# -*- coding: utf-8 -*-

# Copyright (c) 2002 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing some startup helper funcions.
"""

from __future__ import unicode_literals

import os
import sys

from PyQt5.QtCore import QTranslator, QLocale, QLibraryInfo, QDir, QTextCodec
from PyQt5.QtWidgets import QApplication

from E5Gui.E5Application import E5Application

import Globals
from Globals import qVersionTuple

import UI.PixmapCache

from eric6config import getConfig

application = None


def usage(appinfo, optlen=12):
    """
    Module function to show the usage information.
    
    @param appinfo dictionary describing the application
    @param optlen length of the field for the commandline option (integer)
    """
    options = [
        ("--version", "show the program's version number and exit"),
        ("-h, --help", "show this help message and exit")
    ]
    options.extend(appinfo["options"])
    
    print("""\n"""
          """Usage: {bin} [OPTIONS] {arg}\n"""
          """\n"""
          """{name} - {description}\n"""
          """\n"""
          """Options:""".format(**appinfo))
    for opt in options:
        print("  {0}  {1}".format(opt[0].ljust(optlen), opt[1]))
    sys.exit(0)


def version(appinfo):
    """
    Module function to show the version information.
    
    @param appinfo dictionary describing the application
    """
    print("""\n"""
          """{name} {version}\n"""
          """\n"""
          """{description}\n"""
          """\n"""
          """Copyright (c) 2002 - 2019 Detlev Offenbach"""
          """ <detlev@die-offenbachs.de>\n"""
          """This is free software; see LICENSE.GPL3 for copying"""
          """ conditions.\n"""
          """There is NO warranty; not even for MERCHANTABILITY or FITNESS"""
          """ FOR A\n"""
          """PARTICULAR PURPOSE.""".format(**appinfo))
    sys.exit(0)


def handleArgs(argv, appinfo):
    """
    Module function to handle the always present commandline options.
    
    @param argv list of commandline parameters (list of strings)
    @param appinfo dictionary describing the application
    @return index of the '--' option (integer). This is used to tell
        the application, that all additional options don't belong to
        the application.
    """
    ddindex = 30000     # arbitrarily large number
    args = {
        "--version": version,
        "--help": usage,
        "-h": usage
    }
    if '--' in argv:
        ddindex = argv.index("--")
    for a in args:
        if a in argv and argv.index(a) < ddindex:
            args[a](appinfo)
    return ddindex


def loadTranslatorForLocale(dirs, tn):
    """
    Module function to find and load a specific translation.

    @param dirs Searchpath for the translations. (list of strings)
    @param tn The translation to be loaded. (string)
    @return Tuple of a status flag and the loaded translator
        (int, QTranslator)
    """
    trans = QTranslator(None)
    for directory in dirs:
        loaded = trans.load(tn, directory)
        if loaded:
            return (trans, True)
    
    print("Warning: translation file '" + tn + "'could not be loaded.")
    print("Using default.")
    return (None, False)


def initializeResourceSearchPath():
    """
    Module function to initialize the default mime source factory.
    """
    import Preferences
    
    defaultIconPaths = [
        os.path.join(getConfig('ericIconDir'), "default"),
        os.path.join(getConfig('ericIconDir'), "default", "languages"),
    ]
    iconPaths = Preferences.getIcons("Path")
    for iconPath in iconPaths:
        if iconPath:
            UI.PixmapCache.addSearchPath(iconPath)
    for defaultIconPath in defaultIconPaths:
        if defaultIconPath not in iconPaths:
            UI.PixmapCache.addSearchPath(defaultIconPath)


def setLibraryPaths():
    """
    Module function to set the Qt library paths correctly for windows systems.
    """
    if Globals.isWindowsPlatform():
        libPath = os.path.join(Globals.getPyQt5ModulesDirectory(), "plugins")
        if os.path.exists(libPath):
            libPath = QDir.fromNativeSeparators(libPath)
            libraryPaths = QApplication.libraryPaths()
            if libPath not in libraryPaths:
                libraryPaths.insert(0, libPath)
                QApplication.setLibraryPaths(libraryPaths)

# the translator must not be deleted, therefore we save them here
loaded_translators = {}


def loadTranslators(qtTransDir, app, translationFiles=()):
    """
    Module function to load all required translations.
    
