iOS fill in the blanks with inputs (#720)

^ALTAPPS-1016

iosHyperskillApp/iosHyperskillApp/Sources/Extensions/UIKit/UIFont+SizeOfString.swift

@@ -0,0 +1,12 @@
+import UIKit
+
+extension UIFont {
+    func sizeOfString(string: String, constrainedToWidth width: Double) -> CGSize {
+        NSString(string: string).boundingRect(
+            with: CGSize(width: width, height: Double.greatestFiniteMagnitude),
+            options: NSStringDrawingOptions.usesLineFragmentOrigin,
+            attributes: [NSAttributedString.Key.font: self],
+            context: nil
+        ).size
+    }
+}

iosHyperskillApp/iosHyperskillApp/Sources/Models/Constants/Strings.swift

@@ -203,6 +203,12 @@ enum Strings {
         }
     }
 
+    // MARK: - StepQuizFillBlanks-
+
+    enum StepQuizFillBlanks {
+        static let title = sharedStrings.step_quiz_fill_blanks_title.localized()
+    }
+
     // MARK: - StageImplement -
 
     enum StageImplement {

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuiz/ChildProtocols/StepQuizChildQuizAssembly.swift

@@ -108,6 +108,15 @@ enum StepQuizChildQuizViewFactory {
                 moduleOutput: moduleOutput
             )
             .makeModule()
+        case .fillBlanks:
+            StepQuizFillBlanksAssembly(
+                step: step,
+                dataset: dataset,
+                reply: reply,
+                provideModuleInputCallback: provideModuleInputCallback,
+                moduleOutput: moduleOutput
+            )
+            .makeModule()
         case .unsupported(let blockName):
             fatalError("Unsupported quiz = \(blockName)")
         }

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuiz/ChildProtocols/StepQuizChildQuizType.swift

@@ -13,6 +13,7 @@ enum StepQuizChildQuizType {
     case number
     case math
     case parsons
+    case fillBlanks
     case unsupported(blockName: String)
 
     var isCodeRelated: Bool {
@@ -49,6 +50,8 @@ enum StepQuizChildQuizType {
                 self = .math
             case BlockName.shared.PARSONS:
                 self = .parsons
+            case BlockName.shared.FILL_BLANKS:
+                self = .fillBlanks
             default:
                 self = .unsupported(blockName: step.block.name)
             }

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuiz/ViewData/StepQuizViewDataMapper.swift

@@ -12,13 +12,23 @@ final class StepQuizViewDataMapper {
     }
 
     func mapStepDataToViewData(step: Step, state: StepQuizFeatureStepQuizStateKs) -> StepQuizViewData {
-        let quizType: StepQuizChildQuizType = {
-            if state == .unsupported {
-                return .unsupported(blockName: step.block.name)
+        let attemptLoadedState: StepQuizFeatureStepQuizStateAttemptLoaded? = {
+            switch state {
+            case .attemptLoading(let attemptLoadingState):
+                return attemptLoadingState.oldState
+            case .attemptLoaded(let attemptLoadedState):
+                return attemptLoadedState
+            default:
+                return nil
             }
-            return StepQuizChildQuizType(step: step)
         }()
 
+        let quizType = resolveQuizType(
+            step: step,
+            state: state,
+            attemptLoadedState: attemptLoadedState
+        )
+
         if case .unsupported = quizType {
             return StepQuizViewData(
                 formattedStats: nil,
@@ -35,17 +45,6 @@ final class StepQuizViewDataMapper {
             millisSinceLastCompleted: step.millisSinceLastCompleted
         )
 
-        let attemptLoadedState: StepQuizFeatureStepQuizStateAttemptLoaded? = {
-            switch state {
-            case .attemptLoading(let attemptLoadingState):
-                return attemptLoadingState.oldState
-            case .attemptLoaded(let attemptLoadedState):
-                return attemptLoadedState
-            default:
-                return nil
-            }
-        }()
-
         let quizName: String? = {
             guard let dataset = attemptLoadedState?.attempt.dataset else {
                 return nil
@@ -91,4 +90,35 @@ final class StepQuizViewDataMapper {
             stepHasHints: stepHasHints
         )
     }
+
+    private func resolveQuizType(
+        step: Step,
+        state: StepQuizFeatureStepQuizStateKs,
+        attemptLoadedState: StepQuizFeatureStepQuizStateAttemptLoaded?
+    ) -> StepQuizChildQuizType {
+        let unsupportedChildQuizType = StepQuizChildQuizType.unsupported(blockName: step.block.name)
+
+        if state == .unsupported {
+            return unsupportedChildQuizType
+        }
+
+        let childQuizType = StepQuizChildQuizType(step: step)
+
+        if case .fillBlanks = childQuizType {
+            guard let dataset = attemptLoadedState?.attempt.dataset else {
+                return childQuizType
+            }
+
+            do {
+                try FillBlanksResolver.shared.resolve(dataset: dataset)
+            } catch {
+                #if DEBUG
+                print("StepQuizViewDataMapper: failed to resolve fill blanks quiz type, error = \(error)")
+                #endif
+                return unsupportedChildQuizType
+            }
+        }
+
+        return childQuizType
+    }
 }

