# builtins
import os
import mimetypes

# third-party
import markupsafe
import werkzeug
import flask
import peewee

# internals
from application import app

import form
import database
import admin
import markdown

@app.abstract
class Upload(admin.Named):

    subdirectory = None
    published = peewee.BooleanField(null=False, default=False, verbose_name='Published')
    filename = peewee.CharField(null=False, unique=True)
    description = markdown.MarkdownTextField(null=True)
    allowed_extensions = '*'

    @property
    def path(self):
        return f"upload/{self.subdirectory}/{self.filename}"

    @property
    def media_type(self):

        # essentially the same logic werkzeug.utils.send_file uses

        mimetype, _ = mimetypes.guess_type(self.filename)

        if mimetype:
            return mimetype

        return 'application/octet-stream'

    @property
    def filesize(self):

        try:
            return os.path.getsize(self.path)
        except OSError:
            return float('nan') # not a number

    def render(self, mode='full', format='html'):

        if not (self.published or flask.g.user):
            return markupsafe.Markup('<div class="embed-error">Unpublished embedded content</div>')

        return super().render(mode=mode, format=format)

    def form(self, mode, **kwargs):

        f = super().form(mode, **kwargs)

        if self.is_in_db:

            teaser = self.render('inline')

            if f.intro:
                f.intro = teaser + f.intro
            else:
                f.intro = teaser

        return f

    def form_field(self, field_name):

        if field_name == 'filename':

            db_field = getattr(self.__class__, field_name)

            field_label = 'File'
            field_help = db_field.help_text
            field_value = getattr(self, field_name)
            field_required = not self.id

            return form.File(label=field_label, value=field_value, help=field_help, required=field_required)

        return super().form_field(field_name)

    def form_field_handle(self, field, mode):

        if field.name == 'filename':

            if field.valid and field.value:

                self.write_file(field.value)
                flask.flash("Stored new file.", 'info')

    def write_file(self, file: werkzeug.datastructures.file_storage.FileStorage):

        extension = file.filename.split('.')[-1]
        filename = f'{self.name}.{extension}'
        filename_clean = werkzeug.utils.secure_filename(filename)

        if self.filename:

            try:
                os.unlink(self.path)
            except FileNotFoundError as e:
                app.logger.warning("Didn't find associated file '{self.filename}' for {self.__class__.__name__} '{self.name}', storing new file.")

        self.filename = filename_clean
        file.save(self.path)

    def url(self, mode='raw'):

        if mode in ('raw', 'download'):

            url = f'/upload/{self.subdirectory}/{self.name}/' # FIXME: make this less hacky, if possible

            if mode == 'download':
                url += '?download'

            return url

        return super().url(mode=mode)

    def delete_instance(self, **kwargs):

        try:
            os.unlink(self.path)

        except FileNotFoundError as e:

            # all other exception types not caught so db record won't be deleted
            app.logger.warning("Didn't find associated file '{self.filename}' for {self.__class__.__name__} '{self.name}', proceeding with record deletion.")
            flask.flash(f"Didn't find associated file '{self.filename}', deleting record anyhow.", 'warning')

        super().delete_instance(**kwargs)

class File(Upload):

    # NOTE: collides with form.File in ClassAware attributes
    # this is fine tho, because it's defined later (i.e. overwrites)
    # references to form.File which you never want to look up through
    # ClassAware anyhow. And if you do, you can still go through a
    # non-common Ancestor, i.e. form.Field

    subdirectory = 'file'

class Image(Upload):

    subdirectory = 'image'

class Audio(Upload):

    subdirectory = 'audio'

class Video(Upload):

    subdirectory = 'video'

class GalleryForm(admin.AutoForm):

