/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam and QMUL.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "WavFileReader.h"

#include "base/HitCount.h"
#include "base/Profiler.h"

#include <iostream>

#include <QMutexLocker>
#include <QFileInfo>

using namespace std;

WavFileReader::WavFileReader(FileSource source, bool fileUpdating) :
    m_file(0),
    m_source(source),
    m_path(source.getLocalFilename()),
    m_seekable(false),
    m_lastStart(0),
    m_lastCount(0),
    m_updating(fileUpdating)
{
    m_frameCount = 0;
    m_channelCount = 0;
    m_sampleRate = 0;

    m_fileInfo.format = 0;
    m_fileInfo.frames = 0;
    m_file = sf_open(m_path.toLocal8Bit(), SFM_READ, &m_fileInfo);

    if (!m_file || (!fileUpdating && m_fileInfo.channels <= 0)) {
	SVDEBUG << "WavFileReader::initialize: Failed to open file at \""
                << m_path << "\" ("
                << sf_strerror(m_file) << ")" << endl;

	if (m_file) {
	    m_error = QString("Couldn't load audio file '%1':\n%2")
		.arg(m_path).arg(sf_strerror(m_file));
	} else {
	    m_error = QString("Failed to open audio file '%1'")
		.arg(m_path);
	}
	return;
    }

    if (m_fileInfo.channels > 0) {

        m_frameCount = m_fileInfo.frames;
        m_channelCount = m_fileInfo.channels;
        m_sampleRate = m_fileInfo.samplerate;

        m_seekable = (m_fileInfo.seekable != 0);

        int type = m_fileInfo.format & SF_FORMAT_TYPEMASK;
        int subtype = m_fileInfo.format & SF_FORMAT_SUBMASK;

        if (type >= SF_FORMAT_FLAC || type >= SF_FORMAT_OGG) {
            // Our m_seekable reports whether a file is rapidly
            // seekable, so things like Ogg don't qualify. We
            // cautiously report every file type of "at least" the
            // historical period of Ogg or FLAC as non-seekable.
            m_seekable = false;
        } else if (type == SF_FORMAT_WAV && subtype <= SF_FORMAT_DOUBLE) {
            // libsndfile 1.0.26 has a bug (subsequently fixed in the
            // repo) that causes all files to be reported as
            // non-seekable. We know that certain common file types
            // are definitely seekable so, again cautiously, identify
            // and mark those (basically only non-adaptive WAVs).
            m_seekable = true;
        }
    }

    SVDEBUG << "WavFileReader: Filename " << m_path << ", frame count " << m_frameCount << ", channel count " << m_channelCount << ", sample rate " << m_sampleRate << ", format " << m_fileInfo.format << ", seekable " << m_fileInfo.seekable << " adjusted to " << m_seekable << endl;
}

WavFileReader::~WavFileReader()
{
    if (m_file) sf_close(m_file);
}

void
WavFileReader::updateFrameCount()
{
    QMutexLocker locker(&m_mutex);

    sv_frame_t prevCount = m_fileInfo.frames;

    if (m_file) {
        sf_close(m_file);
        m_file = sf_open(m_path.toLocal8Bit(), SFM_READ, &m_fileInfo);
        if (!m_file || m_fileInfo.channels <= 0) {
            SVDEBUG << "WavFileReader::updateFrameCount: Failed to open file at \"" << m_path << "\" ("
                    << sf_strerror(m_file) << ")" << endl;
        }
    }

//    SVDEBUG << "WavFileReader::updateFrameCount: now " << m_fileInfo.frames << endl;

    m_frameCount = m_fileInfo.frames;

    if (m_channelCount == 0) {
        m_channelCount = m_fileInfo.channels;
        m_sampleRate = m_fileInfo.samplerate;
    }

    if (m_frameCount != prevCount) {
        emit frameCountChanged();
    }
}

void
WavFileReader::updateDone()
{
    updateFrameCount();
    m_updating = false;
}

vector<float>
WavFileReader::getInterleavedFrames(sv_frame_t start, sv_frame_t count) const
{
    static HitCount lastRead("WavFileReader: last read");

    if (count == 0) return {};

    QMutexLocker locker(&m_mutex);

    Profiler profiler("WavFileReader::getInterleavedFrames");
    
    if (!m_file || !m_channelCount) {
        return {};
    }

    if (start >= m_fileInfo.frames) {
//        SVDEBUG << "WavFileReader::getInterleavedFrames: " << start
//                  << " > " << m_fileInfo.frames << endl;
	return {};
    }

    if (start + count > m_fileInfo.frames) {
	count = m_fileInfo.frames - start;
    }

    // Because WaveFileModel::getSummaries() is called separately for
    // individual channels, it's quite common for us to be called
    // repeatedly for the same data. So this is worth cacheing.
    if (start == m_lastStart && count == m_lastCount) {
        lastRead.hit();
        return m_buffer;
    }

    // We don't actually support partial cache reads, but let's use
    // the term partial to refer to any forward seek and consider a
    // backward seek to be a miss
    if (start >= m_lastStart) {
        lastRead.partial();
    } else {
        lastRead.miss();
    }
    
    if (sf_seek(m_file, start, SEEK_SET) < 0) {
        return {};
    }

    vector<float> data;
    sv_frame_t n = count * m_fileInfo.channels;
    data.resize(n);

    m_lastStart = start;
    m_lastCount = count;
    
    sf_count_t readCount = 0;
    if ((readCount = sf_readf_float(m_file, data.data(), count)) < 0) {
        return {};
    }

    m_buffer = data;
    return data;
}

void
WavFileReader::getSupportedExtensions(set<QString> &extensions)
{
    int count;

    if (sf_command(0, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof(count))) {
        extensions.insert("wav");
        extensions.insert("aiff");
        extensions.insert("aifc");
        extensions.insert("aif");
        return;
    }

    SF_FORMAT_INFO info;
    for (int i = 0; i < count; ++i) {
        info.format = i;
        if (!sf_command(0, SFC_GET_FORMAT_MAJOR, &info, sizeof(info))) {
            QString ext = QString(info.extension).toLower();
            extensions.insert(ext);
            if (ext == "oga") {
                // libsndfile is awfully proper, it says it only
                // supports .oga but lots of Ogg audio files in the
                // wild are .ogg and it will accept that
                extensions.insert("ogg");
            }
        }
    }
}

bool
WavFileReader::supportsExtension(QString extension)
{
    set<QString> extensions;
    getSupportedExtensions(extensions);
    return (extensions.find(extension.toLower()) != extensions.end());
}

bool
WavFileReader::supportsContentType(QString type)
{
    return (type == "audio/x-wav" ||
            type == "audio/x-aiff" ||
            type == "audio/basic");
}

bool
WavFileReader::supports(FileSource &source)
{
    return (supportsExtension(source.getExtension()) ||
            supportsContentType(source.getContentType()));
}


