using Unity.Entities;
using Unity.NetCode;

namespace ProjectM.Simulation
{
    /// <summary>
    /// Macro-loop state for "The Aether Cycle": which phase the run is in, the cycle number, and the server
    /// tick the current (timed) phase ends. Server-authoritative, maintained by CyclePhaseSystem. Currently a
    /// server-side singleton; the [GhostField]s below are inert until it is moved onto the runtime-spawned
    /// CycleDirector ghost (when the client HUD is wired), at which point the same struct replicates unchanged.
    /// The Defend phase is NOT timed — it ends when the base-defense wave is cleared — so PhaseEndTick is only
    /// meaningful in Expedition/Build (0 during Defend).
    /// </summary>
    public struct CycleState : IComponentData
    {
        /// <summary>Current phase (see <see cref="CyclePhase"/>).</summary>
        [GhostField] public byte Phase;

        /// <summary>1-based cycle counter (increments when a new Expedition begins).</summary>
        [GhostField] public int CycleNumber;

        /// <summary>Server tick the current timed phase ends (Expedition/Build only; 0 in Defend).</summary>
        [GhostField] public uint PhaseEndTick;

        /// <summary>Live Husk wave number during Defend, synced from the server-only WaveState by CyclePhaseSystem so the replicated-state-only HUD can show it (holds the last wave number outside Defend; the HUD gates the display to the Defend phase).</summary>
        [GhostField] public int WaveNumber;
    }

    /// <summary>Phase constants for <see cref="CycleState.Phase"/> — the GLOBAL shared posture (a byte, not an enum, for trivial Burst/serialization). Being out on an expedition is per-player presence (server-only RegionTag), NOT a global phase.</summary>
    public static class CyclePhase
    {
        // Re-meaned IN PLACE — the byte VALUES are unchanged from the old Expedition/Defend/Build, so the
        // [GhostField] serializer layout is identical (the const re-mean alone forces no re-bake). slot 0 (was
        // Expedition) -> Calm; slot 1 (was Defend) -> Siege; slot 2 (was Build) -> retired.

        /// <summary>The persistent, unhurried home base — the DEFAULT posture. No countdown; build/prep at your pace.</summary>
        public const byte Calm = 0;

        /// <summary>The base is under assault by a Husk wave (event-triggered; ends when the wave is cleared).</summary>
        public const byte Siege = 1;

        // ---- Deprecated aliases (kept so HUD/audio/tests keep compiling through the cut-over; cleaned up later). ----

        /// <summary>DEPRECATED alias of <see cref="Calm"/>.</summary>
        public const byte Expedition = 0;

        /// <summary>DEPRECATED alias of <see cref="Siege"/>.</summary>
        public const byte Defend = 1;

        /// <summary>DEPRECATED, unreachable — the timed Build phase is retired.</summary>
        public const byte Build = 2;

        /// <summary>DEPRECATED — the forced Expedition timer is retired (the loop is player-driven). Kept so existing crefs resolve.</summary>
        public const uint ExpeditionTicks = 3600;

        /// <summary>DEPRECATED — the forced Build timer is retired. Kept so existing crefs resolve.</summary>
        public const uint BuildTicks = 1200;
    }

    /// <summary>
    /// Server-only bookkeeping for the run-state machine that must NOT replicate (kept separate from the
    /// replicated <see cref="CycleState"/>). Records the wave number captured when the current Siege began plus
    /// the procedural-expedition-field session epoch (bumped when the expedition region goes empty-&gt;occupied so
    /// the field reseeds per sortie).
    /// </summary>
    public struct CycleRuntime : IComponentData
    {
        /// <summary>WaveState.WaveNumber captured the moment the current Siege started (DefendCleared tests &gt; this).</summary>
        public int DefendStartWave;

        /// <summary>Monotonic expedition-field session counter; bumped on the expedition region's empty-&gt;occupied edge so each sortie reseeds. RNG seed (never tick math; never 0, via max(1, ...)).</summary>
        public int ExpeditionEpoch;

        /// <summary>The <see cref="ExpeditionEpoch"/> the field was last seeded for (compared by int equality).</summary>
        public int LastSpawnedEpoch;

        /// <summary>Previous-tick expedition occupancy (1 = at least one player out), for the empty&lt;-&gt;occupied edge.</summary>
        public byte PrevExpeditionOccupied;

        /// <summary>The <see cref="ExpeditionEpoch"/> a zone-clear Ore reward was last banked for — gates the once-per-epoch reward so two same-tick co-op returners pay once and gate re-entry can't farm (int equality, never tick math).</summary>
        public int LastRewardedEpoch;

        /// <summary>1 once the current epoch's expedition wave has FULLY spawned and been cleared to zero live zone enemies; reset to 0 on the empty-&gt;occupied epoch bump. The reward fires only on a REAL clear.</summary>
        public byte ClearedThisEpoch;
    }

    /// <summary>
    /// DR-042 C7b — a SMALL replicated summary of the current expedition objective so the client HUD can show an
    /// "enemies remaining / cleared — return to claim" readout. Rides the GLOBAL UNTAGGED CycleDirector ghost
    /// (alongside <see cref="CycleState"/> / GoalProgress) so GhostRelevancy.SetIsIrrelevant never hides it
    /// cross-region — a base teammate can't see the expedition's own (region-tagged, relevancy-hidden) enemy
    /// ghosts. SOLE writer: ZoneEnemyDirectorSystem (server, plain group), written ABOVE its early-returns
    /// (snapshot-above-early-return) so the readout never freezes stale. byte/short, never enum (writer is [BurstCompile]).
    /// </summary>
    public struct ExpeditionObjective : IComponentData
    {
        /// <summary>0 = Idle (no sortie active), 1 = Active (wave in progress), 2 = Cleared (return to claim).</summary>
        [GhostField] public byte State;

        /// <summary>Live zone enemies remaining (alive + not-yet-spawned) while Active; 0 when Idle/Cleared.</summary>
        [GhostField] public short Remaining;
    }

    /// <summary>State constants for <see cref="ExpeditionObjective.State"/> (byte, not enum — Burst/serialization).</summary>
    public static class ExpeditionObjectiveState
    {
        public const byte Idle = 0;
        public const byte Active = 1;
        public const byte Cleared = 2;
    }
}