#include "mpg123_decoder.h"

#include <boost/format.hpp>

#include <iostream>
#include <stdexcept>

DecoderMpg123::DecoderMpg123(const std::string& filename) : ifile(filename.c_str()) {
	int error;
	handle = mpg123_new("generic", &error);
	if(error) {
		throw std::runtime_error(mpg123_plain_strerror(error));
	}

	error = mpg123_open_feed(handle);
	if(error) {
		throw std::runtime_error(mpg123_plain_strerror(error));
	}

	mpg123_format_none(handle);
	mpg123_format(handle, 44100, 2, MPG123_ENC_SIGNED_16);
}

DecoderMpg123::~DecoderMpg123() {
	mpg123_close(handle);
	mpg123_delete(handle);
}

size_t DecoderMpg123::decode(const uint8_t *input, size_t input_size, uint8_t *output, size_t output_size) {
	if(mpg123_feed(handle, input, input_size) != MPG123_OK) {
		throw std::runtime_error(mpg123_strerror(handle));
	}

	size_t output_written;
	int error = mpg123_read(handle, output, output_size, &output_written);

	if(error == MPG123_NEW_FORMAT) {
		long rate;
		int channels, enc;
		mpg123_getformat(handle, &rate, &channels, &enc);
		std::cout << boost::format("mpg123: New format: %li Hz, %i channels, encoding value %i") % rate % channels % enc << std::endl;
		error = mpg123_read(handle, output, output_size, &output_written);
	}

	if(error != MPG123_OK && error != MPG123_DONE && error != MPG123_NEED_MORE) {
		throw std::runtime_error(mpg123_plain_strerror(error));
	}

	return output_written;
}

std::size_t DecoderMpg123::read(char* buf, std::size_t buf_size) {
	char src_data[0x2000];
	std::streamsize src_read = ifile.get(src_data, 0x2000).gcount();
	if(src_read < 0)
		src_read = 0;
	return decode((const uint8_t*)src_data, src_read, (uint8_t*)buf, buf_size);
}