# Copyright: Damien Elmes <anki@ichi2.net>
# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html

# Profile handling
##########################################################################
# - Saves in pickles rather than json to easily store Qt window state.
# - Saves in sqlite rather than a flat file so the config can't be corrupted

import os
import random
import pickle
import shutil
import io
import locale
import re

from aqt.qt import *
from anki.db import DB
from anki.utils import isMac, isWin, intTime, checksum
import anki.lang
from aqt.utils import showWarning
from aqt import appHelpSite
import aqt.forms
from send2trash import send2trash

metaConf = dict(
    ver=0,
    updates=True,
    created=intTime(),
    id=random.randrange(0, 2**63),
    lastMsg=-1,
    suppressUpdate=False,
    firstRun=True,
    defaultLang=None,
    disabledAddons=[],
)

profileConf = dict(
    # profile
    mainWindowGeom=None,
    mainWindowState=None,
    numBackups=50,
    lastOptimize=intTime(),
    # editing
    fullSearch=False,
    searchHistory=[],
    lastColour="#00f",
    stripHTML=True,
    pastePNG=False,
    # not exposed in gui
    deleteMedia=False,
    preserveKeyboard=True,
    # syncing
    syncKey=None,
    syncMedia=True,
    autoSync=True,
    # importing
    allowHTML=False,
    importMode=1,
)

class ProfileManager:

    def __init__(self, base=None, profile=None):
        self.name = None
        self.db = None
        # instantiate base folder
        self._setBaseFolder(base)
        # load metadata
        self.firstRun = self._loadMeta()
        # did the user request a profile to start up with?
        if profile:
            if profile not in self.profiles():
                QMessageBox.critical(None, "Error", "Requested profile does not exist.")
                sys.exit(1)
            try:
                self.load(profile)
            except TypeError:
                raise Exception("Provided profile does not exist.")

    # Base creation
    ######################################################################

    def ensureBaseExists(self):
        try:
            self._ensureExists(self.base)
        except:
            # can't translate, as lang not initialized
            QMessageBox.critical(
                None, "Error", """\
Anki could not create the folder %s. Please ensure that location is not \
read-only and you have permission to write to it. If you cannot fix this \
issue, please see the documentation for information on running Anki from \
a flash drive.""" % self.base)
            raise

    # Folder migration
    ######################################################################

    def _oldFolderLocation(self):
        if isMac:
            return os.path.expanduser("~/Documents/Anki")
        elif isWin:
            loc = QStandardPaths.writableLocation(QStandardPaths.DocumentsLocation)
            return os.path.join(loc, "Anki")
        else:
            p = os.path.expanduser("~/Anki")
            if os.path.exists(p):
                return p
            else:
                loc = QStandardPaths.writableLocation(QStandardPaths.DocumentsLocation)
                if loc[:-1] == QStandardPaths.writableLocation(
                        QStandardPaths.HomeLocation):
                    # occasionally "documentsLocation" will return the home
                    # folder because the Documents folder isn't configured
                    # properly; fall back to an English path
                    return os.path.expanduser("~/Documents/Anki")
                else:
                    return os.path.join(loc, "Anki")

    def maybeMigrateFolder(self):
        oldBase = self._oldFolderLocation()

        if not os.path.exists(self.base) and os.path.exists(oldBase):
            shutil.move(oldBase, self.base)

    # Profile load/save
    ######################################################################

    def profiles(self):
        return sorted(x for x in
            self.db.list("select name from profiles")
            if x != "_global")

    def _unpickle(self, data):
        class Unpickler(pickle.Unpickler):
            def find_class(self, module, name):
                fn = super().find_class(module, name)
                if module == "sip" and name == "_unpickle_type":
                    def wrapper(mod, obj, args):
                        if mod.startswith("PyQt4") and obj == "QByteArray":
                            # can't trust str objects from python 2
                            return QByteArray()
                        return fn(mod, obj, args)
                    return wrapper
                else:
                    return fn
        up = Unpickler(io.BytesIO(data), errors="ignore")
        return up.load()

