use redis::RedisError;

pub type CacheResult<T> = Result<T, CacheError>;

#[derive(Debug)]
pub enum CacheError {
    Config(String),
    Backend(RedisError),
    Encode {
        key: String,
        message: String,
    },
    Decode {
        key: String,
        message: String,
    },
    Unsupported {
        feature: &'static str,
        reason: &'static str,
    },
    Lock {
        key: String,
        message: String,
    },
}

impl CacheError {
    pub fn config(message: impl Into<String>) -> Self {
        Self::Config(message.into())
    }

    pub fn encode(key: impl Into<String>, error: serde_json::Error) -> Self {
        Self::Encode {
            key: key.into(),
            message: error.to_string(),
        }
    }

    pub fn decode(key: impl Into<String>, error: serde_json::Error) -> Self {
        Self::Decode {
            key: key.into(),
            message: error.to_string(),
        }
    }

    pub fn unsupported(feature: &'static str, reason: &'static str) -> Self {
        Self::Unsupported { feature, reason }
    }

    pub fn lock(key: impl Into<String>, message: impl Into<String>) -> Self {
        Self::Lock {
            key: key.into(),
            message: message.into(),
        }
    }

    pub fn key(&self) -> Option<&str> {
        match self {
            Self::Encode { key, .. } | Self::Decode { key, .. } | Self::Lock { key, .. } => {
                Some(key)
            }
            _ => None,
        }
    }

    pub fn is_config(&self) -> bool {
        matches!(self, Self::Config(_))
    }

    pub fn is_closed(&self) -> bool {
        match self {
            Self::Backend(error) => error.is_connection_dropped(),
            _ => false,
        }
    }

    pub fn is_retryable(&self) -> bool {
        match self {
            Self::Backend(error) => {
                error.is_io_error()
                    || error.is_timeout()
                    || error.is_connection_refusal()
                    || error.is_connection_dropped()
                    || error.is_cluster_error()
            }
            _ => false,
        }
    }
}

impl std::fmt::Display for CacheError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Config(message) => write!(f, "cache config: {message}"),
            Self::Backend(error) => write!(f, "cache backend: {error}"),
            Self::Encode { key, message } => write!(f, "cache encode {key}: {message}"),
            Self::Decode { key, message } => write!(f, "cache decode {key}: {message}"),
            Self::Unsupported { feature, reason } => {
                write!(f, "cache unsupported {feature}: {reason}")
            }
            Self::Lock { key, message } => write!(f, "cache lock {key}: {message}"),
        }
    }
}

impl std::error::Error for CacheError {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            Self::Backend(error) => Some(error),
            _ => None,
        }
    }
}

impl From<RedisError> for CacheError {
    fn from(error: RedisError) -> Self {
        Self::Backend(error)
    }
}