use diesel::backend::RawValue;
use diesel::deserialize::{self, FromSql, FromSqlRow};
use diesel::serialize::{self, IsNull, Output, ToSql};
use diesel::sql_types::Text;
use diesel::sqlite::Sqlite;
use diesel::AsExpression;
use std::fmt;
use std::fmt::{Display, Formatter};
use std::str;
use uuid::{self, Uuid};

#[derive(Debug, Clone, Copy, FromSqlRow, AsExpression, Hash, Eq, PartialEq)]
#[sql_type = "Text"]
pub struct UUID(pub uuid::Uuid);

impl UUID {
    pub fn random() -> Self {
        Self(uuid::Uuid::new_v4())
    }

    pub fn parse_str(string: &str) -> Result<Self, uuid::Error> {
        Uuid::parse_str(string).map(Self)
    }
}

impl From<UUID> for uuid::Uuid {
    fn from(s: UUID) -> Self {
        s.0
    }
}

impl Display for UUID {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}

impl FromSql<Text, Sqlite> for UUID {
    fn from_sql(bytes: RawValue<'_, Sqlite>) -> deserialize::Result<Self> {
        let value = <Vec<u8>>::from_sql(bytes)?;
        let string = str::from_utf8(&value)?;
        Ok(UUID::parse_str(string)?)
    }
}

impl ToSql<Text, Sqlite> for UUID {
    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Sqlite>) -> serialize::Result {
        out.set_value(self.0.to_string());
        Ok(IsNull::No)
    }
}