#!/usr/bin/env python2
# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
from __future__ import absolute_import, division, print_function, unicode_literals

__license__   = 'GPL v3'
__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'

import os, posixpath, weakref, sys
from functools import partial

from PyQt5.Qt import (QMenu, Qt, QInputDialog, QToolButton, QDialog,
        QDialogButtonBox, QGridLayout, QLabel, QLineEdit, QIcon, QSize,
        QCoreApplication, pyqtSignal, QVBoxLayout, QTimer, QAction)

from calibre import isbytestring, sanitize_file_name
from calibre.constants import (filesystem_encoding, iswindows, get_portable_base, isportable)
from calibre.utils.config import prefs, tweaks
from calibre.utils.icu import sort_key
from calibre.gui2 import (gprefs, warning_dialog, Dispatcher, error_dialog,
    question_dialog, info_dialog, open_local_file, choose_dir)
from calibre.gui2.actions import InterfaceAction
from polyglot.builtins import unicode_type, range


def db_class():
    from calibre.db.legacy import LibraryDatabase
    return LibraryDatabase


class LibraryUsageStats(object):  # {{{

    def __init__(self):
        self.stats = {}
        self.read_stats()
        base = get_portable_base()
        if base is not None:
            lp = prefs['library_path']
            if lp:
                # Rename the current library. Renaming of other libraries is
                # handled by the switch function
                q = os.path.basename(lp)
                for loc in list(self.stats):
                    bn = posixpath.basename(loc)
                    if bn.lower() == q.lower():
                        self.rename(loc, lp)

    def read_stats(self):
        stats = gprefs.get('library_usage_stats', {})
        self.stats = stats

    def write_stats(self):
        locs = list(self.stats.keys())
        locs.sort(key=lambda x: self.stats[x], reverse=True)
        for key in locs[500:]:
            self.stats.pop(key)
        gprefs.set('library_usage_stats', self.stats)

    def remove(self, location):
        self.stats.pop(location, None)
        self.write_stats()

    def canonicalize_path(self, lpath):
        if isbytestring(lpath):
            lpath = lpath.decode(filesystem_encoding)
        lpath = lpath.replace(os.sep, '/')
        return lpath

    def library_used(self, db):
        lpath = self.canonicalize_path(db.library_path)
        if lpath not in self.stats:
            self.stats[lpath] = 0
        self.stats[lpath] += 1
        self.write_stats()
        return self.pretty(lpath)

    def locations(self, db, limit=None):
        lpath = self.canonicalize_path(db.library_path)
        locs = list(self.stats.keys())
        if lpath in locs:
            locs.remove(lpath)
        limit = tweaks['many_libraries'] if limit is None else limit
        key = (lambda x:sort_key(os.path.basename(x))) if len(locs) > limit else self.stats.get
        locs.sort(key=key, reverse=len(locs)<=limit)
        for loc in locs:
            yield self.pretty(loc), loc

    def pretty(self, loc):
        if loc.endswith('/'):
            loc = loc[:-1]
        return loc.split('/')[-1]

    def rename(self, location, newloc):
        newloc = self.canonicalize_path(newloc)
        stats = self.stats.pop(location, None)
        if stats is not None:
            self.stats[newloc] = stats
        self.write_stats()
# }}}


class MovedDialog(QDialog):  # {{{

    def __init__(self, stats, location, parent=None):
        QDialog.__init__(self, parent)
        self.setWindowTitle(_('No library found'))
        self._l = l = QGridLayout(self)
        self.setLayout(l)
        self.stats, self.location = stats, location

