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

#[derive(Debug, Error)]
pub enum AppError {
    #[error("{0}")]
    BadRequest(String),
    #[error("{0}")]
    NotFound(String),
    #[error("{0}")]
    Conflict(String),
    #[error("{0}")]
    ServiceUnavailable(String),
    #[error("{0}")]
    Internal(String),
}

#[derive(Debug, Serialize)]
struct ErrorResponse {
    code: &'static str,
    message: String,
}

impl AppError {
    pub fn bad_request(message: impl Into<String>) -> Self {
        Self::BadRequest(message.into())
    }

    pub fn not_found(message: impl Into<String>) -> Self {
        Self::NotFound(message.into())
    }

    fn status_code(&self) -> StatusCode {
        match self {
            Self::BadRequest(_) => StatusCode::BAD_REQUEST,
            Self::NotFound(_) => StatusCode::NOT_FOUND,
            Self::Conflict(_) => StatusCode::CONFLICT,
            Self::ServiceUnavailable(_) => StatusCode::SERVICE_UNAVAILABLE,
            Self::Internal(_) => StatusCode::INTERNAL_SERVER_ERROR,
        }
    }

    fn code(&self) -> &'static str {
        match self {
            Self::BadRequest(_) => "bad_request",
            Self::NotFound(_) => "not_found",
            Self::Conflict(_) => "conflict",
            Self::ServiceUnavailable(_) => "service_unavailable",
            Self::Internal(_) => "internal_error",
        }
    }
}

impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        let status = self.status_code();
        let body = Json(ErrorResponse {
            code: self.code(),
            message: self.to_string(),
        });

        (status, body).into_response()
    }
}