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuiz/Views/StepQuizSkeletonViewFactory.swift

@@ -20,6 +20,9 @@ enum StepQuizSkeletonViewFactory {
             StepQuizStringSkeletonView()
         case .parsons:
             StepQuizParsonsSkeletonView()
+        case .fillBlanks:
+            #warning("TODO: FillBlanks skeleton view")
+            StepQuizParsonsSkeletonView()
         case .unsupported:
             SkeletonRoundedView()
                 .frame(height: 100)

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuizSubmodules/StepQuizFillBlanks/StepQuizFillBlanksAssembly.swift

@@ -0,0 +1,48 @@
+import Highlightr
+import shared
+import SwiftUI
+
+final class StepQuizFillBlanksAssembly: StepQuizChildQuizAssembly {
+    var moduleInput: StepQuizChildQuizInputProtocol?
+    weak var moduleOutput: StepQuizChildQuizOutputProtocol?
+
+    private let provideModuleInputCallback: (StepQuizChildQuizInputProtocol?) -> Void
+
+    private let step: Step
+    private let dataset: Dataset
+    private let reply: Reply?
+
+    init(
+        step: Step,
+        dataset: Dataset,
+        reply: Reply?,
+        provideModuleInputCallback: @escaping (StepQuizChildQuizInputProtocol?) -> Void,
+        moduleOutput: StepQuizChildQuizOutputProtocol?
+    ) {
+        self.step = step
+        self.dataset = dataset
+        self.reply = reply
+        self.provideModuleInputCallback = provideModuleInputCallback
+        self.moduleOutput = moduleOutput
+    }
+
+    func makeModule() -> StepQuizFillBlanksView {
+        let viewModel = StepQuizFillBlanksViewModel(
+            step: step,
+            dataset: dataset,
+            reply: reply,
+            viewDataMapper: StepQuizFillBlanksViewDataMapper(
+                fillBlanksItemMapper: FillBlanksItemMapper(),
+                highlightr: Highlightr().require(),
+                codeEditorThemeService: CodeEditorThemeService(),
+                cache: StepQuizFillBlanksViewDataMapperCache.shared
+            ),
+            provideModuleInputCallback: provideModuleInputCallback
+        )
+
+        moduleInput = viewModel
+        viewModel.moduleOutput = moduleOutput
+
+        return StepQuizFillBlanksView(viewModel: viewModel)
+    }
+}

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuizSubmodules/StepQuizFillBlanks/StepQuizFillBlanksViewModel.swift

@@ -0,0 +1,73 @@
+import Combine
+import Foundation
+import shared
+
+final class StepQuizFillBlanksViewModel: ObservableObject {
+    weak var moduleOutput: StepQuizChildQuizOutputProtocol?
+    private let provideModuleInputCallback: (StepQuizChildQuizInputProtocol?) -> Void
+
+    @Published private(set) var viewData: StepQuizFillBlanksViewData
+
+    init(
+        step: Step,
+        dataset: Dataset,
+        reply: Reply?,
+        viewDataMapper: StepQuizFillBlanksViewDataMapper,
+        provideModuleInputCallback: @escaping (StepQuizChildQuizInputProtocol?) -> Void
+    ) {
+        self.provideModuleInputCallback = provideModuleInputCallback
+        self.viewData = viewDataMapper.mapToViewData(dataset: dataset, reply: reply)
+    }
+
+    func doProvideModuleInput() {
+        provideModuleInputCallback(self)
+    }
+
+    func doInputTextUpdate(_ inputText: String, for component: StepQuizFillBlankComponent) {
+        guard let index = viewData.components.firstIndex(
+            where: { $0.id == component.id }
+        ) else {
+            return
+        }
+
+        viewData.components[index].inputText = inputText
+        outputCurrentReply()
+    }
+
+    func doSelectComponent(at indexPath: IndexPath) {
+        setIsFirstResponder(true, forComponentAt: indexPath)
+    }
+
+    func doDeselectComponent(at indexPath: IndexPath) {
+        setIsFirstResponder(false, forComponentAt: indexPath)
+    }
+
+    private func setIsFirstResponder(_ isFirstResponder: Bool, forComponentAt indexPath: IndexPath) {
+        guard viewData.components[indexPath.row].type == .input else {
+            return
+        }
+
+        viewData.components[indexPath.row].isFirstResponder = isFirstResponder
+    }
+}
+
+// MARK: - StepQuizFillBlanksViewModel: StepQuizChildQuizInputProtocol -
+
+extension StepQuizFillBlanksViewModel: StepQuizChildQuizInputProtocol {
+    func createReply() -> Reply {
+        let blanks: [String] = viewData.components.compactMap { component in
+            switch component.type {
+            case .text, .lineBreak:
+                return nil
+            case .input:
+                return component.inputText ?? ""
+            }
+        }
+
+        return Reply.companion.fillBlanks(blanks: blanks)
+    }
+
+    private func outputCurrentReply() {
+        moduleOutput?.handleChildQuizSync(reply: createReply())
+    }
+}

