import Foundation
import AppIntents
import CoreSpotlight

/// A Linkding bookmark exposed to Siri, Spotlight, Shortcuts, and the
/// Apple-Intelligence "Use Model" action.
///
/// Conforms to `IndexedEntity` so its title / description / tags become
/// Spotlight-searchable, which is what lets Siri answer "find my bookmark
/// about Swift concurrency". The identifier is the Linkding server id (`Int`),
/// which is stable across devices.
struct BookmarkEntity: AppEntity, IndexedEntity {
    static let typeDisplayRepresentation = TypeDisplayRepresentation(name: "Bookmark")

    let id: Int

    @Property(title: "Title")
    var title: String

    @Property(title: "URL")
    var url: URL

    @Property(title: "Website")
    var host: String

    @Property(title: "Description")
    var details: String

    @Property(title: "Tags")
    var tags: [String]

    @Property(title: "Unread")
    var unread: Bool

    /// AI-generated summary (when one has been produced). Exposed so the
    /// Shortcuts "Use Model" action and Siri can reason over it.
    @Property(title: "Summary")
    var summary: String?

    static let defaultQuery = BookmarkQuery()

    var displayRepresentation: DisplayRepresentation {
        DisplayRepresentation(
            title: "\(title)",
            subtitle: "\(host)",
            image: .init(systemName: "bookmark.fill")
        )
    }

    /// Rich Spotlight attributes so semantic search has real content to match.
    var attributeSet: CSSearchableItemAttributeSet {
        let attrs = CSSearchableItemAttributeSet(contentType: .url)
        attrs.title = title
        attrs.contentDescription = details.isEmpty ? summary : details
        attrs.keywords = tags
        attrs.url = url
        return attrs
    }
}

extension BookmarkEntity {
    init(from b: Bookmark) {
        self.id = b.id
        self.title = b.displayTitle
        self.url = URL(string: b.url) ?? URL(string: "https://example.invalid")!
        self.host = b.domain
        self.details = b.contentExcerpt ?? ""
        self.tags = b.tagNames
        self.unread = b.unread
        self.summary = b.aiSummary
    }

    /// Reconstruct a minimal `Bookmark` from the entity — enough for the
    /// AI enrichment call, which only reads url/title/tags.
    func makeBookmark() -> Bookmark {
        Bookmark(
            id: id,
            url: url.absoluteString,
            title: title,
            description: details,
            tagNames: tags,
            dateAdded: Date(),
            dateModified: Date(),
            isArchived: false,
            unread: unread,
            shared: false,
            websiteTitle: nil,
            websiteDescription: nil,
            faviconUrl: nil,
            previewImageUrl: nil,
            aiSummary: summary,
            aiTags: nil
        )
    }
}

/// Looks bookmarks up by id and resolves free-text queries by hitting the
/// Linkding server live — the recommended path for data that lives on a
/// server and changes too often to pre-index.
struct BookmarkQuery: EntityStringQuery {
    func entities(for identifiers: [Int]) async throws -> [BookmarkEntity] {
        let api = try MarksIntent.api()
        // Linkding has no batch-by-id endpoint; pull a page and filter.
        let response = try await api.fetchBookmarks(limit: 200)
        let wanted = Set(identifiers)
        return response.results
            .filter { wanted.contains($0.id) }
            .map(BookmarkEntity.init(from:))
    }

    func entities(matching string: String) async throws -> [BookmarkEntity] {
        let api = try MarksIntent.api()
        let response = try await api.fetchBookmarks(search: string, limit: 25)
        return response.results.map(BookmarkEntity.init(from:))
    }

    func suggestedEntities() async throws -> [BookmarkEntity] {
        let api = try MarksIntent.api()
        let response = try await api.fetchBookmarks(limit: 10)
        return response.results.map(BookmarkEntity.init(from:))
    }
}