//
// Copyright 2018 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//

import XCTest
@testable import SignalServiceKit

class MessageSenderJobQueueTest: SSKBaseTest {
    private var fakeMessageSender: FakeMessageSender {
        SSKEnvironment.shared.messageSenderRef as! FakeMessageSender
    }

    func test_messageIsSent() async throws {
        let jobQueue = MessageSenderJobQueue(appReadiness: AppReadinessMock())
        let (message, promise) = try await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
            let message = OutgoingMessageFactory().create(transaction: tx)
            let jobRecord = try MessageSenderJobRecord(
                persistedMessage: .init(
                    rowId: message.sqliteRowId!,
                    message: message,
                ),
                isHighPriority: false,
                transaction: tx,
            )
            let preparedMessage = PreparedOutgoingMessage.restore(
                from: jobRecord,
                tx: tx,
            )!
            let promise = jobQueue.add(.promise, message: preparedMessage, transaction: tx)
            return (message, promise)
        }
        fakeMessageSender.stubbedFailingErrors = [nil]
        jobQueue.setUp()
        try await promise.awaitable()
        XCTAssertEqual(fakeMessageSender.sentMessages.map { $0.uniqueId }, [message.uniqueId])
    }

    func test_respectsQueueOrder() async throws {
        let messageCount = 3
        let jobQueue = MessageSenderJobQueue(appReadiness: AppReadinessMock())
        let (messages, promises) = try await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
            let contactThread = ContactThreadFactory().create(transaction: tx)
            let outgoingMessageFactory = OutgoingMessageFactory()
            outgoingMessageFactory.threadCreator = { _ in contactThread }
            let messages = (1...messageCount).map { _ in outgoingMessageFactory.create(transaction: tx) }
            let promises = try messages.map {
                let jobRecord = try MessageSenderJobRecord(
                    persistedMessage: .init(
                        rowId: $0.sqliteRowId!,
                        message: $0,
                    ),
                    isHighPriority: false,
                    transaction: tx,
                )
                let preparedMessage = PreparedOutgoingMessage.restore(
                    from: jobRecord,
                    tx: tx,
                )!
                return jobQueue.add(.promise, message: preparedMessage, transaction: tx)
            }
            return (messages, promises)
        }
        fakeMessageSender.stubbedFailingErrors = Array(repeating: nil, count: messageCount)
        jobQueue.setUp()
        for promise in promises {
            try await promise.awaitable()
        }
        XCTAssertEqual(fakeMessageSender.sentMessages.map { $0.uniqueId }, messages.map { $0.uniqueId })
    }

    func test_sendingInvisibleMessage() async throws {
        let jobQueue = MessageSenderJobQueue(appReadiness: AppReadinessMock())
        fakeMessageSender.stubbedFailingErrors = [nil]
        jobQueue.setUp()
        let (message, promise) = await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
            let message = OutgoingMessageFactory().buildDeliveryReceipt(transaction: tx)
            let preparedMessage = PreparedOutgoingMessage.preprepared(
                transientMessageWithoutAttachments: message,
            )
            let promise = jobQueue.add(
                .promise,
                message: preparedMessage,
                limitToCurrentProcessLifetime: true,
                transaction: tx,
            )
            return (message, promise)
        }
        try await promise.awaitable()
        XCTAssertEqual(fakeMessageSender.sentMessages.map { $0.uniqueId }, [message.uniqueId])
    }

    func test_retryableFailure() async throws {
        let jobQueue = MessageSenderJobQueue(appReadiness: AppReadinessMock())

        let (jobRecord, message, promise) = try await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
            let message = OutgoingMessageFactory().create(transaction: tx)
            let jobRecord = try MessageSenderJobRecord(
                persistedMessage: .init(
                    rowId: message.sqliteRowId!,
                    message: message,
                ),
                isHighPriority: false,
                transaction: tx,
            )
            let preparedMessage = PreparedOutgoingMessage.restore(
                from: jobRecord,
                tx: tx,
            )!
            let promise = jobQueue.add(.promise, message: preparedMessage, transaction: tx)
            return (jobRecord, message, promise)
        }

        // simulate permanent failure (via `maxRetries` retryable failures)
        let retryCount: Int = 110 // Matches MessageSenderOperation
        fakeMessageSender.stubbedFailingErrors = Array(repeating: URLError(.timedOut), count: retryCount + 1)
        jobQueue.setUp()

        do {
            let retryTriggerTask = Task.detached {
                while true {
                    try Task.checkCancellation()
                    try await Task.sleep(nanoseconds: 500 * NSEC_PER_USEC)
                    jobQueue.becameReachable()
                }
            }
            defer {
                retryTriggerTask.cancel()
            }
            try await promise.awaitable()
            XCTFail("Must throw an error.")
        } catch {}

        self.read { transaction in
            XCTAssertNil(jobRecord.fetchLatest(transaction: transaction))
        }

        XCTAssertEqual(fakeMessageSender.stubbedFailingErrors.count, 0)
        XCTAssertEqual(
            fakeMessageSender.sentMessages.map { $0.uniqueId },
            Array(repeating: message.uniqueId, count: retryCount + 1),
        )
    }

    func test_permanentFailure() async throws {
        let jobQueue = MessageSenderJobQueue(appReadiness: AppReadinessMock())

        let (jobRecord, message, promise) = try await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
            let message = OutgoingMessageFactory().create(transaction: tx)
            let jobRecord = try MessageSenderJobRecord(
                persistedMessage: .init(
                    rowId: message.sqliteRowId!,
                    message: message,
                ),
                isHighPriority: false,
                transaction: tx,
            )
            let preparedMessage = PreparedOutgoingMessage.restore(
                from: jobRecord,
                tx: tx,
            )!
            let promise = jobQueue.add(.promise, message: preparedMessage, transaction: tx)
            return (jobRecord, message, promise)
        }

        // simulate permanent failure
        let error = OWSGenericError("")
        fakeMessageSender.stubbedFailingErrors = [error]
        jobQueue.setUp()

        do {
            try await promise.awaitable()
            XCTFail("Must throw an error.")
        } catch {}

        self.read { tx in
            XCTAssertNil(jobRecord.fetchLatest(transaction: tx))
        }
        XCTAssertEqual(fakeMessageSender.sentMessages.map { $0.uniqueId }, [message.uniqueId])
    }
}

private extension MessageSenderJobRecord {
    func fetchLatest(transaction: DBReadTransaction) -> Self? {
        return Self.anyFetch(uniqueId: uniqueId, transaction: transaction)
    }
}