from flask import (abort, current_app, flash, make_response, redirect,
                   render_template, url_for, send_from_directory)
from flask_login import current_user, login_required
from werkzeug.utils import secure_filename
from . import bp
from . import tasks
from .forms import (AddCorpusFileForm, AddCorpusForm, EditCorpusFileForm,
                    ImportCorpusForm)
from .. import db
from ..models import Corpus, CorpusFile
import os
import shutil
import glob
import xml.etree.ElementTree as ET
from zipfile import ZipFile
from .import_corpus import check_zip_contents


@bp.route('/add', methods=['GET', 'POST'])
@login_required
def add_corpus():
    form = AddCorpusForm(prefix='add-corpus-form')
    if form.validate_on_submit():
        corpus = Corpus(
            user=current_user,
            description=form.description.data,
            title=form.title.data
        )
        db.session.add(corpus)
        db.session.flush()
        db.session.refresh(corpus)
        try:
            corpus.makedirs()
        except OSError as e:
            current_app.logger.error(e)
            db.session.rollback()
            flash('Internal Server Error', 'error')
            abort(500)
        db.session.commit()
        flash(f'Corpus "{corpus.title}" added', 'corpus')
        return redirect(url_for('.corpus', corpus_id=corpus.id))
    return render_template(
        'corpora/add_corpus.html.j2',
        form=form,
        title='Add corpus'
    )


@bp.route('/import', methods=['GET', 'POST'])
@login_required
def import_corpus():
    abort(503)
    form = ImportCorpusForm()
    if form.is_submitted():
        if not form.validate():
            return make_response(form.errors, 400)
        corpus = Corpus(
            user=current_user,
            description=form.description.data,
            title=form.title.data
        )
        db.session.add(corpus)
        db.session.flush()
        db.session.refresh(corpus)
        try:
            os.makedirs(corpus.path)
        except OSError as e:
            current_app.logger.error(f'Could not import corpus: {e}')
            db.session.rollback()
            flash('Internal Server Error', 'error')
            return make_response(
                {'redirect_url': url_for('.import_corpus')}, 500)
        # Upload zip
        archive_file = os.path.join(corpus.path, form.file.data.filename)
        form.file.data.save(archive_file)
        # Some checks to verify it is a valid exported corpus
        with ZipFile(archive_file, 'r') as zip:
            contents = zip.namelist()
        if set(check_zip_contents).issubset(contents):
            # Unzip
            shutil.unpack_archive(archive_file, corpus.path)
            # Register vrt files to corpus
            vrts = glob.glob(corpus.path + '/*.vrt')
            for file in vrts:
                element_tree = ET.parse(file)
                text_node = element_tree.find('text')
                corpus_file = CorpusFile(
                    address=text_node.get('address',  'NULL'),
                    author=text_node.get('author', 'NULL'),
                    booktitle=text_node.get('booktitle',  'NULL'),
                    chapter=text_node.get('chapter',  'NULL'),
                    corpus=corpus,
                    editor=text_node.get('editor',  'NULL'),
                    filename=os.path.basename(file),
                    institution=text_node.get('institution',  'NULL'),
                    journal=text_node.get('journal',  'NULL'),
                    pages=text_node.get('pages',  'NULL'),
                    publisher=text_node.get('publisher',  'NULL'),
                    publishing_year=text_node.get('publishing_year', ''),
                    school=text_node.get('school',  'NULL'),
                    title=text_node.get('title', 'NULL')
                )
                db.session.add(corpus_file)
            # finish import and redirect to imported corpus
            corpus.status = 'prepared'
            db.session.commit()
            os.remove(archive_file)
            flash(f'Corpus "{corpus.title}" imported!', 'corpus')
            return make_response(
                {'redirect_url': url_for('.corpus', corpus_id=corpus.id)}, 201)
        else:
            # If imported zip is not valid delete corpus and give feedback
            flash('Can not import corpus "{}" not imported: Invalid archive file!', 'error')  # noqa
            tasks.delete_corpus(corpus.id)
            return make_response(
                {'redirect_url': url_for('.import_corpus')}, 201)
    return render_template('corpora/import_corpus.html.j2', form=form,
                           title='Import Corpus')


@bp.route('/<hashid:corpus_id>')
@login_required
def corpus(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    corpus_files = [corpus_file.to_dict() for corpus_file in corpus.files]
    return render_template('corpora/corpus.html.j2', corpus=corpus,
                           corpus_files=corpus_files, title='Corpus')


@bp.route('/<hashid:corpus_id>/analyse')
@login_required
def analyse_corpus(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    return render_template(
        'corpora/analyse_corpus.html.j2',
        corpus=corpus,
        title=f'Analyse Corpus {corpus.title}'
    )


@bp.route('/<hashid:corpus_id>/download')
@login_required
def download_corpus(corpus_id):
    abort(503)
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    return send_from_directory(
        as_attachment=True,
        directory=os.path.join(corpus.user.path, 'corpora'),
        filename=corpus.archive_file,
        mimetype='zip'
    )