    def _pickle(self, obj):
        return pickle.dumps(obj, protocol=0)

    def load(self, name):
        assert name != "_global"
        data = self.db.scalar("select cast(data as blob) from profiles where name = ?", name)
        self.name = name
        try:
            self.profile = self._unpickle(data)
        except:
            print("resetting corrupt profile")
            self.profile = profileConf.copy()
            self.save()
        return True

    def save(self):
        sql = "update profiles set data = ? where name = ?"
        self.db.execute(sql, self._pickle(self.profile), self.name)
        self.db.execute(sql, self._pickle(self.meta), "_global")
        self.db.commit()

    def create(self, name):
        prof = profileConf.copy()
        self.db.execute("insert or ignore into profiles values (?, ?)",
                        name, self._pickle(prof))
        self.db.commit()

    def remove(self, name):
        p = self.profileFolder()
        if os.path.exists(p):
            send2trash(p)
        self.db.execute("delete from profiles where name = ?", name)
        self.db.commit()

    def trashCollection(self):
        p = self.collectionPath()
        if os.path.exists(p):
            send2trash(p)

    def rename(self, name):
        oldName = self.name
        oldFolder = self.profileFolder()
        self.name = name
        newFolder = self.profileFolder(create=False)
        if os.path.exists(newFolder):
            if (oldFolder != newFolder) and (
                    oldFolder.lower() == newFolder.lower()):
                # OS is telling us the folder exists because it does not take
                # case into account; use a temporary folder location
                midFolder = ''.join([oldFolder, '-temp'])
                if not os.path.exists(midFolder):
                    os.rename(oldFolder, midFolder)
                    oldFolder = midFolder
                else:
                    showWarning(_("Please remove the folder %s and try again.")
                            % midFolder)
                    self.name = oldName
                    return
            else:
                showWarning(_("Folder already exists."))
                self.name = oldName
                return

        # update name
        self.db.execute("update profiles set name = ? where name = ?",
                        name, oldName)
        # rename folder
        try:
            os.rename(oldFolder, newFolder)
        except WindowsError as e:
            self.db.rollback()
            if "Access is denied" in e:
                showWarning(_("""\
Anki could not rename your profile because it could not rename the profile \
folder on disk. Please ensure you have permission to write to Documents/Anki \
and no other programs are accessing your profile folders, then try again."""))
            else:
                raise
        except:
            self.db.rollback()
            raise
        else:
            self.db.commit()

    # Folder handling
    ######################################################################

    def profileFolder(self, create=True):
        path = os.path.join(self.base, self.name)
        if create:
            self._ensureExists(path)
        return path

    def addonFolder(self):
        return self._ensureExists(os.path.join(self.base, "addons21"))

    def backupFolder(self):
        return self._ensureExists(
            os.path.join(self.profileFolder(), "backups"))

    def collectionPath(self):
        return os.path.join(self.profileFolder(), "collection.anki2")

    # Helpers
    ######################################################################

    def _ensureExists(self, path):
        if not os.path.exists(path):
            os.makedirs(path)
        return path

    def _setBaseFolder(self, cmdlineBase):
        if cmdlineBase:
            self.base = os.path.abspath(cmdlineBase)
        elif os.environ.get("ANKI_BASE"):
            self.base = os.path.abspath(os.environ["ANKI_BASE"])
        else:
            self.base = self._defaultBase()
            self.maybeMigrateFolder()
        self.ensureBaseExists()

    def _defaultBase(self):
        if isWin:
            loc = QStandardPaths.writableLocation(QStandardPaths.AppDataLocation)
            # the returned value seem to automatically include the app name, but we use Anki2 rather
            # than Anki
            assert loc.endswith("/Anki")
            loc += "2"
            return loc
        elif isMac:
            return os.path.expanduser("~/Library/Application Support/Anki2")
        else:
            dataDir = os.environ.get(
                "XDG_DATA_HOME", os.path.expanduser("~/.local/share"))
            if not os.path.exists(dataDir):
                os.makedirs(dataDir)
            return os.path.join(dataDir, "Anki2")

