from flask import Flask, request
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import MetaData, event
from sqlalchemy.engine import Engine
from flask_migrate import Migrate
import version
from lib.cachebust import cachebust
from flask_limiter import Limiter
from lib.auth import get_viewer
import os
import mimetypes
import lib.brotli

app = Flask(__name__)

default_config = {
        "SQLALCHEMY_TRACK_MODIFICATIONS": False,
        "SQLALCHEMY_DATABASE_URI": "postgresql+psycopg2:///forget",
        "HTTPS": True,
        "SENTRY_CONFIG": {},
        "REPO_URL": "https://github.com/codl/forget",
        "COMMIT_URL": "https://github.com/codl/forget/commits/{hash}",
        "REDIS_URI": "redis://",
}

app.config.update(default_config)

app.config.from_pyfile('config.py', True)

metadata = MetaData(naming_convention={
    "ix": 'ix_%(column_0_label)s',
    "uq": "uq_%(table_name)s_%(column_0_name)s",
    "ck": "ck_%(table_name)s_%(constraint_name)s",
    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
    "pk": "pk_%(table_name)s"
})

db = SQLAlchemy(app, metadata=metadata)
migrate = Migrate(app, db)

if not 'RATELIMIT_STORAGE_URL' in app.config:
    uri = app.config['REDIS_URI']
    assert not uri.startswith('unix://'), "flask-limiter does not support redis over a unix socket"
    app.config['RATELIMIT_STORAGE_URL'] = uri

if not 'CELERY_BROKER' in app.config:
    uri = app.config['REDIS_URI']
    if uri.startswith('unix://'):
        uri = url.replace('unix', 'redis+socket', 1)
    app.config['CELERY_BROKER'] = uri

sentry = None
if 'SENTRY_DSN' in app.config:
    from raven.contrib.flask import Sentry
    app.config['SENTRY_CONFIG']['release'] = version.version
    sentry = Sentry(app, dsn=app.config['SENTRY_DSN'])

url_for = cachebust(app)


@app.context_processor
def inject_static():
    def static(filename, **kwargs):
        return url_for('static', filename=filename, **kwargs)
    return {'st': static}


def rate_limit_key():
    viewer = get_viewer()
    if viewer:
        return viewer.id
    for address in request.access_route:
        if address != '127.0.0.1':
            print(address)
            return address
    return request.remote_addr


limiter = Limiter(app, key_func=rate_limit_key)


@app.after_request
def install_security_headers(resp):
    csp = ("default-src 'none';"
           "img-src 'self' https:;"
           "style-src 'self' 'unsafe-inline';"
           "frame-ancestors 'none';"
           )
    if 'SENTRY_DSN' in app.config:
        csp += "script-src 'self' https://cdn.ravenjs.com/;"
        csp += "connect-src 'self' https://sentry.io/;"
    else:
        csp += "script-src 'self';"
        csp += "connect-src 'self';"

    if 'CSP_REPORT_URI' in app.config:
        csp += "report-uri " + app.config.get('CSP_REPORT_URI')

    if app.config.get('HTTPS'):
        resp.headers.set('strict-transport-security',
                         'max-age={}'.format(60*60*24*365))
        csp += "; upgrade-insecure-requests"

    resp.headers.set('Content-Security-Policy', csp)
    resp.headers.set('referrer-policy', 'no-referrer')
    resp.headers.set('x-content-type-options', 'nosniff')
    resp.headers.set('x-frame-options', 'DENY')
    resp.headers.set('x-xss-protection', '1')

    return resp


mimetypes.add_type('image/webp', '.webp')

lib.brotli.brotli(app)