// Copyright 2005-2016 The Mumble Developers. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file at the root of the
// Mumble source tree or at <https://www.mumble.info/LICENSE>.

#ifndef MUMBLE_MUMBLE_VOICERECORDER_H_
#define MUMBLE_MUMBLE_VOICERECORDER_H_

#ifndef Q_MOC_RUN
# include <boost/scoped_ptr.hpp>
# include <boost/shared_array.hpp>
#endif

#include <sndfile.h>
#include <QtCore/QDateTime>
#include <QtCore/QHash>
#include <QtCore/QMutex>
#include <QtCore/QObject>
#include <QtCore/QThread>
#include <QtCore/QWaitCondition>

class ClientUser;
class RecordUser;
class Timer;

/// Utilities and enums for voice recorder format handling
namespace VoiceRecorderFormat {

	/// List of all formats currently supported by the recorder.
	enum Format {
		/// WAVE Format
		WAV = 0,
// When switching between a non vorbis capable lib and a vorbis capable one
// this can mess up the selection stored in the config
#ifndef NO_VORBIS_RECORDING
		/// Ogg Vorbis Format
		VORBIS,
#endif
		/// AU Format
		AU,
		/// FLAC Format
		FLAC,
		kEnd
	};

	/// Returns a human readable description of the format id.
	QString getFormatDescription(VoiceRecorderFormat::Format fm);

	/// Returns the default extension for the given format.
	QString getFormatDefaultExtension(VoiceRecorderFormat::Format fm);

}

/// Class for recording audio data.
///
/// Runs as a seperate thread accepting audio data through the addBuffer method
/// which is then encoded using one of the formats of VoiceRecordingFormat::Format
/// and written to disk.
///
class VoiceRecorder : public QThread {
		Q_OBJECT
	public:
		/// Possible error conditions inside the recorder
		enum Error { Unspecified, CreateDirectoryFailed, CreateFileFailed, InvalidSampleRate };

		/// Structure for holding configuration of VoiceRecorder object
		struct Config {
			/// The current sample rate of the recorder.
			int sampleRate;

			/// The path to store recordings.
			QString fileName;

			/// True if multi channel recording is disabled.
			bool mixDownMode;

			/// The current recording format.
			VoiceRecorderFormat::Format recordingFormat;
		};

		/// Creates a new VoiceRecorder instance.
		VoiceRecorder(QObject *p, const Config& config);
		~VoiceRecorder() Q_DECL_OVERRIDE;

		/// The main event loop of the thread, which writes all buffers to files.
		void run() Q_DECL_OVERRIDE;

		/// Stops the main loop.
		/// @param force If true buffers are discarded. Otherwise the thread will not stop before writing everything.
		void stop(bool force = false);

		/// Remembers the current time for a set of coming addBuffer calls
		void prepareBufferAdds();
		
		/// Adds an audio buffer which contains |samples| audio samples to the recorder.
		/// The audio data will be assumed to be recorded at the time
		/// prepareBufferAdds was last called.
		/// @param clientUser User for which to add the audio data. NULL in mixdown mode.
		void addBuffer(const ClientUser *clientUser, boost::shared_array<float> buffer, int samples);
		
		/// Returns the elapsed time since the recording started.
		quint64 getElapsedTime() const;

		/// Returns a refence to the record user which is used to record local audio.
		RecordUser &getRecordUser() const;

		/// Returns true if the recorder is recording mixed down data instead of multichannel
		bool isInMixDownMode() const;
signals:
		/// Emitted if an error is encountered
		void error(int err, QString strerr);

		/// Emitted when recording is started
		void recording_started();
		/// Emitted when recording is stopped
		void recording_stopped();
		
	private:
		
		/// Stores information about a recording buffer.
		struct RecordBuffer {
			/// Constructs a new RecordBuffer object.
			RecordBuffer(int recordInfoIndex_,
			             boost::shared_array<float> buffer_,
			             int samples_,
			             quint64 absoluteStartSample_);

			/// Hashmap index for the user
			const int recordInfoIndex;

			/// The buffer.
			boost::shared_array<float> buffer;

			/// The number of samples in the buffer.
			int samples;

			/// Absolute sample number at the start of this buffer
			quint64 absoluteStartSample;
		};

		/// Stores the recording state for one user.
		struct RecordInfo {
			RecordInfo(const QString& userName_);
			~RecordInfo();

			/// Name of the user being recorded
			const QString userName;
			
			/// libsndfile's handle.
			SNDFILE *soundFile;

			/// The last absolute sample we wrote for this users
			quint64 lastWrittenAbsoluteSample;
		};

		typedef QHash< int, boost::shared_ptr<RecordInfo> > RecordInfoMap;
		
		/// Removes invalid characters in a path component.
		QString sanitizeFilenameOrPathComponent(const QString &str) const;

		/// Expands the template variables in |path| for the given |userName|.
		QString expandTemplateVariables(const QString &path, const QString& userName) const;

		/// Returns the RecordInfo hashmap index for the given user
		int indexForUser(const ClientUser *clientUser) const;
		
		/// Create a sndfile SF_INFO structure describing the currently configured recording format
		SF_INFO createSoundFileInfo() const;
		
		/// Opens the file for the given recording information
		/// Helper function for run method. Will abort recording on failure.
		bool ensureFileIsOpenedFor(SF_INFO &soundFileInfo, boost::shared_ptr<RecordInfo> &ri);
		
		/// Hash which maps the |uiSession| of all users for which we have to keep a recording state to the corresponding RecordInfo object.
		RecordInfoMap m_recordInfo;

		/// List containing all unprocessed RecordBuffer objects.
		QList< boost::shared_ptr<RecordBuffer> > m_recordBuffer;

		/// The user which is used to record local audio.
		boost::scoped_ptr<RecordUser> m_recordUser;

		/// High precision timer for buffer timestamps.
		boost::scoped_ptr<Timer> m_timestamp;

		/// Protects the buffer list |qlRecordBuffer|.
		QMutex m_bufferLock;

		/// Wait condition and mutex to block until there is new data.
		QMutex m_sleepLock;
		QWaitCondition m_sleepCondition;

		/// Configuration for this instance
		const Config m_config;

		/// True if the main loop is active.
		bool m_recording;
		
		/// Tells the recorder to not finish writing its buffers before returning
		bool m_abort;

		/// The timestamp where the recording started.
		const QDateTime m_recordingStartTime;
		
		/// Absolute sample position to assume for buffer adds
		quint64 m_absoluteSampleEstimation;
};

typedef boost::shared_ptr<VoiceRecorder> VoiceRecorderPtr;

#endif