    def _loadMeta(self):
        opath = os.path.join(self.base, "prefs.db")
        path = os.path.join(self.base, "prefs21.db")
        if os.path.exists(opath) and not os.path.exists(path):
            shutil.copy(opath, path)

        new = not os.path.exists(path)
        def recover():
            # if we can't load profile, start with a new one
            if self.db:
                try:
                    self.db.close()
                except:
                    pass
            os.unlink(path)
            QMessageBox.warning(
                None, "Preferences Corrupt", """\
Anki's prefs21.db file was corrupt and has been recreated. If you were using multiple \
profiles, please add them back using the same names to recover your cards.""")
        try:
            self.db = DB(path)
            self.db.execute("""
create table if not exists profiles
(name text primary key, data text not null);""")
            data = self.db.scalar(
                "select cast(data as blob) from profiles where name = '_global'")
        except:
            recover()
            return self._loadMeta()
        if not new:
            # load previously created data
            try:
                self.meta = self._unpickle(data)
                return
            except:
                print("resetting corrupt _global")
        # create a default global profile
        self.meta = metaConf.copy()
        self.db.execute("insert or replace into profiles values ('_global', ?)",
                        self._pickle(metaConf))
        self._setDefaultLang()
        return True

    def ensureProfile(self):
        "Create a new profile if none exists."
        if self.firstRun:
            self.create(_("User 1"))
            p = os.path.join(self.base, "README.txt")
            open(p, "w").write(_("""\
This folder stores all of your Anki data in a single location,
to make backups easy. To tell Anki to use a different location,
please see:

%s
""") % (appHelpSite +  "#startupopts"))

    # Default language
    ######################################################################
    # On first run, allow the user to choose the default language

    def _setDefaultLang(self):
        # the dialog expects _ to be defined, but we're running before
        # setupLang() has been called. so we create a dummy op for now
        import builtins
        builtins.__dict__['_'] = lambda x: x
        # create dialog
        class NoCloseDiag(QDialog):
            def reject(self):
                pass
        d = self.langDiag = NoCloseDiag()
        f = self.langForm = aqt.forms.setlang.Ui_Dialog()
        f.setupUi(d)
        d.accepted.connect(self._onLangSelected)
        d.rejected.connect(lambda: True)
        # default to the system language
        try:
            (lang, enc) = locale.getdefaultlocale()
        except:
            # fails on osx
            lang = "en"
        if lang and lang not in ("pt_BR", "zh_CN", "zh_TW"):
            lang = re.sub("(.*)_.*", "\\1", lang)
        # find index
        idx = None
        en = None
        for c, (name, code) in enumerate(anki.lang.langs):
            if code == "en":
                en = c
            if code == lang:
                idx = c
        # if the system language isn't available, revert to english
        if idx is None:
            idx = en
        # update list
        f.lang.addItems([x[0] for x in anki.lang.langs])
        f.lang.setCurrentRow(idx)
        d.exec_()

    def _onLangSelected(self):
        f = self.langForm
        obj = anki.lang.langs[f.lang.currentRow()]
        code = obj[1]
        name = obj[0]
        en = "Are you sure you wish to display Anki's interface in %s?"
        r = QMessageBox.question(
            None, "Anki", en%name, QMessageBox.Yes | QMessageBox.No,
            QMessageBox.No)
        if r != QMessageBox.Yes:
            return self._setDefaultLang()
        self.setLang(code)

    def setLang(self, code):
        self.meta['defaultLang'] = code
        sql = "update profiles set data = ? where name = ?"
        self.db.execute(sql, self._pickle(self.meta), "_global")
        self.db.commit()
        anki.lang.setLang(code, local=False)
