extern crate regex;

use self::regex::Regex;
use super::{Validated, ValidatedWrapper};

use std::error::Error;
use std::fmt::{self, Debug, Display, Formatter};
use std::ops::Deref;
use std::str::FromStr;

lazy_static! {
    static ref BASE32_RE: Regex = {
        Regex::new("^([A-Z2-7]{8})*(([A-Z2-7]{8})|([A-Z2-7]{7}=)|([A-Z2-7]{5}===)|([A-Z2-7]{4}====)|([A-Z2-7]{2}======))$").unwrap()
    };
}

#[derive(Debug, PartialEq, Clone)]
pub enum Base32Error {
    IncorrectFormat,
}

impl Display for Base32Error {
    #[inline]
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        Debug::fmt(self, f)
    }
}

impl Error for Base32Error {}

pub type Base32Result = Result<Base32, Base32Error>;

#[derive(Debug, PartialEq)]
pub struct Base32Validator {}

#[derive(Clone, PartialEq, Eq, Hash)]
pub struct Base32 {
    base32: String,
}

impl Base32 {
    #[inline]
    pub fn get_base32(&self) -> &str {
        &self.base32
    }

    #[inline]
    pub fn into_string(self) -> String {
        self.base32
    }

    #[inline]
    pub unsafe fn from_string_unchecked(base32: String) -> Base32 {
        Base32 {
            base32,
        }
    }
}

impl Deref for Base32 {
    type Target = str;

    #[inline]
    fn deref(&self) -> &Self::Target {
        &self.base32
    }
}

impl Validated for Base32 {}

impl Debug for Base32 {
    #[inline]
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        impl_debug_for_tuple_struct!(Base32, f, self, let .0 = self.base32);
    }
}

impl Display for Base32 {
    #[inline]
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        f.write_str(&self.base32)?;
        Ok(())
    }
}

impl Base32Validator {
    #[inline]
    pub fn is_base32(&self, base32: &str) -> bool {
        self.parse_inner(base32).is_ok()
    }

    pub fn parse_string(&self, base32: String) -> Base32Result {
        let mut base32_inner = self.parse_inner(&base32)?;

        base32_inner.base32 = base32;

        Ok(base32_inner)
    }

    pub fn parse_str(&self, base32: &str) -> Base32Result {
        let mut base32_inner = self.parse_inner(base32)?;

        base32_inner.base32.push_str(base32);

        Ok(base32_inner)
    }

    #[inline]
    fn parse_inner(&self, base32: &str) -> Base32Result {
        if BASE32_RE.is_match(base32) {
            Ok(Base32 {
                base32: String::new(),
            })
        } else {
            Err(Base32Error::IncorrectFormat)
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_base32_methods() {
        let base32 = "EB2GK43UEBWWK43TMFTWKCQK".to_string();

        let bv = Base32Validator {};

        let base32 = bv.parse_string(base32).unwrap();

        assert_eq!("EB2GK43UEBWWK43TMFTWKCQK", base32.get_base32());
    }

    #[test]
    fn test_base32_lv1() {
        let base32 = "EB2GK43UEBWWK43TMFTWKCQK".to_string();

        let bv = Base32Validator {};

        bv.parse_string(base32).unwrap();
    }
}

// Base32's wrapper struct is itself
impl ValidatedWrapper for Base32 {
    type Error = Base32Error;

    #[inline]
    fn from_string(base32: String) -> Result<Self, Self::Error> {
        Base32::from_string(base32)
    }

    #[inline]
    fn from_str(base32: &str) -> Result<Self, Self::Error> {
        Base32::from_str(base32)
    }
}

impl Base32 {
    #[inline]
    pub fn from_string(base32: String) -> Result<Self, Base32Error> {
        Base32::create_validator().parse_string(base32)
    }

    #[inline]
    #[allow(clippy::should_implement_trait)]
    pub fn from_str(base32: &str) -> Result<Self, Base32Error> {
        Base32::create_validator().parse_str(base32)
    }

    #[inline]
    fn create_validator() -> Base32Validator {
        Base32Validator {}
    }
}

impl FromStr for Base32 {
    type Err = Base32Error;

    #[inline]
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Base32::from_str(s)
    }
}

#[cfg(feature = "rocketly")]
impl<'a> ::rocket::request::FromParam<'a> for Base32 {
    type Error = Base32Error;

    #[inline]
    fn from_param(param: &'a ::rocket::http::RawStr) -> Result<Self, Self::Error> {
        Base32::from_str(param)
    }
}

#[cfg(feature = "rocketly")]
impl<'a> ::rocket::request::FromFormValue<'a> for Base32 {
    type Error = Base32Error;

    #[inline]
    fn from_form_value(form_value: &'a ::rocket::http::RawStr) -> Result<Self, Self::Error> {
        Base32::from_str(form_value)
    }
}

#[cfg(feature = "serdely")]
struct StringVisitor;

#[cfg(feature = "serdely")]
impl<'de> ::serde::de::Visitor<'de> for StringVisitor {
    type Value = Base32;

    #[inline]
    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("a Base32 string")
    }

    #[inline]
    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
    where
        E: ::serde::de::Error, {
        Base32::from_str(v).map_err(|err| E::custom(err.to_string()))
    }

    #[inline]
    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
    where
        E: ::serde::de::Error, {
        Base32::from_string(v).map_err(|err| E::custom(err.to_string()))
    }
}

#[cfg(feature = "serdely")]
impl<'de> ::serde::Deserialize<'de> for Base32 {
    #[inline]
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: ::serde::Deserializer<'de>, {
        deserializer.deserialize_str(StringVisitor)
    }
}

#[cfg(feature = "serdely")]
impl ::serde::Serialize for Base32 {
    #[inline]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ::serde::Serializer, {
        serializer.serialize_str(&self.base32)
    }
}