        loc = self.oldloc = location.replace('/', os.sep)
        self.header = QLabel(_('No existing calibre library was found at %s. '
            'If the library was moved, select its new location below. '
            'Otherwise calibre will forget this library.')%loc)
        self.header.setWordWrap(True)
        ncols = 2
        l.addWidget(self.header, 0, 0, 1, ncols)
        self.cl = QLabel('<br><b>'+_('New location of this library:'))
        l.addWidget(self.cl, 1, 0, 1, ncols)
        self.loc = QLineEdit(loc, self)
        l.addWidget(self.loc, 2, 0, 1, 1)
        self.cd = QToolButton(self)
        self.cd.setIcon(QIcon(I('document_open.png')))
        self.cd.clicked.connect(self.choose_dir)
        l.addWidget(self.cd, 2, 1, 1, 1)
        self.bb = QDialogButtonBox(QDialogButtonBox.Abort)
        b = self.bb.addButton(_('Library moved'), self.bb.AcceptRole)
        b.setIcon(QIcon(I('ok.png')))
        b = self.bb.addButton(_('Forget library'), self.bb.RejectRole)
        b.setIcon(QIcon(I('edit-clear.png')))
        b.clicked.connect(self.forget_library)
        self.bb.accepted.connect(self.accept)
        self.bb.rejected.connect(self.reject)
        l.addWidget(self.bb, 3, 0, 1, ncols)
        self.resize(self.sizeHint() + QSize(100, 50))

    def choose_dir(self):
        d = choose_dir(self, 'library moved choose new loc',
                _('New library location'), default_dir=self.oldloc)
        if d is not None:
            self.loc.setText(d)

    def forget_library(self):
        self.stats.remove(self.location)

    def accept(self):
        newloc = unicode_type(self.loc.text())
        if not db_class().exists_at(newloc):
            error_dialog(self, _('No library found'),
                    _('No existing calibre library found at %s')%newloc,
                    show=True)
            return
        self.stats.rename(self.location, newloc)
        self.newloc = newloc
        QDialog.accept(self)
# }}}


class BackupStatus(QDialog):  # {{{

    def __init__(self, gui):
        QDialog.__init__(self, gui)
        self.l = l = QVBoxLayout(self)
        self.msg = QLabel('')
        self.msg.setWordWrap(True)
        l.addWidget(self.msg)
        self.bb = bb = QDialogButtonBox(QDialogButtonBox.Close)
        bb.accepted.connect(self.accept)
        bb.rejected.connect(self.reject)
        b = bb.addButton(_('Queue &all books for backup'), bb.ActionRole)
        b.clicked.connect(self.mark_all_dirty)
        b.setIcon(QIcon(I('lt.png')))
        l.addWidget(bb)
        self.db = weakref.ref(gui.current_db)
        self.setResult(9)
        self.setWindowTitle(_('Backup status'))
        self.update()
        self.resize(self.sizeHint() + QSize(50, 15))

    def update(self):
        db = self.db()
        if db is None:
            return
        if self.result() != 9:
            return
        dirty_text = 'no'
        try:
            dirty_text = '%s' % db.dirty_queue_length()
        except:
            dirty_text = _('none')
        self.msg.setText('<p>' + _(
            'Book metadata files remaining to be written: %s') % dirty_text)
        QTimer.singleShot(1000, self.update)

    def mark_all_dirty(self):
        db = self.db()
        if db is None:
            return
        db.new_api.mark_as_dirty(db.new_api.all_book_ids())

# }}}


class ChooseLibraryAction(InterfaceAction):

    name = 'Choose Library'
    action_spec = (_('Choose Library'), 'lt.png',
            _('Choose calibre library to work with'), None)
    dont_add_to = frozenset(('context-menu-device',))
    action_add_menu = True
    action_menu_clone_qaction = _('Switch/create library...')
    restore_view_state = pyqtSignal(object)

    def genesis(self):
        self.prev_lname = self.last_lname = ''
        self.count_changed(0)
        self.action_choose = self.menuless_qaction
        self.action_exim = ac = QAction(_('Export/import all calibre data'), self.gui)
        ac.triggered.connect(self.exim_data)

        self.stats = LibraryUsageStats()
        self.popup_type = (QToolButton.InstantPopup if len(self.stats.stats) > 1 else
                QToolButton.MenuButtonPopup)
        if len(self.stats.stats) > 1:
            self.action_choose.triggered.connect(self.choose_library)
        else:
            self.qaction.triggered.connect(self.choose_library)

        self.choose_menu = self.qaction.menu()

