import urllib
import abc
import json
from .db import get_db
from flask import url_for, flash


def abridge(text,maxlen=20):
    if len(text) > maxlen+3:
        return text[:maxlen]+"..."
    else:
        return text

webhook_types = {}
def webhook_type(t):
    def inner(cls):
        webhook_types[t] = cls
        return cls
    return inner

class WebhookType(abc.ABC):
    def __init__(self, url, wh_id):
        self.url = url
        self.wh_id = wh_id

    @abc.abstractmethod
    def on_new_thread(self,thread):
        pass
    @abc.abstractmethod
    def on_new_post(self,post):
        pass

def get_webhooks(forum_id):
    db = get_db()
    # todo inheritance (if needed)
    webhooks = db.execute("select * from webhooks where webhooks.forum = ?;",(forum_id,)).fetchall()

    for wh in webhooks:
        wh_type = wh['type']
        if wh_type not in webhook_types:
            print(f"unknown webhook type {wh_type}")
            continue
        wh_url = wh['url']
        wo = webhook_types[wh_type](wh_url, wh['id'])
        yield wo

def do_webhooks_thread(forum_id,thread):
    for wh in get_webhooks(forum_id):
        try:
            wh.on_new_thread(thread)
        except Exception as e:
            #raise e
            flash(f"error executing webhook with id {wh.wh_id}")

def do_webhooks_post(forum_id,post):
    for wh in get_webhooks(forum_id):
        try:
            wh.on_new_post(post)
        except Exception as e:
            #raise e
            flash(f"error executing webhook with id {wh.wh_id}")


@webhook_type("fake")
class FakeWebhook(WebhookType):
    def on_new_post(self, post):
        print(f'fake wh {self.url} post {post["id"]}')
    def on_new_thread(self, thread):
        print(f'fake wh {self.url} thread {thread["id"]}')

@webhook_type("discord")
class DiscordWebhook(WebhookType):
    def send(self,payload):
        headers = {
            "User-Agent":"apioforum (https://g.gh0.pw/apioforum, v0.0)",
            "Content-Type":"application/json",
        }
        req = urllib.request.Request(
            self.url,
            json.dumps(payload).encode("utf-8"),
            headers
        )
        # todo: read response and things
        urllib.request.urlopen(req)
        #try:
        #    res = urllib.request.urlopen(req)
        #except urllib.error.HTTPError as e:
        #    print(f"error {e.code} {e.read()}")
        #else:
        #    print(f"succ {res.read()}")

    @staticmethod
    def field(name,value):
        return {"name":name,"value":value,"inline":True}

    def on_new_thread(self,thread):
        f = self.field
        db = get_db()
        forum = db.execute("select * from forums where id = ?",(thread['forum'],)).fetchone()
        username = thread['creator']
        userpage = url_for('user.view_user',username=username,_external=True)

        forumpage = url_for('forum.view_forum',forum_id=forum['id'],_external=True)

        post = db.execute("select * from posts where thread = ? order by id asc limit 1",(thread['id'],)).fetchone()

        payload = {
            "username":"apioforum",
            "avatar_url":"https://d.gh0.pw/lib/exe/fetch.php?media=wiki:logo.png",
            "embeds":[
                {
                    "title":"new thread: "+thread['title'],
                    "description":abridge(post['content']),
                    "url": url_for('thread.view_thread',thread_id=thread['id'],_external=True),
                    "color": 0xff00ff,
                    "fields":[
                        f('author',f"[{username}]({userpage})"),
                        f('forum',f"[{forum['name']}]({forumpage})"),
                    ],
                    "footer":{
                        "text":thread['created'].isoformat(' '),
                    },
                },
            ],
        }
        self.send(payload)

    def on_new_post(self,post):
        from .thread import post_jump
        f = self.field
        db = get_db()

        thread = db.execute("select * from threads where id = ?",(post['thread'],)).fetchone()
        threadpage = url_for('thread.view_thread',thread_id=thread['id'],_external=True)

        forum = db.execute("select * from forums where id = ?",(thread['forum'],)).fetchone()
        forumpage = url_for('forum.view_forum',forum_id=forum['id'],_external=True)

        username = post['author']
        userpage = url_for('user.view_user',username=username,_external=True)

        payload = {
            "username":"apioforum",
            "avatar_url":"https://d.gh0.pw/lib/exe/fetch.php?media=wiki:logo.png",
            "embeds":[
                {
                    "title":"re: "+thread['title'],
                    "description":abridge(post['content']),
                    "url": post_jump(post['id'],external=True),
                    "color": 0x00ffff,
                    "fields":[
                        f('author',f"[{username}]({userpage})"),
                        f('thread',f"[{thread['title']}]({threadpage})"),
                        f('forum',f"[{forum['name']}]({forumpage})"),
                    ],
                    "footer":{
                        "text":post['created'].isoformat(' '),
                    },
                },
            ],
        }
        self.send(payload)


@webhook_type("apionet")
class ApionetWebhook(WebhookType):
    MAXMSGLEN = 420

    # using 'url' as path of socket to send to.
    def send(self,payload):
        import socket
        s = socket.socket(socket.AF_UNIX,socket.SOCK_DGRAM)
        s.sendto(payload.encode("utf-8"),self.url)
        s.close()

    def append_url(self,rest,url):
        ub = url.encode("utf-8")
        max_rlen = self.MAXMSGLEN - len(ub) - 1
        
        while len(rest.encode("utf-8")) > max_rlen:
            # chop off characters until short enough
            rest = rest[:-1]

        return rest + " " + url

    def on_new_thread(self,thread):
        # copy paste from above. the great refactor will fix this all
        db = get_db()
        forum = db.execute("select * from forums where id = ?",(thread['forum'],)).fetchone()
        username = thread['creator'][:30]
        post = db.execute("select * from posts where thread = ? order by id asc limit 1",(thread['id'],)).fetchone()
        url = url_for('thread.view_thread',thread_id=thread['id'],_external=True)


        p = ""
        if forum['id'] != 1:
            p = f" in {forum['name']}"
        payload = f"new thread{p}: [{abridge(thread['title'],50)}] {username}: {abridge(post['content'],75)}"
        self.send(self.append_url(payload,"("+url+")"))

    def on_new_post(self,post):
        from .thread import post_jump
        db = get_db()

        thread = db.execute("select * from threads where id = ?",(post['thread'],)).fetchone()
        forum = db.execute("select * from forums where id = ?",(thread['forum'],)).fetchone()
        username = post['author'][:30]

        url = post_jump(post['id'],external=True)


        payload = f"[{abridge(thread['title'],50)}] {username}: {abridge(post['content'],75)}"
        self.send(self.append_url(payload,"("+url+")"))