//! Postgres queries
use crate::{
    config,
    parse_client_request::subscription::{Scope, UserData},
};
use ::postgres;
use hashbrown::HashSet;
use r2d2_postgres::PostgresConnectionManager;
use warp::reject::Rejection;

#[derive(Clone, Debug)]
pub struct PgPool(pub r2d2::Pool<PostgresConnectionManager<postgres::NoTls>>);
impl PgPool {
    pub fn new(pg_cfg: config::PostgresConfig) -> Self {
        let mut cfg = postgres::Config::new();
        cfg.user(&pg_cfg.user)
            .host(&*pg_cfg.host.to_string())
            .port(*pg_cfg.port)
            .dbname(&pg_cfg.database);
        if let Some(password) = &*pg_cfg.password {
            cfg.password(password);
        };

        let manager = PostgresConnectionManager::new(cfg, postgres::NoTls);
        let pool = r2d2::Pool::builder()
            .max_size(10)
            .build(manager)
            .expect("Can connect to local postgres");
        Self(pool)
    }
    pub fn select_user(self, token: &str) -> Result<UserData, Rejection> {
        let mut conn = self.0.get().unwrap();
        let query_rows = conn
            .query(
                "
SELECT oauth_access_tokens.resource_owner_id, users.account_id, users.chosen_languages, oauth_access_tokens.scopes
FROM
oauth_access_tokens
INNER JOIN users ON
oauth_access_tokens.resource_owner_id = users.id
WHERE oauth_access_tokens.token = $1
AND oauth_access_tokens.revoked_at IS NULL
LIMIT 1",
                &[&token.to_owned()],
            )
        .expect("Hard-coded query will return Some([0 or more rows])");
        if let Some(result_columns) = query_rows.get(0) {
            let id = result_columns.get(1);
            let allowed_langs = result_columns
                .try_get::<_, Vec<_>>(2)
                .unwrap_or_else(|_| Vec::new())
                .into_iter()
                .collect();
            let mut scopes: HashSet<Scope> = result_columns
                .get::<_, String>(3)
                .split(' ')
                .filter_map(|scope| match scope {
                    "read" => Some(Scope::Read),
                    "read:statuses" => Some(Scope::Statuses),
                    "read:notifications" => Some(Scope::Notifications),
                    "read:lists" => Some(Scope::Lists),
                    "write" | "follow" => None, // ignore write scopes
                    unexpected => {
                        log::warn!("Ignoring unknown scope `{}`", unexpected);
                        None
                    }
                })
                .collect();
            // We don't need to separately track read auth - it's just all three others
            if scopes.remove(&Scope::Read) {
                scopes.insert(Scope::Statuses);
                scopes.insert(Scope::Notifications);
                scopes.insert(Scope::Lists);
            }

            Ok(UserData {
                id,
                allowed_langs,
                scopes,
            })
        } else {
            Err(warp::reject::custom("Error: Invalid access token"))
        }
    }

    pub fn select_hashtag_id(self, tag_name: &str) -> Result<i64, Rejection> {
        let mut conn = self.0.get().unwrap();
        let rows = &conn
            .query(
                "
SELECT id
FROM tags
WHERE name = $1
LIMIT 1",
                &[&tag_name],
            )
            .expect("Hard-coded query will return Some([0 or more rows])");

        match rows.get(0) {
            Some(row) => Ok(row.get(0)),
            None => Err(warp::reject::custom("Error: Hashtag does not exist.")),
        }
    }

    /// Query Postgres for everyone the user has blocked or muted
    ///
    /// **NOTE**: because we check this when the user connects, it will not include any blocks
    /// the user adds until they refresh/reconnect.
    pub fn select_blocked_users(self, user_id: i64) -> HashSet<i64> {
        self.0
            .get()
            .unwrap()
            .query(
                "
SELECT target_account_id
  FROM blocks
  WHERE account_id = $1
UNION SELECT target_account_id
  FROM mutes
  WHERE account_id = $1",
                &[&user_id],
            )
            .expect("Hard-coded query will return Some([0 or more rows])")
            .iter()
            .map(|row| row.get(0))
            .collect()
    }
    /// Query Postgres for everyone who has blocked the user
    ///
    /// **NOTE**: because we check this when the user connects, it will not include any blocks
    /// the user adds until they refresh/reconnect.
    pub fn select_blocking_users(self, user_id: i64) -> HashSet<i64> {
        self.0
            .get()
            .unwrap()
            .query(
                "
SELECT account_id
  FROM blocks
  WHERE target_account_id = $1",
                &[&user_id],
            )
            .expect("Hard-coded query will return Some([0 or more rows])")
            .iter()
            .map(|row| row.get(0))
            .collect()
    }

    /// Query Postgres for all current domain blocks
    ///
    /// **NOTE**: because we check this when the user connects, it will not include any blocks
    /// the user adds until they refresh/reconnect.
    pub fn select_blocked_domains(self, user_id: i64) -> HashSet<String> {
        self.0
            .get()
            .unwrap()
            .query(
                "SELECT domain FROM account_domain_blocks WHERE account_id = $1",
                &[&user_id],
            )
            .expect("Hard-coded query will return Some([0 or more rows])")
            .iter()
            .map(|row| row.get(0))
            .collect()
    }

    /// Test whether a user owns a list
    pub fn user_owns_list(self, user_id: i64, list_id: i64) -> bool {
        let mut conn = self.0.get().unwrap();
        // For the Postgres query, `id` = list number; `account_id` = user.id
        let rows = &conn
            .query(
                "
SELECT id, account_id
FROM lists
WHERE id = $1
LIMIT 1",
                &[&list_id],
            )
            .expect("Hard-coded query will return Some([0 or more rows])");

        match rows.get(0) {
            None => false,
            Some(row) => {
                let list_owner_id: i64 = row.get(1);
                list_owner_id == user_id
            }
        }
    }
}