import os
from flask import current_app
from sqlalchemy import text
from app import db
from app.models import User, Post, Community
import time
import base64
import requests
from cryptography.hazmat.primitives import serialization, hashes
from cryptography.hazmat.primitives.asymmetric import padding
from app.constants import *


def public_key():
    if not os.path.exists('./public.pem'):
        os.system('openssl genrsa -out private.pem 2048')
        os.system('openssl rsa -in private.pem -outform PEM -pubout -out public.pem')
    else:
        publicKey = open('./public.pem', 'r').read()
        PUBLICKEY = publicKey.replace('\n', '\\n')  # JSON-LD doesn't want to work with linebreaks,
        # but needs the \n character to know where to break the line ;)
        return PUBLICKEY


def users_total():
    return db.session.execute(text(
        'SELECT COUNT(id) as c FROM "user" WHERE ap_id is null AND verified is true AND banned is false AND deleted is false')).scalar()


def active_half_year():
    return db.session.execute(text(
        "SELECT COUNT(id) as c FROM \"user\" WHERE last_seen >= CURRENT_DATE - INTERVAL '6 months' AND ap_id is null AND verified is true AND banned is false AND deleted is false")).scalar()


def active_month():
    return db.session.execute(text(
        "SELECT COUNT(id) as c FROM \"user\" WHERE last_seen >= CURRENT_DATE - INTERVAL '1 month' AND ap_id is null AND verified is true AND banned is false AND deleted is false")).scalar()


def local_posts():
    return db.session.execute(text('SELECT COUNT(id) as c FROM "post" WHERE ap_id is null')).scalar()


def local_comments():
    return db.session.execute(text('SELECT COUNT(id) as c FROM "post_reply" WHERE ap_id is null')).scalar()


def send_activity(sender: User, host: str, content: str):

    date = time.strftime('%a, %d %b %Y %H:%M:%S UTC', time.gmtime())

    private_key = serialization.load_pem_private_key(sender.private_key, password=None)

    # todo: look up instance details to set host_inbox
    host_inbox = '/inbox'

    signed_string = f"(request-target): post {host_inbox}\nhost: {host}\ndate: " + date
    signature = private_key.sign(signed_string.encode('utf-8'), padding.PKCS1v15(), hashes.SHA256())
    encoded_signature = base64.b64encode(signature).decode('utf-8')

    # Construct the Signature header
    header = f'keyId="https://{current_app.config["SERVER_NAME"]}/u/{sender.user_name}",headers="(request-target) host date",signature="{encoded_signature}"'

    # Create headers for the request
    headers = {
        'Host': host,
        'Date': date,
        'Signature': header
    }

    # Make the HTTP request
    try:
        response = requests.post(f'https://{host}{host_inbox}', headers=headers, data=content,
                                 timeout=REQUEST_TIMEOUT)
    except requests.exceptions.RequestException:
        time.sleep(1)
        response = requests.post(f'https://{host}{host_inbox}', headers=headers, data=content,
                                 timeout=REQUEST_TIMEOUT / 2)
    return response.status_code


def post_to_activity(post: Post, community: Community):
    activity_data = {
        "actor": f"https://{current_app.config['SERVER_NAME']}/c/{community.name}",
        "to": [
            "https://www.w3.org/ns/activitystreams#Public"
        ],
        "object": {
            "id": f"https://{current_app.config['SERVER_NAME']}/activities/create/{post.ap_create_id}",
            "actor": f"https://{current_app.config['SERVER_NAME']}/u/{post.author.user_name}",
            "to": [
                "https://www.w3.org/ns/activitystreams#Public"
            ],
            "object": {
                "type": "Page",
                "id": f"https://{current_app.config['SERVER_NAME']}/post/{post.id}",
                "attributedTo": f"https://{current_app.config['SERVER_NAME']}/u/{post.author.user_name}",
                "to": [
                    f"https://{current_app.config['SERVER_NAME']}/c/{community.name}",
                    "https://www.w3.org/ns/activitystreams#Public"
                ],
                "name": post.title,
                "cc": [],
                "content": post.body_html,
                "mediaType": "text/html",
                "source": {
                    "content": post.body,
                    "mediaType": "text/markdown"
                },
                "attachment": [],
                "commentsEnabled": True,
                "sensitive": post.nsfw or post.nsfl,
                "published": post.created_at,
                "audience": f"https://{current_app.config['SERVER_NAME']}/c/{community.name}"
            },
            "cc": [
                f"https://{current_app.config['SERVER_NAME']}/c/{community.name}"
            ],
            "type": "Create",
            "audience": f"https://{current_app.config['SERVER_NAME']}/c/{community.name}"
        },
        "cc": [
            f"https://{current_app.config['SERVER_NAME']}/c/{community.name}/followers"
        ],
        "type": "Announce",
        "id": f"https://{current_app.config['SERVER_NAME']}/activities/announce/{post.ap_announce_id}"
    }
    if post.edited_at is not None:
        activity_data["object"]["object"]["updated"] = post.edited_at
    if post.language is not None:
        activity_data["object"]["object"]["language"] = {"identifier": post.language}
    if post.type == POST_TYPE_LINK and post.url is not None:
        activity_data["object"]["object"]["attachment"] = {"href": post.url, "type": "Link"}
    if post.image_id is not None:
        activity_data["object"]["object"]["image"] = {"href": post.image.source_url, "type": "Image"}
    return activity_data