OSGKeyboard/OSGKeyboard/Views/HistoryView.swift

// HistoryView.swift
// OSGKeyboard · Main App

import SwiftUI
import OSGKeyboardShared

struct HistoryView: View {
    @Environment(\.themePalette) private var palette: ThemePalette
    @ObservedObject private var store = SpeechHistoryStore.shared

    private static let dayFormatter: DateFormatter = {
        let f = DateFormatter()
        f.dateStyle = .medium
        f.timeStyle = .none
        return f
    }()

    private static let timeFormatter: DateFormatter = {
        let f = DateFormatter()
        f.dateStyle = .none
        f.timeStyle = .short
        return f
    }()

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                PageHeaderRow(title: "history.title") {
                    if !store.entries.isEmpty {
                        PageHeaderConfirmButton(
                            systemImage: "trash",
                            accessibilityLabel: "history.clear.button",
                            confirmTitle: "history.clear.title",
                            confirmMessage: "history.clear.message",
                            confirmActionTitle: "history.clear.confirm"
                        ) {
                            store.clearAll()
                        }
                    }
                }

                Text("history.subtitle")
                    .font(TypeStyle.caption2)
                    .foregroundStyle(palette.textSecondary)
                    .frame(maxWidth: .infinity, alignment: .leading)
                    .padding(.horizontal, Spacing.md)
                    .padding(.bottom, Spacing.sm)

                ZStack {
                    palette.background.ignoresSafeArea()

                    if store.entries.isEmpty {
                        emptyState
                    } else {
                        ScrollView {
                            LazyVStack(alignment: .leading, spacing: Spacing.xl) {
                                ForEach(store.groupedByDay, id: \.day) { group in
                                    daySection(day: group.day, items: group.items)
                                }
                            }
                            .padding(.horizontal, Spacing.md)
                            .padding(.vertical, Spacing.md)
                            .padding(.bottom, 100)
                        }
                    }
                }
            }
            .background(palette.background)
            .toolbar(.hidden, for: .navigationBar)
        }
        .task {
            // v0.3.0: each time the user opens History, run a
            // silent pass to lift frequently-dictated English
            // identifiers into the personal dictionary. Cheap
            // (≤ 5 ms for 200 entries on iPhone 12) and idempotent.
            DictionaryLearner().learn(from: store.entries)
        }
    }

    private var emptyState: some View {
        VStack(spacing: Spacing.sm) {
            Spacer()
            MaterialIcon(name: .menuBook, size: 36)
                .foregroundStyle(palette.textTertiary.opacity(0.5))
            Text("history.empty")
                .font(TypeStyle.body)
                .foregroundStyle(palette.textSecondary)
                .multilineTextAlignment(.center)
            Spacer()
        }
        .padding(.horizontal, Spacing.xl)
    }

    private func daySection(day: Date, items: [SpeechHistoryEntry]) -> some View {
        VStack(alignment: .leading, spacing: Spacing.sm) {
            Text(Self.dayFormatter.string(from: day))
                .font(TypeStyle.caption2)
                .foregroundStyle(palette.textTertiary)
                .textCase(.uppercase)
                .tracking(0.5)

            VStack(spacing: 0) {
                ForEach(Array(items.enumerated()), id: \.element.id) { index, entry in
                    historyRow(entry)
                    if index < items.count - 1 {
                        Divider().background(palette.divider)
                    }
                }
            }
            .background(palette.surface, in: RoundedRectangle(cornerRadius: Radius.xl, style: .continuous))
            .overlay(
                RoundedRectangle(cornerRadius: Radius.xl, style: .continuous)
                    .stroke(palette.divider, lineWidth: 0.5)
            )
        }
    }

    private func historyRow(_ entry: SpeechHistoryEntry) -> some View {
        VStack(alignment: .leading, spacing: Spacing.xxs) {
            Text(Self.timeFormatter.string(from: entry.createdAt))
                .font(TypeStyle.caption2)
                .foregroundStyle(palette.textTertiary)
                .monospacedDigit()
            Text(entry.text)
                .font(TypeStyle.body)
                .foregroundStyle(palette.textPrimary)
                .fixedSize(horizontal: false, vertical: true)
        }
        .padding(Spacing.md)
        .frame(maxWidth: .infinity, alignment: .leading)
    }
}