveforms.length - 2) {
			return;
		}
		self.waveform.destroy();
		if (instanceIndex == i) {
			instanceIndex = i + ((i == 0) ? 1 : -1);
			self.waveform.show();
		}
	}
		

	this.undo = function() {
		if (playing) return;
		self.waveform.cover(true);
		operation("twst_undo", globalCallbackHandler, true, null, true);
	};

	this.cut = function() {
		if (playing) return;
		self.waveform.cover(true);
		operation("twst_cut", globalCallbackHandler, true);
	};
	
	this.delete = function() {
		if (playing) return;
		self.waveform.cover(true);
		operation("twst_delete", globalCallbackHandler, true);
	};
	
	this.copy = function() {
		if (playing) return;
		self.waveform.cover(true);
		operation("twst_copy", null, true);
	};
	
	this.paste = function() {
		if (playing) return;
		self.waveform.cover(true);
		operation("twst_paste", globalCallbackHandler, true);
		// keep original play position / offset new
	};
	
	this.moveToStart = function() {
		if (playing) return;
		self.waveform.setSelection(0);
	};
	
	this.moveToEnd = function() {
		if (playing) return;
		self.waveform.setSelection(1);
	};
	
	this.selectAll = function() {
		if (playing) return;
		self.waveform.setSelection(0, 1);
	};
	
	this.selectNone = function() {
		if (playing) return;
		self.waveform.setSelection(0);
	};
	
	this.selectToEnd = function() {
		if (playing) return;
		self.waveform.alterSelection(null, 1);
	}
	
	this.selectFromStart = function() {
		if (playing) return;
		self.waveform.alterSelection(0, null);
	}
	
	this.play = function() {
		if (playing) return;
		auditioning = false;
		recording = false;
		operation("twst_play", playPositionHandler(), false, null, true);
	};
	
	this.stop = function() {
		if (!playing) return;
		self.waveform.cover(false);
		app.insertScore("twst_stop");
	};
	
	function getAutomationData(start, end) {
		var calls = [];
		if (!self.currentTransform) return calls;
		var automations = self.currentTransform.getAutomationData(start, end);
		if (automations && automations.length > 0) {
			for (let i in automations) {
				if (automations[i].type == "modulation") {
					calls.push(automations[i].data[0] + " \\\"" + automations[i].data[1] + "\\\"");
				} else if (automations[i].type == "automation") {
					calls.push("chnset linseg:k(" + automations[i].data + "), \\\"" + automations[i].channel + "\\\"");
				}
			}
		}
		return calls;
	}
	
	function handleAutomation(onready, calls) {					
		if (calls.length == 0) {
			return onready(0);
		}
		var cbid = app.createCallback(function(ndata){
			if (ndata.status == 1) {
				onready(1);
			} else {
				self.errorHandler("Cannot parse automation data");
			}
		});
		
		var call = [0, 1, cbid];
		for (let c of calls) {
			call.push(c);
		}
		app.insertScore("twst_automationprepare", call);
	}
	
	function compileVariScript(script, onComplete) {
		var cbid = app.createCallback(function(ndata){
			onComplete(ndata.status == 1);
			// should maybe automatically refresh
		});
	}
	
	
	function fftsizeCheck(selected, duration) {
		if (self.currentTransform) {
			for (var p in self.currentTransform.parameters) {
				if (p.indexOf("fftsize") != -1) {
					var val = self.currentTransform.parameters[p].getValue();
					var minTime = (val / sr) * 2;
					if ((selected[1] - selected[0]) * duration < minTime) {
						return false;
					}
				}
			}
		}
		return true;
	}
	
	this.record = async function() {
		if (playing) return;
		auditioning = false;
		recording = true;
		await app.enableAudioInput();
		errorState = "Recording error";
		self.waveform.cover(true);
		var cbid = playPositionHandler();
		var s = self.waveform.selected;
		var items = [0, 1, cbid, s[0], s[1], s[2]];
		app.insertScore("twst_record", items);
	};
	
	this.audition = function() {
		if (playing) return;
		if (!self.currentTransform) {
			return self.play();
		}
		self.currentTransform.saveState();
		var s = self.waveform.selected;
		if (!fftsizeCheck(s, self.waveform.duration)) {
			return self.errorHandler("Length too short for this transform");
		}
		
		auditioning = true;
		recording = false;
		errorState = "Playback error";
		handleAutomation(function(automating){
			var cbid = playPositionHandler();
			var items = [
				0, 1, cbid, s[0], s[1], s[2],
				self.currentTransform.instr, automating, 
				elCrossfades[0].val(), elCrossfades[1].val()
			];
			app.insertScore("twst_audition", items);
		}, getAutomationData(s[0], s[1]));
		
