/*
 Copyright 2009-2016 Urban Airship Inc. All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

 1. Redistributions of source code must retain the above copyright notice, this
 list of conditions and the following disclaimer.

 2. Redistributions in binary form must reproduce the above copyright notice,
 this list of conditions and the following disclaimer in the documentation
 and/or other materials provided with the distribution.

 THIS SOFTWARE IS PROVIDED BY THE URBAN AIRSHIP INC ``AS IS'' AND ANY EXPRESS OR
 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 EVENT SHALL URBAN AIRSHIP INC OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import <Foundation/Foundation.h>

#import "UAUser.h"
#import "UADisposable.h"

NS_ASSUME_NONNULL_BEGIN

/**
 * A completion block for message list operations.
 */
typedef void (^UAInboxMessageListCallbackBlock)(void);

/**
 * NSNotification posted when the message list is about to update.
 *
 * Note: this notification is posted regardless of the type of update (retrieval, batch).
 */
extern NSString * const UAInboxMessageListWillUpdateNotification;

/**
 * NSNotification posted when the message list is finished updating.
 *
 * Note: this notification is posted regardless of the type of update (retrieval, batch)
 * and regardless of the success/failure of the underlying operation.
 */
extern NSString * const UAInboxMessageListUpdatedNotification;

@class UAInboxMessage;

/**
 * The primary interface to the contents of the inbox.
 * Use this class to asychronously retrieve messges from the server,
 * delete or mark messages as read, retrieve individual messages from the
 * list.
 */
@interface UAInboxMessageList : NSObject


/**
 * Marks messages read. They will be marked locally as read and synced with
 * Urban Airship on the next message retrieval.
 *
 * @param messages The array of messages to be marked read.
 * @param completionHandler An optional completion handler.
 * @return A UADisposable token which can be used to cancel callback execution,
 * or nil if the array of messages to mark read is empty.
 */
- (nullable UADisposable *)markMessagesRead:(NSArray *)messages
                          completionHandler:(nullable UAInboxMessageListCallbackBlock)completionHandler;

/**
 * Marks messages deleted. They will be marked locally as deleted and synced with
 * Urban Airship on the next message retrieval.
 *
 * @param messages The array of messages to be marked deleted.
 * @param completionHandler An optional completion handler.
 * @return A UADisposable token which can be used to cancel callback execution,
 * or nil if the array of messages to mark deleted is empty.
 */
- (nullable UADisposable *)markMessagesDeleted:(NSArray *)messages
                             completionHandler:(nullable UAInboxMessageListCallbackBlock)completionHandler;

/**
 * Fetch new messages from the server. If the associated user has not yet
 * been created, this will be a no-op.
 *
 * @param successBlock A block to be executed if message retrieval succeeds.
 * @param failureBlock A block to be executed if message retrieval fails.
 * @return A UADisposable token which can be used to cancel callback execution.
 * This value will be nil if the associated user has not yet been created.
 */
- (nullable UADisposable *)retrieveMessageListWithSuccessBlock:(nullable UAInboxMessageListCallbackBlock)successBlock
                                              withFailureBlock:(nullable UAInboxMessageListCallbackBlock)failureBlock;

/**
 * Returns the list of messages on disk as an NSArray, filtered by the supplied predicate.
 * @param predicate The predicate to use as a filter over messages.
 */
- (NSArray<UAInboxMessage *> *)messagesFilteredUsingPredicate:(NSPredicate *)predicate;

/**
 * Returns the number of messages currently in the inbox.
 * @return The message count as an integer.
 */
- (NSUInteger)messageCount;

/**
 * Returns the message associated with a particular URL.
 * @param url The URL of the message
 * @return The associated UAInboxMessage object or nil if a message was
 * unable to be found.
 */
- (nullable UAInboxMessage *)messageForBodyURL:(NSURL *)url;

/**
 * Returns the message associated with a particular ID.
 * @param messageID The message ID as an NSString.
 * @return The associated UAInboxMessage object or nil if a message was
 * unable to be found.
 */
- (nullable UAInboxMessage *)messageForID:(NSString *)messageID;

/**
 * The list of messages on disk as an NSArray.
 */
@property (nonatomic, readonly, strong) NSArray<UAInboxMessage *> *messages;

/**
 * The number of messages that are currently unread or -1
 * if the message list is not loaded.
 */
@property (assign) NSInteger unreadCount;

/**
 * YES if retrieving message list is currently in progress.
 * NO otherwise.
 */
@property (readonly) BOOL isRetrieving;

/**
 * YES if message batching is currently in progress.
 * NO otherwise.
 */
@property (readonly) BOOL isBatchUpdating;

@end

NS_ASSUME_NONNULL_END