namespace HSchool.Content;

/// <summary>Roles the generator and traits talk about. Code, not a def — new roles are a rebuild.</summary>
public static class PersonRoles
{
    public const string Student = "student";
    public const string Staff = "staff";
    public const string Parent = "parent";

    public static bool IsKnown(string role) =>
        role.Equals(Student, StringComparison.OrdinalIgnoreCase)
        || role.Equals(Staff, StringComparison.OrdinalIgnoreCase)
        || role.Equals(Parent, StringComparison.OrdinalIgnoreCase);
}

/// <summary>
/// Derived body type, not a <see cref="BodyAttributeDef"/>. Skill limits may name it the same
/// way they name hair colour; the generator computes it from height and weight.
/// </summary>
public static class BodyBuilds
{
    public const string Attribute = "Build";

    /// <summary>
    /// The two numeric attributes the build is computed from. They are named in code, so a pack
    /// that renames or drops them is rejected at load rather than quietly producing an average
    /// build for everybody.
    /// </summary>
    public const string HeightAttribute = "Height";

    public const string WeightAttribute = "Weight";

    public const string Skinny = "Skinny";
    public const string Average = "Average";
    public const string Athletic = "Athletic";
    public const string Heavy = "Heavy";
    public const string Obese = "Obese";

    public static readonly IReadOnlyList<string> Values =
        [Skinny, Average, Athletic, Heavy, Obese];

    public static bool IsKnown(string value) =>
        Values.Any(candidate => candidate.Equals(value, StringComparison.Ordinal));

    /// <summary>
    /// WHO-ish bands with a fit slice in the healthy range so <c>Athletic</c> is derived, not rolled.
    /// Height in centimetres, weight in kilograms.
    /// </summary>
    public static string FromHeightAndWeight(int heightCm, int weightKg)
    {
        if (heightCm <= 0)
        {
            return Average;
        }

        var metres = heightCm / 100d;
        var bmi = weightKg / (metres * metres);
        if (bmi < 18.5)
        {
            return Skinny;
        }

        if (bmi < 22.0)
        {
            return Average;
        }

        if (bmi < 25.0)
        {
            return Athletic;
        }

        if (bmi < 30.0)
        {
            return Heavy;
        }

        return Obese;
    }
}

public sealed class IntRange
{
    public int Min { get; init; }

    public int Max { get; init; } = 100;
}

public sealed class StatDistribution
{
    public float Mean { get; init; }

    public float StdDev { get; init; } = 1;
}

public sealed class AgeMeanPoint
{
    public int Age { get; init; }

    public float Mean { get; init; }
}

public sealed class BodySkillLimit
{
    public required string Attribute { get; init; }

    public string? Value { get; init; }

    public int? Min { get; init; }

    public int? Max { get; init; }
}

public sealed class SkillDef : Def
{
    public IntRange Range { get; init; } = new();

    public StatDistribution? Distribution { get; init; }

    public IReadOnlyList<AgeMeanPoint> AgeMeans { get; init; } = [];

    public IReadOnlyList<BodySkillLimit> BodyLimits { get; init; } = [];
}

public sealed class SubjectSkillShare
{
    public required string Skill { get; init; }

    public float Share { get; init; }
}

public sealed class SubjectDef : Def
{
    public IntRange Grades { get; init; } = new() { Min = 1, Max = 11 };

    public int HoursPerWeek { get; init; }

    public IReadOnlyList<SubjectSkillShare> Skills { get; init; } = [];

    /// <summary>
    /// RoomDef the lesson needs. Null means the class's homeroom. PE uses a gym, informatics a lab.
    /// </summary>
    public string? Room { get; init; }
}

public sealed class TraitSkillModifier
{
    public required string Skill { get; init; }

    public int Offset { get; init; }
}

public sealed class TraitDef : Def
{
    public int Weight { get; init; } = 1;

    public IReadOnlyList<string> Incompatible { get; init; } = [];

