import json
import traceback
from datetime import datetime
from datetime import timezone

import flask
import requests
from flask import current_app as app
from little_boxes import activitypub as ap
from little_boxes.errors import ActivityGoneError
from little_boxes.errors import ActivityNotFoundError
from little_boxes.errors import NotAnActivityError
from little_boxes.httpsig import HTTPSigAuth
from requests.exceptions import HTTPError

import config
from config import DB
from core import activitypub
from core import gc
from core.activitypub import Box
from core.meta import MetaKey
from core.meta import _meta
from core.notifications import set_inbox_flags
from core.shared import MY_PERSON
from core.shared import _add_answers_to_question
from core.shared import back
from core.shared import p
from core.shared import post_to_outbox
from core.tasks import Tasks
from utils import now
from utils import opengraph

SIG_AUTH = HTTPSigAuth(config.KEY)

blueprint = flask.Blueprint("tasks", __name__)


class TaskError(Exception):
    """Raised to log the error for poussetaches."""

    def __init__(self):
        self.message = traceback.format_exc()


@blueprint.route("/task/update_question", methods=["POST"])
def task_update_question():
    """Sends an Update."""
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        app.logger.info(f"Updating question {iri}")
        cc = [config.ID + "/followers"]
        doc = DB.activities.find_one({"box": Box.OUTBOX.value, "remote_id": iri})
        _add_answers_to_question(doc)
        question = ap.Question(**doc["activity"]["object"])

        raw_update = dict(
            actor=question.id,
            object=question.to_dict(embed=True),
            attributedTo=MY_PERSON.id,
            cc=list(set(cc)),
            to=[ap.AS_PUBLIC],
        )
        raw_update["@context"] = config.DEFAULT_CTX

        update = ap.Update(**raw_update)
        print(update)
        print(update.to_dict())
        post_to_outbox(update)

    except HTTPError as err:
        app.logger.exception("request failed")
        if 400 >= err.response.status_code >= 499:
            app.logger.info("client error, no retry")
            return ""

        raise TaskError() from err
    except Exception as err:
        app.logger.exception("task failed")
        raise TaskError() from err

    return ""


@blueprint.route("/task/fetch_og_meta", methods=["POST"])
def task_fetch_og_meta():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")
        if activity.has_type(ap.ActivityType.CREATE):
            note = activity.get_object()
            links = opengraph.links_from_note(note.to_dict())
            og_metadata = opengraph.fetch_og_metadata(config.USER_AGENT, links)
            for og in og_metadata:
                if not og.get("image"):
                    continue
                config.MEDIA_CACHE.cache_og_image(og["image"], iri)

            app.logger.debug(f"OG metadata {og_metadata!r}")
            DB.activities.update_one(
                {"remote_id": iri}, {"$set": {"meta.og_metadata": og_metadata}}
            )

        app.logger.info(f"OG metadata fetched for {iri}: {og_metadata}")
    except (ActivityGoneError, ActivityNotFoundError):
        app.logger.exception(f"dropping activity {iri}, skip OG metedata")
        return ""
    except requests.exceptions.HTTPError as http_err:
        if 400 <= http_err.response.status_code < 500:
            app.logger.exception("bad request, no retry")
            return ""
        app.logger.exception("failed to fetch OG metadata")
        raise TaskError() from http_err
    except Exception as err:
        app.logger.exception(f"failed to fetch OG metadata for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/cache_object", methods=["POST"])
def task_cache_object():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")
        obj = activity.get_object()
        DB.activities.update_one(
            {"remote_id": activity.id},
            {
                "$set": {
                    "meta.object": obj.to_dict(embed=True),
                    "meta.object_actor": activitypub._actor_to_meta(obj.get_actor()),
                }
            },
        )
    except (ActivityGoneError, ActivityNotFoundError, NotAnActivityError):
        DB.activities.update_one({"remote_id": iri}, {"$set": {"meta.deleted": True}})
        app.logger.exception(f"flagging activity {iri} as deleted, no object caching")
    except Exception as err:
        app.logger.exception(f"failed to cache object for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/finish_post_to_outbox", methods=["POST"])  # noqa:C901
def task_finish_post_to_outbox():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")

        recipients = activity.recipients()

        if activity.has_type(ap.ActivityType.DELETE):
            back.outbox_delete(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.UPDATE):
            back.outbox_update(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.CREATE):
            back.outbox_create(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.ANNOUNCE):
            back.outbox_announce(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.LIKE):
            back.outbox_like(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.UNDO):
            obj = activity.get_object()
            if obj.has_type(ap.ActivityType.LIKE):
                back.outbox_undo_like(MY_PERSON, obj)
            elif obj.has_type(ap.ActivityType.ANNOUNCE):
                back.outbox_undo_announce(MY_PERSON, obj)
            elif obj.has_type(ap.ActivityType.FOLLOW):
                back.undo_new_following(MY_PERSON, obj)

