/*
 * PatchesDialog.cpp - display sf2 patches
 *
 * Copyright (c) 2008 Paul Giblock <drfaygo/at/gmail/dot/com>
 * 
 * This file is part of LMMS - https://lmms.io
 *
 * 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.
 *
 * This program 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 this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */


#include "PatchesDialog.h"

#include <fluidsynth.h>
#include <QHeaderView>
//#include <QFileInfo>
#include <QLabel>
#include <QKeyEvent>
#include <QSortFilterProxyModel>
#include <QStandardItemModel>
#include <QStandardItem>

#include "embed.h"
#include "fluidsynthshims.h"

namespace lmms::gui
{


// Custom list-view item (as for numerical sort purposes...)
class PatchItem : public QTreeWidgetItem
{
public:

	// Constructor.
	PatchItem( QTreeWidget *pListView,
		QTreeWidgetItem *pItemAfter )
		: QTreeWidgetItem( pListView, pItemAfter ) {}

	// Sort/compare overriden method.
	bool operator< ( const QTreeWidgetItem& other ) const override
	{
		int iColumn = QTreeWidgetItem::treeWidget()->sortColumn();
		const QString& s1 = text( iColumn );
		const QString& s2 = other.text( iColumn );
		if( iColumn == 0 || iColumn == 2 )
		{
			return( s1.toInt() < s2.toInt() );
		} 
		else 
		{
			return( s1 < s2 );
		}
	}
};

// Constructor.
PatchesDialog::PatchesDialog( QWidget *pParent, Qt::WindowFlags wflags )
	: QDialog(pParent, wflags)
	, m_pSynth{nullptr}
	, m_iChan{0}
	, m_iBank{0}
	, m_iProg{0}
	, m_selProg{0}
{
	// Setup UI struct...
	setupUi( this );

	// Configure bank list view
	auto bankHeader = m_bankListView->header();
	bankHeader->setSectionResizeMode(0, QHeaderView::Stretch);
	bankHeader->setStretchLastSection(true);
	bankHeader->resizeSection(0, 30);

	m_splitter->setStretchFactor(0, 2);
	m_splitter->setStretchFactor(1, 6);

	// Configure program list models
	m_progListSourceModel.setHorizontalHeaderLabels({tr("Patch"), tr("Name")});
	m_progListProxyModel.setSourceModel(&m_progListSourceModel);
	m_progListProxyModel.setFilterCaseSensitivity(Qt::CaseInsensitive);
	m_progListProxyModel.setFilterKeyColumn(1); // "Name" column
	m_progListProxyModel.setDynamicSortFilter(true);

	// Configure program list view
	m_progListView->setModel(&m_progListProxyModel);
	m_progListView->setEditTriggers(QAbstractItemView::NoEditTriggers);
	m_progListView->setSelectionBehavior(QAbstractItemView::SelectRows);
	m_progListView->setSelectionMode(QAbstractItemView::SingleSelection);
	m_progListView->setSortingEnabled(true);
	m_progListView->sortByColumn(0, Qt::AscendingOrder); // Initial sort by column 0 (Name)

	constexpr int RowHeight = 18;
	auto progVHeader = m_progListView->verticalHeader();
	progVHeader->setSectionResizeMode(QHeaderView::Fixed);
	progVHeader->setMinimumSectionSize(RowHeight);
	progVHeader->setMaximumSectionSize(RowHeight);
	progVHeader->setDefaultSectionSize(RowHeight);
	progVHeader->hide();

	auto progHeader = m_progListView->horizontalHeader();
	progHeader->setDefaultAlignment(Qt::AlignLeft);
	progHeader->setSectionResizeMode(0, QHeaderView::ResizeToContents);
	progHeader->setSectionResizeMode(1, QHeaderView::Stretch);
	progHeader->setSectionsMovable(false);
	progHeader->setStretchLastSection(true);

	// Initial sort order...
	m_bankListView->sortItems(0, Qt::AscendingOrder);

	m_filterEdit->setPlaceholderText(tr("Search"));
	m_filterEdit->setClearButtonEnabled(true);
	m_filterEdit->addAction(embed::getIconPixmap("zoom"), QLineEdit::LeadingPosition);

