import Foundation
import AppIntents

/// Which top-level tab the app is showing. Used so an intent can switch tabs.
enum AppTab: Hashable {
    case bookmarks, tags, sources, podcasts, search
}

/// Bridges App Intents (which run in the main app process, since there is no
/// separate AppIntents extension target) to the live SwiftUI scene.
///
/// Intents mutate this shared, observable singleton; `MainContainer` and
/// `SearchView` observe it and react (present a browser, switch to the search
/// tab, etc.). This is the standard "intent → in-app navigation" pattern when
/// perform() runs in-process.
@MainActor
@Observable
final class IntentRouter {
    static let shared = IntentRouter()
    private init() {}

    /// A bookmark URL an intent asked to open in the in-app browser.
    var openBookmarkURL: String?

    /// A query an intent asked the app to search for.
    var searchRequest: String?

    func openBookmark(url: String) { openBookmarkURL = url }
    func search(_ query: String) { searchRequest = query }
}

/// Errors surfaced to Siri / Shortcuts when an intent can't run.
enum MarksIntentError: Error, CustomLocalizedStringResourceConvertible {
    case notConfigured
    case invalidURL

    var localizedStringResource: LocalizedStringResource {
        switch self {
        case .notConfigured: "Open Marks and connect to your Linkding server first."
        case .invalidURL: "That doesn't look like a valid link."
        }
    }
}

/// Shared plumbing for the intents: build an API client from saved config and
/// keep the widgets in sync after mutations.
enum MarksIntent {
    /// Builds a `LinkdingAPI` from the saved server config, or throws a
    /// user-facing error if the app has never been connected.
    static func api() throws -> LinkdingAPI {
        guard let config = ServerConfig.load() else { throw MarksIntentError.notConfigured }
        return LinkdingAPI(config: config)
    }

    /// Prepend a freshly-saved bookmark into the widget cache so the Recent
    /// widget reflects it immediately (mirrors `BookmarksViewModel.load`).
    static func refreshWidgets(adding b: Bookmark) {
        var items = WidgetDataStore.loadBookmarks()
        items.removeAll { $0.url == b.url }
        items.insert(
            WidgetBookmark(url: b.url, title: b.displayTitle, domain: b.domain, faviconUrl: b.faviconUrl),
            at: 0
        )
        WidgetDataStore.saveBookmarks(Array(items.prefix(20)))
    }
}