// MacDictionaryView.swift
// OSGKeyboard · Mac
//
// Personal dictionary synced via iCloud KVS. ScrollView is full-bleed
// (scrollbar on the window edge); title + cards share `pageHorizontalInset`.

import SwiftUI

struct MacDictionaryView: View {
    @ObservedObject var viewModel: MacDictationViewModel
    @Environment(\.themePalette) private var palette
    @State private var query = ""
    @State private var entryPendingDeletion: PersonalDictionary.Entry?
    @State private var showEntryEditor = false
    @State private var generatingAliasEntryIDs: Set<UUID> = []

    private var lang: AppUILanguage { viewModel.config.uiLanguage }

    private var entries: [PersonalDictionary.Entry] {
        _ = viewModel.dictionaryRevision
        return AppGroupStore(defaults: viewModel.defaults).personalDictionary.entries
    }

    /// Entries filtered by the search field, grouped by category and sorted
    /// (most-used first) — mirrors the iOS Personal Dictionary tab.
    private var sections: [(category: PersonalDictionary.Entry.Category, items: [PersonalDictionary.Entry])] {
        let trimmed = query.trimmingCharacters(in: .whitespacesAndNewlines).lowercased()
        let filtered: [PersonalDictionary.Entry]
        if trimmed.isEmpty {
            filtered = entries
        } else {
            filtered = entries.filter { entry in
                entry.term.lowercased().contains(trimmed)
                    || entry.aliases.contains { $0.lowercased().contains(trimmed) }
            }
        }
        let grouped = Dictionary(grouping: filtered, by: { $0.category })
        return PersonalDictionary.Entry.Category.allCases.compactMap { category in
            guard let bucket = grouped[category], !bucket.isEmpty else { return nil }
            let sorted = bucket.sorted {
                if $0.usageCount != $1.usageCount { return $0.usageCount > $1.usageCount }
                return $0.term.localizedCaseInsensitiveCompare($1.term) == .orderedAscending
            }
            return (category, sorted)
        }
    }

    var body: some View {
        VStack(spacing: 0) {
            MacPageHeader(
                title: MacL10n.string("mac.section.dictionary", language: lang),
                subtitle: MacL10n.string("mac.page.dictionary.subtitle", language: lang)
            ) {
                HStack(spacing: Spacing.sm) {
                    if !entries.isEmpty {
                        searchField
                    }
                    Button {
                        showEntryEditor = true
                    } label: {
                        Label(
                            MacL10n.string("mac.dict.add", language: lang),
                            systemImage: "plus"
                        )
                    }
                    .buttonStyle(MacHeaderActionButtonStyle())
                }
            }

            Group {
                if entries.isEmpty {
                    emptyState
                        .transition(.opacity)
                } else {
                    list
                        .transition(.opacity)
                }
            }
            .frame(maxWidth: .infinity, maxHeight: .infinity)
        }
        .background(palette.background)
        .animation(Motion.soft, value: entries.isEmpty)
        .sheet(isPresented: $showEntryEditor) {
            MacDictionaryEntryEditor(language: lang) { term in
                saveManualEntry(term: term)
            }
        }
        .task {
            await MacICloudSyncBootstrap.dictionarySync.pullAndMergeIfEnabled()
            viewModel.refreshDictionaryFromCloud()
        }
        .onReceive(NotificationCenter.default.publisher(for: .personalDictionaryDidSyncFromCloud)) { _ in
            viewModel.refreshDictionaryFromCloud()
        }
        .confirmationDialog(
            MacL10n.string("mac.dict.deleteTitle", language: lang),
            isPresented: deletionDialogBinding,
            titleVisibility: .visible
        ) {
            Button(MacL10n.string("mac.delete", language: lang), role: .destructive) {
                if let entry = entryPendingDeletion {
                    withAnimation(Motion.soft) { delete(entry) }
                }
                entryPendingDeletion = nil
            }
            Button(MacL10n.string("mac.cancel", language: lang), role: .cancel) {
                entryPendingDeletion = nil
            }
        } message: {
            Text(MacL10n.string("mac.dict.deleteMessage", language: lang))
        }
    }

