namespace BardFrontline.Core;

public sealed record RuntimeConditions(bool Enabled, bool LoggedIn, bool ChangingArea, BattlefieldMode Mode,
    bool DutyStarted, bool DutyCompleted, bool Bard, bool Alive, bool Mounted, bool Occupied, bool CoreReady, bool Piloting = false);

public static class ExecutionPolicy
{
    public static string? PauseReason(RuntimeConditions s)
    {
        if (!s.Enabled) return "已关闭";
        if (!s.LoggedIn) return "等待角色登录";
        if (s.ChangingArea) return "切换区域";
        if (s.Mode is not (BattlefieldMode.Frontline or BattlefieldMode.RivalWings)) return "仅在纷争前线 / 烈羽争锋运行";
        if (!s.DutyStarted || s.DutyCompleted) return "等待对局开始 / 对局已结束";
        if (s.Piloting) return "驾驶机甲中，暂停诗人循环";
        if (!s.Bard) return "仅支持吟游诗人";
        if (!s.Alive) return "角色死亡";
        if (s.Mounted) return "坐骑上暂停";
        if (s.Occupied) return "角色正在交互";
        return s.CoreReady ? null : "核心技能数据缺失";
    }

    public static bool CanDispatch(bool queued, float animationLock, bool casting, bool pending, bool guard) =>
        !queued && animationLock <= 0 && !casting && !pending && !guard;

    public static bool CanWeave(float sharedRecastRemaining) => sharedRecastRemaining <= 0 || sharedRecastRemaining >= .65f;

    // Encore is a time-limited LB follow-up. An extra GCD reservation must not starve it
    // under stacked haste; the runtime still enforces casting, animation lock and native recast.
    public static bool CanWeave(float sharedRecastRemaining, Skill skill) =>
        skill == Skill.EncoreOfLight || CanWeave(sharedRecastRemaining);

    public static bool SharesGcd(int primary, int additional, int shared) => shared >= 0 && (primary == shared || additional == shared);
    public static float RecastRemaining(bool active, float total, float elapsed) =>
        active && float.IsFinite(total) && float.IsFinite(elapsed) ? Math.Max(0, total - elapsed) : 0;

    public static bool OwnsCast(uint ownedId, ulong ownedTarget, ushort ownedSequence,
        uint castId, ulong castTarget, ushort usedSequence) =>
        ownedId == castId && ownedTarget == castTarget && ownedSequence == usedSequence;

    public static bool ShouldCancelCast(Skill castSkill, bool owned, bool invalidTarget, bool enemyGuard,
        bool ignoreGuard, ActionDecision? emergency, bool nearbyThreat, bool hasControl)
    {
        if (!owned) return false;
        if (Actions.IsHostile(castSkill) && (invalidTarget || enemyGuard && !ignoreGuard && castSkill != Skill.EagleEyeShot)) return true;
        if (emergency == null) return false;
        // Recovering HP is the point of elixir. Do not cancel a safe drink just because Recuperate came off CD.
        return castSkill != Skill.Elixir || nearbyThreat || hasControl;
    }
}