	};
	
	
	var scriptStack = [];
	function applyScript(audition) {
		if (playing) return;
		var lastData;
		var script = scriptStack.shift();
		if (!script) {
			setLoadingStatus(false);
			if (lastData) {
			console.log("ass", lastData);
				globalCallbackHandler(lastData);
			}
			twist.setPlaying(false);
			return;
		}
		
		if (audition) auditioning = true;
		twist.setPlaying(true);
		if (script.type == "operation") {
			if (audition) {
				return self.errorHandler("Only transform scripts can be auditioned");
			}
			self.waveform.cover(true);
			onComplete = (script.instr == "twst_copy") ? null : globalCallbackHandler;
			operation(script.instr, function(ndata){
				lastData = ndata;
				self.setPlaying(false);
				applyScript(audition);
			}, true, script.selection);
		} else if (script.type == "transform") {
			errorState = ((audition) ? "Audition" : "Transform" ) + " commit error";
			if (!audition) {
				setLoadingStatus(true, true);
			}
			
			for (let channel in script.channels) {
				app.setControlChannel(channel, script.channels[channel]);
			}
			handleAutomation(function(automating){
				if (audition) {
					var cbid = playPositionHandler();
				} else {
					var cbid = app.createCallback(function(ndata) {
						lastData = ndata;
						self.setPlaying(false);
						applyScript(audition);
					});
				}
				var instr = "twst_" + ((audition) ? "audition" : "commit");
											
				app.insertScore(instr, [
					0, -1, cbid, script.selection[0], script.selection[1], script.selection[2], script.instr, automating, script.crossfades[0], script.crossfades[1]
				]);
			}, script.automation);
		}
	}
	
	this.applyScript = async function(script, audition) {
		if (playing) return;
		scriptStack = [];					
		if (Array.isArray(script)) {
			if (audition) {
				return self.errorHandler("Only single scripts can be auditioned");
			}
			scriptStack = script;
		} else {
			scriptStack = [script];
		}
		if (self.storage.autosave && !audition) {
			self.saveFile(null, function() {
				applyScript(audition);
			});
		} else {
			applyScript(audition);
		}
	};
					
	async function innerCommit() {
		if (playing) return;
		if (!self.currentTransform) return;
		var s = self.waveform.selected;
		if (!fftsizeCheck(s, self.waveform.duration)) {
			return self.errorHandler("Length too short for this transform");
		}
		watchdog.start("commit");
		self.setPlaying(true);			
		setLoadingStatus(true, true);
		var calls = getAutomationData(s[0], s[1]);
		
		self.currentTransform.saveState();
		var state = await self.currentTransform.getState();					
		state.type = "transform";
		state.automation = calls;
		state.crossfades = [elCrossfades[0].val(), elCrossfades[1].val()];
		state.selection = [s[0], s[1], s[2]];
		state.instanceIndex = instanceIndex;
		pushOperationLog(state);
		
		handleAutomation(function(automating){
			var cbid = app.createCallback(function(ndata) {
				watchdog.stop();
				setLoadingStatus(false);
				self.setPlaying(false);
				if (ndata.status > 0) {
					globalCallbackHandler(ndata);
				} else {
					var text;
					if (ndata.status == -2) {
						text = "Resulting file is too large";
					}
					self.errorHandler(text);
				}
			});
			errorState = "Transform commit error";
			app.insertScore("twst_commit", [0, -1, cbid, s[0], s[1], s[2], self.currentTransform.instr, automating, state.crossfades[0],state.crossfades[1]]);
		}, calls);
	}
	
	this.commit = async function() {
		if (self.storage.autosave) {
			self.saveFile(null, function() {
				innerCommit();
			});
		} else {
			innerCommit();
		}
	};
		
}; // end twist