use std::{fmt, str::FromStr};

use serde::{Deserialize, Deserializer, Serialize, Serializer, de::Error as _};

#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct OpaqueId(String);

impl OpaqueId {
    pub fn parse(value: impl Into<String>) -> Result<Self, IdError> {
        let value = value.into();
        let mut chars = value.chars();
        let Some(first) = chars.next() else {
            return Err(IdError);
        };
        if !(8..=128).contains(&value.len())
            || !first.is_ascii_alphanumeric()
            || !chars.all(|character| {
                character.is_ascii_alphanumeric() || matches!(character, '_' | '-')
            })
        {
            return Err(IdError);
        }
        Ok(Self(value))
    }

    #[must_use]
    pub fn as_str(&self) -> &str {
        &self.0
    }
}

impl fmt::Display for OpaqueId {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(formatter)
    }
}

impl FromStr for OpaqueId {
    type Err = IdError;

    fn from_str(value: &str) -> Result<Self, Self::Err> {
        Self::parse(value)
    }
}

impl Serialize for OpaqueId {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        serializer.serialize_str(&self.0)
    }
}

impl<'de> Deserialize<'de> for OpaqueId {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        Self::parse(String::deserialize(deserializer)?).map_err(D::Error::custom)
    }
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct IdError;

impl fmt::Display for IdError {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str("invalid opaque identifier")
    }
}

impl std::error::Error for IdError {}