//! Web server route handlers.

use async_std::channel::Sender;
use log::{debug, warn};
use rocket::{form::Form, get, post, response::Redirect, uri, FromForm, State};
use rocket_dyn_templates::{tera::Context, Template};

use crate::{
    db::{Database, Peer},
    sbot,
    task_loop::Task,
    utils, WhoAmI,
};

#[derive(FromForm)]
pub struct PeerForm {
    pub public_key: String,
}

#[get("/")]
pub async fn home(db: &State<Database>) -> Template {
    let peers = db.get_peers();

    let mut context = Context::new();
    let mut peers_unread = Vec::new();

    for peer in peers {
        let unread_count = db.get_unread_post_count(&peer.public_key);
        peers_unread.push((peer, unread_count.to_string()));
    }

    context.insert("peers", &peers_unread);

    Template::render("base", &context.into_json())
}

#[get("/posts/<public_key>/<msg_id>/delete")]
pub async fn delete_post(db: &State<Database>, public_key: &str, msg_id: &str) -> Redirect {
    // Delete the post from the database. This method cannot panic, so we're
    // safe to unwrap the result.
    db.remove_post(public_key, msg_id).unwrap();

    Redirect::to(uri!(posts(public_key)))
}

#[get("/posts/<public_key>")]
pub async fn posts(db: &State<Database>, public_key: &str) -> Template {
    let peers = db.get_peers();

    let mut context = Context::new();
    let mut peers_unread = Vec::new();

    for peer in peers {
        let unread_count = db.get_unread_post_count(&peer.public_key);
        peers_unread.push((peer, unread_count.to_string()));
    }

    context.insert("peers", &peers_unread);

    let posts = db.get_posts(public_key).unwrap();

    context.insert("selected_peer", &public_key);
    context.insert("posts", &posts);

    Template::render("base", &context.into_json())
}

#[get("/posts/<public_key>/<msg_id>")]
pub async fn post(db: &State<Database>, public_key: &str, msg_id: &str) -> Template {
    let peers = db.get_peers();

    let mut context = Context::new();
    let mut peers_unread = Vec::new();

    for peer in peers {
        let unread_count = db.get_unread_post_count(&peer.public_key);
        peers_unread.push((peer, unread_count.to_string()));
    }

    context.insert("peers", &peers_unread);

    let posts = db.get_posts(public_key).unwrap();
    let post = db.get_post(public_key, msg_id).unwrap();

    context.insert("selected_peer", &public_key);
    context.insert(
        "selected_peer_encoded",
        &uri_encode::encode_uri_component(public_key),
    );
    context.insert("selected_post", &msg_id);
    context.insert(
        "selected_post_encoded",
        &uri_encode::encode_uri_component(msg_id),
    );
    context.insert("posts", &posts);
    context.insert("post", &post);
    context.insert("post_is_selected", &true);

    Template::render("base", &context.into_json())
}

#[get("/posts/<public_key>/<msg_id>/read")]
pub async fn mark_post_read(db: &State<Database>, public_key: &str, msg_id: &str) -> Redirect {
    // Retrieve the post from the database, mark it as read and reinsert it.
    if let Ok(Some(mut post)) = db.get_post(public_key, msg_id) {
        post.read = true;
        db.add_post(public_key, post).unwrap();
    } else {
        warn!(
            "failed to find post {} authored by {} in database",
            msg_id, public_key
        )
    }

    Redirect::to(uri!(post(public_key, msg_id)))
}

#[get("/posts/<public_key>/<msg_id>/unread")]
pub async fn mark_post_unread(db: &State<Database>, public_key: &str, msg_id: &str) -> Redirect {
    // Retrieve the post from the database, mark it as unread and reinsert it.
    if let Ok(Some(mut post)) = db.get_post(public_key, msg_id) {
        post.read = false;
        db.add_post(public_key, post).unwrap();
    } else {
        warn!(
            "failed to find post {} authored by {} in database",
            msg_id, public_key
        )
    }

    Redirect::to(uri!(post(public_key, msg_id)))
}

#[get("/posts/download_latest")]
pub async fn download_latest_posts(db: &State<Database>, tx: &State<Sender<Task>>) -> Redirect {
    for peer in db.get_peers() {
        // Fetch the latest root posts authored by each peer we're
        // subscribed to. Posts will be added to the key-value database.
        if let Err(e) = tx
            .send(Task::FetchLatestPosts(peer.public_key.clone()))
            .await
        {
            warn!("task loop error: {}", e)
        }

        // Fetch the latest name for each peer we're subscribed to and update
        // the database.
        if let Err(e) = tx.send(Task::FetchLatestName(peer.public_key)).await {
            warn!("task loop error: {}", e)
        }
    }

    Redirect::to(uri!(home))
}

#[post("/subscribe", data = "<peer>")]
pub async fn subscribe_form(
    db: &State<Database>,
    whoami: &State<WhoAmI>,
    tx: &State<Sender<Task>>,
    peer: Form<PeerForm>,
) -> Redirect {
    if utils::validate_public_key(&peer.public_key).is_ok() {
        debug!("public key {} is valid", &peer.public_key);

        // Retrieve the name of the peer to which we are subscribing.
        let peer_name = match sbot::get_name(&peer.public_key).await {
            Ok(name) => name,
            Err(e) => {
                warn!("failed to fetch name for {}: {}", &peer.public_key, e);
                String::from("")
            }
        };
        let peer_info = Peer::new(&peer.public_key).set_name(&peer_name);

        // Add the peer to the database and then check the follow state.
        // Follow the peer if our local instance is not already following.
        if db.add_peer(peer_info).is_ok() {
            debug!("added {} to peer tree in database", &peer.public_key);
            match sbot::is_following(&whoami.0, &peer.public_key).await {
                Ok(status) if status.as_str() == "false" => {
                    match sbot::follow_peer(&peer.public_key).await {
                        Ok(_) => debug!("followed {}", &peer.public_key),
                        Err(e) => warn!("failed to follow {}: {}", &peer.public_key, e),
                    }
                }
                Ok(status) if status.as_str() == "true" => {
                    debug!("we already follow {}", &peer.public_key)
                }
                _ => (),
            }

            let peer_id = peer.public_key.to_string();
            // Fetch all root posts authored by the peer we're subscribing
            // to. Posts will be added to the key-value database.
            if let Err(e) = tx.send(Task::FetchAllPosts(peer_id)).await {
                warn!("task loop error: {}", e)
            }
        } else {
            warn!(
                "failed to add {} to peer tree in database",
                &peer.public_key
            )
        }
    } else {
        warn!("{} is invalid", &peer.public_key);
    }

    Redirect::to(uri!(home))
}

#[post("/unsubscribe", data = "<peer>")]
pub fn unsubscribe_form(db: &State<Database>, peer: Form<PeerForm>) -> Redirect {
    if let Err(e) = utils::validate_public_key(&peer.public_key) {
        warn!("{} is invalid: {}", &peer.public_key, e)
    } else {
        debug!("public key {} is valid", &peer.public_key);
        match db.remove_peer(&peer.public_key) {
            Ok(_) => debug!("removed {} from peer tree in database", &peer.public_key),
            Err(_e) => warn!(
                "failed to remove {} from peer tree in database",
                &peer.public_key
            ),
        }
    }

    Redirect::to(uri!(home))
}