import Foundation
import Observation

/// `mr list <repo> --state <s>`, paginated.
@Observable
@MainActor
final class MRListViewModel {

    enum StateFilter: String, CaseIterable, Identifiable, Sendable {
        case open, merged, closed, all
        var id: String { rawValue }
    }

    let list: PagedListModel<MergeRequest>
    let repoPath: String
    var filter: StateFilter = .open {
        didSet {
            guard filter != oldValue else { return }
            configureList()
            Task { await list.reload() }
        }
    }

    init(client: GitbayClient, repoPath: String) {
        self.repoPath = repoPath
        list = PagedListModel(
            client: client,
            argv: ["mr", "list", repoPath, "--state", StateFilter.open.rawValue],
            emptyMessage: "No open merge requests."
        )
    }

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

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

    private func configureList() {
        list.argv = ["mr", "list", repoPath, "--state", filter.rawValue]
        list.emptyMessage =
            "No \(filter == .all ? "" : filter.rawValue + " ")merge requests."
    }
}