[EPAC-743]: Display government's official tabled response for petitions

docs/architecture/use-case-catalog.md

@@ -23,6 +23,8 @@ For the Clean Architecture shape this catalog assumes, see [`docs/architecture/`
 | `MemberID` | The stable source identifier used to address a ParliamentMember across backend artifacts. |
 | `ParliamentMember` | An elected Member of Parliament with riding, party, and contact info. |
 | `Sitting` | A House sitting date with Parliament/session metadata and source URL. |
+| `EPetition` | An e-petition submitted to the House of Commons with signatures, sponsor, deadline, and optional government response. |
+| `PetitionGovernmentResponse` | The government's official written response tabled in the House of Commons for a qualified petition. |
 | `Bill` | A Parliament of Canada bill with number, title, stage, sponsor, and LEGISinfo source URL. |
 | `BillVersion` | Backend-only bill publication/version row with source links for text, PDF, and XML artifacts. |
 | `BillAmendment` | Backend-only House or committee amendment record associated with a bill and chamber stage. |
@@ -145,6 +147,7 @@ to the issue that will build the missing artifact.
 | `DivisionsFetching` | backend Go | outbound | Implemented: `backend/live-vote-poller/internal/usecase/poll_live_divisions.go`; adapter: `backend/live-vote-poller/internal/adapter/ourcommons/divisions_client.go`. | Fetch live parliamentary divisions from ourcommons.ca. |
 | `ArtifactRepository` | backend Go | outbound | Implemented: `backend/live-vote-poller/internal/usecase/poll_live_divisions.go`; adapter: `backend/live-vote-poller/internal/adapter/artifacts/repository.go`. | Check existence and persist completed vote payload artifacts. |
 | `PushDispatching` | backend Go | outbound | Implemented: `backend/live-vote-poller/internal/usecase/poll_live_divisions.go`; adapter: `backend/live-vote-poller/internal/adapter/push/dispatcher.go`. | Forward concluded division payloads to the push-notification dispatcher. |
+| `PetitionGovernmentResponseQueryPort` | iOS Swift | outbound | Implemented: `ios/epac/Domain/Ports/PetitionGovernmentResponseQueryPort.swift`; adapter: `ios/epac/Data/Repositories/BackendPetitionGovernmentResponseQueryPort.swift`. | Load petition government responses from the backend endpoint. |
 
 ## Use Cases
 
@@ -1321,6 +1324,27 @@ Current implementation:
 
 ---
 
+### LoadPetitionGovernmentResponse
+
+```
+Actor: User (iOS app, foreground)
+Goal: Surface the government's tabled written response for a petition in the detail view.
+Inputs: Petition ID.
+Outputs: PetitionGovernmentResponse value object (text, date tabled, responding minister) or nil.
+Entities / values: EPetition, PetitionGovernmentResponse.
+Ports: iOS Swift: `PetitionGovernmentResponseQueryPort`.
+Primary adapters: BackendPetitionGovernmentResponseQueryPort, PetitionDetailView.
+Current implementation:
+  ios/epac/Domain/Ports/PetitionGovernmentResponseQueryPort.swift
+  ios/epac/Domain/UseCases/LoadPetitionGovernmentResponse.swift
+  ios/epac/Data/Repositories/BackendPetitionGovernmentResponseQueryPort.swift
+  ios/epac/Views/Petitions/PetitionDetailView.swift
+```
+
+> Boundary rule: HTML/wire-format parsing of the petitions source lives only in the backend ingestion adapter; iOS consumes a typed JSON shape.
+
+---
+
 ## Boundary Check
 
 Run locally to verify inward files do not import framework types:

