/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface mozIExtensionStorageCallback;
interface nsIFile;
interface nsIVariant;

// Implements the operations needed to support the `StorageArea` WebExtension
// API.
[scriptable, uuid(d8eb3ff1-9b4b-435a-99ca-5b8cbaba2420)]
interface mozIExtensionStorageArea : nsISupports {
    // These constants are exposed by the rust crate, but it's not worth the
    // effort of jumping through the hoops to get them exposed to the JS
    // code in a sane way - so we just duplicate them here. We should consider a
    // test that checks they match the rust code.
    // This interface is agnostic WRT the area, so we prefix the constants with
    // the area - it's the consumer of this interface which knows what to use.
    const unsigned long SYNC_QUOTA_BYTES = 102400;
    const unsigned long SYNC_QUOTA_BYTES_PER_ITEM = 8192;
    const unsigned long SYNC_MAX_ITEMS = 512;

    // Sets one or more key-value pairs specified in `json` for the
    // `extensionId`. If the `callback` implements
    // `mozIExtensionStorageListener`, its `onChange`
    // method will be called with the new and old values.
    void set(in AUTF8String extensionId,
             in AUTF8String json,
             in mozIExtensionStorageCallback callback);

    // Returns the value for the `key` in the storage area for the
    // `extensionId`. `key` must be a JSON string containing either `null`,
    // an array of string key names, a single string key name, or an object
    // where the properties are the key names, and the values are the defaults
    // if the key name doesn't exist in the storage area.
    //
    // If `get()` fails due to the quota being exceeded, the exception will
    // have a result code of NS_ERROR_DOM_QUOTA_EXCEEDED_ERR (==0x80530016)
    void get(in AUTF8String extensionId,
             in AUTF8String key,
             in mozIExtensionStorageCallback callback);

    // Removes the `key` from the storage area for the `extensionId`. If `key`
    // exists and the `callback` implements `mozIExtensionStorageListener`, its
    // `onChanged` method will be called with the removed key-value pair.
    void remove(in AUTF8String extensionId,
                in AUTF8String key,
                in mozIExtensionStorageCallback callback);

    // Removes all keys from the storage area for the `extensionId`. If
    // `callback` implements `mozIExtensionStorageListener`, its `onChange`
    // method will be called with all removed key-value pairs.
    void clear(in AUTF8String extensionId,
               in mozIExtensionStorageCallback callback);

    // Gets the number of bytes in use for the specified keys.
    void getBytesInUse(in AUTF8String extensionId,
                       in AUTF8String keys,
                       in mozIExtensionStorageCallback callback);

    // Gets and clears the information about the migration from the kinto
    // database into the rust one. As "and clears" indicates, this will
    // only produce a non-empty the first time it's called after a
    // migration (which, hopefully, should only happen once).
    void takeMigrationInfo(in mozIExtensionStorageCallback callback);
};

// Implements additional methods for setting up and tearing down the underlying
// database connection for a storage area. This is a separate interface because
// these methods are not part of the `StorageArea` API, and have restrictions on
// when they can be called.
[scriptable, uuid(2b008295-1bcc-4610-84f1-ad4cab2fa9ee)]
interface mozIConfigurableExtensionStorageArea : nsISupports {
    // Sets up the storage area. An area can only be configured once; calling
    // `configure` multiple times will throw. `configure` must also be called
    // before any of the `mozIExtensionStorageArea` methods, or they'll fail
    // with errors.
    // The second param is the path to the kinto database file from which we
    // should migrate. This should always be specified even when there's a
    // chance the file doesn't exist.
    void configure(in nsIFile databaseFile, in nsIFile kintoFile);

    // Tears down the storage area, closing the backing database connection.
    // This is called automatically when Firefox shuts down. Once a storage area
    // has been shut down, all its methods will fail with errors. If `configure`
    // hasn't been called for this area yet, `teardown` is a no-op.
    void teardown(in mozIExtensionStorageCallback callback);
};

// Implements additional methods for syncing a storage area. This is a separate
// interface because these methods are not part of the `StorageArea` API, and
// have restrictions on when they can be called.
[scriptable, uuid(6dac82c9-1d8a-4893-8c0f-6e626aef802c)]
interface mozISyncedExtensionStorageArea : nsISupports {
    // If a sync is in progress, this method fetches pending change
    // notifications for all extensions whose storage areas were updated.
    // `callback` should implement `mozIExtensionStorageListener` to forward
    // the records to `storage.onChanged` listeners. This method should only
    // be called by Sync, after `mozIBridgedSyncEngine.apply` and before
    // `syncFinished`. It fetches nothing if called at any other time.
    void fetchPendingSyncChanges(in mozIExtensionStorageCallback callback);
};

// A listener for storage area notifications.
[scriptable, uuid(8cb3c7e4-d0ca-4353-bccd-2673b4e11510)]
interface mozIExtensionStorageListener : nsISupports {
    // Notifies that an operation has data to pass to `storage.onChanged`
    // listeners for the given `extensionId`. `json` is a JSON array of listener
    // infos. If an operation affects multiple extensions, this method will be
    // called multiple times, once per extension.
    void onChanged(in AUTF8String extensionId, in AUTF8String json);
};

// A generic callback for a storage operation. Either `handleSuccess` or
// `handleError` is guaranteed to be called once.
[scriptable, uuid(870dca40-6602-4748-8493-c4253eb7f322)]
interface mozIExtensionStorageCallback : nsISupports {
    // Called when the operation completes. Operations that return a result,
    // like `get`, will pass a `UTF8String` variant. Those that don't return
    // anything, like `set` or `remove`, will pass a `null` variant.
    void handleSuccess(in nsIVariant result);

    // Called when the operation fails.
    void handleError(in nsresult code, in AUTF8String message);
};