        ac = self.create_action(spec=(_('Pick a random book'), 'random.png',
            None, None), attr='action_pick_random')
        ac.triggered.connect(self.pick_random)

        if not os.environ.get('CALIBRE_OVERRIDE_DATABASE_PATH', None):
            self.choose_menu.addAction(self.action_choose)

            self.quick_menu = QMenu(_('Quick switch'))
            self.quick_menu_action = self.choose_menu.addMenu(self.quick_menu)
            self.rename_menu = QMenu(_('Rename library'))
            self.rename_menu_action = self.choose_menu.addMenu(self.rename_menu)
            self.choose_menu.addAction(ac)
            self.delete_menu = QMenu(_('Remove library'))
            self.delete_menu_action = self.choose_menu.addMenu(self.delete_menu)
            self.choose_menu.addAction(self.action_exim)
        else:
            self.choose_menu.addAction(ac)

        self.rename_separator = self.choose_menu.addSeparator()

        self.switch_actions = []
        for i in range(5):
            ac = self.create_action(spec=('', None, None, None),
                    attr='switch_action%d'%i)
            ac.setObjectName(unicode_type(i))
            self.switch_actions.append(ac)
            ac.setVisible(False)
            connect_lambda(ac.triggered, self, lambda self:
                    self.switch_requested(self.qs_locations[int(self.gui.sender().objectName())]),
                    type=Qt.QueuedConnection)
            self.choose_menu.addAction(ac)

        self.rename_separator = self.choose_menu.addSeparator()

        self.maintenance_menu = QMenu(_('Library maintenance'))
        ac = self.create_action(spec=(_('Library metadata backup status'),
                        'lt.png', None, None), attr='action_backup_status')
        ac.triggered.connect(self.backup_status, type=Qt.QueuedConnection)
        self.maintenance_menu.addAction(ac)
        ac = self.create_action(spec=(_('Check library'), 'lt.png',
                                      None, None), attr='action_check_library')
        ac.triggered.connect(self.check_library, type=Qt.QueuedConnection)
        self.maintenance_menu.addAction(ac)
        ac = self.create_action(spec=(_('Restore database'), 'lt.png',
                                      None, None),
                                      attr='action_restore_database')
        ac.triggered.connect(self.restore_database, type=Qt.QueuedConnection)
        self.maintenance_menu.addAction(ac)

        self.choose_menu.addMenu(self.maintenance_menu)
        self.view_state_map = {}
        self.restore_view_state.connect(self._restore_view_state,
                type=Qt.QueuedConnection)

    @property
    def preserve_state_on_switch(self):
        ans = getattr(self, '_preserve_state_on_switch', None)
        if ans is None:
            self._preserve_state_on_switch = ans = \
                self.gui.library_view.preserve_state(require_selected_ids=False)
        return ans

    def pick_random(self, *args):
        self.gui.iactions['Pick Random Book'].pick_random()

    def exim_data(self):
        if isportable:
            return error_dialog(self.gui, _('Cannot export/import'), _(
                'You are running calibre portable, all calibre data is already in the'
                ' calibre portable folder. Export/import is unavailable.'), show=True)
        if self.gui.job_manager.has_jobs():
            return error_dialog(self.gui, _('Cannot export/import'),
                    _('Cannot export/import data while there are running jobs.'), show=True)
        from calibre.gui2.dialogs.exim import EximDialog
        d = EximDialog(parent=self.gui)
        if d.exec_() == d.Accepted:
            if d.restart_needed:
                self.gui.iactions['Restart'].restart()

    def library_name(self):
        db = self.gui.library_view.model().db
        path = db.library_path
        if isbytestring(path):
            path = path.decode(filesystem_encoding)
        path = path.replace(os.sep, '/')
        return self.stats.pretty(path)

    def update_tooltip(self, count):
        tooltip = self.action_spec[2] + '\n\n' + ngettext('{0} [{1} book]', '{0} [{1} books]', count).format(
            getattr(self, 'last_lname', ''), count)
        a = self.qaction
        a.setToolTip(tooltip)
        a.setStatusTip(tooltip)
        a.setWhatsThis(tooltip)

