// addCharmViaAPI calls the appropriate client API calls to add the
// given charm URL to state. For non-public charm URLs, this function also
// handles the macaroon authorization process using the given csClient.
// The resulting charm URL of the added charm is displayed on stdout.
func addCharmViaAPI(client *api.Client, ctx *cmd.Context, curl *charm.URL, repo charmrepo.Interface, csclient *csClient) (*charm.URL, error) {
	switch curl.Schema {
	case "local":
		ch, err := repo.Get(curl)
		if err != nil {
			return nil, err
		}
		stateCurl, err := client.AddLocalCharm(curl, ch)
		if err != nil {
			return nil, err
		}
		curl = stateCurl
	case "cs":
		if err := client.AddCharm(curl); err != nil {
			if !params.IsCodeUnauthorized(err) {
				return nil, errors.Mask(err)
			}
			m, err := csclient.authorize(curl)
			if err != nil {
				return nil, errors.Mask(err)
			}
			if err := client.AddCharmWithAuthorization(curl, m); err != nil {
				return nil, errors.Mask(err)
			}
		}
	default:
		return nil, fmt.Errorf("unsupported charm URL schema: %q", curl.Schema)
	}
	ctx.Infof("Added charm %q to the environment.", curl)
	return curl, nil
}

// PutCharm uploads the given charm to provider storage, and adds a
// state.Charm to the state.  The charm is not uploaded if a charm with
// the same URL already exists in the state.
// If bumpRevision is true, the charm must be a local directory,
// and the revision number will be incremented before pushing.
func PutCharm(st *state.State, curl *charm.URL, repo charmrepo.Interface, bumpRevision bool) (*state.Charm, error) {
	if curl.Revision == -1 {
		rev, err := charmrepo.Latest(repo, curl)
		if err != nil {
			return nil, fmt.Errorf("cannot get latest charm revision: %v", err)
		}
		curl = curl.WithRevision(rev)
	}
	ch, err := repo.Get(curl)
	if err != nil {
		return nil, fmt.Errorf("cannot get charm: %v", err)
	}
	if bumpRevision {
		chd, ok := ch.(*charm.CharmDir)
		if !ok {
			return nil, fmt.Errorf("cannot increment revision of charm %q: not a directory", curl)
		}
		if err = chd.SetDiskRevision(chd.Revision() + 1); err != nil {
			return nil, fmt.Errorf("cannot increment revision of charm %q: %v", curl, err)
		}
		curl = curl.WithRevision(chd.Revision())
	}
	if sch, err := st.Charm(curl); err == nil {
		return sch, nil
	}
	return addCharm(st, curl, ch)
}

func resolveCharm(ref *charm.Reference, repo charmrepo.Interface) (*charm.URL, error) {
	if ref.Schema != "cs" {
		return nil, fmt.Errorf("only charm store charm references are supported, with cs: schema")
	}

	// Resolve the charm location with the repository.
	curl, err := repo.Resolve(ref)
	if err != nil {
		return nil, err
	}
	return curl.WithRevision(ref.Revision), nil
}