# This file is part of the Frescobaldi project, http://www.frescobaldi.org/
#
# Copyright (c) 2008 - 2012 by Wilbert Berendsen
#
# 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; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# See http://www.gnu.org/licenses/ for more information.

"""
The PDF preview panel.

This file loads even if popplerqt4 is absent, although the PDF preview
panel only shows a message about missing the popplerqt4 module.

The widget module contains the real widget, the documents module a simple
abstraction and caching of Poppler documents with their filename,
and the printing module contains code to print a Poppler document, either
via a PostScript rendering or by printing raster images to a QPrinter.

All the point & click stuff is handled in the pointandclick module.

"""

from __future__ import unicode_literals

import functools
import os
import weakref

from PyQt4.QtCore import QSettings, QTimer, Qt, pyqtSignal
from PyQt4.QtGui import (
    QAction, QComboBox, QLabel, QKeySequence, QSpinBox, QWidgetAction)

import app
import actioncollection
import actioncollectionmanager
import icons
import qutil
import panel
import listmodel
import widgets.drag
import jobattributes

from . import documents


# default zoom percentages
_zoomvalues = [50, 75, 100, 125, 150, 175, 200, 250, 300]

# viewModes from qpopplerview:
from qpopplerview import FixedScale, FitWidth, FitHeight, FitBoth


def activate(func):
    """Decorator for MusicViewPanel methods/slots.
    
    The purpose is to first activate the widget and only perform an action
    when the event loop starts. This gives the PDF widget the chance to resize
    and position itself correctly.
    
    """
    @functools.wraps(func)
    def wrapper(self):
        instantiated = bool(super(panel.Panel, self).widget())
        self.activate()
        if instantiated:
            func(self)
        else:
            QTimer.singleShot(0, lambda: func(self))
    return wrapper


class MusicViewPanel(panel.Panel):
    def __init__(self, mainwindow):
        super(MusicViewPanel, self).__init__(mainwindow)
        self.toggleViewAction().setShortcut(QKeySequence("Meta+Alt+M"))
        mainwindow.addDockWidget(Qt.RightDockWidgetArea, self)
        
        ac = self.actionCollection = Actions(self)
        actioncollectionmanager.manager(mainwindow).addActionCollection(ac)
        ac.music_print.triggered.connect(self.printMusic)
        ac.music_zoom_in.triggered.connect(self.zoomIn)
        ac.music_zoom_out.triggered.connect(self.zoomOut)
        ac.music_zoom_original.triggered.connect(self.zoomOriginal)
        ac.music_zoom_combo.zoomChanged.connect(self.slotZoomChanged)
        ac.music_fit_width.triggered.connect(self.fitWidth)
        ac.music_fit_height.triggered.connect(self.fitHeight)
        ac.music_fit_both.triggered.connect(self.fitBoth)
        ac.music_maximize.triggered.connect(self.maximize)
        ac.music_jump_to_cursor.triggered.connect(self.jumpToCursor)
        ac.music_sync_cursor.triggered.connect(self.toggleSyncCursor)
        ac.music_copy_image.triggered.connect(self.copyImage)
        ac.music_document_select.documentsChanged.connect(self.updateActions)
        ac.music_copy_image.setEnabled(False)
        ac.music_next_page.triggered.connect(self.slotNextPage)
        ac.music_prev_page.triggered.connect(self.slotPreviousPage)
        self.slotPageCountChanged(0)
        ac.music_next_page.setEnabled(False)
        ac.music_prev_page.setEnabled(False)
        self.actionCollection.music_sync_cursor.setChecked(
            QSettings().value("musicview/sync_cursor", False) in (True, "true"))
                
    def translateUI(self):
        self.setWindowTitle(_("window title", "Music View"))
        self.toggleViewAction().setText(_("&Music View"))
    
    def createWidget(self):
        import widget
        w = widget.MusicView(self)
        w.zoomChanged.connect(self.slotMusicZoomChanged)
        w.updateZoomInfo()
        w.view.surface().selectionChanged.connect(self.updateSelection)
        
        import qpopplerview.pager
        self._pager = p = qpopplerview.pager.Pager(w.view)
        p.pageCountChanged.connect(self.slotPageCountChanged)
        p.currentPageChanged.connect(self.slotCurrentPageChanged)
        app.languageChanged.connect(self.updatePagerLanguage)
        
        selector = self.actionCollection.music_document_select
        selector.currentDocumentChanged.connect(w.openDocument)
        selector.documentClosed.connect(w.clear)
        
        if selector.currentDocument():
            # open a document only after the widget has been created;
            # this prevents many superfluous resizes
            def open():
                if selector.currentDocument():
                    w.openDocument(selector.currentDocument())
            QTimer.singleShot(0, open)
        return w
    
    def updateSelection(self, rect):
        self.actionCollection.music_copy_image.setEnabled(bool(rect))
    
    def updatePagerLanguage(self):
        self.actionCollection.music_pager.setPageCount(self._pager.pageCount())
    
    def slotPageCountChanged(self, total):
        self.actionCollection.music_pager.setPageCount(total)
        
    def slotCurrentPageChanged(self, num):
        self.actionCollection.music_pager.setCurrentPage(num)
        self.actionCollection.music_next_page.setEnabled(num < self._pager.pageCount())
        self.actionCollection.music_prev_page.setEnabled(num > 1)
        