	// Configure focus (only allow for search bar and dialog buttons)
	m_filterEdit->setFocus();
	m_filterEdit->setFocusPolicy(Qt::StrongFocus);
	m_bankListView->setFocusPolicy(Qt::NoFocus);
	m_progListView->setFocusPolicy(Qt::NoFocus);

	// UI connections...
	QObject::connect(m_filterEdit, &QLineEdit::textChanged, this, [this](const QString& text) {
		m_progListProxyModel.setFilterRegularExpression(
			QRegularExpression(text, QRegularExpression::CaseInsensitiveOption));
		diffSelectProgRow(0); // fix the selection if it has been invalidated
	});
	QObject::connect(m_bankListView,
		SIGNAL(currentItemChanged(QTreeWidgetItem*,QTreeWidgetItem*)),
		SLOT(bankChanged()));
	QObject::connect(m_progListView,
		&QTableView::doubleClicked, this, &PatchesDialog::accept);
	QObject::connect(m_progListView->selectionModel(), &QItemSelectionModel::currentRowChanged,
		this, &PatchesDialog::progChanged);
	QObject::connect(m_okButton,
		SIGNAL(clicked()),
		SLOT(accept()));
	QObject::connect(m_cancelButton,
		SIGNAL(clicked()),
		SLOT(reject()));
}


// Dialog setup loader.
void PatchesDialog::setup ( fluid_synth_t * pSynth, int iChan,
						const QString & _chanName,
						LcdSpinBoxModel * _bankModel,
						LcdSpinBoxModel * _progModel,
							QLabel * _patchLabel )
{
	// We'll going to changes the whole thing...
	m_dirty = 0;
	m_bankModel = _bankModel;
	m_progModel = _progModel;
	m_patchLabel =  _patchLabel;

	// Set the proper caption...
	setWindowTitle( _chanName + " - Soundfont patches" );

	// set m_pSynth to NULL so we don't trigger any progChanged events
	m_pSynth = nullptr;

	// Load bank list from actual synth stack...
	m_bankListView->setSortingEnabled(false);
	m_bankListView->clear();

	// now it should be safe to set internal stuff
	m_pSynth = pSynth;
	m_iChan  = iChan;

	QTreeWidgetItem *pBankItem = nullptr;
	// For all soundfonts (in reversed stack order) fill the available banks...
	int cSoundFonts = ::fluid_synth_sfcount(m_pSynth);
	for (int i = 0; i < cSoundFonts; i++) {
		fluid_sfont_t *pSoundFont = ::fluid_synth_get_sfont(m_pSynth, i);
		if (pSoundFont) {
#ifdef CONFIG_FLUID_BANK_OFFSET
			int iBankOffset = ::fluid_synth_get_bank_offset(m_pSynth, fluid_sfont_get_id(pSoundFont));
#endif
			fluid_sfont_iteration_start(pSoundFont);
#if FLUIDSYNTH_VERSION_MAJOR < 2
			fluid_preset_t preset;
			fluid_preset_t *pCurPreset = &preset;
#else
			fluid_preset_t *pCurPreset = nullptr;
#endif
			while ((pCurPreset = fluid_sfont_iteration_next_wrapper(pSoundFont, pCurPreset))) {
				int iBank = fluid_preset_get_banknum(pCurPreset);
#ifdef CONFIG_FLUID_BANK_OFFSET
				iBank += iBankOffset;
#endif
				if (!findBankItem(iBank)) {
					pBankItem = new PatchItem(m_bankListView, pBankItem);
					if (pBankItem)
						pBankItem->setText(0, QString::number(iBank));
				}
			}
		}
	}
	m_bankListView->setSortingEnabled(true);

