meeting-assistant/MeetingAssistant.Tests/OutlookMeetingCandidateSelectorTests.cs

using MeetingAssistant.MeetingNotes;

namespace MeetingAssistant.Tests;

public sealed class OutlookMeetingCandidateSelectorTests
{
    [Fact]
    public void SelectIgnoresOverlappingMeetingThatEndsInLessThanFiveMinutes()
    {
        var now = new DateTime(2026, 5, 20, 10, 0, 0);
        var selected = OutlookMeetingCandidateSelector.Select(
            [
                new Candidate(now.AddMinutes(-25), now.AddMinutes(4))
            ],
            now,
            candidate => candidate.Start,
            candidate => candidate.End);

        Assert.Null(selected);
    }

    [Fact]
    public void SelectPrefersSingleGoodOverlappingMeetingOverUpcomingMeeting()
    {
        var now = new DateTime(2026, 5, 20, 10, 0, 0);
        var overlap = new Candidate(now.AddMinutes(-10), now.AddMinutes(30));
        var upcoming = new Candidate(now.AddMinutes(3), now.AddMinutes(33));

        var selected = OutlookMeetingCandidateSelector.Select(
            [upcoming, overlap],
            now,
            candidate => candidate.Start,
            candidate => candidate.End);

        Assert.Same(overlap, selected);
    }

    [Fact]
    public void SelectUsesSingleTeamsMeetingStartingWithinFiveMinutesWhenNoGoodOverlapExists()
    {
        var now = new DateTime(2026, 5, 20, 10, 0, 0);
        var endingOverlap = new Candidate(now.AddMinutes(-25), now.AddMinutes(2));
        var upcoming = new Candidate(now.AddMinutes(5), now.AddMinutes(35));

        var selected = OutlookMeetingCandidateSelector.Select(
            [endingOverlap, upcoming],
            now,
            candidate => candidate.Start,
            candidate => candidate.End);

        Assert.Same(upcoming, selected);
    }

    [Fact]
    public void SelectRejectsAmbiguousUpcomingMeetings()
    {
        var now = new DateTime(2026, 5, 20, 10, 0, 0);

        var selected = OutlookMeetingCandidateSelector.Select(
            [
                new Candidate(now.AddMinutes(2), now.AddMinutes(32)),
                new Candidate(now.AddMinutes(4), now.AddMinutes(34))
            ],
            now,
            candidate => candidate.Start,
            candidate => candidate.End);

        Assert.Null(selected);
    }

    private sealed record Candidate(DateTime Start, DateTime End);
}