use activitypub::{
    activity::Create,
    link,
    object::{Note}
};
use chrono::{self, NaiveDateTime};
use diesel::{self, RunQueryDsl, QueryDsl, ExpressionMethods};
use serde_json;

use plume_common::activity_pub::{
    Id, IntoId, PUBLIC_VISIBILTY,
    inbox::{FromActivity, Notify}
};
use plume_common::utils;
use Connection;
use instance::Instance;
use mentions::Mention;
use notifications::*;
use posts::Post;
use users::User;
use schema::comments;
use safe_string::SafeString;

#[derive(Queryable, Identifiable, Serialize, Clone)]
pub struct Comment {
    pub id: i32,
    pub content: SafeString,
    pub in_response_to_id: Option<i32>,
    pub post_id: i32,
    pub author_id: i32,
    pub creation_date: NaiveDateTime,
    pub ap_url: Option<String>,
    pub sensitive: bool,
    pub spoiler_text: String
}

#[derive(Insertable, Default)]
#[table_name = "comments"]
pub struct NewComment {
    pub content: SafeString,
    pub in_response_to_id: Option<i32>,
    pub post_id: i32,
    pub author_id: i32,
    pub ap_url: Option<String>,
    pub sensitive: bool,
    pub spoiler_text: String
}

impl Comment {
    insert!(comments, NewComment);
    get!(comments);
    list_by!(comments, list_by_post, post_id as i32);
    find_by!(comments, find_by_ap_url, ap_url as String);

    pub fn get_author(&self, conn: &Connection) -> User {
        User::get(conn, self.author_id).expect("Comment::get_author: author error")
    }

    pub fn get_post(&self, conn: &Connection) -> Post {
        Post::get(conn, self.post_id).expect("Comment::get_post: post error")
    }

    pub fn count_local(conn: &Connection) -> usize {
        use schema::users;
        let local_authors = users::table.filter(users::instance_id.eq(Instance::local_id(conn))).select(users::id);
        comments::table.filter(comments::author_id.eq_any(local_authors))
            .load::<Comment>(conn)
            .expect("Comment::count_local: loading error")
            .len()// TODO count in database? 
    }

    pub fn to_json(&self, conn: &Connection, others: &Vec<Comment>) -> serde_json::Value {
        let mut json = serde_json::to_value(self).expect("Comment::to_json: serialization error");
        json["author"] = self.get_author(conn).to_json(conn);
        let mentions = Mention::list_for_comment(conn, self.id).into_iter()
            .map(|m| m.get_mentioned(conn).map(|u| u.get_fqn(conn)).unwrap_or(String::new()))
            .collect::<Vec<String>>();
        json["mentions"] = serde_json::to_value(mentions).expect("Comment::to_json: mention error");
        json["responses"] = json!(others.into_iter()
            .filter(|c| c.in_response_to_id.map(|id| id == self.id).unwrap_or(false))
            .map(|c| c.to_json(conn, others))
            .collect::<Vec<_>>());
        json
    }

    pub fn update_ap_url(&self, conn: &Connection) -> Comment {
        if self.ap_url.is_none() {
            diesel::update(self)
                .set(comments::ap_url.eq(self.compute_id(conn)))
                .execute(conn)
                .expect("Comment::update_ap_url: update error");
            Comment::get(conn, self.id).expect("Comment::update_ap_url: get error")
        } else {
            self.clone()
        }
    }

    pub fn compute_id(&self, conn: &Connection) -> String {
        format!("{}comment/{}", self.get_post(conn).ap_url, self.id)
    }

    pub fn into_activity(&self, conn: &Connection) -> Note {
        let (html, mentions, _hashtags) = utils::md_to_html(self.content.get().as_ref());

        let author = User::get(conn, self.author_id).expect("Comment::into_activity: author error");
        let mut note = Note::default();
        let to = vec![Id::new(PUBLIC_VISIBILTY.to_string())];