ios/epac/Data/Repositories/BackendPetitionGovernmentResponseQueryPort.swift

@@ -0,0 +1,94 @@
+//
+//  BackendPetitionGovernmentResponseQueryPort.swift
+//  epac
+//
+
+import Foundation
+
+@MainActor
+struct BackendPetitionGovernmentResponseQueryPort: PetitionGovernmentResponseQueryPort {
+    fileprivate enum Constants {
+        static let requestTimeout: TimeInterval = 20
+        static let successStatusLowerBound = 200
+        static let successStatusUpperBound = 300
+        static let notFoundStatusCode = 404
+        static let pathPrefix = "api/v1/petitions"
+        static let pathSuffix = "response"
+
+        static var successStatusCodes: Range<Int> {
+            successStatusLowerBound..<successStatusUpperBound
+        }
+    }
+
+    private let network: NetworkService
+    private let baseURL: URL
+    private let decoder: JSONDecoder
+
+    init(
+        network: NetworkService = .shared,
+        baseURL: URL = BackendConfig.shared.baseURL,
+        decoder: JSONDecoder = JSONDecoder()
+    ) {
+        self.network = network
+        self.baseURL = baseURL
+        self.decoder = decoder
+    }
+
+    func fetchGovernmentResponse(for petitionID: String) async throws -> PetitionGovernmentResponse? {
+        let path = "\(Constants.pathPrefix)/\(petitionID)/\(Constants.pathSuffix)"
+        let url = baseURL.appending(path: path)
+        var request = URLRequest(url: url, timeoutInterval: Constants.requestTimeout)
+        request.setValue("application/json", forHTTPHeaderField: "Accept")
+
+        let (data, response) = try await network.data(for: request)
+        guard let http = response as? HTTPURLResponse else {
+            throw URLError(.badServerResponse)
+        }
+
+        if http.statusCode == Constants.notFoundStatusCode {
+            return nil
+        }
+
+        guard Constants.successStatusCodes.contains(http.statusCode) else {
+            throw URLError(.badServerResponse)
+        }
+
+        let dto = try decoder.decode(PetitionGovernmentResponseDTO.self, from: data)
+        return dto.domain
+    }
+}
+
+private struct PetitionGovernmentResponseDTO: Decodable {
+    let text: String
+    let tabledOn: String
+    let respondingMinister: String?
+
+    enum CodingKeys: String, CodingKey {
+        case text
+        case tabledOn = "tabled_on"
+        case respondingMinister = "responding_minister"
+    }
+
+    var domain: PetitionGovernmentResponse {
+        let date = Self.parseDate(tabledOn) ?? Date()
+        return PetitionGovernmentResponse(
+            text: text,
+            tabledOn: date,
+            respondingMinister: respondingMinister
+        )
+    }
+
+    private static func parseDate(_ value: String?) -> Date? {
+        guard let value, !value.isEmpty else { return nil }
+        return dateFormatter.date(from: value)
+    }
+
+    private static let dateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.calendar = Calendar(identifier: .gregorian)
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = TimeZone(secondsFromGMT: 0)
+        formatter.dateFormat = "yyyy-MM-dd"
+        return formatter
+    }()
+}

ios/epac/Domain/Ports/PetitionGovernmentResponseQueryPort.swift

@@ -0,0 +1,11 @@
+//
+//  PetitionGovernmentResponseQueryPort.swift
+//  epac
+//
+
+import Foundation
+
+@MainActor
+protocol PetitionGovernmentResponseQueryPort: Sendable {
+    func fetchGovernmentResponse(for petitionID: String) async throws -> PetitionGovernmentResponse?
+}

ios/epac/Domain/UseCases/LoadPetitionGovernmentResponse.swift

@@ -0,0 +1,19 @@
+//
+//  LoadPetitionGovernmentResponse.swift
+//  epac
+//
+
+import Foundation
+
+@MainActor
+struct LoadPetitionGovernmentResponse {
+    private let queryPort: PetitionGovernmentResponseQueryPort
+
+    init(queryPort: PetitionGovernmentResponseQueryPort) {
+        self.queryPort = queryPort
+    }
+
+    func execute(petitionID: String) async throws -> PetitionGovernmentResponse? {
+        try await queryPort.fetchGovernmentResponse(for: petitionID)
+    }
+}

ios/epac/Model/EPetition.swift

@@ -8,6 +8,12 @@
 import Foundation
 import SwiftUI
 
+struct PetitionGovernmentResponse: Codable, Equatable {
+    let text: String
+    let tabledOn: Date
+    let respondingMinister: String?
+}
+
 struct EPetition: Identifiable {
     let id: String           // petition number, e.g. "e-7344"
     let subject: String      // category / topic (e.g. "Transportation")
@@ -17,6 +23,29 @@ struct EPetition: Identifiable {
     let deadline: Date?
     let status: PetitionStatus
     let petitionURL: URL     // official page on petitions.ourcommons.ca
+    let governmentResponse: PetitionGovernmentResponse?
+
+    init(
+        id: String,
+        subject: String,
+        keywords: [String],
+        sponsorName: String,
+        signatureCount: Int,
+        deadline: Date?,
+        status: PetitionStatus,
+        petitionURL: URL,
+        governmentResponse: PetitionGovernmentResponse? = nil
+    ) {
+        self.id = id
+        self.subject = subject
+        self.keywords = keywords
+        self.sponsorName = sponsorName
+        self.signatureCount = signatureCount
+        self.deadline = deadline
+        self.status = status
+        self.petitionURL = petitionURL
+        self.governmentResponse = governmentResponse
+    }
 }
 
