/**
 * Copyright 2015 CANAL+ Group
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { MediaError } from "../../../../errors";
import SharedReference from "../../../../utils/reference";
/**
 * Produce estimates to know which Representation should be played.
 * @param {Object} content - The Manifest, Period and Adaptation wanted.
 * @param {Object} representationEstimator - `IRepresentationEstimator` which
 * will produce Representation estimates.
 * @param {Object} currentRepresentation - Reference emitting the
 * currently-loaded Representation.
 * @param {Object} playbackObserver - Allows to observe the current playback
 * conditions.
 * @param {Function} onFatalError - Callback called when a fatal error was
 * thrown. Once this callback is called, no estimate will be produced.
 * @param {Object} cancellationSignal - `CancellationSignal` allowing to abort
 * the production of estimates (and clean-up all linked resources).
 * @returns {Object} - Returns an object with the following properties:
 *   - `estimateRef`: Reference emitting the last estimate
 *   - `abrCallbacks`: Callbacks allowing to report back network and playback
 *     activities to improve the estimates given.
 */
export default function getRepresentationEstimate(content, representationEstimator, currentRepresentation, playbackObserver, onFatalError, cancellationSignal) {
    var manifest = content.manifest, adaptation = content.adaptation;
    var representations = new SharedReference([], cancellationSignal);
    updateRepresentationsReference();
    manifest.addEventListener("decipherabilityUpdate", updateRepresentationsReference);
    var unregisterCleanUp = cancellationSignal.register(cleanUp);
    var _a = representationEstimator(content, currentRepresentation, representations, playbackObserver, cancellationSignal), estimateRef = _a.estimates, abrCallbacks = _a.callbacks;
    return { abrCallbacks: abrCallbacks, estimateRef: estimateRef };
    function updateRepresentationsReference() {
        /** Representations for which a `RepresentationStream` can be created. */
        var newRepr = adaptation.getPlayableRepresentations();
        if (newRepr.length === 0) {
            var noRepErr = new MediaError("NO_PLAYABLE_REPRESENTATION", "No Representation in the chosen " +
                adaptation.type + " Adaptation can be played", { adaptation: adaptation });
            cleanUp();
            onFatalError(noRepErr);
            return;
        }
        var prevRepr = representations.getValue();
        if (prevRepr.length === newRepr.length) {
            if (prevRepr.every(function (r, idx) { return r.id === newRepr[idx].id; })) {
                return;
            }
        }
        representations.setValue(newRepr);
    }
    /** Clean-up all resources taken here. */
    function cleanUp() {
        manifest.removeEventListener("decipherabilityUpdate", updateRepresentationsReference);
        // check to protect against the case where it is not yet defined.
        if (typeof unregisterCleanUp !== "undefined") {
            unregisterCleanUp();
        }
    }
}
