use std::num::NonZeroU16;
use std::sync::Arc;

use orchid_api_derive::Coding;

use crate::{Location, TStr};

#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Coding)]
pub struct ErrId(pub NonZeroU16);

#[derive(Clone, Debug, Coding)]
pub struct ErrLocation {
	/// Description of the relation of this location to the error. If not used,
	/// set to empty string
	pub message: Arc<String>,
	/// Location in code where the error emerged. This is usually [Location::Gen].
	pub location: Location,
}

/// Programming errors raised by extensions. At runtime these produce the
/// equivalent of a Haskell bottom. Note that runtime errors produced by
/// fallible operations should return an Orchid result and not a bottom.
/// For example, file reading produces result::err when the file doesn't exist,
/// and a bottom if the file name isn't a string.
#[derive(Clone, Debug, Coding)]
pub struct OrcError {
	/// General description of the kind of error.
	pub description: TStr,
	/// Specific information about the exact error, preferably containing concrete
	/// values.
	pub message: Arc<String>,
	/// Specific code fragments that have contributed to the emergence of the
	/// error.
	pub locations: Vec<ErrLocation>,
}

/// If this is an [`Err`] then the [`Vec`] must not be empty.
pub type OrcResult<T> = Result<T, Vec<OrcError>>;