from datetime import datetime
from flask import (
    abort,
    current_app,
    flash,
    jsonify,
    Markup,
    redirect,
    render_template,
    request,
    send_from_directory,
    url_for
)
from flask_login import current_user, login_required
from threading import Thread
import os
from .decorators import corpus_follower_permission_required, corpus_owner_or_admin_required
from app import db, hashids
from app.models import (
    Corpus,
    CorpusFile,
    CorpusFollowerAssociation,
    CorpusFollowerRole,
    CorpusStatus,
    User
)
from . import bp
from .forms import (
    CreateCorpusFileForm,
    CreateCorpusForm,
    UpdateCorpusFileForm
)


@bp.route('/<hashid:corpus_id>/is_public', methods=['POST'])
@login_required
@corpus_owner_or_admin_required
def update_corpus_is_public(corpus_id):
    is_public = request.json
    if not isinstance(is_public, bool):
        response = jsonify('The request body must be a boolean')
        response.status_code = 400
        abort(response)
    corpus = Corpus.query.get_or_404(corpus_id)
    corpus.is_public = is_public
    db.session.commit()
    return '', 204


@bp.route('/<hashid:corpus_id>/followers/add', methods=['POST'])
@login_required
@corpus_owner_or_admin_required
def add_corpus_followers(corpus_id):
    usernames = request.json
    if not (isinstance(usernames, list) or all(isinstance(u, str) for u in usernames)):
        response = jsonify('The request body must be a list of strings')
        response.status_code = 400
        abort(response)
    corpus = Corpus.query.get_or_404(corpus_id)
    for username in usernames:
        user = User.query.filter_by(username=username, is_public=True).first_or_404()
        user.follow_corpus(corpus)
    db.session.commit()
    return '', 204


@bp.route('/<hashid:corpus_id>/follow/<token>')
@login_required
def follow_corpus(corpus_id, token):
    corpus = Corpus.query.get_or_404(corpus_id)
    if current_user.follow_corpus_by_token(token):
        db.session.commit()
        flash(f'You are following {corpus.title} now', category='corpus')
        return redirect(url_for('corpora.corpus', corpus_id=corpus_id))
    abort(403)    


@bp.route('/<hashid:corpus_id>/followers/<hashid:follower_id>/unfollow', methods=['POST'])
@login_required
def unfollow_corpus(corpus_id, follower_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    follower = User.query.get_or_404(follower_id)
    if not (corpus.user == current_user or follower == current_user or current_user.is_administrator()):
        abort(403)
    if not follower.is_following_corpus(corpus):
        abort(409)  # 'User is not following the corpus'
    follower.unfollow_corpus(corpus)
    db.session.commit()
    flash(f'{follower.username} is not following {corpus.title} anymore', category='corpus')
    return '', 204


@bp.route('/<hashid:corpus_id>/followers/<hashid:follower_id>/role', methods=['POST'])
@corpus_follower_permission_required('UPDATE_FOLLOWER')
def add_permission(corpus_id, follower_id):
    corpus_follower_association = CorpusFollowerAssociation.query.filter_by(corpus_id=corpus_id, follower_id=follower_id).first_or_404()
    if not (corpus_follower_association.corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    role_name = request.json.get('role')
    if role_name is None:
        abort(400)
    corpus_follower_role = CorpusFollowerRole.query.filter_by(name=role_name).first_or_404()
    corpus_follower_association.role = corpus_follower_role
    db.session.commit()
    return '', 204


@bp.route('/public')
@login_required
def public_corpora():
    corpora = [
        c.to_json_serializeable()
        for c in Corpus.query.filter(Corpus.is_public == True).all()
    ]
    return render_template(
        'corpora/public_corpora.html.j2',
        corpora=corpora,
        title='Corpora'
    )


@bp.route('/create', methods=['GET', 'POST'])
@login_required
def create_corpus():
    form = CreateCorpusForm()
    if form.validate_on_submit():
        try:
            corpus = Corpus.create(
                title=form.title.data,
                description=form.description.data,
                user=current_user
            )
        except OSError:
            abort(500)
        db.session.commit()
        message = Markup(
            f'Corpus "<a href="{corpus.url}">{corpus.title}</a>" created'
        )
        flash(message, 'corpus')
        return redirect(corpus.url)
    return render_template(
        'corpora/create_corpus.html.j2',
        form=form,
        title='Create corpus'
    )


@bp.route('/<hashid:corpus_id>')
@login_required
def corpus(corpus_id):
    corpus = Corpus.query.get_or_404(corpus_id)
    corpus_follower_roles = CorpusFollowerRole.query.all()
    if corpus.user == current_user or current_user.is_administrator():
        return render_template(
            'corpora/corpus.html.j2',
            corpus=corpus,
            corpus_follower_roles=corpus_follower_roles,
            title='Corpus'
        )
    if current_user.is_following_corpus(corpus) or corpus.is_public:
        cfa = CorpusFollowerAssociation.query.filter_by(corpus_id=corpus_id, follower_id=current_user.id).first_or_404()
        corpus_files = [x.to_json_serializeable() for x in corpus.files]
        owner = corpus.user.to_json_serializeable()
        return render_template(
            'corpora/public_corpus.html.j2',
            corpus=corpus,
            corpus_files=corpus_files,
            cfa=cfa,
            owner=owner,
            title='Corpus',
        )
    abort(403)


@bp.route('/<hashid:corpus_id>/generate-corpus-share-link', methods=['GET', 'POST'])
@login_required
@corpus_follower_permission_required('GENERATE_SHARE_LINK')
def generate_corpus_share_link(corpus_id):
    corpus_hashid = hashids.encode(corpus_id)
    data = request.get_json('data')
    role_name = data['role']
    exp_data = data['expiration']
    expiration = datetime.strptime(exp_data, '%b %d, %Y')
    token = current_user.generate_follow_corpus_token(corpus_hashid, role_name, expiration)
    link = url_for('corpora.follow_corpus', corpus_id=corpus_id, token=token, _external=True)
    return link


