import flask
import flask_login

from . import db
from . import system

blueprint = flask.Blueprint('rules', __name__, url_prefix='/rules')

@blueprint.route('/', methods=('GET', 'POST'))
@flask_login.login_required
def index():
    try:
        if not flask_login.current_user.is_admin:
            return flask.Response('forbidden', status=403, mimetype='text/plain')

        if flask.request.method == 'POST':
            with db.locked():
                rules = db.read('rules')
                form = flask.request.form
                oldrules = {rule['name']: rule for rule in rules}
                rules = []
                for index, name in sorted(
                        zip(form.getlist('index'), form.getlist('name')), key=lambda e: int(e[0] or 0)):
                    if index and name:
                        rules.append(oldrules.get(name, {'name': name}))
                db.write('rules', rules)
            system.run(system.save_config)

        return flask.render_template('rules/index.html', rules=db.load('rules'))
    except TimeoutError:
        return flask.render_template('busy.html')
    except Exception as e:
        return flask.Response(f'something went catastrophically wrong: {e}',
                status=400, mimetype='text/plain')

@blueprint.route('/edit/<int:index>', methods=('GET', 'POST'))
@flask_login.login_required
def edit(index):
    try:
        if not flask_login.current_user.is_admin:
            return flask.Response('forbidden', status=403, mimetype='text/plain')

        if flask.request.method == 'POST':
            with db.locked():
                form = flask.request.form
                rules = db.read('rules')
                rules[index]['name'] = form.get('name')
                rules[index]['text'] = form.get('text').replace('\r\n', '\n')
                rules[index]['managers'] = [m for m in form.getlist('manager') if m]
                db.write('rules', rules)
            system.run(system.save_config)

        return flask.render_template('rules/edit.html', index=index, rule=db.load('rules')[index])
    except IndexError as e:
        return flask.Response(f'invalid rule: {index}', status=400, mimetype='text/plain')
    except TimeoutError:
        return flask.render_template('busy.html')
    except Exception as e:
        return flask.Response(f'something went catastrophically wrong: {e}',
                status=400, mimetype='text/plain')

def can_toggle(user, rule):
    return user.is_admin or not user.groups.isdisjoint(rule.get('managers', ()))

@blueprint.route('/manage')
@flask_login.login_required
def manage():
    try:
        rules = [rule|{'index': index} for index, rule in enumerate(db.load('rules'))
                 if can_toggle(flask_login.current_user, rule)]
        return flask.render_template('rules/manage.html', rules=rules)
    except TimeoutError:
        return flask.render_template('busy.html')
    except Exception as e:
        return flask.Response(f'something went catastrophically wrong: {e}',
                status=400, mimetype='text/plain')

@blueprint.route('/toggle/<int:index>/<enable>')
@flask_login.login_required
def toggle(index, enable):
    try:
        with db.locked():
            rules = db.read('rules')
            if not can_toggle(flask_login.current_user, rules[index]):
                return flask.Response('forbidden', status=403, mimetype='text/plain')
            rules[index]['enabled'] = (enable == 'true')
            db.write('rules', rules)
        system.run(system.save_config)
        return flask.redirect(flask.url_for('rules.manage'))
    except IndexError as e:
        return flask.Response(f'invalid rule: {index}', status=400, mimetype='text/plain')
    except TimeoutError:
        return flask.render_template('busy.html')
    except Exception as e:
        return flask.Response(f'something went catastrophically wrong: {e}',
                status=400, mimetype='text/plain')