namespace HSchool.People.Tests;

/// <summary>
/// One line per class and person, sorted, so a generator change shows up as the first
/// mismatched line instead of "the snapshots differ".
/// </summary>
internal static class RosterFingerprint
{
    public static string Format(Roster roster, int seed, string country, string native)
    {
        var lines = new List<string>
        {
            $"# seed={seed} country={country} native={native} people={roster.People.Count} classes={roster.Classes.Count}",
        };

        foreach (var schoolClass in roster.Classes.OrderBy(row => row.Id, StringComparer.Ordinal))
        {
            var pupils = string.Join(',', schoolClass.PupilIds.Order(StringComparer.Ordinal));
            lines.Add(
                $"class {schoolClass.Id} year={schoolClass.Year} letter={schoolClass.Letter} room={schoolClass.RoomId} capacity={schoolClass.Capacity} pupils={pupils}");
        }

        foreach (var person in roster.People.OrderBy(row => row.Id, StringComparer.Ordinal))
        {
            lines.Add(PersonLine(person));
        }

        return string.Join('\n', lines) + '\n';
    }

    public static void AssertEqual(string expected, string actual)
    {
        var left = expected.Replace("\r\n", "\n", StringComparison.Ordinal).Split('\n');
        var right = actual.Replace("\r\n", "\n", StringComparison.Ordinal).Split('\n');
        var count = Math.Min(left.Length, right.Length);
        for (var i = 0; i < count; i++)
        {
            if (!string.Equals(left[i], right[i], StringComparison.Ordinal))
            {
                Assert.Fail($"first mismatch at line {i + 1}\nexpected: {left[i]}\nactual:   {right[i]}");
            }
        }

        if (left.Length != right.Length)
        {
            Assert.Fail($"line count {left.Length} vs {right.Length}");
        }
    }

    private static string PersonLine(Person person)
    {
        var roles = string.Join(',', Roles(person));
        var traits = string.Join(',', person.Traits.Order(StringComparer.Ordinal));
        var skills = string.Join(
            ',',
            person.Skills.OrderBy(pair => pair.Key, StringComparer.Ordinal).Select(pair => $"{pair.Key}={pair.Value}"));
        return
            $"person {person.Id} {person.Name.Full} female={person.Female} roles={roles} class={person.ClassId ?? "-"} born={person.BirthDate:yyyy-MM-dd} traits={traits} skills={skills}";
    }

    private static IEnumerable<string> Roles(Person person)
    {
        if (person.IsStudent)
        {
            yield return "student";
        }

        if (person.IsStaff)
        {
            yield return "staff";
        }

        if (person.IsParent)
        {
            yield return "parent";
        }
    }
}