pageta-native/Sources/Features/MarkierungenTabView.swift

import ManaAuthUI
import ManaCore
import SwiftUI

/// Globale Sammlung aller Highlights über alle Artikel hinweg.
///
/// **Layout-Entscheidung 2026-05-21:** flat sortiert nach `createdAt`
/// desc (jüngste zuerst). Keine Gruppierung by Article — Till will
/// "was hab ich zuletzt markiert" als primärer Use-Case. Artikel-
/// Kontext (Titel, Site) steht pro Row als Untertitel.
///
/// Tap auf eine Row navigiert in die `ArticleDetailView` des
/// zugehörigen Artikels. Swipe-Delete entfernt nur den Highlight,
/// nicht den Artikel.
struct MarkierungenTabView: View {
	@Environment(AuthClient.self) private var auth
	@Environment(PendingShareSignal.self) private var shareSignal
	private var api: PagetaAPI { PagetaAPI(auth: auth) }

	@State private var items: [HighlightWithArticle] = []
	@State private var loadState: LoadState = .idle
	@State private var editingNoteFor: HighlightWithArticle?
	@State private var writeError: String?

	enum LoadState: Equatable {
		case idle
		case loading
		case loaded
		case error(String)
	}

	var body: some View {
		NavigationStack {
			Group {
				if items.isEmpty {
					emptyOrLoadingView
				} else {
					listView
				}
			}
			.navigationTitle("Marker")
			.navigationDestination(for: String.self) { articleId in
				ArticleDetailView(articleId: articleId)
			}
			.alert(
				"Aktion fehlgeschlagen",
				isPresented: Binding(
					get: { writeError != nil },
					set: { if !$0 { writeError = nil } }
				),
				presenting: writeError
			) { _ in
				Button("OK", role: .cancel) { writeError = nil }
			} message: { msg in
				Text(msg)
			}
			.paperBackground()
			.task {
				if items.isEmpty { await load() }
			}
			.onAppear {
				// Reload bei Re-Appear (gleiche Logik wie LeseListe) —
				// fängt z.B. Highlight-Löschungen aus dem Detail-View ab.
				if !items.isEmpty {
					Task { await load() }
				}
			}
			.refreshable { await load() }
			.onChange(of: shareSignal.flushedTick) { _, _ in
				// Wenn ein frisch gespeicherter Artikel via ShareExt
				// reinkommt + der User direkt aus dem Web Highlights
				// gesetzt hat (Cross-Device-Sync), kann sich die Liste
				// ändern. Billiger Re-Load.
				Task { await load() }
			}
		}
	}

	@ViewBuilder
	private var emptyOrLoadingView: some View {
		switch loadState {
		case .idle, .loading:
			ProgressView()
				.frame(maxWidth: .infinity, maxHeight: .infinity)
		case let .error(message):
			ContentUnavailableView(
				"Marker konnten nicht geladen werden",
				systemImage: "exclamationmark.triangle",
				description: Text(message)
			)
		case .loaded:
			ContentUnavailableView(
				"Noch nichts markiert",
				systemImage: "highlighter",
				description: Text("Markiere Textstellen in einem Artikel — sie erscheinen hier zusammen.")
			)
		}
	}

	private var listView: some View {
		List {
			ForEach(items) { item in
				NavigationLink(value: item.highlight.articleId) {
					MarkierungRow(
						item: item,
						onColorChange: { color in
							Task { await setColor(for: item.highlight, to: color) }
						}
					)
				}
				.listRowInsets(EdgeInsets(top: 10, leading: 16, bottom: 10, trailing: 16))
				.swipeActions(edge: .leading) {
					Button {
						editingNoteFor = item
					} label: {
						Label(item.highlight.note == nil ? "Notiz" : "Notiz bearbeiten", systemImage: "note.text")
					}
					.tint(.indigo)
				}
				.swipeActions(edge: .trailing) {
					Button(role: .destructive) {
						Task { await delete(item.highlight) }
					} label: {
						Label("Löschen", systemImage: "trash")
					}
				}
				.contextMenu {
					highlightContextMenu(item)
				}
			}
		}
		.listStyle(.plain)
		.macReadingWidth()
		.sheet(item: $editingNoteFor) { item in
			HighlightNoteSheet(
				highlightText: item.highlight.text,
				initialNote: item.highlight.note,
				color: item.highlight.color,
				onSave: { newNote in
					await saveNote(for: item.highlight, newNote: newNote)
				}
			)
		}
	}

