using System;

namespace IdleSpectator;

/// <summary>
/// Adds a meaningful transformed-variant tone without replacing the recovered base mob voice.
/// Native authored forms keep their own complete voice and do not pass through this overlay.
/// </summary>
public static class ActivityModifierVoiceOverlay
{
    private const string PlaceToken = "{place_at}";

    public static string Apply(
        string basePhrase,
        ProseVoice voice,
        string verb,
        long subjectId,
        int lineIndex)
    {
        if (string.IsNullOrEmpty(basePhrase)
            || voice == null
            || voice.Modifier == ActivityModifier.None
            || voice.LiveSpeciesId.Equals(voice.BaseSpeciesId, StringComparison.OrdinalIgnoreCase))
        {
            return basePhrase;
        }

        string[] bag = OverlayBag(voice.Modifier, voice.BaseBodyTag, verb);
        if (bag == null || bag.Length == 0)
        {
            return basePhrase;
        }

        int index = (int)((subjectId ^ (lineIndex * 397L)) & 1L) % bag.Length;
        string core = basePhrase
            .Replace("{job_as}", "")
            .Replace("{job}", "");

        bool restorePlace = false;
        if (WantsPlace(verb) && core.EndsWith(PlaceToken, StringComparison.Ordinal))
        {
            core = core.Substring(0, core.Length - PlaceToken.Length);
            restorePlace = true;
        }
        else if (core.EndsWith(PlaceToken, StringComparison.Ordinal))
        {
            // Never introduce or keep place on non-place-centric verbs via overlay.
            core = core.Substring(0, core.Length - PlaceToken.Length);
        }

        string result = core + bag[index];
        if (restorePlace)
        {
            result += PlaceToken;
        }

        return result;
    }

    private static bool WantsPlace(string verb)
    {
        return verb == "settle" || verb == "trade" || verb == "farm";
    }

    private static string[] OverlayBag(
        ActivityModifier modifier,
        ActivityBodyTag body,
        string verb)
    {
        return modifier switch
        {
            ActivityModifier.Undead => UndeadBag(body, verb),
            ActivityModifier.Elemental => ElementalBag(verb),
            ActivityModifier.Mush => MushBag(verb),
            ActivityModifier.Tumor => TumorBag(verb),
            ActivityModifier.Alien => AlienBag(verb),
            ActivityModifier.Construct => ConstructBag(verb),
            _ => null
        };
    }

    private static string[] UndeadBag(ActivityBodyTag body, string verb)
    {
        if (verb == "move")
        {
            return body switch
            {
                ActivityBodyTag.Canine => V(
                    ", its paws landing in stiff, uneven beats",
                    ", its muzzle fixed ahead as its gait falters"),
                ActivityBodyTag.Feline => V(
                    ", each silent step held rigid too long",
                    ", its once-fluid gait broken into sharp jolts"),
                ActivityBodyTag.Bird => V(
                    ", its lifeless wings beating out of rhythm",
                    ", each ragged motion ending in a hard twitch"),
                ActivityBodyTag.Insect => V(
                    ", its joints clicking in lifeless sequence",
                    ", each small step snapping into the next"),
                ActivityBodyTag.Plant => V(
                    ", its withered growth dragging behind",
                    ", every deadened limb moving in rigid turns"),
                ActivityBodyTag.Dragon => V(
                    ", its ruined frame carrying deathly weight",
                    ", every ancient joint grinding through the motion"),
                _ => V(
                    ", its gait broken by stiff, uneven jolts",
                    ", every step landing with lifeless weight")
            };
        }

        return verb switch
        {
            "wait" => V(
                ", holding an unnaturally rigid posture",
                ", without breath or any easy motion"),
            "play" => V(
                ", repeating each motion in empty jerks",
                ", the movement breaking into stiff, empty rhythms"),
            "eat" => V(
                ", driven by a hunger that never eases",
                ", consuming each bite without satisfaction"),
            "sleep" => V(
                ", lying rigid even at rest",
                ", never fully losing its restless tension"),
            "hunt" => V(
                ", pursuing without tiring",
                ", never slowing as the chase continues"),
            "fight" => V(
                ", striking without fear or pain",
                ", pressing the attack with deathless persistence"),
            "social" => V(
                ", answering with hollow, halting sounds",
                ", holding close in an uneasy silence"),
            "laugh" => V(
                ", the sound collapsing into a dry rasp",
                ", each note ending in a hollow groan"),
            "work" => V(
                ", continuing in tireless, rigid motions",
                ", never pausing as its joints grind on"),
            _ => V(
                ", its body moving with lifeless stiffness",
                ", each motion marked by restless undeath")
        };
    }

    private static string[] ElementalBag(string verb)
    {
        return verb switch
        {
            "wait" => V(", flickering without becoming still", ", its glow rising and falling"),
            "sleep" => V(", dimming to a banked glow", ", its brightness settling low"),
            "eat" => V(", drawing the meal into its inner heat", ", feeding the flame within"),
            "fight" => V(", shedding sparks with every strike", ", flaring brighter through the clash"),
            _ => V(", edged by quick tongues of flame", ", trailing brief curls of heat")
        };
    }

    private static string[] MushBag(string verb)
    {
        return verb switch
        {
            "wait" => V(", faint spores drifting from every pause", ", its soft growth gently pulsing"),
            "eat" => V(", drawing nourishment through fibrous growth", ", feeding in slow, spreading pulses"),
            "fight" => V(", bursting spores through every impact", ", its soft mass recoiling and swelling"),
            _ => V(", shedding a faint wake of spores", ", its softened form flexing with each motion")
        };
    }

    private static string[] TumorBag(string verb)
    {
        return verb switch
        {
            "wait" => V(", its swollen mass quivering in place", ", uneven pulses passing through its body"),
            "eat" => V(", absorbing the meal into its growing mass", ", folding each bite into hungry tissue"),
            "fight" => V(", its mass surging behind every blow", ", new growth tightening through the clash"),
            _ => V(", its form shifting in uneven pulses", ", swollen tissue rolling through each motion")
        };
    }

    private static string[] AlienBag(string verb)
    {
        return verb switch
        {
            "wait" => V(", holding a posture that is difficult to read", ", its unfamiliar joints locking at odd angles"),
            "social" => V(", answering in precise, unfamiliar signals", ", mirroring the exchange with uncanny timing"),
            "fight" => V(", changing angles without warning", ", every strike arriving with uncanny precision"),
            _ => V(", following an unfamiliar rhythm", ", each motion precise but difficult to predict")
        };
    }

    private static string[] ConstructBag(string verb)
    {
        return verb switch
        {
            "wait" => V(", every mechanism settling into a fixed hold", ", its joints locking into measured stillness"),
            "sleep" => V(", its moving parts falling dormant", ", the last small mechanisms winding down"),
            "fight" => V(", every joint driving the next strike", ", its rigid frame absorbing the impact"),
            "work" => V(", repeating each step with exact precision", ", its mechanisms keeping a flawless cadence"),
            _ => V(", every joint moving in measured sequence", ", its mechanisms keeping a precise cadence")
        };
    }

    private static string[] V(string first, string second)
    {
        return new[] { first, second };
    }
}