    /// <summary>Empty means every role. Values are <see cref="PersonRoles"/> ids.</summary>
    public IReadOnlyList<string> Roles { get; init; } = [];

    public IntRange? Age { get; init; }

    public IReadOnlyList<TraitSkillModifier> SkillModifiers { get; init; } = [];

    /// <summary>
    /// Added to the hourly wage ask. Positive means the person wants more at the same skills.
    /// </summary>
    public float WageAsk { get; init; }
}

public sealed class StaffingDef : Def
{
    public int PoolSize { get; init; }

    public float StayChance { get; init; }

    public float ParentChance { get; init; }

    public float HourlyWageBase { get; init; }

    public float HourlyWagePerSkill { get; init; }

    /// <summary>
    /// One full rate. A hired person is paid for at least this many hours even with nothing
    /// assigned; hours beyond it are paid on top.
    /// </summary>
    public float BaseWeeklyHours { get; init; }

    /// <summary>
    /// Most hours one person can carry. A subject whose curriculum needs more than this needs a
    /// second teacher — the hours are then shared between them.
    /// </summary>
    public float MaxWeeklyHours { get; init; }

    public float WeeksPerMonth { get; init; }
}

public enum BodyAttributeKind
{
    Number,
    Choice,
}

public sealed class SexAgeDistribution
{
    /// <summary><c>male</c>, <c>female</c>, or omit for both.</summary>
    public string? Sex { get; init; }

    public int? AgeMin { get; init; }

    public int? AgeMax { get; init; }

    public required StatDistribution Distribution { get; init; }

    public IntRange? Range { get; init; }
}

public sealed class WeightedOption
{
    public required string Value { get; init; }

    public int Weight { get; init; } = 1;

    public string? Sex { get; init; }

    public int? AgeMin { get; init; }

    public int? AgeMax { get; init; }
}

public sealed class BodyAttributeDef : Def
{
    public BodyAttributeKind Kind { get; init; }

    public IReadOnlyList<SexAgeDistribution> Distributions { get; init; } = [];

    public IReadOnlyList<WeightedOption> Options { get; init; } = [];
}

public sealed class NeedDef : Def
{
    public float Initial { get; init; } = 1;

    public float DecayPerHour { get; init; }

    public float Min { get; init; }

    public float Max { get; init; } = 1;
}

public sealed class CaseTable
{
    public required string Nom { get; init; }

    public required string Gen { get; init; }

    public required string Dat { get; init; }

    public required string Acc { get; init; }

    public required string Ins { get; init; }

    public required string Pre { get; init; }

    public string this[GrammaticalCase grammaticalCase] => grammaticalCase switch
    {
        GrammaticalCase.Nominative => Nom,
        GrammaticalCase.Genitive => Gen,
        GrammaticalCase.Dative => Dat,
        GrammaticalCase.Accusative => Acc,
        GrammaticalCase.Instrumental => Ins,
        GrammaticalCase.Prepositional => Pre,
        _ => Nom,
    };
}

public sealed class GivenNameEntry
{
    public required string Form { get; init; }

    public string? Declension { get; init; }

    public CaseTable? Cases { get; init; }
}

public sealed class SurnameEntry
{
    public required string Male { get; init; }

    public required string Female { get; init; }

    public string? Declension { get; init; }

    public CaseTable? MaleCases { get; init; }

    public CaseTable? FemaleCases { get; init; }
}

public sealed class NameSetDef : Def
{
    public string PatronymicRule { get; init; } = NameGrammar.SlavicPatronymic;

    public string DefaultGivenDeclension { get; init; } = NameGrammar.Hard;

    public string DefaultSurnameDeclension { get; init; } = NameGrammar.Ov;

    public IReadOnlyList<GivenNameEntry> MaleGiven { get; init; } = [];

    public IReadOnlyList<GivenNameEntry> FemaleGiven { get; init; } = [];

    public IReadOnlyList<SurnameEntry> Surnames { get; init; } = [];
}