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"/> (a byte, not an enum, for trivial Burst/serialization).</summary>
    public static class CyclePhase
    {
        /// <summary>Out in the procedural field gathering resources (timed).</summary>
        public const byte Expedition = 0;

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

        /// <summary>Calm at base: spend resources to build/upgrade (timed).</summary>
        public const byte Build = 2;

        /// <summary>Expedition phase duration in server ticks (SimulationTickRate = 60). Tunable; short for the M6 slice.</summary>
        public const uint ExpeditionTicks = 3600; // ~60s cap (early return via the gate ends it sooner)

        /// <summary>Build phase duration in server ticks.</summary>
        public const uint BuildTicks = 1200;     // ~20s
    }

    /// <summary>
    /// Server-only bookkeeping for the cycle state machine that must NOT replicate (kept separate from the
    /// replicated <see cref="CycleState"/>). Records the wave number captured when the Defend phase began so
    /// the director can detect "this Defend's wave has now been spawned and cleared".
    /// </summary>
    public struct CycleRuntime : IComponentData
    {
        /// <summary>WaveState.WaveNumber captured at the moment the current Defend phase started.</summary>
        public int DefendStartWave;

        /// <summary>Cycle phase from the previous tick — lets ExpeditionFieldSystem edge-detect entering/leaving Expedition.</summary>
        public byte PrevPhase;

        /// <summary>CycleNumber the expedition field was last seeded for (compared by int equality, never tick math).</summary>
        public int LastSpawnedCycle;
    }
}