using System;

namespace Jovian.EncounterSystem {
    /// <summary>
    /// Cross-table reference to an <see cref="IEncounter"/>. Stores the owning
    /// <see cref="EncounterTable"/> asset and the target encounter's <see cref="EncounterDefinition.internalId"/>.
    /// Rename-safe because the stored key is a GUID.
    /// </summary>
    [Serializable]
    public struct EncounterLink {
        /// <summary>The table that owns the linked encounter.</summary>
        public EncounterTable table;

        /// <summary>The target encounter's stable GUID (<see cref="EncounterDefinition.internalId"/>).</summary>
        public string internalId;

        /// <summary>Look up the referenced encounter, or <c>null</c> if the table is missing or the id
        /// no longer exists in it.</summary>
        public IEncounter Resolve() {
            if(table == null || table.encounters == null || string.IsNullOrEmpty(internalId)) {
                return null;
            }

            foreach(var encounter in table.encounters) {
                if(encounter?.EncounterDefinition?.internalId == internalId) {
                    return encounter;
                }
            }

            return null;
        }
    }
}