    def library_changed(self, db):
        lname = self.stats.library_used(db)
        if lname != self.last_lname:
            self.prev_lname = self.last_lname
            self.last_lname = lname
        if len(lname) > 16:
            lname = lname[:16] + '…'
        a = self.qaction
        a.setText(lname.replace('&', '&&&'))  # I have no idea why this requires a triple ampersand
        self.update_tooltip(db.count())
        self.build_menus()
        state = self.view_state_map.get(self.stats.canonicalize_path(
            db.library_path), None)
        if state is not None:
            self.restore_view_state.emit(state)

    def _restore_view_state(self, state):
        self.preserve_state_on_switch.state = state

    def initialization_complete(self):
        self.library_changed(self.gui.library_view.model().db)

    def build_menus(self):
        if os.environ.get('CALIBRE_OVERRIDE_DATABASE_PATH', None):
            return
        db = self.gui.library_view.model().db
        locations = list(self.stats.locations(db))

        for ac in self.switch_actions:
            ac.setVisible(False)
        self.quick_menu.clear()
        self.rename_menu.clear()
        self.delete_menu.clear()
        quick_actions, rename_actions, delete_actions = [], [], []
        for name, loc in locations:
            is_prev_lib = name == self.prev_lname
            name = name.replace('&', '&&')
            ac = self.quick_menu.addAction(name, Dispatcher(partial(self.switch_requested,
                loc)))
            ac.setStatusTip(_('Switch to: %s') % loc)
            if is_prev_lib:
                f = ac.font()
                f.setBold(True)
                ac.setFont(f)
            quick_actions.append(ac)
            ac = self.rename_menu.addAction(name, Dispatcher(partial(self.rename_requested,
                name, loc)))
            rename_actions.append(ac)
            ac.setStatusTip(_('Rename: %s') % loc)
            ac = self.delete_menu.addAction(name, Dispatcher(partial(self.delete_requested,
                name, loc)))
            delete_actions.append(ac)
            ac.setStatusTip(_('Remove: %s') % loc)
            if is_prev_lib:
                ac.setFont(f)

        qs_actions = []
        locations_by_frequency = locations
        if len(locations) >= tweaks['many_libraries']:
            locations_by_frequency = list(self.stats.locations(db, limit=sys.maxsize))
        for i, x in enumerate(locations_by_frequency[:len(self.switch_actions)]):
            name, loc = x
            name = name.replace('&', '&&')
            ac = self.switch_actions[i]
            ac.setText(name)
            ac.setStatusTip(_('Switch to: %s') % loc)
            ac.setVisible(True)
            qs_actions.append(ac)
        self.qs_locations = [i[1] for i in locations_by_frequency]

        self.quick_menu_action.setVisible(bool(locations))
        self.rename_menu_action.setVisible(bool(locations))
        self.delete_menu_action.setVisible(bool(locations))
        self.gui.location_manager.set_switch_actions(quick_actions,
                rename_actions, delete_actions, qs_actions,
                self.action_choose)
        # Allow the cloned actions in the OS X global menubar to update
        for a in (self.qaction, self.menuless_qaction):
            a.changed.emit()

    def location_selected(self, loc):
        enabled = loc == 'library'
        self.qaction.setEnabled(enabled)
        self.menuless_qaction.setEnabled(enabled)