        note.object_props.set_id_string(self.ap_url.clone().unwrap_or(String::new())).expect("Comment::into_activity: id error");
        note.object_props.set_summary_string(self.spoiler_text.clone()).expect("Comment::into_activity: summary error");
        note.object_props.set_content_string(html).expect("Comment::into_activity: content error");
        note.object_props.set_in_reply_to_link(Id::new(self.in_response_to_id.map_or_else(|| Post::get(conn, self.post_id).expect("Comment::into_activity: post error").ap_url, |id| {
            let comm = Comment::get(conn, id).expect("Comment::into_activity: comment error");
            comm.ap_url.clone().unwrap_or(comm.compute_id(conn))
        }))).expect("Comment::into_activity: in_reply_to error");
        note.object_props.set_published_string(chrono::Utc::now().to_rfc3339()).expect("Comment::into_activity: published error");
        note.object_props.set_attributed_to_link(author.clone().into_id()).expect("Comment::into_activity: attributed_to error");
        note.object_props.set_to_link_vec(to.clone()).expect("Comment::into_activity: to error");
        note.object_props.set_tag_link_vec(mentions.into_iter().map(|m| Mention::build_activity(conn, m)).collect::<Vec<link::Mention>>())
            .expect("Comment::into_activity: tag error");
        note
    }

    pub fn create_activity(&self, conn: &Connection) -> Create {
        let author = User::get(conn, self.author_id).expect("Comment::create_activity: author error");

        let note = self.into_activity(conn);
        let mut act = Create::default();
        act.create_props.set_actor_link(author.into_id()).expect("Comment::create_activity: actor error");
        act.create_props.set_object_object(note.clone()).expect("Comment::create_activity: object error");
        act.object_props.set_id_string(format!("{}/activity", self.ap_url.clone().expect("Comment::create_activity: ap_url error"))).expect("Comment::create_activity: id error");
        act.object_props.set_to_link_vec(note.object_props.to_link_vec::<Id>().expect("Comment::create_activity: id error")).expect("Comment::create_activity: to error");
        act.object_props.set_cc_link_vec::<Id>(vec![]).expect("Comment::create_activity: cc error");
        act
    }
}

impl FromActivity<Note, Connection> for Comment {
    fn from_activity(conn: &Connection, note: Note, actor: Id) -> Comment {
        let previous_url = note.object_props.in_reply_to.clone().expect("Comment::from_activity: not an answer error").as_str().expect("Comment::from_activity: in_reply_to parsing error").to_string();
        let previous_comment = Comment::find_by_ap_url(conn, previous_url.clone());

        let comm = Comment::insert(conn, NewComment {
            content: SafeString::new(&note.object_props.content_string().expect("Comment::from_activity: content deserialization error")),
            spoiler_text: note.object_props.summary_string().unwrap_or(String::from("")),
            ap_url: note.object_props.id_string().ok(),
            in_response_to_id: previous_comment.clone().map(|c| c.id),
            post_id: previous_comment
                .map(|c| c.post_id)
                .unwrap_or_else(|| Post::find_by_ap_url(conn, previous_url).expect("Comment::from_activity: post error").id),
            author_id: User::from_url(conn, actor.clone().into()).expect("Comment::from_activity: author error").id,
            sensitive: false // "sensitive" is not a standard property, we need to think about how to support it with the activitypub crate
        });

        // save mentions
        if let Some(serde_json::Value::Array(tags)) = note.object_props.tag.clone() {
            for tag in tags.into_iter() {
                serde_json::from_value::<link::Mention>(tag)
                    .map(|m| {
                        let author = &Post::get(conn, comm.post_id).expect("Comment::from_activity: error").get_authors(conn)[0];
                        let not_author = m.link_props.href_string().expect("Comment::from_activity: no href error") != author.ap_url.clone();
                        Mention::from_activity(conn, m, comm.id, false, not_author)
                    }).ok();
            }
        }

        comm.notify(conn);
        comm
    }
}

impl Notify<Connection> for Comment {
    fn notify(&self, conn: &Connection) {
        for author in self.get_post(conn).get_authors(conn) {
            Notification::insert(conn, NewNotification {
                kind: notification_kind::COMMENT.to_string(),
                object_id: self.id,
                user_id: author.id
            });
        }
    }
}