import Foundation
import Observation

/// The `repo list` screen, paginated. A typed query searches server-side
/// (`repo search` covers name, description and topics across everything
/// reachable — including repos not in your list), with the loaded pages
/// filtered client-side while the search is in flight.
@Observable
@MainActor
final class RepoListViewModel {

    let list: PagedListModel<RepoSummary>
    var searchText = "" {
        didSet {
            guard searchText != oldValue else { return }
            scheduleSearch()
        }
    }
    /// Server results for the current query; nil while none has landed.
    private(set) var searchResults: [RepoSummary]?

    private let client: GitbayClient
    private var searchTask: Task<Void, Never>?

    init(client: GitbayClient) {
        self.client = client
        list = PagedListModel(
            client: client,
            argv: ["repo", "list"],
            emptyMessage: "No repositories yet. Create one over SSH: gitbay repo create <name>",
            pageSize: 100
        )
    }

    var state: LoadState<[RepoSummary]> { list.state }

    var visibleRepos: [RepoSummary] {
        let query = searchText.trimmingCharacters(in: .whitespaces).lowercased()
        guard !query.isEmpty else { return list.state.value ?? [] }
        if let searchResults {
            return searchResults
        }
        // The server search has not answered yet; filter what is loaded.
        return (list.state.value ?? []).filter {
            $0.path.lowercased().contains(query)
                || ($0.description ?? "").lowercased().contains(query)
        }
    }

    func load() async {
        await list.reload()
    }

    private func scheduleSearch() {
        searchTask?.cancel()
        searchResults = nil
        let query = searchText.trimmingCharacters(in: .whitespaces)
        guard !query.isEmpty else { return }
        searchTask = Task { [client] in
            // Debounce a person typing; a cancelled sleep throws.
            guard (try? await Task.sleep(for: .milliseconds(300))) != nil else { return }
            let results = try? await client.readList(
                ["repo", "search", query], of: RepoSummary.self
            )
            guard !Task.isCancelled, let results else { return }
            self.searchResults = results
        }
    }
}