using System;

namespace IdleSpectator;

/// <summary>Single deterministic action-selection pipeline.</summary>
public static class ActivityActionComposer
{
    public static string Compose(
        ActivityContext ctx,
        string key,
        string rawFact,
        bool hasTarget,
        long subjectId,
        int lineIndex)
    {
        ctx ??= ActivityContext.Empty;
        ProseVoice voice = EnsureVoice(ctx);

        string verb = ActivityVerbMap.Resolve(key);
        if (string.IsNullOrEmpty(verb))
        {
            // Future unknown tasks still get the mob's authored work voice.
            // The exhaustive runtime audit blocks every current task from reaching this branch.
            verb = "work";
        }

        string[] bag = ActivityActionLexicon.GetBag(voice, verb, hasTarget, ctx.Terrain);
        string phrase = Pick(bag, subjectId, lineIndex);
        return ActivityModifierVoiceOverlay.Apply(phrase, voice, verb, subjectId, lineIndex);
    }

    private static ProseVoice EnsureVoice(ActivityContext ctx)
    {
        if (ctx.Voice != null
            && ctx.Voice.LiveSpeciesId.Equals(ctx.SpeciesId ?? "", StringComparison.Ordinal))
        {
            return ctx.Voice;
        }

        ProseVoice voice = ActivityVoiceResolver.Resolve(ctx.SpeciesId);
        ctx.Voice = voice;
        ctx.BaseSpeciesId = voice.BaseSpeciesId;
        ctx.ModifierTag = ActivityVoiceResolver.ModifierName(voice.Modifier);
        ctx.Family = voice.BaseFamily;
        ctx.MannerTag = ActivityVoiceResolver.TagName(voice.EffectiveActionTag);
        ctx.IsCiv = voice.BaseIsCiv;
        ctx.IsHumanoid = voice.BaseIsHumanoid;
        ctx.IsAnimal = voice.BaseIsAnimal;
        return voice;
    }

    private static string Pick(
        string[] bag,
        long subjectId,
        int lineIndex)
    {
        if (bag == null || bag.Length == 0)
        {
            return "moves along{place_at}{job_as}";
        }

        if (bag.Length == 1)
        {
            return bag[0];
        }

        int actorVariation = (int)((subjectId ^ (lineIndex * 397L)) & 1L);
        int index = actorVariation % Math.Min(2, bag.Length);
        return bag[index];
    }
}