        app.logger.info(f"recipients={recipients}")
        activity = ap.clean_activity(activity.to_dict())

        payload = json.dumps(activity)
        for recp in recipients:
            app.logger.debug(f"posting to {recp}")
            Tasks.post_to_remote_inbox(payload, recp)
    except (ActivityGoneError, ActivityNotFoundError):
        app.logger.exception(f"no retry")
    except Exception as err:
        app.logger.exception(f"failed to post to remote inbox for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/finish_post_to_inbox", methods=["POST"])  # noqa: C901
def task_finish_post_to_inbox():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")

        if activity.has_type(ap.ActivityType.DELETE):
            back.inbox_delete(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.UPDATE):
            back.inbox_update(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.CREATE):
            back.inbox_create(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.ANNOUNCE):
            back.inbox_announce(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.LIKE):
            back.inbox_like(MY_PERSON, activity)
        elif activity.has_type(ap.ActivityType.FOLLOW):
            # Reply to a Follow with an Accept
            actor_id = activity.get_actor().id
            accept = ap.Accept(
                actor=config.ID,
                object={
                    "type": "Follow",
                    "id": activity.id,
                    "object": activity.get_object_id(),
                    "actor": actor_id,
                },
                to=[actor_id],
                published=now(),
            )
            post_to_outbox(accept)
        elif activity.has_type(ap.ActivityType.UNDO):
            obj = activity.get_object()
            if obj.has_type(ap.ActivityType.LIKE):
                back.inbox_undo_like(MY_PERSON, obj)
            elif obj.has_type(ap.ActivityType.ANNOUNCE):
                back.inbox_undo_announce(MY_PERSON, obj)
            elif obj.has_type(ap.ActivityType.FOLLOW):
                back.undo_new_follower(MY_PERSON, obj)
    except (ActivityGoneError, ActivityNotFoundError, NotAnActivityError):
        app.logger.exception(f"no retry")
    except Exception as err:
        app.logger.exception(f"failed to cache attachments for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/cache_attachments", methods=["POST"])
def task_cache_attachments():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")
        # Generates thumbnails for the actor's icon and the attachments if any

        obj = activity.get_object()

        # Iter the attachments
        for attachment in obj._data.get("attachment", []):
            try:
                config.MEDIA_CACHE.cache_attachment(attachment, iri)
            except ValueError:
                app.logger.exception(f"failed to cache {attachment}")

        app.logger.info(f"attachments cached for {iri}")

    except (ActivityGoneError, ActivityNotFoundError, NotAnActivityError):
        app.logger.exception(f"dropping activity {iri}, no attachment caching")
    except Exception as err:
        app.logger.exception(f"failed to cache attachments for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/cache_actor", methods=["POST"])
def task_cache_actor() -> str:
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload["iri"]
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")

        # Fetch the Open Grah metadata if it's a `Create`
        if activity.has_type(ap.ActivityType.CREATE):
            Tasks.fetch_og_meta(iri)

        actor = activity.get_actor()
        if actor.icon:
            if isinstance(actor.icon, dict) and "url" in actor.icon:
                config.MEDIA_CACHE.cache_actor_icon(actor.icon["url"])
            else:
                app.logger.warning(f"failed to parse icon {actor.icon} for {iri}")

        if activity.has_type(ap.ActivityType.FOLLOW):
            if actor.id == config.ID:
                # It's a new following, cache the "object" (which is the actor we follow)
                DB.activities.update_one(
                    {"remote_id": iri},
                    {
                        "$set": {
                            "meta.object": activity.get_object().to_dict(embed=True)
                        }
                    },
                )

        # Cache the actor info
        DB.activities.update_one(
            {"remote_id": iri}, {"$set": {"meta.actor": actor.to_dict(embed=True)}}
        )

        app.logger.info(f"actor cached for {iri}")
        if activity.has_type([ap.ActivityType.CREATE, ap.ActivityType.ANNOUNCE]):
            Tasks.cache_attachments(iri)

    except (ActivityGoneError, ActivityNotFoundError):
        DB.activities.update_one({"remote_id": iri}, {"$set": {"meta.deleted": True}})
        app.logger.exception(f"flagging activity {iri} as deleted, no actor caching")
    except Exception as err:
        app.logger.exception(f"failed to cache actor for {iri}")
        raise TaskError() from err

    return ""


