import { Deferred } from '@firebase/util';

/**
 * Component for service name T, e.g. `auth`, `auth-internal`
 */
class Component {
    /**
     *
     * @param name The public service name, e.g. app, auth, firestore, database
     * @param instanceFactory Service factory responsible for creating the public interface
     * @param type whether the service provided by the component is public or private
     */
    constructor(name, instanceFactory, type) {
        this.name = name;
        this.instanceFactory = instanceFactory;
        this.type = type;
        this.multipleInstances = false;
        /**
         * Properties to be added to the service namespace
         */
        this.serviceProps = {};
        this.instantiationMode = "LAZY" /* LAZY */;
    }
    setInstantiationMode(mode) {
        this.instantiationMode = mode;
        return this;
    }
    setMultipleInstances(multipleInstances) {
        this.multipleInstances = multipleInstances;
        return this;
    }
    setServiceProps(props) {
        this.serviceProps = props;
        return this;
    }
}

/**
 * @license
 * Copyright 2019 Google LLC
 *
 * 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.
 */
const DEFAULT_ENTRY_NAME = '[DEFAULT]';

/**
 * @license
 * Copyright 2019 Google LLC
 *
 * 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.
 */
/**
 * Provider for instance for service name T, e.g. 'auth', 'auth-internal'
 * NameServiceMapping[T] is an alias for the type of the instance
 */
class Provider {
    constructor(name, container) {
        this.name = name;
        this.container = container;
        this.component = null;
        this.instances = new Map();
        this.instancesDeferred = new Map();
    }
    /**
     * @param identifier A provider can provide mulitple instances of a service
     * if this.component.multipleInstances is true.
     */
    get(identifier = DEFAULT_ENTRY_NAME) {
        // if multipleInstances is not supported, use the default name
        const normalizedIdentifier = this.normalizeInstanceIdentifier(identifier);
        if (!this.instancesDeferred.has(normalizedIdentifier)) {
            const deferred = new Deferred();
            this.instancesDeferred.set(normalizedIdentifier, deferred);
            // If the service instance is available, resolve the promise with it immediately
            try {
                const instance = this.getOrInitializeService(normalizedIdentifier);
                if (instance) {
                    deferred.resolve(instance);
                }
            }
            catch (e) {
                // when the instance factory throws an exception during get(), it should not cause
                // a fatal error. We just return the unresolved promise in this case.
            }
        }
        return this.instancesDeferred.get(normalizedIdentifier).promise;
    }
    getImmediate(options) {
        const { identifier, optional } = Object.assign({ identifier: DEFAULT_ENTRY_NAME, optional: false }, options);
        // if multipleInstances is not supported, use the default name
        const normalizedIdentifier = this.normalizeInstanceIdentifier(identifier);
        try {
            const instance = this.getOrInitializeService(normalizedIdentifier);
            if (!instance) {
                if (optional) {
                    return null;
                }
                throw Error(`Service ${this.name} is not available`);
            }
            return instance;
        }
        catch (e) {
            if (optional) {
                return null;
            }
            else {
                throw e;
            }
        }
    }
    getComponent() {
        return this.component;
    }
    setComponent(component) {
        if (component.name !== this.name) {
            throw Error(`Mismatching Component ${component.name} for Provider ${this.name}.`);
        }
        if (this.component) {
            throw Error(`Component for ${this.name} has already been provided`);
        }
        this.component = component;
        // if the service is eager, initialize the default instance
        if (isComponentEager(component)) {
            try {
                this.getOrInitializeService(DEFAULT_ENTRY_NAME);
            }
            catch (e) {
                // when the instance factory for an eager Component throws an exception during the eager
                // initialization, it should not cause a fatal error.
                // TODO: Investigate if we need to make it configurable, because some component may want to cause
                // a fatal error in this case?
            }
        }
        // Create service instances for the pending promises and resolve them
        // NOTE: if this.multipleInstances is false, only the default instance will be created
        // and all promises with resolve with it regardless of the identifier.
        for (const [instanceIdentifier, instanceDeferred] of this.instancesDeferred.entries()) {
            const normalizedIdentifier = this.normalizeInstanceIdentifier(instanceIdentifier);
            try {
                // `getOrInitializeService()` should always return a valid instance since a component is guaranteed. use ! to make typescript happy.
                const instance = this.getOrInitializeService(normalizedIdentifier);
                instanceDeferred.resolve(instance);
            }
            catch (e) {
                // when the instance factory throws an exception, it should not cause
                // a fatal error. We just leave the promise unresolved.
            }
        }
    }
    clearInstance(identifier = DEFAULT_ENTRY_NAME) {
        this.instancesDeferred.delete(identifier);
        this.instances.delete(identifier);
    }
    // app.delete() will call this method on every provider to delete the services
    // TODO: should we mark the provider as deleted?
    async delete() {
        const services = Array.from(this.instances.values());
        await Promise.all(services
            .filter(service => 'INTERNAL' in service)
            // eslint-disable-next-line @typescript-eslint/no-explicit-any
            .map(service => service.INTERNAL.delete()));
    }
    isComponentSet() {
        return this.component != null;
    }
    getOrInitializeService(identifier) {
        let instance = this.instances.get(identifier);
        if (!instance && this.component) {
            instance = this.component.instanceFactory(this.container, normalizeIdentifierForFactory(identifier));
            this.instances.set(identifier, instance);
        }
        return instance || null;
    }
    normalizeInstanceIdentifier(identifier) {
        if (this.component) {
            return this.component.multipleInstances ? identifier : DEFAULT_ENTRY_NAME;
        }
        else {
            return identifier; // assume multiple instances are supported before the component is provided.
        }
    }
}
// undefined should be passed to the service factory for the default instance
function normalizeIdentifierForFactory(identifier) {
    return identifier === DEFAULT_ENTRY_NAME ? undefined : identifier;
}
function isComponentEager(component) {
    return component.instantiationMode === "EAGER" /* EAGER */;
}

/**
 * @license
 * Copyright 2019 Google LLC
 *
 * 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.
 */
/**
 * ComponentContainer that provides Providers for service name T, e.g. `auth`, `auth-internal`
 */
class ComponentContainer {
    constructor(name) {
        this.name = name;
        this.providers = new Map();
    }
    /**
     *
     * @param component Component being added
     * @param overwrite When a component with the same name has already been registered,
     * if overwrite is true: overwrite the existing component with the new component and create a new
     * provider with the new component. It can be useful in tests where you want to use different mocks
     * for different tests.
     * if overwrite is false: throw an exception
     */
    addComponent(component) {
        const provider = this.getProvider(component.name);
        if (provider.isComponentSet()) {
            throw new Error(`Component ${component.name} has already been registered with ${this.name}`);
        }
        provider.setComponent(component);
    }
    addOrOverwriteComponent(component) {
        const provider = this.getProvider(component.name);
        if (provider.isComponentSet()) {
            // delete the existing provider from the container, so we can register the new component
            this.providers.delete(component.name);
        }
        this.addComponent(component);
    }
    /**
     * getProvider provides a type safe interface where it can only be called with a field name
     * present in NameServiceMapping interface.
     *
     * Firebase SDKs providing services should extend NameServiceMapping interface to register
     * themselves.
     */
    getProvider(name) {
        if (this.providers.has(name)) {
            return this.providers.get(name);
        }
        // create a Provider for a service that hasn't registered with Firebase
        const provider = new Provider(name, this);
        this.providers.set(name, provider);
        return provider;
    }
    getProviders() {
        return Array.from(this.providers.values());
    }
}

export { Component, ComponentContainer, Provider };
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