import base64
import secrets
import importlib
from flask import Flask

from .common.common import *
from .common.user import init_login

app = Flask(__name__)
app.secret_key = base64.b64decode(cf['frontend'].get('secret_key','')) or \
    secrets.token_bytes(16) # development fallback; CSRF/cookies won't persist.
init_login(app)

for name in cf['frontend']['modules'].split(','):
    blueprint = importlib.import_module('.'+name, __name__)
    app.register_blueprint(blueprint.frontend)

# TODO: move this somewhere else
@app.template_global()
def querystring_page(fields):
    def try_int(i):
        try: return int(i)
        except: return None
    tmp = dict(request.args)
    for field,what in fields.items():
        if type(what) is tuple:
            (plusminus, default) = what
            tmp[field] = (try_int(tmp.get(field)) or int(default)) + plusminus
        elif type(what) is type(None):
            if field in tmp: del tmp[field]
        else:
            tmp[field] = what
    from werkzeug.urls import url_encode
    return url_encode(tmp)

# TODO: should this go somewhere else?
# This error handler logs requests to external apis, and POST data. this makes debugging of api responses easier, as the request can be reconstructed and replayed.
from flask import g, request
from werkzeug.exceptions import InternalServerError
@app.errorhandler(InternalServerError)
def log_errors(e):
    if request.method == "POST":
        app.logger.error(request.data)
    if 'api_requests' in g:
        app.logger.error(g.api_requests)
    return e

from .common import anticsrf
anticsrf.init(app)