use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
    Json,
};
use serde_json::json;
use thiserror::Error;

#[derive(Debug, Error)]
pub enum AppError {
    #[error("not found: {0}")]
    NotFound(String),
    #[error("invalid request: {0}")]
    BadRequest(String),
    #[error("conflict: {0}")]
    Conflict(String),
    #[error("unauthorized")]
    Unauthorized,
    #[error("device communication failed: {0}")]
    Device(String),
    #[error("external dependency failed: {0}")]
    Dependency(String),
    #[error(transparent)]
    Internal(#[from] anyhow::Error),
}

impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        let (status, message) = match &self {
            Self::NotFound(v) => (StatusCode::NOT_FOUND, v.clone()),
            Self::BadRequest(v) => (StatusCode::BAD_REQUEST, v.clone()),
            Self::Conflict(v) => (StatusCode::CONFLICT, v.clone()),
            Self::Unauthorized => (StatusCode::UNAUTHORIZED, "unauthorized".into()),
            Self::Device(v) => (StatusCode::BAD_GATEWAY, v.clone()),
            // Cloud/provider outages are an expected external-dependency failure, not a
            // controller-side 502. Keep Local's historical Device -> 502 mapping unchanged.
            Self::Dependency(v) => (StatusCode::FAILED_DEPENDENCY, v.clone()),
            Self::Internal(v) => {
                tracing::error!(error = ?v, "internal error");
                (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    "internal server error".into(),
                )
            }
        };
        (status, Json(json!({"error": message}))).into_response()
    }
}

impl From<rusqlite::Error> for AppError {
    fn from(value: rusqlite::Error) -> Self {
        Self::Internal(value.into())
    }
}

impl From<serde_json::Error> for AppError {
    fn from(value: serde_json::Error) -> Self {
        Self::Internal(value.into())
    }
}