/*
    This file is part of gnix (https://codeberg.org/metamuffin/gnix)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2025 metamuffin <metamuffin.org>
*/
#[derive(Debug, thiserror::Error)]
pub enum ServiceError {
    #[error("no response generated; the proxy is misconfigured")]
    NoResponse,
    #[error("request taken; the proxy is misconfigured")]
    RequestTaken,
    #[error("limit reached. try again")]
    Limit(#[from] tokio::sync::TryAcquireError),
    #[error("hyper error: {0}")]
    Hyper(hyper::Error),
    #[error("h3 error: {0}")]
    H3(h3::Error),
    #[error("host header missing")]
    NoHost,
    #[error("unknown host")]
    UnknownHost,
    #[error("unknown path")]
    UnknownPath,
    #[error("can't connect to the backend")]
    CantConnect,
    #[error("not found")]
    NotFound,
    #[error("io error: {0}")]
    Io(#[from] std::io::Error),
    #[error("bad range")]
    BadRange,
    #[error("bad utf8")]
    BadUtf8(#[from] std::str::Utf8Error),
    #[error("bad utf8")]
    BadUtf82(#[from] std::string::FromUtf8Error),
    #[error("bad utf8")]
    BadUtf83(#[from] http::header::ToStrError),
    #[error("bad path")]
    BadPath,
    #[error("bad auth")]
    BadAuth,
    #[error("unauthorized")]
    Unauthorized,
    #[error("bad base64: {0}")]
    BadBase64(#[from] base64::DecodeError),
    #[error("connection upgrade failed")]
    UpgradeFailed,
    #[error("{0}")]
    Custom(String),
    #[error("{0}")]
    CustomStatic(&'static str),
    #[error("parse int error: {0}")]
    ParseIntError(#[from] std::num::ParseIntError),
    #[error("invalid header")]
    InvalidHeader,
    #[error("X-Real-IP header missing, your proxy is misconfigured")]
    XRealIPMissing,
    #[error("invalid uri")]
    InvalidUri,
    #[error("too many concurrent users, please retry later")]
    TooManyIdentities,
    #[error("impossible error")]
    Other,
}

impl ServiceError {
    pub fn status_code(&self) -> http::StatusCode {
        use http::StatusCode;
        match self {
            ServiceError::NoResponse => todo!(),
            ServiceError::RequestTaken => StatusCode::INTERNAL_SERVER_ERROR,
            ServiceError::Limit(_) => StatusCode::TOO_MANY_REQUESTS,
            ServiceError::Hyper(_) => StatusCode::INTERNAL_SERVER_ERROR,
            ServiceError::H3(_) => StatusCode::INTERNAL_SERVER_ERROR,
            ServiceError::NoHost => StatusCode::BAD_REQUEST,
            ServiceError::UnknownHost => StatusCode::NOT_FOUND,
            ServiceError::UnknownPath => StatusCode::NOT_FOUND,
            ServiceError::CantConnect => StatusCode::BAD_GATEWAY,
            ServiceError::NotFound => StatusCode::NOT_FOUND,
            ServiceError::Io(_) => StatusCode::BAD_REQUEST,
            ServiceError::BadRange => StatusCode::RANGE_NOT_SATISFIABLE,
            ServiceError::BadUtf8(_) => StatusCode::BAD_REQUEST,
            ServiceError::BadUtf82(_) => StatusCode::BAD_REQUEST,
            ServiceError::BadUtf83(_) => StatusCode::BAD_REQUEST,
            ServiceError::BadPath => StatusCode::BAD_REQUEST,
            ServiceError::BadAuth => StatusCode::UNAUTHORIZED,
            ServiceError::Unauthorized => StatusCode::UNAUTHORIZED,
            ServiceError::BadBase64(_) => StatusCode::BAD_REQUEST,
            ServiceError::UpgradeFailed => StatusCode::UPGRADE_REQUIRED,
            ServiceError::Custom(_) => StatusCode::BAD_REQUEST,
            ServiceError::CustomStatic(_) => StatusCode::BAD_REQUEST,
            ServiceError::ParseIntError(_) => StatusCode::BAD_REQUEST,
            ServiceError::InvalidHeader => StatusCode::BAD_REQUEST,
            ServiceError::XRealIPMissing => StatusCode::INTERNAL_SERVER_ERROR,
            ServiceError::InvalidUri => StatusCode::BAD_REQUEST,
            ServiceError::TooManyIdentities => StatusCode::TOO_MANY_REQUESTS,
            ServiceError::Other => StatusCode::INTERNAL_SERVER_ERROR,
        }
    }
}