    @activate
    def slotNextPage(self):
        self._pager.setCurrentPage(self._pager.currentPage() + 1)
    
    @activate
    def slotPreviousPage(self):
        self._pager.setCurrentPage(self._pager.currentPage() - 1)
    
    def setCurrentPage(self, num):
        self.activate()
        self._pager.setCurrentPage(num)
        
    def updateActions(self):
        ac = self.actionCollection
        ac.music_print.setEnabled(bool(ac.music_document_select.documents()))
        
    def printMusic(self):
        doc = self.actionCollection.music_document_select.currentDocument()
        if doc and doc.document():
            import popplerprint
            popplerprint.printDocument(doc, self)
    
    @activate
    def zoomIn(self):
        self.widget().view.zoomIn()
    
    @activate
    def zoomOut(self):
        self.widget().view.zoomOut()
    
    @activate
    def zoomOriginal(self):
        self.widget().view.zoom(1.0)
    
    @activate
    def fitWidth(self):
        self.widget().view.setViewMode(FitWidth)
    
    @activate
    def fitHeight(self):
        self.widget().view.setViewMode(FitHeight)

    @activate
    def fitBoth(self):
        self.widget().view.setViewMode(FitBoth)
    
    @activate
    def jumpToCursor(self):
        self.widget().showCurrentLinks()
    
    def toggleSyncCursor(self):
        QSettings().setValue("musicview/sync_cursor",
            self.actionCollection.music_sync_cursor.isChecked())
     
    def copyImage(self):
        from . import image
        image.copy(self)
        
    def slotZoomChanged(self, mode, scale):
        """Called when the combobox is changed, changes view zoom."""
        self.activate()
        if mode == FixedScale:
            self.widget().view.zoom(scale)
        else:
            self.widget().view.setViewMode(mode)
    
    def slotMusicZoomChanged(self, mode, scale):
        """Called when the music view is changed, updates the toolbar actions."""
        ac = self.actionCollection
        ac.music_fit_width.setChecked(mode == FitWidth)
        ac.music_fit_height.setChecked(mode == FitHeight)
        ac.music_fit_both.setChecked(mode == FitBoth)
        ac.music_zoom_combo.updateZoomInfo(mode, scale)
        

class Actions(actioncollection.ActionCollection):
    name = "musicview"
    def createActions(self, panel):
        self.music_document_select = DocumentChooserAction(panel)
        self.music_print = QAction(panel)
        self.music_zoom_in = QAction(panel)
        self.music_zoom_out = QAction(panel)
        self.music_zoom_original = QAction(panel)
        self.music_zoom_combo = ZoomerAction(panel)
        self.music_fit_width = QAction(panel, checkable=True)
        self.music_fit_height = QAction(panel, checkable=True)
        self.music_fit_both = QAction(panel, checkable=True)
        self.music_maximize = QAction(panel)
        self.music_jump_to_cursor = QAction(panel)
        self.music_sync_cursor = QAction(panel, checkable=True)
        self.music_copy_image = QAction(panel)
        self.music_pager = PagerAction(panel)
        self.music_next_page = QAction(panel)
        self.music_prev_page = QAction(panel)

        self.music_print.setIcon(icons.get('document-print'))
        self.music_zoom_in.setIcon(icons.get('zoom-in'))
        self.music_zoom_out.setIcon(icons.get('zoom-out'))
        self.music_zoom_original.setIcon(icons.get('zoom-original'))
        self.music_fit_width.setIcon(icons.get('zoom-fit-width'))
        self.music_fit_height.setIcon(icons.get('zoom-fit-height'))
        self.music_fit_both.setIcon(icons.get('zoom-fit-best'))
        self.music_maximize.setIcon(icons.get('view-fullscreen'))
        self.music_jump_to_cursor.setIcon(icons.get('go-jump'))
        self.music_copy_image.setIcon(icons.get('edit-copy'))
        self.music_next_page.setIcon(icons.get('go-next'))
        self.music_prev_page.setIcon(icons.get('go-previous'))
        
