using System.Text;
using TMPro;
using UnityEngine;

namespace FloodSWE.Debugging
{
    public sealed class SweStatsOverlay : MonoBehaviour
    {
        public SweTileSimulator simulator;
        public TextMeshProUGUI targetText;
        public float updateInterval = 0.25f;

        private float elapsed;
        private readonly StringBuilder builder = new StringBuilder(256);

        private void Update()
        {
            if (targetText == null)
            {
                return;
            }

            elapsed += Time.deltaTime;
            if (elapsed < updateInterval)
            {
                return;
            }

            elapsed = 0.0f;
            targetText.text = BuildStats();
        }

        private string BuildStats()
        {
            builder.Clear();

            if (simulator == null)
            {
                builder.AppendLine("SWE: simulator not set");
                return builder.ToString();
            }

            builder.AppendLine("SWE Stats");
            builder.Append("Grid: ").Append(simulator.gridRes).Append("  ");
            builder.Append("Tile: ").Append(simulator.tileSizeMeters.ToString("F0")).Append("m  ");
            builder.Append("dx: ").Append(simulator.CellSizeMeters.ToString("F3")).Append("m");
            builder.AppendLine();
            builder.Append("Depth: ").Append(simulator.LastMaxDepth.ToString("F3")).Append("m  ");
            builder.Append("Speed: ").Append(simulator.LastMaxSpeed.ToString("F3")).Append("m/s");
            builder.AppendLine();
            builder.Append("TotalDepth: ").Append(simulator.LastTotalDepth.ToString("F3")).Append("m  ");
            builder.Append("Volume: ").Append(simulator.LastTotalVolume.ToString("F3")).Append("m^3");
            builder.AppendLine();
            builder.Append("Clamped: ").Append(simulator.LastClampedCells);
            builder.Append(" (").Append((simulator.LastClampedRatio * 100.0f).ToString("F1")).Append("%)");
            builder.Append("  NaN: ").Append(simulator.LastNanCells);
            builder.AppendLine();
            builder.Append("dtMax: ").Append(simulator.LastDtMax.ToString("F4")).Append("s  ");
            builder.Append("substeps: ").Append(simulator.LastSubsteps).Append("  ");
            builder.Append("dt: ").Append(simulator.LastDt.ToString("F4")).Append("s");

            return builder.ToString();
        }
    }
}