use axum::http::StatusCode;
use axum::response::{IntoResponse, Response};
use axum::Json;
use serde::Serialize;
use thiserror::Error;

#[derive(Error, Debug)]
pub enum ApiError {
    #[error("entity not found: {0}")]
    NotFound(String),
    #[error("bad request: {0}")]
    BadRequest(String),
    #[error("unauthorized")]
    Unauthorized,
    #[error("service not registered: {domain}.{service}")]
    ServiceNotRegistered { domain: String, service: String },
    #[error("internal error: {0}")]
    Internal(String),
}

pub type ApiResult<T> = Result<T, ApiError>;

#[derive(Serialize)]
struct ErrorPayload { message: String }

impl IntoResponse for ApiError {
    fn into_response(self) -> Response {
        let (status, message) = match &self {
            Self::NotFound(_) => (StatusCode::NOT_FOUND, self.to_string()),
            Self::BadRequest(_) => (StatusCode::BAD_REQUEST, self.to_string()),
            Self::Unauthorized => (StatusCode::UNAUTHORIZED, self.to_string()),
            Self::ServiceNotRegistered { .. } => (StatusCode::BAD_REQUEST, self.to_string()),
            Self::Internal(_) => (StatusCode::INTERNAL_SERVER_ERROR, self.to_string()),
        };
        (status, Json(ErrorPayload { message })).into_response()
    }
}