        self.music_document_select.setShortcut(QKeySequence(Qt.SHIFT | Qt.CTRL | Qt.Key_O))
        self.music_print.setShortcuts(QKeySequence.Print)
        self.music_zoom_in.setShortcuts(QKeySequence.ZoomIn)
        self.music_zoom_out.setShortcuts(QKeySequence.ZoomOut)
        self.music_jump_to_cursor.setShortcut(QKeySequence(Qt.CTRL | Qt.Key_J))
        self.music_copy_image.setShortcut(QKeySequence(Qt.SHIFT | Qt.CTRL | Qt.Key_C))
        
    def translateUI(self):
        self.music_document_select.setText(_("Select Music View Document"))
        self.music_print.setText(_("&Print Music..."))
        self.music_zoom_in.setText(_("Zoom &In"))
        self.music_zoom_out.setText(_("Zoom &Out"))
        self.music_zoom_original.setText(_("Original &Size"))
        self.music_zoom_combo.setText(_("Zoom Music"))
        self.music_fit_width.setText(_("Fit &Width"))
        self.music_fit_height.setText(_("Fit &Height"))
        self.music_fit_both.setText(_("Fit &Page"))
        self.music_maximize.setText(_("&Maximize"))
        self.music_jump_to_cursor.setText(_("&Jump to Cursor Position"))
        self.music_sync_cursor.setText(_("S&ynchronize with Cursor Position"))
        self.music_copy_image.setText(_("Copy to &Image..."))
        self.music_next_page.setText(_("Next Page"))
        self.music_next_page.setIconText(_("Next"))
        self.music_prev_page.setText(_("Previous Page"))
        self.music_prev_page.setIconText(_("Previous"))


class ComboBoxAction(QWidgetAction):
    """A widget action that opens a combobox widget popup when triggered."""
    def __init__(self, panel):
        super(ComboBoxAction, self).__init__(panel)
        self.triggered.connect(self.showPopup)
        
    def showPopup(self):
        """Called when our action is triggered by a keyboard shortcut."""
        # find the widget in our floating panel, if available there
        for w in self.createdWidgets():
            if w.window() == self.parent():
                w.showPopup()
                return
        # find the one in the main window
        for w in self.createdWidgets():
            if w.window() == self.parent().mainwindow():
                w.showPopup()
                return
    

class DocumentChooserAction(ComboBoxAction):
    """A ComboBoxAction that keeps track of the current text document.
    
    It manages the list of generated PDF documents for every text document.
    If the mainwindow changes its current document and there are PDFs to display,
    it switches the current document.
    
    It also switches to a text document if a job finished for that document,
    and it generated new PDF documents.
    
    """
    
    documentClosed = pyqtSignal()
    documentsChanged = pyqtSignal()
    currentDocumentChanged = pyqtSignal(documents.Document)
    
    def __init__(self, panel):
        super(DocumentChooserAction, self).__init__(panel)
        self._model = None
        self._document = None
        self._documents = []
        self._currentIndex = -1
        self._indices = weakref.WeakKeyDictionary()
        panel.mainwindow().currentDocumentChanged.connect(self.slotDocumentChanged)
        documents.documentUpdated.connect(self.slotDocumentUpdated)
        
    def createWidget(self, parent):
        w = DocumentChooser(parent)
        w.activated[int].connect(self.setCurrentIndex)
        if self._model:
            w.setModel(self._model)
        return w
    
    def slotDocumentChanged(self, doc):
        """Called when the mainwindow changes its current document."""
        # only switch our document if there are PDF documents to display
        if self._document is None or documents.group(doc).documents():
            self.setCurrentDocument(doc)
    
    def slotDocumentUpdated(self, doc, job):
        """Called when a Job, finished on the document, has created new PDFs."""
        if (doc == self._document or
                jobattributes.get(job).mainwindow == self.parent().mainwindow()):
            self.setCurrentDocument(doc)
    
    def setCurrentDocument(self, document):
        """Displays the DocumentGroup of the given text Document in our chooser."""
        prev = self._document
        self._document = document
        if prev:
            prev.loaded.disconnect(self.updateDocument)
            prev.closed.disconnect(self.closeDocument)
            self._indices[prev] = self._currentIndex
        document.loaded.connect(self.updateDocument)
        document.closed.connect(self.closeDocument)
        self.updateDocument()
        
    def updateDocument(self):
        """(Re)read the output documents of the current document and show them."""
        docs = self._documents = documents.group(self._document).documents()
        self.setVisible(bool(docs))
        self.setEnabled(bool(docs))
        
