using System.Collections.Generic;
using Godot;

namespace WorldSim;

/// <summary>
/// Main loop and time system (SPEC §9).
/// 1 tick = 1 in-game minute; 1440 ticks = 1 day.
/// Day/night drives activity bias: gather/build by day, rest/socialize by night.
/// </summary>
public partial class GameManager : Node2D
{
    public static GameManager? Instance { get; private set; }

    [Export] public int Seed = 12345;
    [Export] public int NpcCount = 15;

    [Export(PropertyHint.Range, "0,15,1")]
    public int SelfishCount = 3;             // the contrast test (SPEC §11 amendment)

    [Export(PropertyHint.Range, "1,2000,1")]
    public float TicksPerRealSecond = 20f;   // sim speed; ~1500 ≈ one day/sec for soaks

    public World World { get; private set; } = null!;
    public List<Npc> Npcs { get; } = new();
    public List<Building> Buildings { get; } = new();

    public long TotalTicks { get; private set; }
    public int Day => (int)(TotalTicks / 1440);
    public int MinuteOfDay => (int)(TotalTicks % 1440);
    public bool IsNight => MinuteOfDay < 6 * 60 || MinuteOfDay >= 22 * 60;

    // --- Seasons: the pressure that makes community structure matter ------

    [Export] public int DaysPerSeason = 30;

    public int SeasonIndex => (Day / DaysPerSeason) % 4;

    public string SeasonName => SeasonIndex switch
    {
        0 => "spring", 1 => "summer", 2 => "autumn", _ => "winter",
    };

    /// <summary>Food regen multiplier — winter gives almost nothing.</summary>
    public float SeasonFoodMult => SeasonIndex switch
    {
        0 => 1.5f, 1 => 1.0f, 2 => 0.8f, _ => 0.05f,
    };

    /// <summary>Wood regen multiplier — growth slows in the cold.</summary>
    public float SeasonWoodMult => SeasonIndex switch
    {
        0 => 1.2f, 1 => 1.0f, 2 => 1.0f, _ => 0.4f,
    };

    private double _tickAccumulator;

    public override void _Ready()
    {
        Instance = this;
        TotalTicks = 8 * 60;   // start at 08:00 — day one begins mid-morning, not asleep
        World = new World(Seed);
        World.Generate();
        SpawnNpcs();
        StatsLogger.Init();
        GD.Print($"[WorldSim] World generated (seed {Seed}), {Npcs.Count} NPCs dropped in.");
    }

    private void SpawnNpcs()
    {
        // Dropped near the map center with scatter — no scripted town layout.
        // Where the community forms is the experiment (SPEC §11).
        var rng = new System.Random(Seed);
        for (int i = 0; i < NpcCount; i++)
        {
            bool selfish = i >= NpcCount - SelfishCount;
            Npcs.Add(new Npc
            {
                Name = $"Villager_{(char)('A' + i)}",
                Soul = selfish ? SoulProfile.SelfishSoul() : SoulProfile.NatureSoul(),
                PersonalityModifier = (float)(rng.NextDouble() * 0.4 - 0.2),
                Position = new Vector2(
                    World.GridSize / 2f + rng.Next(-20, 21),
                    World.GridSize / 2f + rng.Next(-20, 21)),
            });
        }
    }

    public override void _Process(double delta)
    {
        _tickAccumulator += delta * TicksPerRealSecond;
        while (_tickAccumulator >= 1.0)
        {
            _tickAccumulator -= 1.0;
            Tick();
        }
    }

    /// <summary>Where the community's feet actually are — new communal
    /// buildings are founded here, not at a scripted town center.</summary>
    public Vector2 CommunityCentroid()
    {
        if (Npcs.Count == 0) return new Vector2(World.GridSize / 2f, World.GridSize / 2f);
        Vector2 sum = Vector2.Zero;
        foreach (var npc in Npcs) sum += npc.Position;
        return sum / Npcs.Count;
    }

    private void Tick()
    {
        TotalTicks++;

        foreach (var npc in Npcs)
            npc.Tick(World, this);

        if (TotalTicks % 1440 == 0)
        {
            World.RegenerateDaily(SeasonFoodMult, SeasonWoodMult);
            foreach (var building in Buildings)
                building.DailyUpkeep();
            StatsLogger.LogDay(this);
            if (Day % 10 == 0)
                GD.Print($"[WorldSim] Day {Day} complete.");
        }
    }
}