use chrono::DateTime;
use diesel::prelude::*;
use gpodder::AuthErr;

use super::SqliteRepository;
use crate::{
    DbError,
    models::{
        session::Session,
        signup_link::SignupLink,
        user::{NewUser, User},
    },
    schema::*,
};

impl From<User> for gpodder::User {
    fn from(value: User) -> Self {
        Self {
            id: value.id,
            username: value.username,
            password_hash: value.password_hash,
            admin: value.admin,
        }
    }
}

impl From<SignupLink> for gpodder::SignupLink {
    fn from(value: SignupLink) -> Self {
        Self {
            id: value.id,
            time_created: DateTime::from_timestamp(value.created_at, 0).unwrap(),
        }
    }
}

impl gpodder::GpodderAuthStore for SqliteRepository {
    fn get_user(&self, username: &str) -> Result<Option<gpodder::models::User>, AuthErr> {
        Ok(users::table
            .select(User::as_select())
            .filter(users::username.eq(username))
            .first(&mut self.pool.get().map_err(DbError::from)?)
            .optional()
            .map_err(DbError::from)?
            .map(gpodder::User::from))
    }

    fn insert_user(&self, username: &str, password_hash: &str) -> Result<gpodder::User, AuthErr> {
        let conn = &mut self.pool.get().map_err(DbError::from)?;

        Ok(diesel::insert_into(users::table)
            .values(NewUser {
                username,
                password_hash,
            })
            .returning(User::as_returning())
            .get_result(conn)
            .map(gpodder::User::from)
            .map_err(DbError::from)?)
    }

    fn get_session(&self, session_id: i64) -> Result<Option<gpodder::models::Session>, AuthErr> {
        match sessions::table
            .inner_join(users::table)
            .filter(sessions::id.eq(session_id))
            .select((Session::as_select(), User::as_select()))
            .get_result(&mut self.pool.get().map_err(DbError::from)?)
            .optional()
        {
            Ok(Some((session, user))) => Ok(Some(gpodder::Session {
                id: session.id,
                last_seen: DateTime::from_timestamp(session.last_seen, 0).unwrap(),
                user: user.into(),
                user_agent: session.user_agent.clone(),
            })),
            Ok(None) => Ok(None),
            Err(err) => Err(DbError::from(err).into()),
        }
    }

    fn remove_session(&self, session_id: i64) -> Result<(), AuthErr> {
        Ok(
            diesel::delete(sessions::table.filter(sessions::id.eq(session_id)))
                .execute(&mut self.pool.get().map_err(DbError::from)?)
                .map(|_| ())
                .map_err(DbError::from)?,
        )
    }

    fn insert_session(&self, session: &gpodder::Session) -> Result<(), AuthErr> {
        Ok(Session {
            id: session.id,
            user_id: session.user.id,
            last_seen: session.last_seen.timestamp(),
            user_agent: session.user_agent.clone(),
        }
        .insert_into(sessions::table)
        .execute(&mut self.pool.get().map_err(DbError::from)?)
        .map(|_| ())
        .map_err(DbError::from)?)
    }

    fn refresh_session(
        &self,
        session: &gpodder::Session,
        timestamp: DateTime<chrono::Utc>,
    ) -> Result<(), AuthErr> {
        if diesel::update(sessions::table.filter(sessions::id.eq(session.id)))
            .set(sessions::last_seen.eq(timestamp.timestamp()))
            .execute(&mut self.pool.get().map_err(DbError::from)?)
            .map_err(DbError::from)?
            == 0
        {
            Err(AuthErr::UnknownSession)
        } else {
            Ok(())
        }
    }

    fn remove_old_sessions(&self, min_last_seen: DateTime<chrono::Utc>) -> Result<usize, AuthErr> {
        let min_last_seen = min_last_seen.timestamp();

        Ok(
            diesel::delete(sessions::table.filter(sessions::last_seen.lt(min_last_seen)))
                .execute(&mut self.pool.get().map_err(DbError::from)?)
                .map_err(DbError::from)?,
        )
    }

    fn paginated_sessions(
        &self,
        user: &gpodder::User,
        page: gpodder::Page,
    ) -> Result<Vec<gpodder::Session>, AuthErr> {
        (|| {
            let sessions = sessions::table
                .filter(sessions::user_id.eq(user.id))
                .order(sessions::last_seen.desc())
                .offset((page.page * page.per_page) as i64)
                .limit(page.per_page as i64)
                .select(Session::as_select())
                .get_results(&mut self.pool.get()?)?
                .into_iter()
                .map(|session| gpodder::Session {
                    id: session.id,
                    last_seen: DateTime::from_timestamp(session.last_seen, 0).unwrap(),
                    user_agent: session.user_agent,
                    user: user.clone(),
                })
                .collect();

            Ok::<_, DbError>(sessions)
        })()
        .map_err(AuthErr::from)
    }

    fn paginated_users(
        &self,
        page: gpodder::Page,
        filter: &gpodder::UserFilter,
    ) -> Result<Vec<gpodder::User>, AuthErr> {
        (|| {
            let mut query = users::table
                .select(User::as_select())
                .order(users::username.asc())
                .offset((page.page * page.per_page) as i64)
                .limit(page.per_page as i64)
                .into_boxed();

            if let Some(username) = &filter.username {
                // Case insensitive by default for SQLite
                query = query.filter(users::username.like(format!("%{username}%")));
            }

            Ok::<_, DbError>(
                query
                    .load_iter(&mut self.pool.get()?)?
                    .map(|res| res.map(gpodder::User::from))
                    .collect::<Result<Vec<_>, _>>()?,
            )
        })()
        .map_err(AuthErr::from)
    }

    fn get_signup_link(&self, id: i64) -> Result<Option<gpodder::SignupLink>, AuthErr> {
        match signup_links::table
            .find(id)
            .select(SignupLink::as_select())
            .first(&mut self.pool.get().map_err(DbError::from)?)
            .optional()
        {
            Ok(Some(link)) => Ok(Some(gpodder::SignupLink::from(link))),
            Ok(None) => Ok(None),
            Err(err) => Err(DbError::from(err).into()),
        }
    }

    fn insert_signup_link(&self, link: &gpodder::SignupLink) -> Result<(), AuthErr> {
        diesel::insert_into(signup_links::table)
            .values(SignupLink {
                id: link.id,
                created_at: link.time_created.timestamp(),
            })
            .execute(&mut self.pool.get().map_err(DbError::from)?)
            .map_err(DbError::from)?;

        Ok(())
    }

    fn remove_signup_link(&self, id: i64) -> Result<bool, AuthErr> {
        match diesel::delete(signup_links::table.filter(signup_links::id.eq(id)))
            .execute(&mut self.pool.get().map_err(DbError::from)?)
        {
            Ok(0) => Ok(false),
            Ok(_) => Ok(true),
            Err(err) => Err(DbError::from(err).into()),
        }
    }
}