use ammonia::clean;
use serde::{self, Serialize, Deserialize,
    Serializer, Deserializer, de::Visitor};
use std::{fmt::{self, Display},
    borrow::Borrow, io::Write,
    ops::Deref};
use diesel::{self, deserialize::Queryable,
    types::ToSql,
    sql_types::Text,
    serialize::{self, Output}};

#[derive(Debug, Clone, AsExpression, FromSqlRow, Default)]
#[sql_type = "Text"]
pub struct SafeString{
    value: String,
}

impl SafeString{
pub fn new(value: &str) -> Self {
    SafeString{
            value: clean(&value),
        }
    }
    pub fn set(&mut self, value: &str) {
        self.value = clean(value);
    }
    pub fn get(&self) -> &String {
        &self.value
    }
}

impl Serialize for SafeString {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where S: Serializer, {
        serializer.serialize_str(&self.value)
    }
}

struct SafeStringVisitor;

impl<'de> Visitor<'de> for SafeStringVisitor {
    type Value = SafeString;

    fn expecting(&self, formatter:&mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("a string")
    }

    fn visit_str<E>(self, value: &str) -> Result<SafeString, E>
    where E: serde::de::Error{
        Ok(SafeString::new(value))
    }
}

impl<'de> Deserialize<'de> for SafeString {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where D: Deserializer<'de>, {
        Ok(
            deserializer.deserialize_string(SafeStringVisitor)?
        )
    }
}

impl Queryable<Text, diesel::pg::Pg> for SafeString {
    type Row = String;
    fn build(value: Self::Row) -> Self {
        SafeString::new(&value)
    }
}

impl<DB> ToSql<diesel::sql_types::Text, DB> for SafeString
where
    DB: diesel::backend::Backend,
    str: ToSql<diesel::sql_types::Text, DB>, {
    fn to_sql<W: Write>(&self, out: &mut Output<W, DB>) -> serialize::Result {
        str::to_sql(&self.value, out)
    }
}


impl Borrow<str> for SafeString {
    fn borrow(&self) -> &str {
        &self.value
    }
}

impl Display for SafeString {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self.value)
    }
}

impl Deref for SafeString {
    type Target = str;
    fn deref(&self) -> &str {
        &self.value
    }
}

impl AsRef<str> for SafeString {
    fn as_ref(&self) -> &str {
        &self.value
    }
}

use rocket::request::FromFormValue;
use rocket::http::RawStr;

impl<'v> FromFormValue<'v> for SafeString {
    type Error = &'v RawStr;

    fn from_form_value(form_value: &'v RawStr) -> Result<SafeString, &'v RawStr> {
        let val = String::from_form_value(form_value)?;
        Ok(SafeString {
          value: val,
        })
    }
}