    def rename_requested(self, name, location):
        LibraryDatabase = db_class()
        loc = location.replace('/', os.sep)
        base = os.path.dirname(loc)
        old_name = name.replace('&&', '&')
        newname, ok = QInputDialog.getText(self.gui, _('Rename') + ' ' + old_name,
                '<p>'+_(
                    'Choose a new name for the library <b>%s</b>. ')%name + '<p>'+_(
                    'Note that the actual library folder will be renamed.'),
                text=old_name)
        newname = sanitize_file_name(unicode_type(newname))
        if not ok or not newname or newname == old_name:
            return
        newloc = os.path.join(base, newname)
        if os.path.exists(newloc):
            return error_dialog(self.gui, _('Already exists'),
                    _('The folder %s already exists. Delete it first.') %
                    newloc, show=True)
        if (iswindows and len(newloc) > LibraryDatabase.WINDOWS_LIBRARY_PATH_LIMIT):
            return error_dialog(self.gui, _('Too long'),
                    _('Path to library too long. Must be less than'
                    ' %d characters.')%LibraryDatabase.WINDOWS_LIBRARY_PATH_LIMIT,
                    show=True)
        if not os.path.exists(loc):
            error_dialog(self.gui, _('Not found'),
                    _('Cannot rename as no library was found at %s. '
                      'Try switching to this library first, then switch back '
                      'and retry the renaming.')%loc, show=True)
            return
        self.gui.library_broker.remove_library(loc)
        try:
            os.rename(loc, newloc)
        except:
            import traceback
            det_msg = 'Location: %r New Location: %r\n%s'%(loc, newloc,
                                                        traceback.format_exc())
            error_dialog(self.gui, _('Rename failed'),
                    _('Failed to rename the library at %s. '
                'The most common cause for this is if one of the files'
                ' in the library is open in another program.') % loc,
                    det_msg=det_msg, show=True)
            return
        self.stats.rename(location, newloc)
        self.build_menus()
        self.gui.iactions['Copy To Library'].build_menus()

    def delete_requested(self, name, location):
        loc = location.replace('/', os.sep)
        if not question_dialog(
                self.gui, _('Library removed'), _(
                'The library %s has been removed from calibre. '
                'The files remain on your computer, if you want '
                'to delete them, you will have to do so manually.') % ('<code>%s</code>' % loc),
                override_icon='dialog_information.png',
                yes_text=_('&OK'), no_text=_('&Undo'), yes_icon='ok.png', no_icon='edit-undo.png'):
            return
        self.stats.remove(location)
        self.gui.library_broker.remove_library(location)
        self.build_menus()
        self.gui.iactions['Copy To Library'].build_menus()
        if os.path.exists(loc):
            open_local_file(loc)

    def backup_status(self, location):
        self.__backup_status_dialog = d = BackupStatus(self.gui)
        d.show()

    def mark_dirty(self):
        db = self.gui.library_view.model().db
        db.dirtied(list(db.data.iterallids()))
        info_dialog(self.gui, _('Backup metadata'),
            _('Metadata will be backed up while calibre is running, at the '
              'rate of approximately 1 book every three seconds.'), show=True)

    def restore_database(self):
        LibraryDatabase = db_class()
        m = self.gui.library_view.model()
        db = m.db
        if (iswindows and len(db.library_path) > LibraryDatabase.WINDOWS_LIBRARY_PATH_LIMIT):
            return error_dialog(self.gui, _('Too long'),
                    _('Path to library too long. Must be less than'
                    ' %d characters. Move your library to a location with'
                    ' a shorter path using Windows Explorer, then point'
                    ' calibre to the new location and try again.')%
                    LibraryDatabase.WINDOWS_LIBRARY_PATH_LIMIT,
                    show=True)

        from calibre.gui2.dialogs.restore_library import restore_database
        m = self.gui.library_view.model()
        m.stop_metadata_backup()
        db = m.db
        db.prefs.disable_setting = True
        if restore_database(db, self.gui):
            self.gui.library_moved(db.library_path)

    def check_library(self):
        from calibre.gui2.dialogs.check_library import CheckLibraryDialog, DBCheck
        self.gui.library_view.save_state()
        m = self.gui.library_view.model()
        m.stop_metadata_backup()
        db = m.db
        db.prefs.disable_setting = True
        library_path = db.library_path

        d = DBCheck(self.gui, db)
        d.start()
        try:
            m.close()
        except:
            pass
        d.break_cycles()
        self.gui.library_moved(library_path)
        if d.rejected:
            return
        if d.error is None:
            if not question_dialog(self.gui, _('Success'),
                    _('Found no errors in your calibre library database.'
                        ' Do you want calibre to check if the files in your '
                        ' library match the information in the database?')):
                return
        else:
            return error_dialog(self.gui, _('Failed'),
                    _('Database integrity check failed, click Show details'
                        ' for details.'), show=True, det_msg=d.error[1])

