//! Error type

use core::fmt;

#[cfg(feature = "password-hash")]

use {crate::Params, core::cmp::Ordering, password_hash::errors::InvalidValue};

/// Result with argon2's [`Error`] type.

pub type Result<T> = core::result::Result<T, Error>;

/// Error type.

#[derive(Copy, Clone, Debug, Eq, PartialEq)]

pub enum Error {

    /// Associated data is too long.

    AdTooLong,

    /// Algorithm identifier invalid.

    AlgorithmInvalid,

    /// "B64" encoding is invalid.

    B64Encoding(base64ct::Error),

    /// Key ID is too long.

    KeyIdTooLong,

    /// Memory cost is too small.

    MemoryTooLittle,

    /// Memory cost is too large.

    MemoryTooMuch,

    /// Output is too short.

    OutputTooShort,

    /// Output is too long.

    OutputTooLong,

    /// Password is too long.

    PwdTooLong,

    /// Salt is too short.

    SaltTooShort,

    /// Salt is too long.

    SaltTooLong,

    /// Secret is too long.

    SecretTooLong,

    /// Not enough threads.

    ThreadsTooFew,

    /// Too many threads.

    ThreadsTooMany,

    /// Time cost is too small.

    TimeTooSmall,

    /// Invalid version

    VersionInvalid,

}

impl fmt::Display for Error {

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

        f.write_str(match self {

            Error::AdTooLong => "associated data is too long",

            Error::AlgorithmInvalid => "algorithm identifier invalid",

            Error::B64Encoding(inner) => return write!(f, "B64 encoding invalid: {inner}"),

            Error::KeyIdTooLong => "key ID is too long",

            Error::MemoryTooLittle => "memory cost is too small",

            Error::MemoryTooMuch => "memory cost is too large",

            Error::OutputTooShort => "output is too short",

            Error::OutputTooLong => "output is too long",

            Error::PwdTooLong => "password is too long",

            Error::SaltTooShort => "salt is too short",

            Error::SaltTooLong => "salt is too long",

            Error::SecretTooLong => "secret is too long",

            Error::ThreadsTooFew => "not enough threads",

            Error::ThreadsTooMany => "too many threads",

            Error::TimeTooSmall => "time cost is too small",

            Error::VersionInvalid => "invalid version",

        })

    }

}

impl From<base64ct::Error> for Error {

    fn from(err: base64ct::Error) -> Error {

        Error::B64Encoding(err)

    }

}

#[cfg(feature = "password-hash")]

#[cfg_attr(docsrs, doc(cfg(feature = "password-hash")))]

impl From<Error> for password_hash::Error {

    fn from(err: Error) -> password_hash::Error {

        match err {

            Error::AdTooLong => InvalidValue::TooLong.param_error(),

            Error::AlgorithmInvalid => password_hash::Error::Algorithm,

            Error::B64Encoding(inner) => password_hash::Error::B64Encoding(inner),

            Error::KeyIdTooLong => InvalidValue::TooLong.param_error(),

            Error::MemoryTooLittle => InvalidValue::TooShort.param_error(),

            Error::MemoryTooMuch => InvalidValue::TooLong.param_error(),

            Error::PwdTooLong => password_hash::Error::Password,

            Error::OutputTooShort => password_hash::Error::OutputSize {

                provided: Ordering::Less,

                expected: Params::MIN_OUTPUT_LEN,

            },

            Error::OutputTooLong => password_hash::Error::OutputSize {

                provided: Ordering::Greater,

                expected: Params::MAX_OUTPUT_LEN,

            },

            Error::SaltTooShort => InvalidValue::TooShort.salt_error(),

            Error::SaltTooLong => InvalidValue::TooLong.salt_error(),

            Error::SecretTooLong => InvalidValue::TooLong.param_error(),

            Error::ThreadsTooFew => InvalidValue::TooShort.param_error(),

            Error::ThreadsTooMany => InvalidValue::TooLong.param_error(),

            Error::TimeTooSmall => InvalidValue::TooShort.param_error(),

            Error::VersionInvalid => password_hash::Error::Version,

        }

    }

}

#[cfg(feature = "std")]

impl std::error::Error for Error {

    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {

        match self {

            Self::B64Encoding(err) => Some(err),

            _ => None,

        }

    }

}