/*
  This file is part of Ingen.
  Copyright 2007-2012 David Robillard <http://drobilla.net/>

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

  Ingen 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 Affero General Public License for details.

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

#ifndef INGEN_ENGINE_AUDIOBUFFER_HPP
#define INGEN_ENGINE_AUDIOBUFFER_HPP

#include <cassert>
#include <cmath>
#include <cstddef>

#include <boost/utility.hpp>

#include "ingen/shared/URIs.hpp"

#include "Buffer.hpp"
#include "BufferFactory.hpp"
#include "Context.hpp"
#include "types.hpp"

namespace Ingen {
namespace Server {

class AudioBuffer : public Buffer
{
public:
	AudioBuffer(BufferFactory& bufs, LV2_URID type, uint32_t size);

	void clear();

	void set_value(Sample val, FrameTime cycle_start, FrameTime time);
	void set_block(Sample val, size_t start_offset, size_t end_offset);
	void copy(const Sample* src, size_t start_sample, size_t end_sample);
	void copy(Context& context, const Buffer* src);
	void accumulate(Context& context, const AudioBuffer* src);

	float peak(Context& context) const;

	inline bool is_control() const { return _type == _factory.uris().atom_Float; }

	inline Sample* data() const {
		return (is_control())
			? (Sample*)LV2_ATOM_BODY(atom())
			: (Sample*)LV2_ATOM_CONTENTS(LV2_Atom_Vector, atom());
	}

	inline SampleCount nframes() const {
		return (is_control())
			? 1
			: (_capacity - sizeof(LV2_Atom_Vector)) / sizeof(Sample);
	}

	inline Sample& value_at(size_t offset) const {
		assert(offset < nframes());
		return data()[offset];
	}

	void prepare_read(Context& context);
	void prepare_write(Context& context) {}

private:
	enum State { OK, HALF_SET_CYCLE_1, HALF_SET_CYCLE_2 };

	LV2_Atom_Vector* vector() { return (LV2_Atom_Vector*)atom(); }

	State     _state;     ///< State of buffer for setting values next cycle
	Sample    _set_value; ///< Value set by set_value (for completing the set next cycle)
	FrameTime _set_time;  ///< Time _set_value was set (to reset next cycle)
};

/** Accumulate a block of @a src into buffer.
 */
inline void
AudioBuffer::accumulate(Context& context, const AudioBuffer* const src)
{
	Sample* const       buf     = data();
	const Sample* const src_buf = src->data();

	if (is_control()) {
		if (src->is_control()) { // control => control
			buf[0] += src_buf[0];
		} else { // audio => control
			buf[0] += src_buf[context.offset()];
		}
	} else {
		const SampleCount end = context.offset() + context.nframes();
		if (src->is_control()) { // control => audio
			for (SampleCount i = context.offset(); i < end; ++i) {
				buf[i] += src_buf[0];
			}
		} else { // audio => audio
			for (SampleCount i = context.offset(); i < end; ++i) {
				buf[i] += src_buf[i];
			}
		}
	}
}

} // namespace Server
} // namespace Ingen

#endif // INGEN_ENGINE_AUDIOBUFFER_HPP