    @param qtTransDir directory of the Qt translations files (string)
    @param app reference to the application object (QApplication)
    @param translationFiles tuple of additional translations to
        be loaded (tuple of strings)
    @return the requested locale (string)
    """
    import Preferences
    
    global loaded_translators
    
    if qVersionTuple() < (5, 0, 0):
        # set the default encoding for tr()
        QTextCodec.setCodecForTr(QTextCodec.codecForName("utf-8"))
    
    translations = ("qt", "eric6") + translationFiles
    loc = Preferences.getUILanguage()
    if loc is None:
        return ""

    if loc == "System":
        loc = QLocale.system().name()
    if loc != "C":
        dirs = [getConfig('ericTranslationsDir'), Globals.getConfigDir()]
        if qtTransDir is not None:
            dirs.append(qtTransDir)

        loca = loc
        for tf in ["{0}_{1}".format(tr, loc) for tr in translations]:
            translator, ok = loadTranslatorForLocale(dirs, tf)
            loaded_translators[tf] = translator
            if ok:
                app.installTranslator(translator)
            else:
                if tf.startswith("eric6"):
                    loca = None
        loc = loca
    else:
        loc = None
    return loc


def simpleAppStartup(argv, appinfo, mwFactory, quitOnLastWindowClosed=True,
                     app=None, raiseIt=True, installErrorHandler=False):
    """
    Module function to start up an application that doesn't need a specialized
    start up.
    
    This function is used by all of eric6's helper programs.
    
    @param argv list of commandline parameters (list of strings)
    @param appinfo dictionary describing the application
    @param mwFactory factory function generating the main widget. This
        function must accept the following parameter.
        <dl>
            <dt>argv</dt>
            <dd>list of commandline parameters (list of strings)</dd>
        </dl>
    @keyparam quitOnLastWindowClosed flag indicating to quit the application,
        if the last window was closed (boolean)
    @keyparam app reference to the application object (QApplication or None)
    @keyparam raiseIt flag indicating to raise the generated application
        window (boolean)
    @keyparam installErrorHandler flag indicating to install an error
        handler dialog (boolean)
    @return exit result (integer)
    """
    global application
    
    if "__PYVENV_LAUNCHER__" in os.environ:
        del os.environ["__PYVENV_LAUNCHER__"]
    
    handleArgs(argv, appinfo)
    if app is None:
        # set the library paths for plugins
        setLibraryPaths()
        app = E5Application(argv)
        application = app
    app.setQuitOnLastWindowClosed(quitOnLastWindowClosed)
    
    # the following code depends upon a valid application object
    import Preferences
    
    initializeResourceSearchPath()
    QApplication.setWindowIcon(UI.PixmapCache.getIcon("eric.png"))
    
    qtTransDir = Preferences.getQtTranslationsDir()
    if not qtTransDir:
        qtTransDir = QLibraryInfo.location(QLibraryInfo.TranslationsPath)
    loadTranslators(qtTransDir, app, ("qscintilla",))
    # qscintilla needed for web browser
    
    w = mwFactory(argv)
    if w is None:
        return 100
    
    if quitOnLastWindowClosed:
        app.lastWindowClosed.connect(app.quit)
    w.show()
    if raiseIt:
        w.raise_()
    
    if installErrorHandler:
        # generate a graphical error handler
        from E5Gui import E5ErrorMessage
        eMsg = E5ErrorMessage.qtHandler()
        eMsg.setMinimumSize(600, 400)
    
    return app.exec_()

#
# eflag: noqa = M801