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuizSubmodules/StepQuizFillBlanks/ViewData/StepQuizFillBlanksViewData.swift

@@ -0,0 +1,21 @@
+import Foundation
+
+struct StepQuizFillBlanksViewData: Hashable {
+    var components: [StepQuizFillBlankComponent]
+}
+
+struct StepQuizFillBlankComponent: Hashable, Identifiable {
+    var id: Int = 0
+    let type: ComponentType
+    // text
+    var attributedText: NSAttributedString?
+    // input
+    var inputText: String?
+    var isFirstResponder = false
+
+    enum ComponentType {
+        case text
+        case input
+        case lineBreak
+    }
+}

iosHyperskillApp/iosHyperskillApp/Sources/Modules/StepQuizSubmodules/StepQuizFillBlanks/ViewData/StepQuizFillBlanksViewDataMapper.swift

@@ -0,0 +1,89 @@
+import Foundation
+import Highlightr
+import shared
+
+final class StepQuizFillBlanksViewDataMapper {
+    private let fillBlanksItemMapper: FillBlanksItemMapper
+    private let highlightr: Highlightr
+    private let codeEditorThemeService: CodeEditorThemeServiceProtocol
+    private let cache: StepQuizFillBlanksViewDataMapperCacheProtocol
+
+    init(
+        fillBlanksItemMapper: FillBlanksItemMapper,
+        highlightr: Highlightr,
+        codeEditorThemeService: CodeEditorThemeServiceProtocol,
+        cache: StepQuizFillBlanksViewDataMapperCacheProtocol
+    ) {
+        let theme = codeEditorThemeService.theme
+        highlightr.setTheme(to: theme.name)
+        highlightr.theme.setCodeFont(theme.font)
+
+        self.highlightr = highlightr
+        self.codeEditorThemeService = codeEditorThemeService
+        self.cache = cache
+        self.fillBlanksItemMapper = fillBlanksItemMapper
+    }
+
+    func mapToViewData(dataset: Dataset, reply: Reply?) -> StepQuizFillBlanksViewData {
+        guard let fillBlanksData = fillBlanksItemMapper.map(dataset: dataset, reply: reply) else {
+            return .init(components: [])
+        }
+
+        return mapFillBlanksDataToViewData(fillBlanksData)
+    }
+
+    private func mapFillBlanksDataToViewData(_ fillBlanksData: FillBlanksData) -> StepQuizFillBlanksViewData {
+        let language = fillBlanksData.language
+
+        var components = fillBlanksData.fillBlanks
+            .map { mapFillBlanksItem($0, language: language) }
+            .flatMap { $0 }
+        for index in components.indices {
+            components[index].id = index
+        }
+
+        return StepQuizFillBlanksViewData(components: components)
+    }
+
+    private func mapFillBlanksItem(
+        _ fillBlanksItem: FillBlanksItem,
+        language: String?
+    ) -> [StepQuizFillBlankComponent] {
+        switch FillBlanksItemKs(fillBlanksItem) {
+        case .text(let data):
+            var result = [StepQuizFillBlankComponent]()
+
+            if data.startsWithNewLine {
+                result.append(StepQuizFillBlankComponent(type: .lineBreak))
+            }
+
+            let hash = data.text.hashValue ^ UITraitCollection.current.userInterfaceStyle.hashValue
+
+            if let cachedCode = cache.getHighlightedCode(for: hash) {
+                result.append(StepQuizFillBlankComponent(type: .text, attributedText: cachedCode))
+            } else {
+                let unescaped = HTMLString.unescape(string: data.text)
+
+                if let highlightedCode = highlight(code: unescaped, language: language) {
+                    cache.setHighlightedCode(highlightedCode, for: hash)
+                    result.append(StepQuizFillBlankComponent(type: .text, attributedText: highlightedCode))
+                } else {
+                    let attributedText = NSAttributedString(
+                        string: unescaped,
+                        attributes: [.font: codeEditorThemeService.theme.font]
+                    )
+                    cache.setHighlightedCode(attributedText, for: hash)
+                    result.append(StepQuizFillBlankComponent(type: .text, attributedText: attributedText))
+                }
+            }
+
+            return result
+        case .input(let data):
+            return [StepQuizFillBlankComponent(type: .input, inputText: data.inputText)]
+        }
+    }
+
+    private func highlight(code: String, language: String?) -> NSAttributedString? {
+        highlightr.highlight(code, as: language, fastRender: true)
+    }
+}