import XCTest
@testable import KeeVaultCore

final class GroupSelectionTests: XCTestCase {
    private func makeSampleTree() -> (root: Group, work: Group, email: Group, personal: Group) {
        let email = Group(name: "Email")
        let work = Group(name: "Work", subgroups: [email])
        let personal = Group(name: "Personal")
        let root = Group(name: "Root", subgroups: [work, personal])
        return (root, work, email, personal)
    }

    func test_subtreeIds_includesGroupAndAllDescendants() {
        let (root, work, email, _) = makeSampleTree()
        let ids = GroupSelection.subtreeIds(of: work.id, in: root)
        XCTAssertEqual(ids, [work.id, email.id])
    }

    func test_subtreeIds_leafGroup_returnsOnlyItself() {
        let (root, _, email, _) = makeSampleTree()
        let ids = GroupSelection.subtreeIds(of: email.id, in: root)
        XCTAssertEqual(ids, [email.id])
    }

    func test_toggling_selectsGroupAndSubtree() {
        let (root, work, email, _) = makeSampleTree()
        let result = GroupSelection.toggling(work.id, in: root, current: [])
        XCTAssertEqual(result, [work.id, email.id])
    }

    func test_toggling_deselectsGroupAndSubtree() {
        let (root, work, email, _) = makeSampleTree()
        let result = GroupSelection.toggling(work.id, in: root, current: [work.id, email.id])
        XCTAssertEqual(result, [])
    }

    func test_toggling_doesNotAffectUnrelatedSelection() {
        let (root, work, email, personal) = makeSampleTree()
        let result = GroupSelection.toggling(work.id, in: root, current: [personal.id])
        XCTAssertEqual(result, [personal.id, work.id, email.id])
    }

    func test_subtreeIds_groupNotFound_returnsEmptySet() {
        let (root, _, _, _) = makeSampleTree()
        let nonExistentId = UUID()
        let ids = GroupSelection.subtreeIds(of: nonExistentId, in: root)
        XCTAssertEqual(ids, [])
    }

    func test_toggling_groupNotFound_returnsCurrentUnchanged() {
        let (root, _, _, personal) = makeSampleTree()
        let nonExistentId = UUID()
        let current: Set<UUID> = [personal.id]
        let result = GroupSelection.toggling(nonExistentId, in: root, current: current)
        XCTAssertEqual(result, current)
    }
}