//
//  FeedlySyncStreamContentsOperationTests.swift
//  AccountTests
//
//  Created by Kiel Gillard on 26/10/19.
//  Copyright © 2019 Ranchero Software, LLC. All rights reserved.
//

import XCTest
@testable import Account

class FeedlySyncStreamContentsOperationTests: XCTestCase {
	
	private var account: Account!
	private let support = FeedlyTestSupport()
	
	override func setUp() {
		super.setUp()
		account = support.makeTestAccount()
	}
	
	override func tearDown() {
		if let account = account {
			support.destroy(account)
		}
		super.tearDown()
	}
	
	func testIngestsOnePageSuccess() throws {
		let service = TestGetStreamContentsService()
		let resource = FeedlyCategoryResourceId(id: "user/1234/category/5678")
		let newerThan: Date? = Date(timeIntervalSinceReferenceDate: 0)
		let items = service.makeMockFeedlyEntryItem()
		service.mockResult = .success(FeedlyStream(id: resource.id, updated: nil, continuation: nil, items: items))
		
		let getStreamContentsExpectation = expectation(description: "Did Get Page of Stream Contents")
		getStreamContentsExpectation.expectedFulfillmentCount = 1
		
		service.getStreamContentsExpectation = getStreamContentsExpectation
		service.parameterTester = { serviceResource, continuation, serviceNewerThan, serviceUnreadOnly in
			XCTAssertEqual(serviceResource.id, resource.id)
			XCTAssertEqual(serviceNewerThan, newerThan)
			XCTAssertNil(continuation)
			XCTAssertNil(serviceUnreadOnly)
		}
		
		let syncStreamContents = FeedlySyncStreamContentsOperation(account: account, resource: resource, service: service, isPagingEnabled: true, newerThan: newerThan, log: support.log)
		
		let completionExpectation = expectation(description: "Did Finish")
		syncStreamContents.completionBlock = { _ in
			completionExpectation.fulfill()
		}
		
		MainThreadOperationQueue.shared.add(syncStreamContents)
		
		waitForExpectations(timeout: 2)
		
		let expectedArticleIds = Set(items.map { $0.id })
		let expectedArticles = try account.fetchArticles(.articleIDs(expectedArticleIds))
		XCTAssertEqual(expectedArticles.count, expectedArticleIds.count, "Did not fetch all the articles.")
	}
	
	func testIngestsOnePageFailure() {
		let service = TestGetStreamContentsService()
		let resource = FeedlyCategoryResourceId(id: "user/1234/category/5678")
		let newerThan: Date? = Date(timeIntervalSinceReferenceDate: 0)
		
		service.mockResult = .failure(URLError(.timedOut))
		
		let getStreamContentsExpectation = expectation(description: "Did Get Page of Stream Contents")
		getStreamContentsExpectation.expectedFulfillmentCount = 1
		
		service.getStreamContentsExpectation = getStreamContentsExpectation
		service.parameterTester = { serviceResource, continuation, serviceNewerThan, serviceUnreadOnly in
			XCTAssertEqual(serviceResource.id, resource.id)
			XCTAssertEqual(serviceNewerThan, newerThan)
			XCTAssertNil(continuation)
			XCTAssertNil(serviceUnreadOnly)
		}
		
		let syncStreamContents = FeedlySyncStreamContentsOperation(account: account, resource: resource, service: service, isPagingEnabled: true, newerThan: newerThan, log: support.log)
		
		let completionExpectation = expectation(description: "Did Finish")
		syncStreamContents.completionBlock = { _ in
			completionExpectation.fulfill()
		}
		
		MainThreadOperationQueue.shared.add(syncStreamContents)
		
		waitForExpectations(timeout: 2)
	}
	
	func testIngestsManyPagesSuccess() throws {
		let service = TestGetPagedStreamContentsService()
		let resource = FeedlyCategoryResourceId(id: "user/1234/category/5678")
		let newerThan: Date? = Date(timeIntervalSinceReferenceDate: 0)
		
		let continuations = (1...10).map { "\($0)" }
		service.addAtLeastOnePage(for: resource, continuations: continuations, numberOfEntriesPerPage: 1000)
		
		let getStreamContentsExpectation = expectation(description: "Did Get Page of Stream Contents")
		getStreamContentsExpectation.expectedFulfillmentCount = 1 + continuations.count
		
		var remainingContinuations = Set(continuations)
		let getStreamPageExpectation = expectation(description: "Did Request Page")
		getStreamPageExpectation.expectedFulfillmentCount = 1 + continuations.count
		
		service.getStreamContentsExpectation = getStreamContentsExpectation
		service.parameterTester = { serviceResource, continuation, serviceNewerThan, serviceUnreadOnly in
			XCTAssertEqual(serviceResource.id, resource.id)
			XCTAssertEqual(serviceNewerThan, newerThan)
			XCTAssertNil(serviceUnreadOnly)
			
			if let continuation = continuation {
				XCTAssertTrue(remainingContinuations.contains(continuation))
				remainingContinuations.remove(continuation)
			}
			
			getStreamPageExpectation.fulfill()
		}
		
		let syncStreamContents = FeedlySyncStreamContentsOperation(account: account, resource: resource, service: service, isPagingEnabled: true, newerThan: newerThan, log: support.log)
		
		let completionExpectation = expectation(description: "Did Finish")
		syncStreamContents.completionBlock = { _ in
			completionExpectation.fulfill()
		}
		
		MainThreadOperationQueue.shared.add(syncStreamContents)
		
		waitForExpectations(timeout: 30)
		
		// Find articles inserted.
		let articleIds = Set(service.pages.values.map { $0.items }.flatMap { $0 }.map { $0.id })
		let articles = try account.fetchArticles(.articleIDs(articleIds))
		XCTAssertEqual(articleIds.count, articles.count)
	}
}
