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

/// Erro centralizado da aplicação.
/// Toda camada retorna `Result<T, AppError>`.
#[derive(Debug, thiserror::Error)]
pub enum AppError {
    #[error("not found")]
    NotFound,

    #[error("unauthorized")]
    Unauthorized,

    #[error("forbidden")]
    Forbidden,

    #[error("email not verified")]
    EmailNotVerified,

    #[error("validation error: {0}")]
    Validation(String),

    #[error("bad request: {0}")]
    BadRequest(String),

    #[error("conflict: {0}")]
    Conflict(String),

    #[error("unprocessable entity: {0}")]
    UnprocessableEntity(String),

    #[error("internal error")]
    Internal(#[from] anyhow::Error),
}

impl AppError {
    fn status_and_code(&self) -> (StatusCode, &'static str) {
        match self {
            Self::NotFound => (StatusCode::NOT_FOUND, "NOT_FOUND"),
            Self::Unauthorized => (StatusCode::UNAUTHORIZED, "UNAUTHORIZED"),
            Self::Forbidden => (StatusCode::FORBIDDEN, "FORBIDDEN"),
            Self::EmailNotVerified => (StatusCode::FORBIDDEN, "EMAIL_NOT_VERIFIED"),
            Self::Validation(_) => (StatusCode::BAD_REQUEST, "VALIDATION_ERROR"),
            Self::BadRequest(_) => (StatusCode::BAD_REQUEST, "BAD_REQUEST"),
            Self::Conflict(_) => (StatusCode::CONFLICT, "CONFLICT"),
            Self::UnprocessableEntity(_) => (StatusCode::UNPROCESSABLE_ENTITY, "UNPROCESSABLE_ENTITY"),
            Self::Internal(_) => (StatusCode::INTERNAL_SERVER_ERROR, "INTERNAL_ERROR"),
        }
    }
}

impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        let (status, code) = self.status_and_code();

        if status == StatusCode::INTERNAL_SERVER_ERROR {
            tracing::error!(error = %self, "Internal server error");
        }

        let body = Json(json!({
            "error": self.to_string(),
            "code": code,
        }));

        (status, body).into_response()
    }
}

impl From<sqlx::Error> for AppError {
    fn from(err: sqlx::Error) -> Self {
        match err {
            sqlx::Error::RowNotFound => Self::NotFound,
            _ => Self::Internal(err.into()),
        }
    }
}

impl From<validator::ValidationErrors> for AppError {
    fn from(err: validator::ValidationErrors) -> Self {
        Self::Validation(err.to_string())
    }
}