"""

Part of the tagit module.
A copy of the license is provided with the project.
Author: Matthias Baumgartner, 2022
"""
# standard imports
from functools import reduce, partial
import operator
import os

# external imports
import urllib.parse

# kivy imports
from kivy.lang import Builder
import kivy.properties as kp

# tagit imports
from tagit import config, dialogues
from tagit.utils import ns
from tagit.utils.bsfs import Namespace
from tagit.widgets import Binding

# inner-module imports
from .action import Action

# constants
TAGS_SEPERATOR = ','
TAG_PREFIX = Namespace('http://example.com/me/tag')()

# exports
__all__ = []


## code ##

# load kv
Builder.load_file(os.path.join(os.path.dirname(__file__), 'tagging.kv'))

# classes
class AddTag(Action):
    """Add tags to the selected items."""
    text = kp.StringProperty('Add tag')

    def ktrigger(self, evt):
        return Binding.check(evt, self.cfg('bindings', 'objects', 'add_tag'))

    def apply(self):
        if len(self.root.browser.selection) > 0:
            tags = self.root.session.storage.all(ns.bsn.Tag).label(node=True)
            dlg = dialogues.SimpleInput(
                    suggestions=set(tags.values()),
                    suggestion_sep=TAGS_SEPERATOR)
            dlg.bind(on_ok=partial(self.add_tags, tags))
            dlg.open()

        else:
            dialogues.Error(text='You must select some images first.').open()

    def add_tags(self, tags, wx):
        # user-specified labels
        labels = {t.strip() for t in wx.text.split(TAGS_SEPERATOR) if len(t.strip())}
        # label to tag mapping
        lut = {label: tag for tag, label in tags.items()}
        # get previous tags
        tags = {lut[lbl] for lbl in labels if lbl in lut}
        # create new tag nodes and set their label
        # FIXME: deny adding tags if tag vocabulary is fixed (ontology case)
        # FIXME: replace with proper tag factory
        for lbl in labels:
            if lbl not in lut:
                tag = self.root.session.storage.node(ns.bsn.Tag,
                    getattr(TAG_PREFIX, urllib.parse.quote(lbl)))
                tag.set(ns.bst.label, lbl)
                tags.add(tag)
        with self.root.browser as browser, \
             self.root.session as session:
            # get objects
            ents = browser.unfold(browser.selection)
            # collect tags
            tags = reduce(operator.add, tags, self.root.session.storage.empty(ns.bsn.Tag)) # FIXME: mb/port: pass set once supported by Nodes.set
            # set tags
            ents.set(ns.bse.tag, tags)
            session.dispatch('on_predicate_modified', ns.bse.tag, ents, tags)
            # cursor and selection might become invalid. Will be fixed in Browser.


class EditTag(Action):
    """Edit tags of the selected items"""
    text = kp.StringProperty('Edit tags')

    def ktrigger(self, evt):
        return Binding.check(evt, self.cfg('bindings', 'objects', 'edit_tag'))

    def apply(self):
        with self.root.browser as browser:
            if len(browser.selection) > 0:
                # get all known tags
                all_tags = self.root.session.storage.all(ns.bsn.Tag).label(node=True)
                # get selection tags
                ent_tags = browser.unfold(browser.selection).tag.label(node=True)
                if len(ent_tags) == 0:
                    text = ''
                else:
                    sep = TAGS_SEPERATOR + ' '
                    text = sep.join(sorted(set.intersection(*ent_tags.values())))

                dlg = dialogues.SimpleInput(
                        text=text,
                        suggestions=set(all_tags.values()),
                        suggestion_sep=TAGS_SEPERATOR,
                        )
                dlg.bind(on_ok=partial(self.edit_tag, ent_tags, all_tags))
                dlg.open()

            else:
                dialogues.Error(text='You must select some images first.').open()

    def edit_tag(self, original, tags, wx):
        """Add or remove tags from images.
        *original* and *modified* are strings, split at *TAGS_SEPERATOR*.
        Tags are added and removed with respect to the difference between those two sets.
        """
        # user-specified labels
        labels = {t.strip() for t in wx.text.split(TAGS_SEPERATOR) if len(t.strip())}
        # label differences
        original_labels = {lbl for lbls in original.values() for lbl in lbls}
        removed_labels = original_labels - labels
        added_labels = labels - original_labels
        # get tags of removed labels
        removed = {tag for tag, lbl in tags.items() if lbl in removed_labels}
        removed = reduce(operator.add, removed, self.root.session.storage.empty(ns.bsn.Tag))
        # get tags of added labels
        # FIXME: deny adding tags if tag vocabulary is fixed (ontology case)
        lut = {label: tag for tag, label in tags.items()}
        added = {lut[lbl] for lbl in added_labels if lbl in lut}
        # FIXME: replace with proper tag factory
        for lbl in added_labels:
            if lbl not in lut:
                tag = self.root.session.storage.node(ns.bsn.Tag,
                    getattr(TAG_PREFIX, urllib.parse.quote(lbl)))
                tag.set(ns.bst.label, lbl)
                added.add(tag)
        added = reduce(operator.add, added, self.root.session.storage.empty(ns.bsn.Tag))
        # apply differences
        with self.root.browser as browser, \
             self.root.session as session:
            ents = browser.unfold(browser.selection)
            ents.set(ns.bse.tag, added)
            #ents.remove(ns.bse.tag, removed) # FIXME: mb/port
            session.dispatch('on_predicate_modified', ns.bse.tag, ents, added | removed)
            # cursor and selection might become invalid. Will be fixed in Browser.

## config ##

# keybindings

config.declare(('bindings', 'objects', 'add_tag'),
    config.Keybind(), Binding.simple('t', Binding.mCTRL, Binding.mSHIFT),
    __name__, AddTag.text.defaultvalue, AddTag.__doc__)

config.declare(('bindings', 'objects', 'edit_tag'),
    config.Keybind(), Binding.simple('e',  Binding.mCTRL),
    __name__, EditTag.text.defaultvalue, EditTag.__doc__)

## EOF ##