using System.Collections.Generic;

namespace MazeGen
{
    public enum CombatEventKind
    {
        FightStart,
        RoundStart,
        MovementStart,         // Actor begins moving
        MovementComplete,      // Actor completes movement
        OutOfRange,            // Attack failed: target out of weapon range
        TooFarForMelee,        // Attack failed: not adjacent for melee
        TargetUnreachable,     // Movement failed: destination unreachable
        Hit,
        Miss,
        Death,
        FightEnd,
        HealthPotionUsed
    }

    /// <summary>
    /// One atomic thing that happened during a battle. A resolved battle is nothing but an
    /// ordered list of these.
    ///
    /// This is the seam that lets "just log it" and "watch it on a grid" share one outcome: the
    /// resolver runs to completion up front and emits this list, log-only mode prints it, and the
    /// arena replays the exact same list as animation. The view therefore cannot desync from the
    /// simulation, and switching modes can never change who wins.
    /// </summary>
    public class CombatEvent
    {
        public CombatEventKind Kind;
        public int Round;

        /// <summary>Combatant id of whoever acted, or -1 for battle/round-level events.</summary>
        public int ActorId = -1;

        /// <summary>Combatant id of whoever was acted upon, or -1.</summary>
        public int TargetId = -1;

        /// <summary>Damage dealt (Hit), or the target's remaining health (Death).</summary>
        public float Amount;

        /// <summary>Pre-rendered log line, so the log/thought/feed surfaces don't each re-describe it.</summary>
        public string Text;

        /// <summary>Starting position for movement events (grid coordinates).</summary>
        public UnityEngine.Vector2Int SourcePosition = UnityEngine.Vector2Int.zero;

        /// <summary>Destination position for movement events, or target position for attacks (grid coordinates).</summary>
        public UnityEngine.Vector2Int TargetPosition = UnityEngine.Vector2Int.zero;

        /// <summary>Distance moved in squares (for MovementComplete events).</summary>
        public int MovementDistance = 0;
    }

    public enum BattleOutcome
    {
        AgentsVictory,
        MonstersVictory,
        Stalemate
    }

    /// <summary>The complete, already-decided result of one battle.</summary>
    public class BattleResult
    {
        public BattleOutcome Outcome;
        public int Rounds;
        public readonly List<CombatEvent> Events = new List<CombatEvent>();
        public IReadOnlyList<Combatant> Combatants;

        /// <summary>Agents who were reduced to 0 health in this battle.</summary>
        public readonly List<Combatant> FallenAgents = new List<Combatant>();

        /// <summary>Monsters killed in this battle.</summary>
        public readonly List<Combatant> FallenMonsters = new List<Combatant>();

        /// <summary>Agents still standing when the battle ended.</summary>
        public readonly List<Combatant> SurvivingAgents = new List<Combatant>();

        public string Summary
        {
            get
            {
                switch (Outcome)
                {
                    case BattleOutcome.AgentsVictory:
                        return $"Agents won in {Rounds} round(s) - {FallenMonsters.Count} monster(s) killed, {FallenAgents.Count} agent(s) lost.";
                    case BattleOutcome.MonstersVictory:
                        return $"Monsters won in {Rounds} round(s) - all {FallenAgents.Count} agent(s) died.";
                    default:
                        return $"Stalemate after {Rounds} round(s) - both sides still standing, everyone disengages.";
                }
            }
        }
    }
}