@bp.route('/<hashid:corpus_id>', methods=['DELETE'])
@login_required
@corpus_owner_or_admin_required
def delete_corpus(corpus_id):
    def _delete_corpus(app, corpus_id):
        with app.app_context():
            corpus = Corpus.query.get(corpus_id)
            corpus.delete()
            db.session.commit()

    corpus = Corpus.query.get_or_404(corpus_id)
    thread = Thread(
        target=_delete_corpus,
        args=(current_app._get_current_object(), corpus_id)
    )
    thread.start()
    return {}, 202


@bp.route('/<hashid:corpus_id>/analyse')
@login_required
@corpus_follower_permission_required('VIEW')
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>/build', methods=['POST'])
@login_required
@corpus_owner_or_admin_required
def build_corpus(corpus_id):
    def _build_corpus(app, corpus_id):
        with app.app_context():
            corpus = Corpus.query.get(corpus_id)
            corpus.build()
            db.session.commit()

    corpus = Corpus.query.get_or_404(corpus_id)
    if not (corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    # Check if the corpus has corpus files
    if not corpus.files.all():
        response = {'errors': {'message': 'Corpus file(s) required'}}
        return response, 409
    thread = Thread(
        target=_build_corpus,
        args=(current_app._get_current_object(), corpus_id)
    )
    thread.start()
    return {}, 202


@bp.route('/<hashid:corpus_id>/files/create', methods=['GET', 'POST'])
@login_required
@corpus_follower_permission_required('ADD_CORPUS_FILE')
def create_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 = CreateCorpusFileForm()
    if form.is_submitted():
        if not form.validate():
            response = {'errors': form.errors}
            return response, 400
        try:
            corpus_file = CorpusFile.create(
                form.vrt.data,
                address=form.address.data,
                author=form.author.data,
                booktitle=form.booktitle.data,
                chapter=form.chapter.data,
                editor=form.editor.data,
                institution=form.institution.data,
                journal=form.journal.data,
                pages=form.pages.data,
                publisher=form.publisher.data,
                publishing_year=form.publishing_year.data,
                school=form.school.data,
                title=form.title.data,
                mimetype='application/vrt+xml',
                corpus=corpus
            )
        except (AttributeError, OSError):
            abort(500)
        corpus.status = CorpusStatus.UNPREPARED
        db.session.commit()
        message = Markup(
            'Corpus file'
            f'"<a href="{corpus_file.url}">{corpus_file.filename}</a>" added'
        )
        flash(message, category='corpus')
        return {}, 201, {'Location': corpus.url}
    return render_template(
        'corpora/create_corpus_file.html.j2',
        corpus=corpus,
        form=form,
        title='Add corpus file'
    )


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>', methods=['GET', 'POST'])
@login_required
@corpus_follower_permission_required('ADD_CORPUS_FILE', 'UPDATE_CORPUS_FILE', 'REMOVE_CORPUS_FILE')
def corpus_file(corpus_id, corpus_file_id):
    corpus_file = CorpusFile.query.filter_by(corpus_id = corpus_id, id=corpus_file_id).first_or_404()
    form = UpdateCorpusFileForm(data=corpus_file.to_json_serializeable())
    if form.validate_on_submit():
        form.populate_obj(corpus_file)
        if db.session.is_modified(corpus_file):
            corpus_file.corpus.status = CorpusStatus.UNPREPARED
            db.session.commit()
            message = Markup(f'Corpus file "<a href="{corpus_file.url}">{corpus_file.filename}</a>" updated')
            flash(message, category='corpus')
        return redirect(corpus_file.corpus.url)
    return render_template(
        'corpora/corpus_file.html.j2',
        corpus=corpus_file.corpus,
        corpus_file=corpus_file,
        form=form,
        title='Edit corpus file'
    )


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>', methods=['DELETE'])
@login_required
@corpus_follower_permission_required('REMOVE_CORPUS_FILE')
def delete_corpus_file(corpus_id, corpus_file_id):
    def _delete_corpus_file(app, corpus_file_id):
        with app.app_context():
            corpus_file = CorpusFile.query.get(corpus_file_id)
            corpus_file.delete()
            db.session.commit()

    corpus_file = CorpusFile.query.filter_by(corpus_id = corpus_id, id=corpus_file_id).first_or_404()
    if not (corpus_file.corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    thread = Thread(
        target=_delete_corpus_file,
        args=(current_app._get_current_object(), corpus_file_id)
    )
    thread.start()
    return {}, 202


@bp.route('/<hashid:corpus_id>/files/<hashid:corpus_file_id>/download')
@login_required
@corpus_follower_permission_required('VIEW')
def download_corpus_file(corpus_id, corpus_file_id):
    corpus_file = CorpusFile.query.filter_by(corpus_id = corpus_id, id=corpus_file_id).first_or_404()
    if not (corpus_file.corpus.user == current_user or current_user.is_administrator()):
        abort(403)
    return send_from_directory(
        os.path.dirname(corpus_file.path),
        os.path.basename(corpus_file.path),
        as_attachment=True,
        attachment_filename=corpus_file.filename,
        mimetype=corpus_file.mimetype
    )


@bp.route('/import', methods=['GET', 'POST'])
@login_required
def import_corpus():
    abort(503)


@bp.route('/<hashid:corpus_id>/export')
@login_required
def export_corpus(corpus_id):
    abort(503)