/*
  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.
*/

#include <QVarLengthArray>
#include <QMutexLocker>
#include <QDateTime>
#include <QDir>

#include <sys/inotify.h>
#include <stropts.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <errno.h>

#include "smdirwatcher.h"
#include "smtreeitem.h"
#include "helper.h"

extern int errno;

SmDirWatcher::SmDirWatcher(QObject *parent) : QThread(parent), mFd(0), mDescr(0) {
    mFd = inotify_init1(IN_NONBLOCK);
}

SmDirWatcher::~SmDirWatcher(){
    if(mFd && mDescr){
        inotify_rm_watch(mFd, mDescr);
    }
}

void SmDirWatcher::setDir(const QString &dir){
    QMutexLocker lock(&mWatchMx);
    if(mDescr){
        inotify_rm_watch(mFd, mDescr); //generates IN_IGNORE ???
    }
    /* mask rationale:
     * IN_DELETE_SELF cannot happen since we're only
     * watching one directory at all time.
     * We don't care about the other events
     */
    mDescr = inotify_add_watch(mFd, qPrintable(dir), IN_CLOSE_WRITE | IN_CREATE | IN_DELETE | IN_MODIFY | IN_MOVED_FROM | IN_MOVED_TO);
    mCurrent = dir;
}

void SmDirWatcher::run(){
    QMutexLocker lock(&mWatchMx);
    QVarLengthArray<char, 4096> data(4096);
    int r = read(mFd, data.data(), data.size());
    int err = errno;
    if(r < 0){
        if(err != EAGAIN){
            return;
        }
        r = read(mFd, data.data(), data.size());
    }
    // inspect data
    char *at = data.data();
    inotify_event *e = reinterpret_cast<inotify_event*>(at);
    if(!e->len){
        return;
    }
    char *end = at + data.size();
    while(at < end){
        if(e->mask & IN_IGNORED){
            at += sizeof(inotify_event) + e->len;
            continue;
        }
        quint32 mask = e->mask;
        QString name = QString("%1/%2").arg(mCurrent).arg(e->name);
        at += sizeof(inotify_event) + e->len;
        if(mask & IN_CREATE){
            emit dwEvent(name, Added);
            return;
        }
        if(mask & IN_DELETE){
            emit dwEvent(name, Deleted);
            return;
        }
        if(mask & IN_CLOSE_WRITE || e->mask & IN_MODIFY){
            emit dwEvent(name, Modified);
            return;
        }
        if(mask & IN_MOVED_FROM || e->mask & IN_MOVED_TO){
            emit needRefresh();
            return;
        }
    }
}

SmDataGatherer::SmDataGatherer(const int numFields, QObject *parent) : QThread(parent), mNumFields(numFields) {}

void SmDataGatherer::setCurrent(const QString &current, int mode){
    QMutexLocker lock(&mSetMx);
    mCurrent = current;
    mMode = mode;
}

void SmDataGatherer::run(){
    QMutexLocker lock(&mRunMx);
    QFileInfo fi(mCurrent);
    if(fi.isDir()){
        SmTreeItem *rv = populate();
        emit population(rv);
        return;
    }
    if(fi.isFile()){
        QList<QVariant> fd = fileData(fi);
        emit newData(fd, mMode);
    }
}

SmTreeItem * SmDataGatherer::populate(){
    SmTreeItem *retval = new SmTreeItem(mNumFields);
    QDir d = QDir(mCurrent);
    foreach(QFileInfo fi, d.entryInfoList()){
        if(fi.fileName() == "."){
            continue;
        }
        QList<QVariant> data = fileData(fi);
        SmTreeItem *newItem = new SmTreeItem(data, retval);
        retval->appendChild(newItem);
    }
    return retval;
}

const QList<QVariant> SmDataGatherer::fileData(const QFileInfo &fi) const{
    QList<QVariant> data;
    data << fi.fileName() << fi.size();
    QString mime = Helper::mimeType(fi.absoluteFilePath());
    data << mime;
    data << fi.lastModified();
    QList<QVariant> si = QList<QVariant>() << QVariant() << QVariant();
    if(mime.startsWith("video")){
        si = Helper::duration(fi.absoluteFilePath());
    }
    data << Helper::md5Sum(fi.absoluteFilePath());
    data << si << fi.absoluteFilePath();
    return data;
}