// Copyright (C) 2023-2099 The crate authors.
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU Affero General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
// for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

use std::env::VarError;
use std::error::Error as StdError;
use std::io::Error as IoError;
use std::str::Utf8Error;

use hex::FromHexError;
use hmac::digest::InvalidLength as HmacInvalidLength;
use hyper::StatusCode;

#[derive(Debug)]
pub(crate) enum Error {
	MethodMismatch(hyper::Method),
	InvalidSecret,
	InvalidContentType,
	InvalidSignature,
	InvalidRequest,
	Hex(FromHexError),
	Hmac(HmacInvalidLength),
	Hyper(hyper::Error),
	Io(IoError),
	SerdeJson(serde_json::Error),
	Toml(toml::de::Error),
	Utf8(Utf8Error),
	Var(VarError),
}

impl Error {
	pub fn status(&self) -> StatusCode {
		match self {
			Self::MethodMismatch(_) => StatusCode::METHOD_NOT_ALLOWED,
			Self::InvalidSecret => StatusCode::FORBIDDEN,
			Self::InvalidContentType => StatusCode::UNSUPPORTED_MEDIA_TYPE,
			Self::InvalidSignature => StatusCode::FORBIDDEN,
			Self::InvalidRequest => StatusCode::BAD_REQUEST,
			_ => StatusCode::INTERNAL_SERVER_ERROR,
		}
	}
}

impl StdError for Error {}

impl std::fmt::Display for Error {
	fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
		match self {
			Error::MethodMismatch(method) => {
				write!(fmt, "method is invalid {method}, expected POST")
			}
			Error::InvalidSecret => write!(fmt, "the secret is invalid"),
			Error::InvalidContentType => write!(fmt, "the content-type is invalid"),
			Error::InvalidSignature => write!(fmt, "the signature is invalid"),
			Error::InvalidRequest => write!(fmt, "the request is invalid"),
			Error::Hex(e) => write!(fmt, "hex error: {}", e),
			Error::Hmac(e) => write!(fmt, "hmac error: {}", e),
			Error::Hyper(e) => write!(fmt, "hyper error: {}", e),
			Error::Io(e) => write!(fmt, "Io error: {}", e),
			Error::SerdeJson(e) => write!(fmt, "serde_json error: {}", e),
			Error::Toml(e) => write!(fmt, "toml deserialization error: {}", e),
			Error::Utf8(e) => write!(fmt, "Utf8 error: {}", e),
			Error::Var(e) => write!(fmt, "Var error: {}", e),
		}
	}
}

impl From<FromHexError> for Error {
	fn from(err: FromHexError) -> Error {
		Error::Hex(err)
	}
}

impl From<HmacInvalidLength> for Error {
	fn from(err: HmacInvalidLength) -> Error {
		Error::Hmac(err)
	}
}

impl From<hyper::Error> for Error {
	fn from(err: hyper::Error) -> Error {
		Error::Hyper(err)
	}
}

impl From<IoError> for Error {
	fn from(err: IoError) -> Error {
		Error::Io(err)
	}
}

impl From<serde_json::Error> for Error {
	fn from(err: serde_json::Error) -> Error {
		Error::SerdeJson(err)
	}
}

impl From<toml::de::Error> for Error {
	fn from(err: toml::de::Error) -> Error {
		Error::Toml(err)
	}
}

impl From<Utf8Error> for Error {
	fn from(err: Utf8Error) -> Error {
		Error::Utf8(err)
	}
}

impl From<VarError> for Error {
	fn from(err: VarError) -> Error {
		Error::Var(err)
	}
}