use std::ops::Deref;

use argon2::{password_hash::SaltString, Argon2, PasswordHasher};
use rocket::{
    async_trait,
    http::Status,
    request::{self, FromRequest, Outcome},
    Request,
};
use serde::{Deserialize, Serialize};
use sqlx::{FromRow, SqlitePool};

#[derive(FromRow, Debug, Serialize, Deserialize)]
pub struct User {
    pub id: i64,
    pub name: String,
    pw: Option<String>,
    pub is_cox: bool,
    is_admin: bool,
    is_guest: bool,
}

pub struct AdminUser {
    user: User,
}

impl TryFrom<User> for AdminUser {
    type Error = LoginError;

    fn try_from(user: User) -> Result<Self, Self::Error> {
        if user.is_admin {
            Ok(AdminUser { user })
        } else {
            Err(LoginError::NotAnAdmin)
        }
    }
}

pub struct CoxUser {
    user: User,
}

impl Deref for CoxUser {
    type Target = User;

    fn deref(&self) -> &Self::Target {
        &self.user
    }
}

impl TryFrom<User> for CoxUser {
    type Error = LoginError;

    fn try_from(user: User) -> Result<Self, Self::Error> {
        if user.is_cox {
            Ok(CoxUser { user })
        } else {
            Err(LoginError::NotACox)
        }
    }
}

#[derive(Debug)]
pub enum LoginError {
    SqlxError(sqlx::Error),
    InvalidAuthenticationCombo,
    NotLoggedIn,
    NotAnAdmin,
    NotACox,
    NoPasswordSet(User),
}

impl From<sqlx::Error> for LoginError {
    fn from(sqlx_error: sqlx::Error) -> Self {
        Self::SqlxError(sqlx_error)
    }
}
impl User {
    pub async fn update(&self, db: &SqlitePool, is_cox: bool, is_admin: bool, is_guest: bool) {
        sqlx::query!(
            "UPDATE user SET is_cox = ?, is_admin = ?, is_guest = ? where id = ?",
            is_cox,
            is_admin,
            is_guest,
            self.id
        )
        .execute(db)
        .await
        .unwrap(); //TODO: fixme
    }

    pub async fn find_by_id(db: &SqlitePool, id: i32) -> Result<Self, sqlx::Error> {
        let user: User = sqlx::query_as!(
            User,
            "
SELECT id, name, pw, is_cox, is_admin, is_guest
FROM user 
WHERE id like ?
        ",
            id
        )
        .fetch_one(db)
        .await?;

        Ok(user)
    }

    async fn find_by_name(db: &SqlitePool, name: String) -> Result<Self, sqlx::Error> {
        let user: User = sqlx::query_as!(
            User,
            "
SELECT id, name, pw, is_cox, is_admin, is_guest
FROM user 
WHERE name like ?
        ",
            name
        )
        .fetch_one(db)
        .await?;

        Ok(user)
    }

    fn get_hashed_pw(pw: String) -> String {
        let salt = SaltString::from_b64("dS/X5/sPEKTj4Rzs/CuvzQ").unwrap();
        let argon2 = Argon2::default();
        argon2
            .hash_password(&pw.as_bytes(), &salt)
            .unwrap()
            .to_string()
    }

    pub async fn login(db: &SqlitePool, name: String, pw: String) -> Result<Self, LoginError> {
        let user = User::find_by_name(db, name).await?;

        match user.pw.clone() {
            Some(user_pw) => {
                let password_hash = Self::get_hashed_pw(pw);
                if password_hash == user_pw {
                    return Ok(user);
                }

                Err(LoginError::InvalidAuthenticationCombo)
            }
            None => Err(LoginError::NoPasswordSet(user)),
        }
    }

    pub async fn all(db: &SqlitePool) -> Vec<Self> {
        sqlx::query_as!(
            User,
            "
SELECT id, name, pw, is_cox, is_admin, is_guest
FROM user 
        "
        )
        .fetch_all(db)
        .await
        .unwrap() //TODO: fixme
    }

    pub async fn reset_pw(&self, db: &SqlitePool) {
        sqlx::query!("UPDATE user SET pw = null where id = ?", self.id)
            .execute(db)
            .await
            .unwrap(); //TODO: fixme
    }

    pub async fn update_pw(&self, db: &SqlitePool, pw: String) {
        let pw = Self::get_hashed_pw(pw);
        sqlx::query!("UPDATE user SET pw = ? where id = ?", pw, self.id)
            .execute(db)
            .await
            .unwrap(); //TODO: fixme
    }
}

#[async_trait]
impl<'r> FromRequest<'r> for User {
    type Error = LoginError;

    async fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
        match req.cookies().get_private("loggedin_user") {
            Some(user) => {
                let user: User = serde_json::from_str(&user.value()).unwrap(); //TODO: fixme
                Outcome::Success(user)
            }
            None => Outcome::Failure((Status::Unauthorized, LoginError::NotLoggedIn)),
        }
    }
}

#[async_trait]
impl<'r> FromRequest<'r> for AdminUser {
    type Error = LoginError;

    async fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
        match req.cookies().get_private("loggedin_user") {
            Some(user) => {
                let user: User = serde_json::from_str(&user.value()).unwrap(); //TODO: fixme
                match user.try_into() {
                    Ok(user) => Outcome::Success(user),
                    Err(_) => Outcome::Failure((Status::Unauthorized, LoginError::NotAnAdmin)),
                }
            }
            None => Outcome::Failure((Status::Unauthorized, LoginError::NotLoggedIn)),
        }
    }
}

#[async_trait]
impl<'r> FromRequest<'r> for CoxUser {
    type Error = LoginError;

    async fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
        match req.cookies().get_private("loggedin_user") {
            Some(user) => {
                let user: User = serde_json::from_str(&user.value()).unwrap(); //TODO: fixme
                match user.try_into() {
                    Ok(user) => Outcome::Success(user),
                    Err(_) => Outcome::Failure((Status::Unauthorized, LoginError::NotAnAdmin)),
                }
            }
            None => Outcome::Failure((Status::Unauthorized, LoginError::NotLoggedIn)),
        }
    }
}

#[cfg(test)]
mod test {
    use crate::testdb;

    use super::User;
    use sqlx::SqlitePool;

    #[sqlx::test]
    fn succ_login_with_test_db() {
        let pool = testdb!();
        User::login(&pool, "admin".into(), "admin".into())
            .await
            .unwrap();
    }

    #[sqlx::test]
    fn wrong_pw() {
        let pool = testdb!();
        assert!(User::login(&pool, "admin".into(), "admi".into())
            .await
            .is_err());
    }

    #[sqlx::test]
    fn wrong_username() {
        let pool = testdb!();
        assert!(User::login(&pool, "admi".into(), "admin".into())
            .await
            .is_err());
    }
}