@blueprint.route("/task/forward_activity", methods=["POST"])
def task_forward_activity():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        recipients = back.followers_as_recipients()
        app.logger.debug(f"Forwarding {activity!r} to {recipients}")
        activity = ap.clean_activity(activity.to_dict())
        payload = json.dumps(activity)
        for recp in recipients:
            app.logger.debug(f"forwarding {activity!r} to {recp}")
            Tasks.post_to_remote_inbox(payload, recp)
    except Exception as err:
        app.logger.exception("task failed")
        raise TaskError() from err

    return ""


@blueprint.route("/task/post_to_remote_inbox", methods=["POST"])
def task_post_to_remote_inbox():
    """Post an activity to a remote inbox."""
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    payload, to = task.payload["payload"], task.payload["to"]
    try:
        app.logger.info("payload=%s", payload)
        app.logger.info("generating sig")
        signed_payload = json.loads(payload)

        # XXX Disable JSON-LD signature crap for now (as HTTP signatures are enough for most implementations)
        # Don't overwrite the signature if we're forwarding an activity
        # if "signature" not in signed_payload:
        #    generate_signature(signed_payload, KEY)

        app.logger.info("to=%s", to)
        resp = requests.post(
            to,
            data=json.dumps(signed_payload),
            auth=SIG_AUTH,
            headers={
                "Content-Type": config.HEADERS[1],
                "Accept": config.HEADERS[1],
                "User-Agent": config.USER_AGENT,
            },
        )
        app.logger.info("resp=%s", resp)
        app.logger.info("resp_body=%s", resp.text)
        resp.raise_for_status()
    except HTTPError as err:
        app.logger.exception("request failed")
        if 400 >= err.response.status_code >= 499:
            app.logger.info("client error, no retry")
            return ""

        raise TaskError() from err
    except Exception as err:
        app.logger.exception("task failed")
        raise TaskError() from err

    return ""


@blueprint.route("/task/fetch_remote_question", methods=["POST"])
def task_fetch_remote_question():
    """Fetch a remote question for implementation that does not send Update."""
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        app.logger.info(f"Fetching remote question {iri}")
        local_question = DB.activities.find_one(
            {
                "box": Box.INBOX.value,
                "type": ap.ActivityType.CREATE.value,
                "activity.object.id": iri,
            }
        )
        remote_question = ap.get_backend().fetch_iri(iri, no_cache=True)
        # FIXME(tsileo): compute and set `meta.object_visiblity` (also update utils.py to do it)
        if (
            local_question
            and (
                local_question["meta"].get("voted_for")
                or local_question["meta"].get("subscribed")
            )
            and not DB.notifications.find_one({"activity.id": remote_question["id"]})
        ):
            DB.notifications.insert_one(
                {
                    "type": "question_ended",
                    "datetime": datetime.now(timezone.utc).isoformat(),
                    "activity": remote_question,
                }
            )

        # Update the Create if we received it in the inbox
        if local_question:
            DB.activities.update_one(
                {"remote_id": local_question["remote_id"], "box": Box.INBOX.value},
                {"$set": {"activity.object": remote_question}},
            )

        # Also update all the cached copies (Like, Announce...)
        DB.activities.update_many(
            {"meta.object.id": remote_question["id"]},
            {"$set": {"meta.object": remote_question}},
        )

    except HTTPError as err:
        app.logger.exception("request failed")
        if 400 >= err.response.status_code >= 499:
            app.logger.info("client error, no retry")
            return ""

        raise TaskError() from err
    except Exception as err:
        app.logger.exception("task failed")
        raise TaskError() from err

    return ""


@blueprint.route("/task/cleanup", methods=["POST"])
def task_cleanup():
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    gc.perform()
    return ""


@blueprint.route("/task/process_new_activity", methods=["POST"])  # noqa:c901
def task_process_new_activity():
    """Process an activity received in the inbox"""
    task = p.parse(flask.request)
    app.logger.info(f"task={task!r}")
    iri = task.payload
    try:
        activity = ap.fetch_remote_activity(iri)
        app.logger.info(f"activity={activity!r}")

        flags = {}

        if not activity.published:
            flags[_meta(MetaKey.PUBLISHED)] = now()
        else:
            flags[_meta(MetaKey.PUBLISHED)] = activity.published

        set_inbox_flags(activity, flags)
        app.logger.info(f"a={activity}, flags={flags!r}")
        if flags:
            DB.activities.update_one({"remote_id": activity.id}, {"$set": flags})

        app.logger.info(f"new activity {iri} processed")
        if not activity.has_type(ap.ActivityType.DELETE):
            Tasks.cache_actor(iri)
    except (ActivityGoneError, ActivityNotFoundError):
        app.logger.exception(f"dropping activity {iri}, skip processing")
        return ""
    except Exception as err:
        app.logger.exception(f"failed to process new activity {iri}")
        raise TaskError() from err

    return ""