import SwiftUI
import AppKit
import OnyxDesign
import OnyxWidgetKit

/// Der Verlauf der Zwischenablage, zum Zurückholen.
public struct ClipboardView: View {
    private let store: ClipboardStore
    private let compact: Bool
    @State private var hovered: UUID?
    @State private var justCopied: UUID?

    public init(store: ClipboardStore, compact: Bool = false) {
        self.store = store
        self.compact = compact
    }

    public var body: some View {
        VStack(alignment: .leading, spacing: Onyx.Space.sm) {
            if store.items.isEmpty {
                OnyxNotice(symbol: "doc.on.clipboard",
                           text: store.isRecording
                               ? String(localized: "clipboard.empty", bundle: .module)
                               : String(localized: "clipboard.paused", bundle: .module))
            } else {
                ScrollView {
                    LazyVStack(spacing: 0) {
                        ForEach(Array(store.items.prefix(compact ? 5 : 40).enumerated()),
                                id: \.element.id) { index, item in
                            if index > 0 { OnyxHairline() }
                            row(item)
                        }
                    }
                }
                .scrollIndicators(.never)
            }
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)
    }

    private func row(_ item: ClipboardItem) -> some View {
        // Die ganze Zeile ist der Knopf. Ein kleines Ziel neben dem Text wäre
        // genauer zu treffen zu verlangen, als die Aufgabe es hergibt.
        Button { copy(item) } label: {
            HStack(spacing: Onyx.Space.row) {
                Image(systemName: item.kind == .image ? "photo" : "text.alignleft")
                    .font(.system(size: Onyx.Symbol.small))
                    .foregroundStyle(Onyx.Color.textTertiary)
                    .frame(width: 16)

                Text(item.preview)
                    .font(Onyx.Font.footnote)
                    .foregroundStyle(Onyx.Color.textPrimary)
                    .lineLimit(1)
                    .truncationMode(.tail)

                Spacer(minLength: Onyx.Space.xs)

                if justCopied == item.id {
                    // Eine Rückmeldung, die nichts verschiebt: ohne sie sieht
                    // ein Klick, der die Ablage füllt, wie ein Klick aus, der
                    // nichts getan hat.
                    Image(systemName: "checkmark")
                        .font(.system(size: Onyx.Symbol.caption))
                        .foregroundStyle(Onyx.Color.positive)
                } else if hovered == item.id {
                    Button { store.remove(item) } label: {
                        Image(systemName: "xmark.circle.fill")
                            .font(.system(size: Onyx.Symbol.small))
                            .foregroundStyle(Onyx.Color.textTertiary)
                    }
                    .buttonStyle(.plain)
                }
            }
            .padding(.horizontal, Onyx.Space.row)
            .padding(.vertical, compact ? Onyx.Space.sm : Onyx.Space.md)
            .contentShape(.rect)
        }
        .buttonStyle(.plain)
        .background(hovered == item.id ? Onyx.Color.elevated : .clear)
        .onHover { hovered = $0 ? item.id : (hovered == item.id ? nil : hovered) }
    }

    private func copy(_ item: ClipboardItem) {
        store.copyBack(item)
        justCopied = item.id
        Task {
            try? await Task.sleep(for: .seconds(1.2))
            if justCopied == item.id { justCopied = nil }
        }
    }
}

public struct ClipboardWidget: OnyxWidget {
    public let id = "clipboard"
    public var displayName: String { String(localized: "clipboard.name", bundle: .module) }
    public let symbolName = "doc.on.clipboard"

    private let store: ClipboardStore

    public init(store: ClipboardStore) { self.store = store }

    public func makeView() -> AnyView {
        AnyView(ClipboardView(store: store))
    }
}