// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.sys2;

/// An interface for resolving a URL to a component.
///
/// This interface is implemented by components that provide support
/// for loading components with a particular URL scheme.   For example,
/// the Fuchsia package component resolver exposes a service with this
/// interface to resolve component URLs using the "fuchsia-pkg://" scheme.
///
/// To use a resolver to resolve URLs within your realm, register it
/// in your realm's manifest.  (TODO: explain in more detail)
///
/// Note: The component manager is the only intended direct client of this
/// interface.
[Discoverable]
protocol ComponentResolver {
    /// Resolves a component with the given URL.
    ///
    /// `component_url` is the unescaped URL of the component to resolve.
    ///
    /// If successful, returns information about the component
    /// that was resolved.
    ///
    /// On failure, returns a `ResolverError` error.
    Resolve(string component_url)
        -> (Component component) error ResolverError;
};

/// The possible error conditions returned by ComponentResolver.
// TODO(fxbug.dev/72139): API review of ResolverError.
enum ResolverError {
    /// An unexpected error occurred.
    INTERNAL = 1;
    /// A general IO error occurred.
    IO = 2;
    /// The component URL was malformed.
    INVALID_ARGS = 3;
    /// The repository specified in the URL is unsupported.
    NOT_SUPPORTED = 4;
    /// The component manifest was not found.
    MANIFEST_NOT_FOUND = 5;
    /// The component's package was not found.
    PACKAGE_NOT_FOUND = 6;
    /// Insufficient space on device to store component's package.
    NO_SPACE = 7;
    /// The component is temporarily unavailable.
    RESOURCE_UNAVAILABLE = 8;
};