using HSchool.Content;

namespace HSchool.Ai;

/// <summary>Why someone should walk to their locker room.</summary>
public enum ApparelGoalKind
{
    None,
    Pe,
    Everyday,
    Weather,
}

/// <summary>
/// Dress-code and weather goals beside duty. Triggered on bells and arrival, not every tick.
/// </summary>
public static class ApparelGoals
{
    public static Intent? Goal(
        DefCatalog catalog,
        MapLayout map,
        WalkGraph walks,
        ApparelActor apparel,
        ActorState state,
        OccupiedCount occupied)
    {
        ArgumentNullException.ThrowIfNull(catalog);
        ArgumentNullException.ThrowIfNull(map);
        ArgumentNullException.ThrowIfNull(walks);

        if (apparel.Issues == ApparelIssue.None || apparel.LockerRoomNode is null)
        {
            return null;
        }

        var weight = catalog.BehaviorRules?.ApparelGoalWeight ?? 5.5f;
        var actionId = ApparelActions.For(apparel.Female);
        if (!catalog.Actions.TryGetValue(actionId, out var action) || action.Abstract)
        {
            return null;
        }

        if (state.BoundToLesson && (apparel.Kind == ApparelGoalKind.Pe || apparel.Kind == ApparelGoalKind.Everyday))
        {
            return null;
        }

        var room = RoomFor(catalog, map, walks, state, occupied, action, apparel.LockerRoomNode);
        if (room is null)
        {
            return null;
        }

        var id = apparel.Kind switch
        {
            ApparelGoalKind.Pe => "pe",
            ApparelGoalKind.Everyday => "everyday",
            ApparelGoalKind.Weather => "weather",
            _ => null,
        };
        if (id is null)
        {
            return null;
        }

        return new Intent(GoalKind.Apparel, id, weight, actionId);
    }

    public static ApparelGoalKind Classify(ApparelIssue issues)
    {
        if (issues.HasFlag(ApparelIssue.PeRequired))
        {
            return ApparelGoalKind.Pe;
        }

        if (issues.HasFlag(ApparelIssue.PeForbidden))
        {
            return ApparelGoalKind.Everyday;
        }

        if (issues.HasFlag(ApparelIssue.OuterRequired) || issues.HasFlag(ApparelIssue.OuterForbidden))
        {
            return ApparelGoalKind.Weather;
        }

        if (issues.HasFlag(ApparelIssue.Formality)
            || issues.HasFlag(ApparelIssue.Color)
            || issues.HasFlag(ApparelIssue.SkirtLength))
        {
            return ApparelGoalKind.Everyday;
        }

        return ApparelGoalKind.None;
    }

    private static string? RoomFor(
        DefCatalog catalog,
        MapLayout map,
        WalkGraph walks,
        ActorState state,
        OccupiedCount occupied,
        ActionDef action,
        string preferredNode)
    {
        foreach (var room in map.Rooms)
        {
            if (!room.Id.Equals(preferredNode, StringComparison.Ordinal))
            {
                continue;
            }

            if (!action.Room!.Equals(room.Def, StringComparison.Ordinal))
            {
                continue;
            }

            if (!HasSlot(catalog, map, occupied, room.Id, action.Thing))
            {
                continue;
            }

            return room.Id;
        }

        if (state.NodeId is not null && state.NodeId.Equals(preferredNode, StringComparison.Ordinal))
        {
            return preferredNode;
        }

        var from = state.NodeId ?? walks.TerritoryId;
        var cost = walks.Minutes(from, preferredNode);
        return float.IsInfinity(cost) ? null : preferredNode;
    }

    private static bool HasSlot(DefCatalog catalog, MapLayout map, OccupiedCount occupied, string nodeId, string? thing)
    {
        if (string.IsNullOrWhiteSpace(thing))
        {
            return true;
        }

        var available = RoomOccupancy.ThingCount(catalog, map, nodeId, thing);
        return ActionStepper.CanOccupy(available, occupied(nodeId, thing));
    }
}

/// <summary>Apparel inputs the generic planner does not carry.</summary>
public readonly record struct ApparelActor(
    bool Female,
    ApparelIssue Issues,
    ApparelGoalKind Kind,
    string? LockerRoomNode);