@bp.route('/<hashid:corpus_id>/delete')
@login_required
def delete_corpus(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    flash(f'Corpus "{corpus.title}" marked for deletion!', 'corpus')
    tasks.delete_corpus(corpus_id)
    return redirect(url_for('main.dashboard'))


@bp.route('/<hashid:corpus_id>/files/add', methods=['GET', 'POST'])
@login_required
def add_corpus_file(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    form = AddCorpusFileForm(corpus, prefix='add-corpus-file-form')
    if form.is_submitted():
        if not form.validate():
            return make_response(form.errors, 400)
        # Save the file
        filename = secure_filename(form.file.data.filename)
        corpus_file = CorpusFile(
            address=form.address.data,
            author=form.author.data,
            booktitle=form.booktitle.data,
            chapter=form.chapter.data,
            corpus=corpus,
            editor=form.editor.data,
            filename=filename,
            institution=form.institution.data,
            journal=form.journal.data,
            mimetype='application/vrt+xml',
            pages=form.pages.data,
            publisher=form.publisher.data,
            publishing_year=form.publishing_year.data,
            school=form.school.data,
            title=form.title.data
        )
        db.session.add(corpus_file)
        db.session.flush(objects=[corpus_file])
        db.session.refresh(corpus_file)
        try:
            form.file.data.save(corpus_file.path)
        except OSError as e:
            current_app.logger.error(e)
            db.session.rollback()
            flash('Internal Server Error', 'error')
            return make_response({'redirect_url': url_for('.add_corpus_file', corpus_id=corpus.id)}, 500)  # noqa
        corpus.status = 'unprepared'
        db.session.commit()
        flash(f'Corpus file "{corpus_file.title}" added!', 'corpus')
        return make_response({'redirect_url': url_for('.corpus', corpus_id=corpus.id)}, 201)  # noqa
    return render_template(
        'corpora/add_corpus_file.html.j2',
        corpus=corpus,
        form=form,
        title='Add corpus file'
    )


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>/delete')
@login_required
def delete_corpus_file(corpus_id, corpus_file_id):
    corpus_file = CorpusFile.query.get_or_404(corpus_file_id)
    if not corpus_file.corpus_id == corpus_id:
        abort(404)
    if not (corpus_file.corpus.user == current_user
            or current_user.is_administrator()):
        abort(403)
    flash(
        f'Corpus file "{corpus_file.filename}" marked for deletion!', 'corpus')
    tasks.delete_corpus_file(corpus_file_id)
    return redirect(url_for('.corpus', corpus_id=corpus_id))


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>/download')
@login_required
def download_corpus_file(corpus_id, corpus_file_id):
    corpus_file = CorpusFile.query.get_or_404(corpus_file_id)
    if not corpus_file.corpus_id == corpus_id:
        abort(404)
    if not (corpus_file.corpus.user == current_user
            or current_user.is_administrator()):
        abort(403)
    return send_from_directory(as_attachment=True,
                               directory=os.path.dirname(corpus_file.path),
                               filename=corpus_file.filename)


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>', methods=['GET', 'POST'])
@login_required
def corpus_file(corpus_id, corpus_file_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    corpus_file = CorpusFile.query.get_or_404(corpus_file_id)
    if corpus_file.corpus != corpus:
        abort(404)
    form = EditCorpusFileForm(prefix='edit-corpus-file-form')
    if form.validate_on_submit():
        corpus_file.address = form.address.data
        corpus_file.author = form.author.data
        corpus_file.booktitle = form.booktitle.data
        corpus_file.chapter = form.chapter.data
        corpus_file.editor = form.editor.data
        corpus_file.institution = form.institution.data
        corpus_file.journal = form.journal.data
        corpus_file.pages = form.pages.data
        corpus_file.publisher = form.publisher.data
        corpus_file.publishing_year = form.publishing_year.data
        corpus_file.school = form.school.data
        corpus_file.title = form.title.data
        corpus.status = 'unprepared'
        db.session.commit()
        flash(f'Corpus file "{corpus_file.filename}" edited!', 'corpus')
        return redirect(url_for('.corpus', corpus_id=corpus_id))
    # If no form is submitted or valid, fill out fields with current values
    form.address.data = corpus_file.address
    form.author.data = corpus_file.author
    form.booktitle.data = corpus_file.booktitle
    form.chapter.data = corpus_file.chapter
    form.editor.data = corpus_file.editor
    form.institution.data = corpus_file.institution
    form.journal.data = corpus_file.journal
    form.pages.data = corpus_file.pages
    form.publisher.data = corpus_file.publisher
    form.publishing_year.data = corpus_file.publishing_year
    form.school.data = corpus_file.school
    form.title.data = corpus_file.title
    return render_template('corpora/corpus_file.html.j2', corpus=corpus,
                           corpus_file=corpus_file, form=form,
                           title='Edit corpus file')


@bp.route('/<hashid:corpus_id>/build')
@login_required
def build_corpus(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    if corpus.files.all():
        tasks.build_corpus(corpus_id)
        flash(f'Corpus "{corpus.title}" marked for building!', 'corpus')
    else:
        flash(f'Can\'t build corpus "{corpus.title}": No corpus file(s)!', 'error')  # noqa
    return redirect(url_for('.corpus', corpus_id=corpus_id))