using HSchool.Content;
using HSchool.People;

namespace HSchool.Server.Api;

internal enum PersonLookupError
{
    None,
    UnknownSchool,
    UnknownPerson,
}

internal sealed record PersonCardResult(PersonCardResponse? Card, PersonLookupError Error);

internal sealed record PersonLogResult(PersonLogResponse? Page, PersonLookupError Error);

internal sealed record PersonLogResponse(
    int Total,
    int Page,
    int PageSize,
    IReadOnlyList<PersonLogEntryResponse> Entries);

internal sealed record PersonLogEntryResponse(DateTime Time, string Type, string Label, string? ThingDef);

internal sealed record PeopleListResponse(
    int Total,
    int Page,
    int PageSize,
    IReadOnlyList<PersonListItemResponse> People,
    PeopleFilterOptionsResponse Filters);

internal sealed record PeopleFilterOptionsResponse(
    IReadOnlyList<int> Years,
    IReadOnlyList<string> Letters,
    IReadOnlyList<DefLabelResponse> Positions);

internal sealed record DefLabelResponse(string DefName, string Label);

internal sealed record PersonListItemResponse(
    string Id,
    string FullName,
    string Surname,
    string Given,
    string Patronymic,
    bool Female,
    int Age,
    IReadOnlyList<string> Roles,
    int? ClassYear,
    string? ClassLetter,
    string? Position,
    string? PositionLabel);

internal sealed record PersonCardResponse(
    string Id,
    string FullName,
    string Surname,
    string Given,
    string Patronymic,
    bool Female,
    int Age,
    DateTime BirthDate,
    IReadOnlyList<string> Roles,
    int? ClassYear,
    string? ClassLetter,
    string? ClassId,
    string? Position,
    string? PositionLabel,
    IReadOnlyList<LabeledStatResponse> Body,
    IReadOnlyList<LabeledStatResponse> Skills,
    IReadOnlyList<DefLabelResponse> Traits,
    IReadOnlyList<NeedStatResponse> Needs,
    string? Activity,
    string? ActivityLabel,
    PersonFamilyResponse Family,
    IReadOnlyList<WornItemResponse> Worn,
    IReadOnlyList<CarriedItemResponse> Carried,
    float CarryMass,
    float CarryCapacity,
    bool HasLocker,
    int HomeCount);

internal sealed record WornItemResponse(
    string DefName,
    string Label,
    string? Color,
    string? ColorLabel,
    IReadOnlyList<DefLabelResponse> Layers,
    float Condition,
    string? ConditionLabel);

internal sealed record CarriedItemResponse(
    string DefName,
    string Label,
    string? Color,
    string? ColorLabel,
    string? Subject,
    string? SubjectLabel,
    float Mass);

internal sealed record LabeledStatResponse(string Id, string Label, string Value);

internal sealed record NeedStatResponse(string Id, string Label, float Value);

internal sealed record PersonFamilyResponse(
    IReadOnlyList<PersonRelResponse> Parents,
    IReadOnlyList<PersonRelResponse> Children,
    IReadOnlyList<PersonRelResponse> Siblings,
    IReadOnlyList<PersonRelResponse> Partners);

internal sealed record PersonRelResponse(string Id, string FullName, bool Female);

internal sealed record DirectoryResponse(IReadOnlyList<DirectoryPersonResponse> People);

internal sealed record DirectoryPersonResponse(string Id, string FullName);

internal static class PeopleListMapper
{
    public static PeopleListResponse From(
        Roster roster,
        RosterPage page,
        DateTime asOf,
        DefCatalog? catalog,
        string locale,
        RosterQuery query)
    {
        var classes = roster.Classes.ToDictionary(schoolClass => schoolClass.Id, StringComparer.Ordinal);
        var people = page.People
            .Select(person => Item(person, classes, asOf, catalog, locale))
            .ToArray();
        return new PeopleListResponse(page.Total, query.Page, query.PageSize, people, FilterOptions(roster, catalog, locale));
    }

