using System;

namespace ProjectM.Simulation
{
    /// <summary>One serialized ledger row (item id + count). An array FIELD of <see cref="SaveData"/>.</summary>
    [Serializable]
    public struct LedgerRow
    {
        public int ItemId;
        public int Count;
    }

    /// <summary>One persisted per-class PERMANENT meta-upgrade tier (v6). ClassId = the normalized FrameKind
    /// (Bathynaut=2/Harpooner=3); UpgradeId = the append-only meta-catalog key (unknown ids round-trip preserved and are
    /// skipped live); Tier clamps to the catalog's MaxTier at seed/shop/spend, never at rest.</summary>
    [Serializable]
    public struct MetaUpgradeSave
    {
        public byte ClassId;
        public byte UpgradeId;
        public byte Tier;
    }

    /// <summary>One serialized player-built structure. Flat scalars (JsonUtility has no int2).</summary>
    [Serializable]
    public struct StructureSave
    {
        public byte Type;
        public int CellX;
        public int CellZ;
        public float HP; // EB-1: hit points at save time (0 -> restored to baked Max)
    }

    /// <summary>
    /// Versioned, host-authoritative save slice: the shared resource ledger + player-built structures + the
    /// permanent meta. JsonUtility-friendly — a class with flat fields and an array FIELD (never a root array).
    /// The schema is ADDITIVE going forward, gated by <see cref="Version"/> migration.
    /// </summary>
    [Serializable]
    public class SaveData
    {
        public const int CurrentVersion = 7; // v7: LANTERN fresh epoch — goal/core/outcome + conveyor/machine-I/O fields dropped

        /// <summary>Oldest save schema the loader accepts. v7 is a FRESH EPOCH (operator-approved): older saves are ignored.</summary>
        public const int MinLoadableVersion = 7;

        public int Version = CurrentVersion;

        // Permanent meta-progression:
        public int RunsCompleted;     // boss-cleared runs (the HUD counter + the HostSalt fold at restore)
        public int MaxDepthReached;   // deepest room actually CLEARED across all runs (honest depth, never planned)
        public MetaUpgradeSave[] MetaUpgrades = Array.Empty<MetaUpgradeSave>(); // sparse per-class tiers

        public LedgerRow[] Ledger = Array.Empty<LedgerRow>();
        public StructureSave[] Structures = Array.Empty<StructureSave>();
        public long SavedAtMs;
    }
}