    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)

        if self.mode == 'edit':

            self['items'] = form.Fieldset()

            for item in self.administerable.items_ordered:

                fieldset_item = form.ProxyFieldset(item.form('edit'), name=f'item-{item.id}')
                fieldset_item['gallery_id'] = form.ValueField(value=self.administerable.id)
                del(fieldset_item['order_pos'])

                fieldset_delete = form.ProxyFieldset(item.form('delete'), name=f'item-{item.id}-delete')
                fieldset_delete.intro = None
                fieldset_delete.buttons['delete'].label = '⊗'

                fieldset_order = form.Fieldset(name='order')
                fieldset_order.buttons['up'] = form.Button(name='up', label='⌃')
                fieldset_order.buttons['down'] = form.Button(name='down', label='⌄')

                # HERE
                fieldset = form.Fieldset(name=f'{fieldset_item.name}-wrapper', extra_classes=['galleryitem-wrapper'])
                fieldset['item'] = fieldset_item
                fieldset['delete'] = fieldset_delete
                fieldset['order'] = fieldset_order

                self['items'][fieldset.name] = fieldset

            fieldset = form.ProxyFieldset(GalleryItem().form('create'), name='item-new')
            fieldset['gallery_id'] = form.ValueField(value=self.administerable.id)
            del(fieldset['order_pos'])

            self['items']['new'] = fieldset

    def handle(self, skip_bind=False):

        if 'submit' not in flask.request.form:
            self.errors.append(form.ValidationError("Missing submit information."))
            return

        submit = flask.request.form.get('submit')

        if not skip_bind:
            self.bind(flask.request.form, flask.request.files)

        fieldset = self.submitted_fieldset(submit)

        if fieldset is not None:

            if submit.endswith('.order.up') or submit.endswith('.order.down'):
                # one of the arrow buttons to reorder propagandapieceitems was pressed
                self.process_order(submit, fieldset)
                return flask.redirect('')

            fieldset.handle(skip_bind=True) # execute fieldset handle, but ignore any returned redirects
            return flask.redirect('') # instead reload current page to update form

        else:
            submit_relative = self.submit_relative(submit)
            self.validate(submit_relative)
            return self.process(submit_relative)

    def process_order(self, submit, fieldset):

        inner_fieldset = fieldset.submitted_fieldset(submit)
        item = inner_fieldset['item'].form.administerable # grab PropagandaPieceItem from ProxyFieldset

        if submit.endswith('.up'):
            item.order_pos -= 1

        elif submit.endswith('.down'):
            item.order_pos += 1

        flask.flash("Moved gallery item.", 'success')
        item.save()

class Gallery(admin.Named):

    autoform_class = GalleryForm

    @property
    def items_ordered(self):
        return self.items.order_by(GalleryItem.order_pos)

class GalleryItemForm(admin.AutoForm):

    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)

        if self.mode == 'edit':

            self['file'] = form.File()

class GalleryItem(admin.Administerable):

    autoform_class = GalleryItemForm

    gallery = peewee.ForeignKeyField(Gallery, null=False, backref='items', verbose_name='Gallery', on_delete='CASCADE')
    order_pos = peewee.IntegerField(null=False, default=0, verbose_name='Order position')
    image = peewee.ForeignKeyField(Image, null=False, verbose_name='Image', backref='in_galleries', on_delete='CASCADE')
    description = markdown.MarkdownTextField(null=True, verbose_name='Description')

    def form(self, mode):

        f = super().form(mode)

        if self.is_in_db:

            teaser = self.image.render('teaser')

            if f.intro:
                f.intro = teaser + f.intro
            else:
                f.intro = teaser

        return f

upload_class_lookup = {
    'file': File,
    'image': Image,
    'audio': Audio,
    'video': Video,
}

@app.route('/upload/<string:class_key>/<string:name>/')
def serve_upload(class_key, name):

    if class_key in upload_class_lookup:

        cls = upload_class_lookup[class_key]
        instance = cls.load(name) # this failing is handled by error_catchall

        if flask.g.user or instance.published:

            download = 'download' in flask.request.args

            return flask.send_from_directory(f'upload/{cls.subdirectory}', instance.filename, as_attachment=download)

    flask.abort(404)