    // MARK: - List

    private var list: some View {
        // Full-bleed ScrollView → scrollbar on the detail pane's right edge.
        ScrollView {
            LazyVStack(alignment: .leading, spacing: Spacing.xl) {
                if sections.isEmpty {
                    MacCard {
                        Text(MacL10n.string("mac.dict.noMatch", language: lang))
                            .foregroundStyle(palette.textTertiary)
                            .frame(maxWidth: .infinity, alignment: .center)
                    }
                } else {
                    ForEach(sections, id: \.category) { section in
                        categorySection(section)
                    }
                }
            }
            .padding(.horizontal, MacMetrics.pageHorizontalInset)
            .padding(.bottom, Spacing.md)
            .animation(Motion.soft, value: query)
        }
    }

    private func categorySection(
        _ section: (category: PersonalDictionary.Entry.Category, items: [PersonalDictionary.Entry])
    ) -> some View {
        VStack(alignment: .leading, spacing: Spacing.sm) {
            Text(MacL10n.string(section.category.labelKey, language: lang))
                .font(MacSettingsType.sectionTitle)
                .foregroundStyle(palette.textSecondary)
                .textCase(.uppercase)

            MacCard(padding: 0) {
                VStack(spacing: 0) {
                    ForEach(section.items, id: \.id) { entry in
                        row(entry)
                            .padding(.horizontal, Spacing.md)
                            .padding(.vertical, Spacing.sm)
                    }
                }
            }
        }
    }

    private var deletionDialogBinding: Binding<Bool> {
        Binding(
            get: { entryPendingDeletion != nil },
            set: { if !$0 { entryPendingDeletion = nil } }
        )
    }

    private var searchField: some View {
        HStack(spacing: Spacing.xs) {
            Image(systemName: "magnifyingglass")
                .foregroundStyle(palette.textTertiary)
            TextField(MacL10n.string("mac.dict.search", language: lang), text: $query)
                .textFieldStyle(.plain)
                .font(TypeStyle.footnote)
        }
        .padding(.horizontal, Spacing.sm)
        .frame(width: 220, height: MacMetrics.pageHeaderControlHeight)
        .background(palette.formSurface, in: Capsule())
        .overlay(Capsule().stroke(palette.divider, lineWidth: 0.5))
    }

    private func row(_ entry: PersonalDictionary.Entry) -> some View {
        MacDictionaryRow(
            entry: entry,
            subtitle: subtitle(for: entry),
            language: lang,
            copy: { viewModel.copyToClipboard(entry.term) },
            delete: { entryPendingDeletion = entry }
        )
    }

    /// "Manual · ×3 · k8s / kube" — same metadata line as iOS.
    private func subtitle(for entry: PersonalDictionary.Entry) -> String? {
        var parts: [String] = [MacL10n.string(entry.source.labelKey, language: lang)]
        if entry.usageCount > 1 {
            parts.append("×\(entry.usageCount)")
        }
        if !entry.aliases.isEmpty {
            parts.append(entry.aliases.joined(separator: " / "))
        } else if generatingAliasEntryIDs.contains(entry.id) {
            parts.append(MacL10n.string("mac.dict.aliasesGenerating", language: lang))
        }
        return parts.isEmpty ? nil : parts.joined(separator: " · ")
    }

    // MARK: - Empty state

    private var emptyState: some View {
        VStack(spacing: Spacing.sm) {
            Image(systemName: "character.book.closed")
                .font(.system(size: 34, weight: .light))
                .foregroundStyle(palette.textTertiary.opacity(0.55))
                .symbolRenderingMode(.hierarchical)
            Text(MacL10n.string("mac.dict.empty", language: lang))
                .font(TypeStyle.headline)
                .foregroundStyle(palette.textSecondary)
            Text(MacL10n.string("mac.dict.emptyBody", language: lang))
                .font(TypeStyle.footnote)
                .foregroundStyle(palette.textTertiary)
                .multilineTextAlignment(.center)
                .frame(maxWidth: 320)
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private func delete(_ entry: PersonalDictionary.Entry) {
        let store = AppGroupStore(defaults: viewModel.defaults)
        store.deletePersonalDictionaryEntry(id: entry.id)
        generatingAliasEntryIDs.remove(entry.id)
        viewModel.refreshDictionaryFromCloud()
        Task {
            try? await MacICloudSyncBootstrap.dictionarySync.pushLocalIfEnabled(store.personalDictionary)
        }
    }