        self.gui.status_bar.show_message(
                _('Starting library scan, this may take a while'))
        try:
            QCoreApplication.processEvents()
            d = CheckLibraryDialog(self.gui, m.db)

            if not d.do_exec():
                info_dialog(self.gui, _('No problems found'),
                        _('The files in your library match the information '
                        'in the database.'), show=True)
        finally:
            self.gui.status_bar.clear_message()

    def look_for_portable_lib(self, db, location):
        base = get_portable_base()
        if base is None:
            return False, None
        loc = location.replace('/', os.sep)
        candidate = os.path.join(base, os.path.basename(loc))
        if db.exists_at(candidate):
            newloc = candidate.replace(os.sep, '/')
            self.stats.rename(location, newloc)
            return True, newloc
        return False, None

    def switch_requested(self, location):
        if not self.change_library_allowed():
            return
        db = self.gui.library_view.model().db
        current_lib = self.stats.canonicalize_path(db.library_path)
        self.view_state_map[current_lib] = self.preserve_state_on_switch.state
        loc = location.replace('/', os.sep)
        exists = db.exists_at(loc)
        if not exists:
            exists, new_location = self.look_for_portable_lib(db, location)
            if exists:
                location = new_location
                loc = location.replace('/', os.sep)

        if not exists:
            d = MovedDialog(self.stats, location, self.gui)
            ret = d.exec_()
            self.build_menus()
            self.gui.iactions['Copy To Library'].build_menus()
            if ret == d.Accepted:
                loc = d.newloc.replace('/', os.sep)
            else:
                return

        # from calibre.utils.mem import memory
        # import weakref
        # from PyQt5.Qt import QTimer
        # self.dbref = weakref.ref(self.gui.library_view.model().db)
        # self.before_mem = memory()
        self.gui.library_moved(loc, allow_rebuild=True)
        # QTimer.singleShot(5000, self.debug_leak)

    def debug_leak(self):
        import gc
        from calibre.utils.mem import memory
        ref = self.dbref
        for i in range(3):
            gc.collect()
        if ref() is not None:
            print('DB object alive:', ref())
            for r in gc.get_referrers(ref())[:10]:
                print(r)
                print()
        print('before:', self.before_mem)
        print('after:', memory())
        print()
        self.dbref = self.before_mem = None

    def count_changed(self, new_count):
        self.update_tooltip(new_count)

    def choose_library(self, *args):
        if not self.change_library_allowed():
            return
        from calibre.gui2.dialogs.choose_library import ChooseLibrary
        self.gui.library_view.save_state()
        db = self.gui.library_view.model().db
        location = self.stats.canonicalize_path(db.library_path)
        self.pre_choose_dialog_location = location
        c = ChooseLibrary(db, self.choose_library_callback, self.gui)
        c.exec_()

    def choose_library_callback(self, newloc, copy_structure=False, library_renamed=False):
        self.gui.library_moved(newloc, copy_structure=copy_structure,
                allow_rebuild=True)
        if library_renamed:
            self.stats.rename(self.pre_choose_dialog_location, prefs['library_path'])
        self.build_menus()
        self.gui.iactions['Copy To Library'].build_menus()

    def change_library_allowed(self):
        if os.environ.get('CALIBRE_OVERRIDE_DATABASE_PATH', None):
            warning_dialog(self.gui, _('Not allowed'),
                    _('You cannot change libraries while using the environment'
                        ' variable CALIBRE_OVERRIDE_DATABASE_PATH.'), show=True)
            return False
        if self.gui.job_manager.has_jobs():
            warning_dialog(self.gui, _('Not allowed'),
                    _('You cannot change libraries while jobs'
                        ' are running.'), show=True)
            return False

        if self.gui.proceed_question.questions:
            warning_dialog(self.gui, _('Not allowed'),
                    _('You cannot change libraries until all'
                        ' updates are accepted or rejected.'), show=True)
            return False

        return True
