//
//  ConversationListViewPureLogicTests.swift
//  oAITests
//
// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0
// Copyright (C) 2026 Rune Olsen

import Testing
import Foundation
@testable import Confab

@Suite("ConversationListView.idsInRange")
struct ConversationListViewPureLogicTests {

    private let ids = (0..<6).map { _ in UUID() }

    @Test("Forward range includes anchor and target inclusive")
    func forwardRange() {
        let result = ConversationListView.idsInRange(orderedIds: ids, anchorId: ids[1], targetId: ids[4])
        #expect(result == Set(ids[1...4]))
    }

    @Test("Backward range (target above anchor) still selects the span between them")
    func backwardRange() {
        let result = ConversationListView.idsInRange(orderedIds: ids, anchorId: ids[4], targetId: ids[1])
        #expect(result == Set(ids[1...4]))
    }

    @Test("Anchor equal to target selects just that one id")
    func sameAnchorAndTarget() {
        let result = ConversationListView.idsInRange(orderedIds: ids, anchorId: ids[2], targetId: ids[2])
        #expect(result == [ids[2]])
    }

    @Test("Nil anchor (first Shift-click) falls back to just the target")
    func nilAnchorFallsBackToTarget() {
        let result = ConversationListView.idsInRange(orderedIds: ids, anchorId: nil, targetId: ids[3])
        #expect(result == [ids[3]])
    }

    @Test("Anchor no longer present in the ordered list falls back to just the target")
    func missingAnchorFallsBackToTarget() {
        let staleAnchor = UUID()
        let result = ConversationListView.idsInRange(orderedIds: ids, anchorId: staleAnchor, targetId: ids[3])
        #expect(result == [ids[3]])
    }

    @Test("Single-element list selects that element")
    func singleElementList() {
        let solo = [ids[0]]
        let result = ConversationListView.idsInRange(orderedIds: solo, anchorId: ids[0], targetId: ids[0])
        #expect(result == [ids[0]])
    }
}