# -*- coding: utf-8 -*-
#
# Copyright © 2018-2020 Nick Bowler
#
# License GPLv3+: GNU General Public License version 3 or any later version.
# This is free software: you are free to change and redistribute it.
# There is NO WARRANTY, to the extent permitted by law.

PLUGIN_NAME = u"Tweak Filename Filter"
PLUGIN_AUTHOR = u"Nick Bowler"
PLUGIN_DESCRIPTION = u'''<p>Adds additional options to tweak file naming.</p>
<p>Currently, this overrides the default methods to substitute forward and
back-slashes, allowing alternate behaviours.</p>

<dl>

<dt>tweak_file_replace_backslash (bool)</dt>
<dd>if true, backslashes will be replaced when renaming files. (default:
true)</dd>

<dt>tweak_file_replacement_char (string)</dt>
<dd>matching characters will be replaced by this string (default: _)</dd>

</dl>
'''
PLUGIN_VERSION = "2"
PLUGIN_API_VERSIONS = ["2.0"]
PLUGIN_LICENSE = "GPL-3.0-or-later"

from PyQt5 import QtWidgets

from picard import (config, log)
from picard.ui.options import (
    OptionsPage, OptionsCheckError,
    register_options_page
)
import picard.util

import sre_constants
import re

def modulename():
    return modulename.__module__[len("picard.plugins."):]

class UI_TweakFilenameFilter(object):
    def setupUi(self, TweakFilenameOptionsPage):
        top = QtWidgets.QVBoxLayout(TweakFilenameOptionsPage)

        group = QtWidgets.QGroupBox(TweakFilenameOptionsPage)
        group.setTitle("Filename Sanitizer")
        top.addWidget(group)

        box = QtWidgets.QVBoxLayout(group)

        msg = QtWidgets.QLabel(group)
        msg.setText('''<em>Picard normally replaces slashes and backslashes
        with underscores in all metadata tags prior to running the file-naming
        script.  This substitution may be customized here.  Replacement text
        may use <a href='https://docs.python.org/3/library/re.html#re.sub'
        >backslash sequences supported by <code>re.sub</code></a>.</em>''')
        msg.setOpenExternalLinks(True)
        box.addWidget(msg)

        self.replace_slashes = QtWidgets.QCheckBox(group)
        self.replace_slashes.setText("Replace slashes in metadata")
        self.replace_slashes.setChecked(True)
        self.replace_slashes.setEnabled(False)
        box.addWidget(self.replace_slashes)

        self.replace_backslashes = QtWidgets.QCheckBox(group)
        self.replace_backslashes.setText("Replace backslashes in metadata")
        box.addWidget(self.replace_backslashes)

        label = QtWidgets.QLabel()
        label.setText("Replacement text:")
        box.addWidget(label)

        self.sanitize_replacement = QtWidgets.QLineEdit(group)
        box.addWidget(self.sanitize_replacement)
        label.setBuddy(self.sanitize_replacement)

        top.addStretch()

class TweakFilenameOptionsPage(OptionsPage):
    NAME = PLUGIN_NAME
    TITLE = PLUGIN_NAME
    PARENT = None
    SORT_ORDER = 99
    ACTIVE = True

    options = [
        config.TextOption("setting", "tweak_file_replacement_char", "_"),
        config.BoolOption("setting", "tweak_file_replace_backslash", True)
    ]

    def __init__(self, parent=None):
        super().__init__(parent)
        self.ui = UI_TweakFilenameFilter()
        self.ui.setupUi(self)

    def load(self):
        self.ui.replace_backslashes.setChecked(
            config.setting["tweak_file_replace_backslash"]
        )
        self.ui.sanitize_replacement.setText(
            config.setting["tweak_file_replacement_char"]
        )

    def check(self):
        test = SanitizeHook(self.ui.replace_backslashes.isChecked())
        test.replacement = self.ui.sanitize_replacement.text()
        try:
            test.sub("xyzzy", "a/b/c")
        except sre_constants.error as err:
            raise OptionsCheckError(_("Error"),
                                    "Error in substitution: %s" % err);

    def save(self):
        config.setting["tweak_file_replace_backslash"] = \
            self.ui.replace_backslashes.isChecked()
        config.setting["tweak_file_replacement_char"] = \
            self.ui.sanitize_replacement.text()
        install_tweaker()

# Hook picard.util.sanitize_filename by replacing the underying re object.
class SanitizeHook(object):
    def __init__(self, bs = config.setting["tweak_file_replace_backslash"]):
        if bs:
            self.re_match = re.compile(r'[\\/]', re.UNICODE)
        else:
            self.re_match = re.compile(r'[/]', re.UNICODE)
        self.replacement = config.setting["tweak_file_replacement_char"]

    def sub(self, repl, string):
        ret = self.re_match.sub(self.replacement, string)
        return ret

def install_tweaker():
    re = SanitizeHook()
    if not hasattr(picard.util, "_re_slashes"):
        # Harder to globally monkey patch this picard.util function on newer
        # Picard, so instead we patch it in the two modules which import it.
        orig_sanitize_filename = picard.util.sanitize_filename
        def sanitize_filename_hook(string, **kwargs):
            return orig_sanitize_filename(re.sub(None, string), **kwargs)

        picard.util.scripttofilename.sanitize_filename = sanitize_filename_hook
        picard.util.textencoding.sanitize_filename = sanitize_filename_hook
    else:
        # On older picard we can monkey patch the underlying re object.
        picard.util._re_slashes = re

    log.info("%s activated" % (modulename()))

if modulename() in config.setting["enabled_plugins"]:
    register_options_page(TweakFilenameOptionsPage)
    install_tweaker()
else:
    log.debug("%s disabled in configuration" % (modulename()))