/*
 Copyright © 2018 Hasan Yavuz Özderya

 This file is part of serialplot.

 serialplot 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 3 of the License, or
 (at your option) any later version.

 serialplot is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with serialplot. If not, see <http://www.gnu.org/licenses/>.
*/

#include <QTime>
#include <QMenuBar>
#include <QKeySequence>
#include <QFileDialog>
#include <QFile>
#include <QTextStream>
#include <QVector>
#include <QPointF>
#include <QIcon>
#include <QtDebug>

#include "mainwindow.h"
#include "snapshotmanager.h"

SnapshotManager::SnapshotManager(MainWindow* mainWindow,
 ChannelManager* channelMan) :
 _menu("&Snapshots"),
 _takeSnapshotAction("&Take Snapshot", this),
 loadSnapshotAction("&Load Snapshots", this),
 clearAction("&Clear Snapshots", this)
{
 _mainWindow = mainWindow;
 _channelMan = channelMan;

 _takeSnapshotAction.setToolTip("Take a snapshot of current plot");
 _takeSnapshotAction.setShortcut(QKeySequence("F5"));
 _takeSnapshotAction.setIcon(QIcon::fromTheme("camera"));
 loadSnapshotAction.setToolTip("Load snapshots from CSV files");
 clearAction.setToolTip("Delete all snapshots");
 connect(&_takeSnapshotAction, SIGNAL(triggered(bool)),
 this, SLOT(takeSnapshot()));
 connect(&clearAction, SIGNAL(triggered(bool)),
 this, SLOT(clearSnapshots()));
 connect(&loadSnapshotAction, SIGNAL(triggered(bool)),
 this, SLOT(loadSnapshots()));

 updateMenu();
}

SnapshotManager::~SnapshotManager()
{
 for (auto snapshot : snapshots)
 {
 delete snapshot;
 }
}

Snapshot* SnapshotManager::makeSnapshot()
{
 QString name = QTime::currentTime().toString("'Snapshot ['HH:mm:ss']'");
 auto snapshot = new Snapshot(_mainWindow, name, *(_channelMan->infoModel()));

 unsigned numOfChannels = _channelMan->numOfChannels();
 unsigned numOfSamples = _channelMan->numOfSamples();

 for (unsigned ci = 0; ci < numOfChannels; ci++)
 {
 snapshot->data.append(QVector<QPointF>(numOfSamples));
 for (unsigned i = 0; i < numOfSamples; i++)
 {
 snapshot->data[ci][i] = QPointF(i, _channelMan->channelBuffer(ci)->sample(i));
 }
 }

 return snapshot;
}

void SnapshotManager::takeSnapshot()
{
 addSnapshot(makeSnapshot());
}

void SnapshotManager::addSnapshot(Snapshot* snapshot, bool update_menu)
{
 snapshots.append(snapshot);
 QObject::connect(snapshot, &Snapshot::deleteRequested,
 this, &SnapshotManager::deleteSnapshot);
 if (update_menu) updateMenu();
}

void SnapshotManager::updateMenu()
{
 _menu.clear();
 _menu.addAction(&_takeSnapshotAction);
 _menu.addAction(&loadSnapshotAction);
 if (snapshots.size())
 {
 _menu.addSeparator();
 for (auto ss : snapshots)
 {
 _menu.addAction(ss->showAction());
 }
 _menu.addSeparator();
 _menu.addAction(&clearAction);
 }
}

void SnapshotManager::clearSnapshots()
{
 for (auto snapshot : snapshots)
 {
 delete snapshot;
 }
 snapshots.clear();
 updateMenu();
}

void SnapshotManager::deleteSnapshot(Snapshot* snapshot)
{
 snapshots.removeOne(snapshot);
 snapshot->deleteLater(); // regular delete causes a crash when triggered from menu
 updateMenu();
}

void SnapshotManager::loadSnapshots()
{
 auto files = QFileDialog::getOpenFileNames(_mainWindow, tr("Load CSV File"));

 for (auto f : files)
 {
 if (!f.isNull()) loadSnapshotFromFile(f);
 }

 updateMenu();
}

void SnapshotManager::loadSnapshotFromFile(QString fileName)
{
 QFile file(fileName);
 if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
 {
 qCritical() << "Couldn't open file: " << fileName;
 qCritical() << file.errorString();
 return;
 }

 // read first row as headlines and determine number of channels
 auto headLine = QString(file.readLine());
 QStringList channelNames = headLine.split(',');
 unsigned numOfChannels = channelNames.size();

 // read data
 QVector<QVector<QPointF>> data(numOfChannels);
 QTextStream ts(&file);
 QString line;
 unsigned lineNum = 1;
 while (ts.readLineInto(&line))
 {
 // parse line
 auto split = line.split(',');

 if (split.size() != (int) numOfChannels)
 {
 qCritical() << "Parsing error at line " << lineNum
 << ": number of columns is not consistent.";
 qCritical() << "Line " << lineNum << ": " << line;
 return;
 }

 for (unsigned ci = 0; ci < numOfChannels; ci++)
 {
 // parse column
 bool ok;
 double y = split[ci].toDouble(&ok);
 if (!ok)
 {
 qCritical() << "Parsing error at line " << lineNum
 << ", column " << ci
 << ": can't convert \"" << split[ci]
 << "\" to double.";
 return;
 }
 data[ci].append(QPointF(lineNum-1, y));
 }
 lineNum++;
 }

 auto snapshot = new Snapshot(
 _mainWindow, QFileInfo(fileName).baseName(),
 ChannelInfoModel(channelNames), true);
 snapshot->data = data;

 addSnapshot(snapshot, false);
}

QMenu* SnapshotManager::menu()
{
 return &_menu;
}

QAction* SnapshotManager::takeSnapshotAction()
{
 return &_takeSnapshotAction;
}

bool SnapshotManager::isAllSaved()
{
 for (auto snapshot : snapshots)
 {
 if (!snapshot->isSaved()) return false;
 }
 return true;
}