// Copyright (c) 2007-2008, Niels Martin Hansen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//   * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//   * Neither the name of the Aegisub Group nor the names of its contributors
//     may be used to endorse or promote products derived from this software
//     without specific prior written permission.
//
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// Aegisub Project http://www.aegisub.org/

#include "include/aegisub/audio_provider.h"

#include <memory>
#include <vector>

namespace agi { class file_mapping; }
namespace boost { namespace interprocess { class mapped_region; } }

class PCMAudioProvider : public AudioProvider {
	std::unique_ptr<agi::file_mapping> file;
	mutable std::unique_ptr<boost::interprocess::mapped_region> region;
	mutable int64_t mapping_start = 0;

protected:
	PCMAudioProvider(agi::fs::path const& filename); // Create base object and open the file mapping
	~PCMAudioProvider(); // Closes the file mapping
	char *EnsureRangeAccessible(int64_t range_start, int64_t range_length) const; // Ensure that the given range of bytes are accessible in the file mapping and return a pointer to the first byte of the requested range

	/// Size of the opened file
	int64_t file_size = 0;

	struct IndexPoint {
		int64_t start_byte;
		int64_t start_sample;
		int64_t num_samples;
	};

	typedef std::vector<IndexPoint> IndexVector;

	IndexVector index_points;

	void FillBuffer(void *buf, int64_t start, int64_t count) const override;
};

// Construct the right PCM audio provider (if any) for the file
std::unique_ptr<AudioProvider> CreatePCMAudioProvider(agi::fs::path const& filename);