	// Set the selected bank.
	m_iBank = 0;
	fluid_preset_t *pPreset = ::fluid_synth_get_channel_preset(m_pSynth, m_iChan);
	if (pPreset) {
		m_iBank = fluid_preset_get_banknum(pPreset);
#ifdef CONFIG_FLUID_BANK_OFFSET
		m_iBank += ::fluid_synth_get_bank_offset(m_pSynth, fluid_sfont_get_id(fluid_preset_get_sfont(sfont)));
#endif
	}

	pBankItem = findBankItem(m_iBank);
	m_bankListView->setCurrentItem(pBankItem);
	m_bankListView->scrollToItem(pBankItem);
	bankChanged();

	// Set the selected program.
	if (pPreset) { m_iProg = fluid_preset_get_num(pPreset); }

	if (auto progItem = findProgItem(m_iProg); progItem != nullptr)
	{
		auto sourceIdx = progItem->index();
		auto proxyIdx = m_progListProxyModel.mapFromSource(sourceIdx);

		if (proxyIdx.isValid())
		{
			constexpr auto setMask = QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows;
			int row = proxyIdx.row();
			auto idx = m_progListView->model()->index(row, 0);

			m_progListView->selectionModel()->setCurrentIndex(idx, setMask);
			m_progListView->scrollTo(idx);
		}
	}

	// Done with setup...
	//m_iDirtySetup--;
}


// Stabilize current state form.
void PatchesDialog::stabilizeForm()
{
	m_okButton->setEnabled(validateForm());
}


// Validate form fields.
bool PatchesDialog::validateForm()
{
	bool bValid = true;

	bValid = bValid && (m_bankListView->currentItem() != nullptr);

	return bValid;
}


// Realize a bank-program selection preset.
void PatchesDialog::setBankProg ( int iBank, int iProg )
{
	if (m_pSynth == nullptr)
		return;

	// just select the synth's program preset...
	::fluid_synth_bank_select(m_pSynth, m_iChan, iBank);
	::fluid_synth_program_change(m_pSynth, m_iChan, iProg);
	// Maybe this is needed to stabilize things around.
	::fluid_synth_program_reset(m_pSynth);
}


// Validate form fields and accept it valid.
void PatchesDialog::accept()
{
	if (validateForm()) {
		bool updateUi = m_dirty > 0;
		updatePatch(updateUi);

		// Do remember preview state...
		// if (m_pOptions)
			// m_pOptions->bPresetPreview = m_ui.PreviewCheckBox->isChecked();
		// We got it.

		QDialog::accept();
	}
}


// Reject settings (Cancel button slot).
void PatchesDialog::reject ()
{
	// Reset selection to initial selection, if applicable...
	if (m_dirty > 0)
		setBankProg(m_bankModel->value(), m_progModel->value());
	// Done (hopefully nothing).
	QDialog::reject();
}


// Find the bank item of given bank number id.
QTreeWidgetItem *PatchesDialog::findBankItem ( int iBank )
{
	QList<QTreeWidgetItem *> banks
		= m_bankListView->findItems(
			QString::number(iBank), Qt::MatchExactly, 0);

	QListIterator<QTreeWidgetItem *> iter(banks);
	if (iter.hasNext())
		return iter.next();
	else
		return nullptr;
}

QStandardItem* PatchesDialog::findProgItem(int iProg)
{
	QList<QStandardItem*> progs = m_progListSourceModel.findItems(QString::number(iProg), Qt::MatchExactly, 0);

	auto it = QListIterator<QStandardItem*>(progs);
	return it.hasNext() ? it.next() : nullptr;
}


// Bank change slot.
void PatchesDialog::bankChanged ()
{
	if (m_pSynth == nullptr)
		return;

	QTreeWidgetItem *pBankItem = m_bankListView->currentItem();
	if (pBankItem == nullptr)
		return;

	int iBankSelected = pBankItem->text(0).toInt();

	// Clear up the program list to refill
	m_progListView->setSortingEnabled(false);
	m_progListSourceModel.setRowCount(0);

