/*
**  ClanLib SDK
**  Copyright (c) 1997-2020 The ClanLib Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries ClanLib may link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Magnus Norddahl
*/

#include "Sound/precomp.h"
#include "API/Sound/SoundProviders/soundprovider_wave.h"
#include "API/Core/IOData/file_system.h"
#include "API/Core/Text/string_help.h"
#include "API/Core/IOData/path_help.h"
#include "API/Core/IOData/iodevice.h"
#include "API/Core/IOData/cl_endian.h"
#include "API/Core/Text/string_format.h"
#include "API/Core/Text/logger.h"
#include "soundprovider_wave_impl.h"
#include "soundprovider_wave_session.h"

namespace clan
{
	SoundProvider_Wave::SoundProvider_Wave(
		const std::string &filename,
		const FileSystem &fs,
		bool stream) : impl(std::make_shared<SoundProvider_Wave_Impl>())
	{
		IODevice source = fs.open_file(filename, File::open_existing, File::access_read, File::share_read);
		impl->load(source);
	}

	SoundProvider_Wave::SoundProvider_Wave(
		const std::string &fullname, bool stream)
		: impl(std::make_shared<SoundProvider_Wave_Impl>())
	{
		std::string path = PathHelp::get_fullpath(fullname, PathHelp::path_type_file);
		std::string filename = PathHelp::get_filename(fullname, PathHelp::path_type_file);
		FileSystem vfs(path);
		IODevice input = vfs.open_file(filename, File::open_existing, File::access_read, File::share_all);
		impl->load(input);
	}

	SoundProvider_Wave::SoundProvider_Wave(
		IODevice &file, bool stream)
		: impl(std::make_shared<SoundProvider_Wave_Impl>())
	{
		impl->load(file);
	}

	SoundProvider_Wave::~SoundProvider_Wave()
	{
	}

	SoundProvider_Session *SoundProvider_Wave::begin_session()
	{
		return new SoundProvider_Wave_Session(*this);
	}

	void SoundProvider_Wave::end_session(SoundProvider_Session *session)
	{
		delete session;
	}

	void SoundProvider_Wave_Impl::load(IODevice &source)
	{
		source.set_little_endian_mode();

		char chunk_id[4];
		source.read(chunk_id, 4);
		if (memcmp(chunk_id, "RIFF", 4))
			throw Exception("Expected RIFF header!");
		uint32_t chunk_size = source.read_uint32();

		char format_id[4];
		source.read(format_id, 4);
		if (memcmp(format_id, "WAVE", 4))
			throw Exception("Expected WAVE header!");

		uint32_t subchunk_pos = source.get_position();
		find_subchunk("fmt ", source, subchunk_pos, chunk_size);	//uint32_t subchunk1_size

		source.read_uint16();	// uint16_t audio_format
		num_channels = source.read_uint16();
		frequency = source.read_uint32();
		source.read_uint32();		//uint32_t byte_rate
		uint16_t block_align = source.read_uint16();
		uint16_t bits_per_sample = source.read_uint16();

		if (bits_per_sample == 16)
			format = SoundFormat::sf_16bit_signed;
		else if (bits_per_sample == 8)
			format = SoundFormat::sf_8bit_unsigned;
		else
			throw Exception("Unsupported wave sample format");

		uint32_t subchunk2_size = find_subchunk("data", source, subchunk_pos, chunk_size);

		data = new char[subchunk2_size];
		source.read(data, subchunk2_size);

		num_samples = subchunk2_size / block_align;
	}

	unsigned int SoundProvider_Wave_Impl::find_subchunk(const char *chunk, IODevice &source, unsigned int file_offset, unsigned int max_offset)
	{
		char subchunk1_id[4];

		max_offset -= 8;	// Each subchunk must contains at least name and size
		while (file_offset < max_offset)
		{
			source.seek(file_offset);
			source.read(subchunk1_id, 4);
			uint32_t subchunk1_size = source.read_uint32();
			if (!memcmp(subchunk1_id, chunk, 4))
			{
				// Found chunk
				return subchunk1_size;
			}
			file_offset += subchunk1_size + 8;
		}

		throw Exception("Block not found!");
	}
}