	/// Long-Press-Kontextmenü für eine Markierung. Spiegelt die Swipe-
	/// Aktionen (Notiz, Löschen) und ergänzt sie um Kopieren, Farbe und
	/// Teilen — der Tap navigiert weiterhin in den Artikel.
	@ViewBuilder
	private func highlightContextMenu(_ item: HighlightWithArticle) -> some View {
		Button {
			PlatformClipboard.copy(item.highlight.text)
		} label: {
			Label("Marker kopieren", systemImage: "doc.on.doc")
		}
		Button {
			editingNoteFor = item
		} label: {
			Label(
				item.highlight.note == nil ? "Notiz hinzufügen" : "Notiz bearbeiten",
				systemImage: "note.text"
			)
		}
		Menu {
			ForEach(HighlightColor.allCases) { color in
				Button {
					Task { await setColor(for: item.highlight, to: color) }
				} label: {
					Label(
						color.label,
						systemImage: color == item.highlight.color ? "checkmark" : "circle.fill"
					)
				}
			}
		} label: {
			Label("Farbe", systemImage: "paintpalette")
		}
		ShareLink(item: highlightShareText(item)) {
			Label("Teilen …", systemImage: "square.and.arrow.up")
		}
		Divider()
		Button(role: .destructive) {
			Task { await delete(item.highlight) }
		} label: {
			Label("Löschen", systemImage: "trash")
		}
	}

	/// Markierungs-Text mit Quellen-Attribution für Teilen.
	private func highlightShareText(_ item: HighlightWithArticle) -> String {
		var out = "\u{201C}\(item.highlight.text)\u{201D}"
		if let note = item.highlight.note, !note.isEmpty {
			out += "\n\n\(note)"
		}
		out += "\n— \(item.article.title)"
		return out
	}

	private func load() async {
		loadState = .loading
		do {
			items = try await api.fetchAllHighlights()
			loadState = .loaded
		} catch {
			loadState = .error(error.localizedDescription)
		}
	}

	private func delete(_ highlight: Highlight) async {
		do {
			try await api.deleteHighlight(id: highlight.id)
			items.removeAll { $0.highlight.id == highlight.id }
		} catch {
			writeError = error.localizedDescription
		}
	}

	private func saveNote(for highlight: Highlight, newNote: String?) async {
		do {
			try await api.setHighlightNote(id: highlight.id, note: newNote)
			// Lokal patchen — der Pull holt es später ein, aber UI muss sofort
			// reagieren.
			if let idx = items.firstIndex(where: { $0.highlight.id == highlight.id }) {
				items[idx].highlight.note = newNote
			}
		} catch {
			writeError = error.localizedDescription
		}
	}

	private func setColor(for highlight: Highlight, to color: HighlightColor) async {
		do {
			try await api.setHighlightColor(id: highlight.id, color: color)
			if let idx = items.firstIndex(where: { $0.highlight.id == highlight.id }) {
				items[idx].highlight.color = color
			}
		} catch {
			writeError = error.localizedDescription
		}
	}
}

/// Eine Markierung in der Liste — Farb-Strich links, Highlight-Text,
/// Artikel-Kontext + Datum als Untertitel.
struct MarkierungRow: View {
	let item: HighlightWithArticle
	let onColorChange: (HighlightColor) -> Void

	private var subtitle: String {
		var parts: [String] = []
		parts.append(item.article.title)
		if let site = item.article.siteName, !site.isEmpty {
			parts.append(site)
		}
		if let date = formattedDate(item.highlight.createdAt) {
			parts.append(date)
		}
		return parts.joined(separator: " · ")
	}

	var body: some View {
		HStack(alignment: .top, spacing: 10) {
			Menu {
				ForEach(HighlightColor.allCases) { color in
					Button {
						onColorChange(color)
					} label: {
						Label(color.label, systemImage: color == item.highlight.color ? "checkmark" : "")
					}
				}
			} label: {
				RoundedRectangle(cornerRadius: 2)
					.fill(item.highlight.color.swiftUIColor)
					.frame(width: 4)
			}
			.buttonStyle(.plain)
			.menuStyle(.borderlessButton)
			VStack(alignment: .leading, spacing: 4) {
				Text(item.highlight.text)
					.font(.callout)
					.foregroundStyle(PagetaTheme.foreground)
					.lineLimit(4)
				if let note = item.highlight.note, !note.isEmpty {
					HStack(alignment: .top, spacing: 6) {
						Image(systemName: "note.text")
							.font(.caption2)
							.foregroundStyle(.secondary)
						Text(note)
							.font(.footnote)
							.foregroundStyle(PagetaTheme.foreground.opacity(0.85))
							.lineLimit(3)
					}
					.padding(.top, 2)
				}
				Text(subtitle)
					.font(.caption)
					.foregroundStyle(.secondary)
					.lineLimit(2)
			}
		}
		.padding(.vertical, 4)
	}

	/// `createdAt` ist ISO8601 vom Server. Auf "vor 3 Stunden" /
	/// "21.05.2026"-Format mappen.
	private func formattedDate(_ iso: String) -> String? {
		let formatter = ISO8601DateFormatter()
		formatter.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
		var date = formatter.date(from: iso)
		if date == nil {
			formatter.formatOptions = [.withInternetDateTime]
			date = formatter.date(from: iso)
		}
		guard let date else { return nil }
		let relative = RelativeDateTimeFormatter()
		relative.unitsStyle = .short
		// Über 7 Tage absolut anzeigen — "vor 3 Wochen" hilft niemandem.
		if abs(date.timeIntervalSinceNow) > 7 * 24 * 3600 {
			let abs = DateFormatter()
			abs.dateStyle = .medium
			abs.timeStyle = .none
			return abs.string(from: date)
		}
		return relative.localizedString(for: date, relativeTo: Date())
	}
}