    private static PersonListItemResponse Item(
        Person person,
        IReadOnlyDictionary<string, SchoolClass> classes,
        DateTime asOf,
        DefCatalog? catalog,
        string locale)
    {
        int? year = null;
        string? letter = null;
        if (person.ClassId is { } classId && classes.TryGetValue(classId, out var schoolClass))
        {
            year = schoolClass.Year;
            letter = schoolClass.Letter;
        }

        return new PersonListItemResponse(
            person.Id,
            person.Name.Full,
            person.Name.Surname,
            person.Name.Given,
            person.Name.Patronymic,
            person.Female,
            person.AgeOn(asOf),
            RolesOf(person),
            year,
            letter,
            person.Position,
            PositionLabel(catalog, locale, person.Position));
    }

    internal static string[] RolesOf(Person person)
    {
        var roles = new List<string>(3);
        if (person.IsStudent)
        {
            roles.Add(PersonRoles.Student);
        }

        if (person.IsStaff)
        {
            roles.Add(PersonRoles.Staff);
        }

        if (person.IsParent)
        {
            roles.Add(PersonRoles.Parent);
        }

        return [.. roles];
    }

    internal static string? PositionLabel(DefCatalog? catalog, string locale, string? position)
    {
        if (position is null)
        {
            return null;
        }

        if (catalog is not null && catalog.Positions.TryGetValue(position, out var def))
        {
            return catalog.Label(locale, def);
        }

        return position;
    }

    private static PeopleFilterOptionsResponse FilterOptions(Roster roster, DefCatalog? catalog, string locale)
    {
        var years = roster.Classes.Select(schoolClass => schoolClass.Year).Distinct().OrderBy(year => year).ToArray();
        var letters = roster.Classes.Select(schoolClass => schoolClass.Letter).Distinct().OrderBy(letter => letter, StringComparer.Ordinal).ToArray();
        var positions = roster.People
            .Select(person => person.Position)
            .Where(position => position is not null)
            .Distinct(StringComparer.Ordinal)
            .OrderBy(position => PositionLabel(catalog, locale, position) ?? position, StringComparer.Ordinal)
            .Select(position => new DefLabelResponse(position!, PositionLabel(catalog, locale, position) ?? position!))
            .ToArray();
        return new PeopleFilterOptionsResponse(years, letters, positions);
    }
}

internal sealed record HireStaffRequest(string? PersonId, string? Position);

internal sealed record AssignSubjectRequest(string? Subject);

internal sealed record StaffingResponse(
    float Allocated,
    float Payroll,
    float Remaining,
    IReadOnlyList<UncoveredSubjectResponse> Uncovered,
    IReadOnlyList<ApplicantResponse> Applicants,
    IReadOnlyList<StaffMemberResponse> Staff,
    IReadOnlyList<DefLabelResponse> Positions,
    IReadOnlyList<UncoveredSubjectResponse> Subjects);

internal sealed record UncoveredSubjectResponse(
    string DefName,
    string Label,
    int GradeMin,
    int GradeMax,
    int HoursPerWeek,
    int TeachersShort);

internal sealed record ApplicantResponse(
    string Id,
    string FullName,
    bool Female,
    int Age,
    bool IsParent,
    float HourlyWageAsk,
    float MonthlyBase,
    IReadOnlyList<LabeledStatResponse> Skills,
    IReadOnlyList<DefLabelResponse> Traits);

internal sealed record StaffMemberResponse(
    string Id,
    string FullName,
    bool Female,
    int Age,
    bool IsParent,
    string Position,
    string PositionLabel,
    float HourlyWageAsk,
    float WeeklyHours,
    float MonthlyPay,
    IReadOnlyList<DefLabelResponse> Subjects);

internal static class StaffingMapper
{
    public static StaffingResponse From(
        Roster? roster,
        ApplicantPool? pool,
        DefCatalog? catalog,
        DateTime asOf,
        float allocated,
        string locale)
    {
        roster ??= new Roster([], [], []);
        pool ??= ApplicantPool.Empty;
        var rules = catalog?.StaffingRules;
        var payroll = rules is null || catalog is null ? 0f : Staffing.Payroll(catalog, rules, roster);
        var remaining = MathF.Round(MathF.Max(0f, allocated - payroll), 2);

