// Assets/_Project/Scripts/Gameplay/GoldConfig.cs
using System;
using UnityEngine;
using UnityEngine.Serialization;

namespace TD.Gameplay
{
    /// <summary>
    /// Gold rules for one encounter slot, addressed by position in the run rather than by
    /// which wave happens to occupy it.
    /// </summary>
    /// <remarks>
    /// <b>Position, not identity.</b> Under the 2.0 run structure the waves filling each slot are
    /// drawn at random from a phase pool, so "the gold for wave 3" means the run's third
    /// encounter, whatever spawns in it. Payouts are a property of how far the players have
    /// progressed — not of which enemy they happened to draw.
    /// </remarks>
    [Serializable]
    public class EncounterGoldEntry
    {
        [Tooltip("Gold awarded to the killing player per enemy slain during this encounter. " +
                 "Applies uniformly to every enemy type.")]
        public int GoldPerEnemy = 10;

        [Tooltip("Flat bonus gold awarded to every active player when this encounter is fully " +
                 "cleared (all enemies dead or reached the goal).")]
        public int CompletionBonus = 50;

        [Tooltip("Extra bonus gold awarded to a player who cleared this encounter without any " +
                 "enemy from their own zone escaping their leak volume. Stacks on top of " +
                 "CompletionBonus.")]
        public int NoLeaksBonus = 50;

        /// <summary>
        /// Guaranteed gold for a player who clears this encounter: the two bonuses, with no
        /// kill income counted.
        /// </summary>
        /// <remarks>
        /// Kill income can't be known here — the wave occupying this slot is drawn at runtime, so
        /// its enemy count varies per run. <see cref="GoldConfig.PreviewEnemiesPerEncounter"/>
        /// supplies an estimate for the inspector's projected totals.
        /// </remarks>
        public int GuaranteedBonusGold => CompletionBonus + NoLeaksBonus;

        /// <summary>
        /// Projected best-case earnings for one player this encounter, given an assumed enemy
        /// count. Editor tuning aid only — nothing at runtime reads it.
        /// </summary>
        public int ProjectedTotal(int assumedEnemyCount)
            => GoldPerEnemy * Mathf.Max(0, assumedEnemyCount) + GuaranteedBonusGold;
    }

    /// <summary>
    /// Single source of truth for every gold-related tunable in the game.
    /// </summary>
    /// <remarks>
    /// <b>Wiring.</b> Assign one GoldConfig asset to <c>WaveManager.goldConfig</c> in the Match
    /// scene. WaveManager seeds per-player starting gold from <see cref="StartingGold"/>, reads
    /// <see cref="EncounterGoldEntry.GoldPerEnemy"/> for kill rewards, and awards the completion
    /// and no-leak bonuses as each encounter clears.
    ///
    /// <para><b>No per-enemy-type bounties.</b> Every enemy killed in a given encounter grants the
    /// same reward regardless of <see cref="EnemyDefinition"/>. With enemy types now drawn at
    /// random per phase, per-type bounties would make income depend on the luck of the draw
    /// rather than on progression.</para>
    /// </remarks>
    [CreateAssetMenu(fileName = "GoldConfig", menuName = "TD/Gold Config", order = 2)]
    public class GoldConfig : ScriptableObject
    {
        [Tooltip("Gold each player starts the match with. Same for every player.")]
        public int StartingGold = 100;

        [Tooltip("Gold rules per encounter, in run order. Element 0 = the run's first encounter. " +
                 "Encounters are counted continuously — cycles do NOT restart the count — so one " +
                 "phase of 5 waves × 3 cycles + a boss needs 16 entries. Missing entries pay " +
                 "zero for that encounter.")]
        [FormerlySerializedAs("Waves")]
        public EncounterGoldEntry[] Encounters;

        [Header("Editor preview")]
        [Tooltip("Assumed enemies per encounter, used ONLY to project totals in this inspector. " +
                 "Nothing at runtime reads it — the real count comes from whichever wave the run " +
                 "draws into each slot.")]
        [Min(0)]
        public int PreviewEnemiesPerEncounter = 40;

        /// <summary>
        /// Returns the gold rules for the given 1-based encounter number
        /// (<c>RunState.GlobalEncounterNumber</c>), or null if out of range.
        /// </summary>
        /// <remarks>
        /// Keyed by <b>run position</b>, not by wave slot within a cycle. The same five waves come
        /// round three times per phase, so a slot-keyed table would pay the same on cycle 3 as on
        /// cycle 1 while the enemies grew steadily stronger from the buffs voted onto them. A
        /// run-long counter lets payouts climb with the difficulty.
        /// </remarks>
        public EncounterGoldEntry GetEncounterEntry(int encounterNumber)
        {
            if (Encounters == null) return null;
            int index = encounterNumber - 1;
            if (index < 0 || index >= Encounters.Length) return null;
            return Encounters[index];
        }

        /// <summary>Number of authored encounter entries.</summary>
        public int EncounterCount => Encounters?.Length ?? 0;

        /// <summary>
        /// Editor tuning aid: cumulative projected earnings for one player from the run's first
        /// encounter through <paramref name="encounterNumber"/> inclusive, assuming
        /// <see cref="PreviewEnemiesPerEncounter"/> kills each time and no leaks.
        /// </summary>
        public int ProjectedCumulativeThrough(int encounterNumber)
        {
            if (Encounters == null) return StartingGold;

            int total = StartingGold;
            int last  = Mathf.Min(encounterNumber, Encounters.Length);
            for (int i = 0; i < last; i++)
            {
                if (Encounters[i] == null) continue;
                total += Encounters[i].ProjectedTotal(PreviewEnemiesPerEncounter);
            }
            return total;
        }
    }
}