        # make model for the docs
        m = self._model = listmodel.ListModel([d.filename() for d in docs],
            display = os.path.basename, icon = icons.file_type)
        m.setRoleFunction(Qt.UserRole, lambda f: f)
        for w in self.createdWidgets():
            w.setModel(m)
        
        index = self._indices.get(self._document, 0)
        if index < 0 or index >= len(docs):
            index = 0
        self.documentsChanged.emit()
        self.setCurrentIndex(index)
    
    def closeDocument(self):
        """Called when the current document is closed by the user."""
        self._document = None
        self._documents = []
        self._currentIndex = -1
        self.setVisible(False)
        self.setEnabled(False)
        self.documentClosed.emit()
        self.documentsChanged.emit()
        
    def documents(self):
        return self._documents
        
    def setCurrentIndex(self, index):
        if self._documents:
            self._currentIndex = index
            for w in self.createdWidgets():
                w.setCurrentIndex(index)
            self.currentDocumentChanged.emit(self._documents[index])
    
    def currentIndex(self):
        return self._currentIndex
    
    def currentDocument(self):
        """Returns the currently selected Music document (Note: NOT the text document!)"""
        if self._documents:
            return self._documents[self._currentIndex]


class DocumentChooser(QComboBox):
    def __init__(self, parent):
        super(DocumentChooser, self).__init__(parent)
        self.setSizeAdjustPolicy(QComboBox.AdjustToContents)
        self.setEditable(True)
        self.lineEdit().setReadOnly(True)
        self.setFocusPolicy(Qt.NoFocus)
        app.translateUI(self)
        widgets.drag.ComboDrag(self).role = Qt.UserRole
        
    def translateUI(self):
        self.setToolTip(_("Choose the PDF document to display."))
        self.setWhatsThis(_(
            "Choose the PDF document to display or drag the file "
            "to another application or location."))


class ZoomerAction(ComboBoxAction):
    zoomChanged = pyqtSignal(int, float)
    
    def createWidget(self, parent):
        return Zoomer(self, parent)
    
    def setCurrentIndex(self, index):
        """Called when a user manipulates a Zoomer combobox.
        
        Updates the other widgets and calls the corresponding method of the panel.
        
        """
        for w in self.createdWidgets():
            w.setCurrentIndex(index)
        if index == 0:
            self.zoomChanged.emit(FitWidth, 0)
        elif index == 1:
            self.zoomChanged.emit(FitHeight, 0)
        elif index == 2:
            self.zoomChanged.emit(FitBoth, 0)
        else:
            self.zoomChanged.emit(FixedScale, _zoomvalues[index-3] / 100.0)
    
    def updateZoomInfo(self, mode, scale):
        """Connect view.viewModeChanged and layout.scaleChanged to this."""
        if mode == FixedScale:
            text = "{0:.0f}%".format(round(scale * 100.0))
            for w in self.createdWidgets():
                w.setEditText(text)
        else:
            if mode == FitWidth:
                index = 0
            elif mode == FitHeight:
                index = 1
            else: # qpopplerview.FitBoth:
                index = 2
            for w in self.createdWidgets():
                w.setCurrentIndex(index)


class Zoomer(QComboBox):
    def __init__(self, action, parent):
        super(Zoomer, self).__init__(parent)
        self.setSizeAdjustPolicy(QComboBox.AdjustToContents)
        self.setEditable(True)
        self.lineEdit().setReadOnly(True)
        self.setFocusPolicy(Qt.NoFocus)
        self.activated[int].connect(action.setCurrentIndex)
        self.addItems(['']*3)
        self.addItems(list(map("{0}%".format, _zoomvalues)))
        self.setMaxVisibleItems(20)
        app.translateUI(self)
    
    def translateUI(self):
        self.setItemText(0, _("Fit Width"))
        self.setItemText(1, _("Fit Height"))
        self.setItemText(2, _("Fit Page"))
        

class PagerAction(QWidgetAction):
    def __init__(self, panel):
        super(PagerAction, self).__init__(panel)
    
    def createWidget(self, parent):
        w = QSpinBox(parent, buttonSymbols=QSpinBox.NoButtons)
        w.setFocusPolicy(Qt.ClickFocus)
        w.valueChanged[int].connect(self.slotValueChanged)
        return w
    
    def setPageCount(self, total):
        if total:
            self.setVisible(True)
            # L10N: page numbering: page {num} of {total}
            prefix, suffix = _("{num} of {total}").split('{num}')
            def adjust(w):
                w.setRange(1, total)
                w.setSuffix(suffix.format(total=total))
                w.setPrefix(prefix.format(total=total))
        else:
            self.setVisible(False)
            def adjust(w):
                w.setRange(0, 0)
                w.clear()
        for w in self.createdWidgets():
            with qutil.signalsBlocked(w):
                adjust(w)
    
    def setCurrentPage(self, num):
        if num:
            for w in self.createdWidgets():
                with qutil.signalsBlocked(w):
                    w.setValue(num)
                    w.lineEdit().deselect()
    
    def slotValueChanged(self, num):
        self.parent().setCurrentPage(num)