        var uncovered = catalog is null
            ? Array.Empty<UncoveredSubjectResponse>()
            : Staffing.Uncovered(catalog, roster)
                .Select(row => new UncoveredSubjectResponse(
                    row.Subject.DefName,
                    catalog.Label(locale, row.Subject),
                    row.Subject.Grades.Min,
                    row.Subject.Grades.Max,
                    row.Subject.HoursPerWeek,
                    row.TeachersShort))
                .ToArray();

        var applicants = pool.Applicants
            .Select(applicant => new ApplicantResponse(
                applicant.Person.Id,
                applicant.Person.Name.Full,
                applicant.Person.Female,
                applicant.Person.AgeOn(asOf),
                applicant.Person.IsParent,
                applicant.HourlyWageAsk,
                rules is null ? 0f : Staffing.MonthlyBase(rules, applicant.HourlyWageAsk),
                SkillsOf(applicant.Person, catalog, locale),
                TraitsOf(applicant.Person, catalog, locale)))
            .ToArray();

        var staff = roster.People
            .Where(person => person.IsStaff)
            .OrderBy(person => person.Name.Surname, StringComparer.Ordinal)
            .ThenBy(person => person.Id, StringComparer.Ordinal)
            .Select(person => Member(person, roster, catalog, rules, locale, asOf))
            .ToArray();

        var positions = catalog is null
            ? Array.Empty<DefLabelResponse>()
            : catalog.Positions.Values
                .Where(def => !def.Abstract)
                .Select(def => new DefLabelResponse(def.DefName, catalog.Label(locale, def)))
                .OrderBy(row => row.Label, StringComparer.Ordinal)
                .ToArray();

        var subjects = catalog is null
            ? Array.Empty<UncoveredSubjectResponse>()
            : catalog.Subjects.Values
                .Where(def => !def.Abstract)
                .Select(def => new UncoveredSubjectResponse(
                    def.DefName,
                    catalog.Label(locale, def),
                    def.Grades.Min,
                    def.Grades.Max,
                    def.HoursPerWeek,
                    0))
                .ToArray();

        return new StaffingResponse(allocated, payroll, remaining, uncovered, applicants, staff, positions, subjects);
    }

    private static IReadOnlyList<LabeledStatResponse> SkillsOf(Person person, DefCatalog? catalog, string locale)
    {
        return person.Skills
            .OrderByDescending(pair => pair.Value)
            .ThenBy(pair => pair.Key, StringComparer.Ordinal)
            .Select(pair => new LabeledStatResponse(
                pair.Key,
                catalog is not null && catalog.Skills.TryGetValue(pair.Key, out var def)
                    ? catalog.Label(locale, def)
                    : pair.Key,
                pair.Value.ToString()))
            .ToArray();
    }

    private static IReadOnlyList<DefLabelResponse> TraitsOf(Person person, DefCatalog? catalog, string locale)
    {
        return person.Traits
            .Select(name => new DefLabelResponse(
                name,
                catalog is not null && catalog.Traits.TryGetValue(name, out var def)
                    ? catalog.Label(locale, def)
                    : name))
            .ToArray();
    }

    private static StaffMemberResponse Member(
        Person person,
        Roster roster,
        DefCatalog? catalog,
        StaffingDef? rules,
        string locale,
        DateTime asOf)
    {
        var ask = person.HourlyWageAsk ?? 0f;
        var hours = catalog is null ? 0f : Staffing.WeeklyHours(catalog, roster, person);
        var pay = rules is null ? 0f : Staffing.MonthlyPay(rules, ask, hours);
        var subjects = person.Subjects
            .Select(name => new DefLabelResponse(
                name,
                catalog is not null && catalog.Subjects.TryGetValue(name, out var def)
                    ? catalog.Label(locale, def)
                    : name))
            .ToArray();

        return new StaffMemberResponse(
            person.Id,
            person.Name.Full,
            person.Female,
            person.AgeOn(asOf),
            person.IsParent,
            person.Position ?? string.Empty,
            PeopleListMapper.PositionLabel(catalog, locale, person.Position) ?? person.Position ?? string.Empty,
            ask,
            MathF.Round(hours, 1),
            pay,
            subjects);
    }
}