	// For all soundfonts (in reversed stack order) fill the available programs...
	bool stop = false; // replaces the `pProgItem` check that used to exist here
	int cSoundFonts = ::fluid_synth_sfcount(m_pSynth);
	for (int i = 0; i < cSoundFonts && !stop; i++) {
		fluid_sfont_t *pSoundFont = ::fluid_synth_get_sfont(m_pSynth, i);
		if (pSoundFont) {
#ifdef CONFIG_FLUID_BANK_OFFSET
			int iBankOffset = ::fluid_synth_get_bank_offset(m_pSynth, fluid_sfont_get_id(pSoundFont));
#endif
			fluid_sfont_iteration_start(pSoundFont);
#if FLUIDSYNTH_VERSION_MAJOR < 2
			fluid_preset_t preset;
			fluid_preset_t *pCurPreset = &preset;
#else
			fluid_preset_t *pCurPreset = nullptr;
#endif
			while ((pCurPreset = fluid_sfont_iteration_next_wrapper(pSoundFont, pCurPreset))) {
				int iBank = fluid_preset_get_banknum(pCurPreset);
#ifdef CONFIG_FLUID_BANK_OFFSET
				iBank += iBankOffset;
#endif
				int iProg = fluid_preset_get_num(pCurPreset);
				if (iBank == iBankSelected && !findProgItem(iProg)) {
					// Numeric value on the batch number column - allows for numerical sorting
					auto patchNumItem = new QStandardItem();
					patchNumItem->setData(iProg, Qt::DisplayRole);

					auto patchNameItem = new QStandardItem(fluid_preset_get_name(pCurPreset));

					stop = true;

					m_progListSourceModel.appendRow({patchNumItem, patchNameItem});
					// Old columns:
					// Col. 2: QString::number(fluid_sfont_get_id(pSoundFont))
					// Col. 3: QFileInfo(fluid_sfont_get_name(pSoundFont).baseName())
				}
			}
		}
	}
	m_progListView->setSortingEnabled(true);

	// Stabilize the form.
	stabilizeForm();
}

void PatchesDialog::updatePatch(bool updateUi)
{
	int iBank = m_bankListView->currentItem()->text(0).toInt();
	setBankProg(iBank, m_selProg);

	if (updateUi)
	{
		m_bankModel->setValue(iBank);
		m_progModel->setValue(m_selProg);
		m_patchLabel->setText(m_selProgName);
	}
}

void PatchesDialog::progChanged(const QModelIndex& cur, const QModelIndex& prev)
{
	if (m_pSynth == nullptr) { return; }

	auto curRow = m_progListProxyModel.mapToSource(cur).row();
	if (curRow < 0) { return; }

	auto progIdx = m_progListSourceModel.index(curRow, 0);
	m_selProg = m_progListSourceModel.data(progIdx).toInt();

	auto nameIdx = m_progListSourceModel.index(curRow, 1);
	m_selProgName = m_progListSourceModel.data(nameIdx).toString();

	// Which preview state...
	if (validateForm())
	{
		updatePatch(false);

		// Now we're dirty nuff.
		m_dirty++;
	}

	// Stabilize the form.
	stabilizeForm();
}

void PatchesDialog::keyPressEvent(QKeyEvent* event)
{
	const auto key = event->key();

	if (key == Qt::Key_Up || key == Qt::Key_Down)
	{
		event->accept();
		int rowDiff = (key == Qt::Key_Up) ? -1 : +1;
		diffSelectProgRow(rowDiff);
	}
	else if (key == Qt::Key_Return || key == Qt::Key_Enter)
	{
		event->accept();
		accept();
	}
	else if (key == Qt::Key_Escape)
	{
		event->accept();
		reject();
	}
}

void PatchesDialog::diffSelectProgRow(int offset)
{
	QItemSelectionModel* selectionModel = m_progListView->selectionModel();

	int curRow = selectionModel->currentIndex().row();
	int newRow = curRow + offset;
	int rowCount = m_progListView->model()->rowCount();
	newRow = qBound(0, newRow, rowCount - 1);

	constexpr auto selMask = QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows;
	const auto idx = m_progListView->model()->index(newRow, 0);
	selectionModel->setCurrentIndex(idx, selMask);
	m_progListView->scrollTo(idx);
}

} // namespace lmms::gui