//
// Copyright 2026 Novaloop AG
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
// Please see LICENSE files in the repository root for full details.
//

import Compound
import SwiftUI

struct HealthChatMemberDirectoryScreen: View {
    @Bindable var context: HealthChatMemberDirectoryScreenViewModel.Context
    
    var body: some View {
        content
            .navigationTitle(HealthChatL10n.screenMemberDirectoryTitle)
            .navigationBarTitleDisplayMode(.inline)
            .background(Color.compound.bgCanvasDefault.ignoresSafeArea())
            .searchController(query: $context.searchQuery,
                              placeholder: HealthChatL10n.screenMemberDirectorySearchPlaceholder)
            .toolbar { toolbar }
            .alert(item: $context.alertInfo)
    }
    
    @ToolbarContentBuilder
    private var toolbar: some ToolbarContent {
        ToolbarItem(placement: .primaryAction) {
            Button {
                context.send(viewAction: .editProfile)
            } label: {
                CompoundIcon(\.edit)
            }
            .accessibilityLabel(L10n.screenEditProfileTitle)
        }
        
        if context.viewState.isApproved {
            ToolbarItem(placement: .primaryAction) {
                Button {
                    context.send(viewAction: .invite)
                } label: {
                    CompoundIcon(\.userAdd)
                }
                .accessibilityLabel(HealthChatL10n.screenInviteMemberTitle)
            }
        }
    }
    
    // MARK: - Private
    
    @ViewBuilder
    private var content: some View {
        switch context.viewState.content {
        case .loading:
            ProgressView()
                .frame(maxWidth: .infinity, maxHeight: .infinity)
        case .pendingApproval(let message):
            statusView(icon: \.time, message: message)
        case .failure:
            failureView
        case .members(let members) where members.isEmpty:
            statusView(icon: \.search, message: L10n.commonNoResults)
        case .members(let members):
            memberList(members)
        }
    }
    
    private func memberList(_ members: [HealthChatMember]) -> some View {
        Form {
            if let completenessMessage = context.viewState.completenessMessage {
                Section {
                    ListRow(label: .default(title: completenessMessage, icon: \.info),
                            kind: .button {
                                context.send(viewAction: .editProfile)
                            })
                }
            }
            
            Section {
                ForEach(members) { member in
                    HealthChatMemberListRow(member: member, mediaProvider: context.mediaProvider) {
                        context.send(viewAction: .selectMember(member))
                    } startChatAction: {
                        context.send(viewAction: .startChat(member))
                    }
                }
            }
        }
        .compoundList()
    }
    
    private var failureView: some View {
        VStack(spacing: 16) {
            statusContent(icon: \.error, message: L10n.commonSomethingWentWrong)
            
            Button(L10n.actionRetry) {
                context.send(viewAction: .retry)
            }
            .buttonStyle(.compound(.secondary, size: .medium))
            .fixedSize()
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .padding(16)
    }
    
    private func statusView(icon: KeyPath<CompoundIcons, Image>, message: String) -> some View {
        statusContent(icon: icon, message: message)
            .frame(maxWidth: .infinity, maxHeight: .infinity)
            .padding(16)
    }
    
    private func statusContent(icon: KeyPath<CompoundIcons, Image>, message: String) -> some View {
        VStack(spacing: 16) {
            BigIcon(icon: icon)
            
            Text(message)
                .font(.compound.bodyLG)
                .foregroundColor(.compound.textSecondary)
                .multilineTextAlignment(.center)
        }
    }
}

// MARK: - Previews

struct HealthChatMemberDirectoryScreen_Previews: PreviewProvider, TestablePreview {
    static let loadedViewModel = makeViewModel(configuration: .members)
    static let incompleteProfileViewModel = makeViewModel(configuration: .incompleteProfile)
    static let pendingViewModel = makeViewModel(configuration: .pendingApproval)
    static let failureViewModel = makeViewModel(configuration: .failure)
    
    static var previews: some View {
        ElementNavigationStack {
            HealthChatMemberDirectoryScreen(context: loadedViewModel.context)
        }
        .snapshotPreferences(expect: loadedViewModel.context.observe(\.viewState.content).map { $0 != .loading })
        .previewDisplayName("Members")
        
