import Foundation

/// Configuration for a timeline fetch.
public struct TimelineOptions: Sendable {

    /// URL of the relay server.
    /// Used only when `useRelay` is `true`.
    public var relayURL: URL

    /// When `true` (default), the timeline is built from all feeds known to the relay
    /// instead of only the profile's `#+FOLLOW:` list. If the relay is unreachable,
    /// the client falls back to the local follow list automatically.
    ///
    /// Set to `false` to always use only the follows in the local profile.
    public var useRelay: Bool

    /// Maximum number of feeds downloaded in parallel.
    public var maxConcurrentDownloads: Int

    /// Only include posts newer than this many days. `nil` fetches all posts.
    public var maxPostAgeDays: Int?

    /// If non-empty, only posts whose `lang` matches one of these ISO 639-1
    /// codes are included. An empty array (default) shows all languages.
    public var languageFilter: [String]

    /// When `false` (default), restrict the timeline to feeds listed in `#+FOLLOW:`
    /// even if `useRelay` is `true`. Set to `true` to aggregate every feed known to
    /// the relay (busier timeline, good for discovery).
    public var showAllRelayFeeds: Bool

    /// Default options: relay enabled, 20 concurrent downloads, 14-day cutoff,
    /// all languages.
    public static let `default` = TimelineOptions()

    public init(
        relayURL: URL = URL(string: "https://relay.org-social.org")!,
        useRelay: Bool = true,
        maxConcurrentDownloads: Int = 20,
        maxPostAgeDays: Int? = 14,
        languageFilter: [String] = [],
        showAllRelayFeeds: Bool = false
    ) {
        self.relayURL = relayURL
        self.useRelay = useRelay
        self.maxConcurrentDownloads = maxConcurrentDownloads
        self.maxPostAgeDays = maxPostAgeDays
        self.languageFilter = languageFilter
        self.showAllRelayFeeds = showAllRelayFeeds
    }
}