using CounterStrikeSharp.API.Core;

namespace Outnumbered.Engine;

// The weapon-inventory read surface (WeaponServices: MyWeapons / ActiveWeapon) plus the slot-select client commands.
// Centralizes the null-safe "walk / read the player's weapons" idiom shared by Abilities + Shop, so a
// CSSharp rename of WeaponServices/MyWeapons/ActiveWeapon — or a change to slot-select semantics — is one edit here.
// (The bare GiveNamedItem/RemoveItemByDesignerName loadout calls stay at their call sites: single-call, nothing to share.)
internal static class Inventory
{
    // Slot-select client commands (engine INPUT, not schema). slot3 (the melee slot) is the neutral "rest" anchor; the zeus
    // is deployed by name because the engine auto-deploys a granted grenade over the knife but not over a real weapon.
    public const string SlotPrimary = "slot1";
    public const string SlotSecondary = "slot2";
    public const string SlotMelee = "slot3";
    public const string UseZeus = "use weapon_taser";

    // The player's currently-deployed weapon, or null (null-safe through pawn -> WeaponServices -> handle, IsValid-checked).
    public static CBasePlayerWeapon? ActiveWeapon(CCSPlayerPawn? pawn)
    {
        var w = pawn?.WeaponServices?.ActiveWeapon.Value;
        return w is { IsValid: true } ? w : null;
    }

    public static CBasePlayerWeapon? ActiveWeapon(CCSPlayerController p) => ActiveWeapon(p.PlayerPawn.Value);

    // The active weapon's designer name, or "" when none — the common "what is this player holding?" probe.
    public static string ActiveWeaponName(CCSPlayerPawn? pawn) => ActiveWeapon(pawn)?.DesignerName ?? "";

    // TRUE if the designer name is a knife (any skin — weapon_knife, weapon_knife_t, weapon_bayonet, …) or the zeus. Lets the
    // thorns abuse-guard tell "real melee in hand" from a gun (mirrors Shop's knife-neutral test, plus the zeus).
    public static bool IsMeleeOrZeus(string designerName) =>
        designerName == EngineNames.ShopMelee || designerName.Contains("knife") || designerName.Contains("bayonet");

    // Every valid weapon the player holds (null-safe walk of WeaponServices.MyWeapons). Empty if no pawn / no services.
    // Lazy (iterator) — fine for the cold classify-all walk; the hot exact-match check uses Holds (no enumerator alloc).
    public static IEnumerable<CBasePlayerWeapon> Weapons(CCSPlayerController p)
    {
        var weapons = p.PlayerPawn.Value?.WeaponServices?.MyWeapons;
        if (weapons is null) yield break;
        foreach (var h in weapons)
        {
            var w = h.Value;
            if (w is { IsValid: true }) yield return w;
        }
    }

    // The weapon's full magazine size from its VData, or -1 if unavailable (the No-Reload / infinite-clip top-up reads it).
    public static int MaxClip(CBasePlayerWeapon w) => w.As<CCSWeaponBase>().VData?.MaxClip1 ?? -1;

    // Whether the pawn's weapon inventory is readable at all (pawn + WeaponServices + MyWeapons present) — distinguishes
    // "no inventory" from "an empty inventory" for callers that branch on it (e.g. PreferredSlotCmd's no-services fallback).
    public static bool HasWeaponServices(CCSPlayerController p) => p.PlayerPawn.Value?.WeaponServices?.MyWeapons is not null;

    // True if the player holds a weapon with this designer name. Direct walk (no iterator alloc) for the per-reconcile path.
    public static bool Holds(CCSPlayerController p, string designerName)
    {
        var weapons = p.PlayerPawn.Value?.WeaponServices?.MyWeapons;
        if (weapons is null) return false;
        foreach (var h in weapons)
        {
            var w = h.Value;
            if (w is { IsValid: true } && w.DesignerName == designerName) return true;
        }
        return false;
    }
}