        ElementNavigationStack {
            HealthChatMemberDirectoryScreen(context: incompleteProfileViewModel.context)
        }
        .snapshotPreferences(expect: incompleteProfileViewModel.context.observe(\.viewState.completenessMessage).map { $0 != nil })
        .previewDisplayName("Incomplete profile")
        
        ElementNavigationStack {
            HealthChatMemberDirectoryScreen(context: pendingViewModel.context)
        }
        .snapshotPreferences(expect: pendingViewModel.context.observe(\.viewState.content).map { $0 != .loading })
        .previewDisplayName("Pending approval")
        
        ElementNavigationStack {
            HealthChatMemberDirectoryScreen(context: failureViewModel.context)
        }
        .snapshotPreferences(expect: failureViewModel.context.observe(\.viewState.content).map { $0 != .loading })
        .previewDisplayName("Failure")
    }
    
    enum PreviewConfiguration {
        case members
        case incompleteProfile
        case pendingApproval
        case failure
    }
    
    static func makeViewModel(configuration: PreviewConfiguration) -> HealthChatMemberDirectoryScreenViewModel {
        let apiService = HealthChatAPIServiceMock()
        
        switch configuration {
        case .members:
            let members = try? JSONDecoder().decode([HealthChatMember].self, from: Data("""
            [
                {
                    "userId": "@alice:healthchat.ch",
                    "displayName": "Dr. Alice Alpha",
                    "specialty": "Physiotherapie",
                    "practiceName": "Praxis Alpha",
                    "businessCity": "Zürich"
                },
                {
                    "userId": "@bob:healthchat.ch",
                    "displayName": "Bob Beta",
                    "specialty": "Ergotherapie",
                    "businessCity": "Basel"
                },
                {
                    "userId": "@carol:healthchat.ch",
                    "displayName": "Dr. Carol Gamma"
                }
            ]
            """.utf8))
            apiService.membersSearchQueryReturnValue = .success(.init(users: members ?? [],
                                                                      isApproved: true,
                                                                      pendingMessage: nil))
            apiService.profileCompletenessReturnValue = try? .success(JSONDecoder().decode(HealthChatProfileCompleteness.self,
                                                                                           from: Data(#"{ "isComplete": true }"#.utf8)))
        case .incompleteProfile:
            let member = try? JSONDecoder().decode(HealthChatMember.self, from: Data("""
            { "userId": "@alice:healthchat.ch", "displayName": "Dr. Alice Alpha", "specialty": "Physiotherapie" }
            """.utf8))
            apiService.membersSearchQueryReturnValue = .success(.init(users: member.map { [$0] } ?? [],
                                                                      isApproved: true,
                                                                      pendingMessage: nil))
            apiService.profileCompletenessReturnValue = try? .success(JSONDecoder().decode(HealthChatProfileCompleteness.self,
                                                                                           from: Data(#"{ "isComplete": false, "message": "Profil unvollständig – Fehlende Angaben: Fachgebiet, Ort" }"#.utf8)))
        case .pendingApproval:
            apiService.membersSearchQueryReturnValue = .success(.init(users: [],
                                                                      isApproved: false,
                                                                      pendingMessage: "Ihr Konto wird derzeit geprüft. Sie erhalten Zugriff auf das Mitgliederverzeichnis, sobald Ihr Konto freigegeben wurde."))
        case .failure:
            apiService.membersSearchQueryReturnValue = .failure(.networkFailure)
        }
        
        return HealthChatMemberDirectoryScreenViewModel(apiService: apiService,
                                                        clientProxy: ClientProxyMock(.init()),
                                                        mediaProvider: MediaProviderMock(.init()),
                                                        userIndicatorController: UserIndicatorControllerMock())
    }
}