//
// Copyright 2026 Element Creations Ltd.
//
// 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 SettingsScreenUserStatusRow: View {
    enum Mode: Equatable {
        case pickStatusButton, customStatusInput(emoji: Character), showingStatus(UserStatus.Displayed)
        
        var isCustomStatusInput: Bool {
            switch self {
            case .customStatusInput: true
            default: false
            }
        }
    }
    
    let mode: Mode
    let action: (SettingsScreenViewAction.UserStatusAction) -> Void
    
    @State private var customText = ""
    @FocusState private var isCustomFieldFocused: Bool
    
    var body: some View {
        rowContent
            .onChange(of: mode.isCustomStatusInput) { _, newValue in
                guard newValue else { return }
                customText = ""
            }
    }
    
    @ViewBuilder
    var rowContent: some View {
        switch mode {
        case .pickStatusButton:
            ListRow(label: .default(title: L10n.screenSettingsUserStatusPlaceholder, icon: \.reaction),
                    kind: .button { action(.pickStatus) })
        case .customStatusInput(let emoji):
            ListRow(kind: .custom {
                HStack(spacing: ListRowPadding.labelIconSpacing) {
                    Button { action(.pickCustomEmoji) } label: {
                        Text(String(emoji))
                            .font(.compound.headingSM)
                            .foregroundStyle(.compound.textPrimary)
                            .accessibilityLabel(L10n.a11yCustomEmoji)
                            .accessibilityValue(String(emoji))
                    }
                    .buttonStyle(EditEmojiButtonStyle())
                    
                    TextField(L10n.screenSettingsUserStatusCustomHint, text: $customText)
                        .textFieldStyle(.compound(.raised))
                        .focused($isCustomFieldFocused)
                        .onAppear { isCustomFieldFocused = true }
                        .accessibilityLabel(L10n.screenSettingsUserStatusCustomHint)
                        .padding(.vertical, 3)
                    
                    ZStack { // ZStack to stop the text field from resizing.
                        Button(L10n.actionCancel) { action(.cancel) }
                            .opacity(customText.isEmpty ? 1 : 0)
                        Button(L10n.actionSave, action: saveCustomStatus)
                            .opacity(customText.isEmpty ? 0 : 1)
                    }
                    .buttonStyle(.compound(.textLink))
                }
                .listRowBackground(Color.clear)
            })
        case .showingStatus(let status):
            ListRow(kind: .custom {
                HStack(spacing: ListRowPadding.labelIconSpacing) {
                    Button { action(.pickStatus) } label: {
                        HStack(spacing: ListRowPadding.labelIconSpacing) {
                            CompoundIcon(\.reaction)
                                .hidden()
                                .overlay {
                                    Text(String(status.emoji))
                                        .font(.compound.bodyLG)
                                        .foregroundStyle(.compound.textPrimary)
                                }
                            
                            Text(status.text)
                                .font(.compound.bodyLG)
                                .foregroundStyle(.compound.textPrimary)
                                .frame(maxWidth: .infinity, alignment: .leading)
                        }
                        .contentShape(Rectangle())
                    }
                    .accessibilityLabel(L10n.a11yStatus)
                    .accessibilityValue(Text(String(status.emoji)) + Text(status.text))
                    .buttonStyle(.plain)
                    
                    Button(L10n.actionClear) { action(.clear) }
                        .buttonStyle(.compound(.textLink))
                }
                .padding(ListRowPadding.insets)
            })
        }
    }
    
    private func saveCustomStatus() {
        guard case let .customStatusInput(emoji) = mode else { return }
        action(.set(.init(text: customText, emoji: emoji)))
    }
    
    struct EditEmojiButtonStyle: ButtonStyle {
        func makeBody(configuration: Configuration) -> some View {
            configuration.label
                .padding(12)
                .background {
                    ZStack {
                        Circle().fill(.compound.bgCanvasDefaultLevel1)
                        Circle().inset(by: 0.5).stroke(.compound.borderInteractiveSecondary)
                    }
                }
                .drawingGroup()
                .opacity(configuration.isPressed ? 0.6 : 1)
        }
    }
}

struct SettingsScreenUserStatusRow_Previews: PreviewProvider, TestablePreview {
    static var previews: some View {
        Form {
            Section {
                SettingsScreenUserStatusRow(mode: .pickStatusButton) { _ in }
            }
            
            Section {
                SettingsScreenUserStatusRow(mode: .customStatusInput(emoji: "😄")) { _ in }
            }
            
            Section {
                SettingsScreenUserStatusRow(mode: .showingStatus(.userSet(.init(text: "Away", emoji: "🌴")))) { _ in }
            }
            
            Section {
                SettingsScreenUserStatusRow(mode: .showingStatus(.inCall(.init(joinedDate: nil)))) { _ in }
            }
        }
        .compoundList()
    }
}