    private func saveManualEntry(term: String) {
        let store = AppGroupStore(defaults: viewModel.defaults)
        let service = PersonalDictionaryEntryService(
            store: store,
            cloudPush: { dictionary in
                try? await MacICloudSyncBootstrap.dictionarySync.pushLocalIfEnabled(dictionary)
            }
        )
        guard let saved = service.saveEntry(term: term, source: .manual) else { return }
        viewModel.refreshDictionaryFromCloud()
        if saved.shouldGenerateAliases {
            generatingAliasEntryIDs.insert(saved.entryID)
        }

        Task {
            await service.finishSaving(saved)
            generatingAliasEntryIDs.remove(saved.entryID)
            viewModel.refreshDictionaryFromCloud()
        }
    }
}

private struct MacDictionaryEntryEditor: View {
    let language: AppUILanguage
    let onSave: (String) -> Void

    @Environment(\.dismiss) private var dismiss
    @Environment(\.themePalette) private var palette
    @State private var term = ""
    @FocusState private var termFocused: Bool

    private var trimmedTerm: String {
        term.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    var body: some View {
        VStack(alignment: .leading, spacing: Spacing.md) {
            Text(MacL10n.string("mac.dict.add", language: language))
                .font(TypeStyle.title2)

            TextField(
                MacL10n.string("mac.dict.addField", language: language),
                text: $term
            )
            .textFieldStyle(.roundedBorder)
            .focused($termFocused)
            .onSubmit(save)

            Text(MacL10n.string("mac.dict.addFooter", language: language))
                .font(TypeStyle.caption2)
                .foregroundStyle(palette.textTertiary)
                .fixedSize(horizontal: false, vertical: true)

            HStack {
                Spacer()
                Button(MacL10n.string("mac.cancel", language: language)) {
                    dismiss()
                }
                .tint(palette.textPrimary)
                Button(action: save) {
                    Text(MacL10n.string("mac.save", language: language))
                        .foregroundStyle(palette.background)
                }
                    .buttonStyle(.borderedProminent)
                    .tint(palette.textPrimary)
                    .disabled(trimmedTerm.isEmpty)
            }
        }
        .padding(Spacing.xl)
        .frame(width: 440)
        .background(palette.background)
        .onAppear {
            termFocused = true
        }
    }

    private func save() {
        guard !trimmedTerm.isEmpty else { return }
        onSave(trimmedTerm)
        dismiss()
    }
}

private struct MacDictionaryRow: View {
    let entry: PersonalDictionary.Entry
    let subtitle: String?
    let language: AppUILanguage
    let copy: () -> Void
    let delete: () -> Void

    @Environment(\.themePalette) private var palette
    @State private var isHovering = false

    var body: some View {
        HStack(alignment: .top, spacing: Spacing.sm) {
            VStack(alignment: .leading, spacing: 2) {
                Text(entry.term)
                    .font(TypeStyle.body)
                    .foregroundStyle(palette.textPrimary)
                    .lineLimit(1)
                if let subtitle {
                    Text(subtitle)
                        .font(TypeStyle.caption)
                        .foregroundStyle(palette.textTertiary)
                        .lineLimit(1)
                }
            }
            Spacer(minLength: Spacing.sm)
            Button(action: delete) {
                Image(systemName: "trash")
                    .font(.system(size: 13, weight: .medium))
                    .frame(width: 24, height: 24)
            }
            .buttonStyle(.borderless)
            .foregroundStyle(isHovering ? palette.danger : palette.textTertiary)
            .opacity(isHovering ? 1 : 0)
            .accessibilityLabel(MacL10n.string("mac.delete", language: language))
        }
        .frame(maxWidth: .infinity, alignment: .leading)
        .contentShape(Rectangle())
        .animation(Motion.quick, value: isHovering)
        .onHover { isHovering = $0 }
        .contextMenu {
            Button(action: copy) {
                Label(MacL10n.string("mac.copy", language: language), systemImage: "doc.on.doc")
            }
            Button(role: .destructive, action: delete) {
                Label(MacL10n.string("mac.delete", language: language), systemImage: "trash")
            }
        }
    }
}