 enum PetitionStatus: String {

ios/epac/Views/Petitions/PetitionDetailView.swift

@@ -20,6 +20,19 @@ private enum PetitionDetailLayout {
 
 struct PetitionDetailView: View {
     let petition: EPetition
+    private let queryPort: any PetitionGovernmentResponseQueryPort
+
+    @State private var response: PetitionGovernmentResponse?
+    @State private var isLoading = false
+    @State private var loadFailed = false
+
+    init(
+        petition: EPetition,
+        queryPort: any PetitionGovernmentResponseQueryPort = BackendPetitionGovernmentResponseQueryPort()
+    ) {
+        self.petition = petition
+        self.queryPort = queryPort
+    }
 
     var body: some View {
         List {
@@ -84,6 +97,9 @@ struct PetitionDetailView: View {
                 }
             }
 
+            // MARK: - Government Response Section
+            responseSection
+
             // MARK: - Sign link
             Section {
                 Link(
@@ -100,6 +116,101 @@ struct PetitionDetailView: View {
         .adaptiveReadingWidth()
         .navigationTitle(petition.id)
         .navigationBarTitleDisplayMode(.inline)
+        .task {
+            await loadResponse()
+        }
+    }
+
+    // MARK: - Government Response UI
+
+    @ViewBuilder
+    private var responseSection: some View {
+        if isLoading {
+            Section(NSLocalizedString("petitions.response.section", comment: "")) {
+                HStack {
+                    Spacer()
+                    ProgressView()
+                    Spacer()
+                }
+            }
+        } else if let response = response {
+            Section(NSLocalizedString("petitions.response.section", comment: "")) {
+                VStack(alignment: .leading, spacing: EpacSpacing.xs) {
+                    if let minister = response.respondingMinister, !minister.isEmpty {
+                        Text(NSLocalizedString("petitions.response.minister", comment: ""))
+                            .font(.caption2.weight(.semibold))
+                            .foregroundStyle(.secondary)
+                        Text(minister)
+                            .font(.subheadline)
+                    }
+
+                    Text(String(format: NSLocalizedString("petitions.response.tabled", comment: ""), response.tabledOn.formatted(date: .abbreviated, time: .omitted)))
+                        .font(.caption2)
+                        .foregroundStyle(.secondary)
+
+                    Divider()
+                        .padding(.vertical, EpacSpacing.xxs)
+
+                    Text(response.text)
+                        .font(.body)
+                }
+            }
+        } else if loadFailed {
+            Section(NSLocalizedString("petitions.response.section", comment: "")) {
+                HStack {
+                    Text(NSLocalizedString("petitions.error.description", comment: ""))
+                        .font(.subheadline)
+                        .foregroundStyle(.secondary)
+                    Spacer()
+                    Button(NSLocalizedString("Retry", comment: "")) {
+                        Task {
+                            await loadResponse()
+                        }
+                    }
+                    .buttonStyle(.borderless)
+                }
+            }
+        } else {
+            // Check if it qualified
+            if petition.signatureCount >= 500 {
+                Section(NSLocalizedString("petitions.response.section", comment: "")) {
+                    HStack(spacing: EpacSpacing.xs) {
+                        Image(systemName: "clock.fill")
+                            .foregroundStyle(.orange)
+                        Text(NSLocalizedString("petitions.response.awaiting", comment: ""))
+                            .font(.subheadline)
+                            .foregroundStyle(.secondary)
+                    }
+                }
+            } else if petition.status == .closed || petition.status == .certified || petition.status == .responseReceived {
+                // Closed or certified and did not reach 500 signatures: did not qualify
+                Section(NSLocalizedString("petitions.response.section", comment: "")) {
+                    HStack(spacing: EpacSpacing.xs) {
+                        Image(systemName: "xmark.circle.fill")
+                            .foregroundStyle(.secondary)
+                        Text(NSLocalizedString("petitions.response.notQualified", comment: ""))
+                            .font(.subheadline)
+                            .foregroundStyle(.secondary)
+                    }
+                }
+            }
+        }
+    }
+
+    private func loadResponse() async {
+        if let existing = petition.governmentResponse {
+            self.response = existing
+            return
+        }
+        isLoading = true
+        loadFailed = false
+        defer { isLoading = false }
+        do {
+            let useCase = LoadPetitionGovernmentResponse(queryPort: queryPort)
+            self.response = try await useCase.execute(petitionID: petition.id)
+        } catch {
+            loadFailed = true
+        }
     }
 }