using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Godot;
using IslaApocalypse.Core;

namespace IslaApocalypse.Tools
{
	/// <summary>
	/// ⭐ THE COASTAL-FRAGMENTATION BATCH (chat2/09, exploration) — at a FIXED stretch, a perimeter-wide
	/// fragmentation-noise amplitude ladder: light → heavy, 4 levels × 2 seeds, options to pick from.
	///
	/// ═══ TWO MODES ═══
	///
	///   ISLA_PROBE=1   numbers only at ISLA_CALIB_SIZE: a frequency × amplitude sweep on both seeds
	///                  (island counts and sizes per hemisphere, mainland size) — used to fix the
	///                  frequency and place the amplitude ladder. Written to scratch/frag_probe.md.
	///   (default)      the BATCH: 4 amplitudes × 2 seeds at ISLA_MAPSIZE, lean render per field
	///                  (labeled-regions overlay + relief + .f32), the hemisphere-split count/size table,
	///                  the asymmetric oracle (interior locked, coast free).
	///
	/// Every field: pass 1 + stretch (FIXED) + fragmentation (the axis), region labeling ON, speck revert
	/// at a LOW threshold (true 1–3-cell noise only), offshore OFF, shelf OFF. The curve is the tagged
	/// curve, unchanged.
	///
	/// ═══ RUNNING IT ═══
	///
	///   xvfb-run -a Godot_v4.7.2-stable_mono_linux.x86_64 \
	///     --path ~/celerNexus/islaApocalypse-v2 res://Tools/Scenes/CoastalFragmentTool.tscn
	///
	///   ISLA_TASK / ISLA_BATCH / ISLA_SKIP_RAW / ISLA_OUTPUT_DIR
	///   ISLA_MAPSIZE / ISLA_CALIB_SIZE       (default 4096 / 2048)
	///   ISLA_SEEDS                           the two seeds (default 1063685222, 999999937 — task 08's)
	///   ISLA_STRETCH                         the fixed stretch (default 2)
	///   ISLA_FRAG_LEVELS                     the 4 amplitudes (default: the probe-chosen ladder)
	///   ISLA_FRAG_FREQ                       the fixed frequency, periods per map width
	///   ISLA_SPECK_FRAC                      the speck-revert threshold, fraction of map area (default 2.5e-7 ≈ 4 cells at 4096)
	///   ISLA_PROBE=1 · ISLA_PROBE_FREQS · ISLA_PROBE_AMPS    the probe sweep
	///   ISLA_FRAG_BITES=1                    bites-only noise ([0,1]) instead of zero-mean ([-1,1])
	///   ISLA_SKIP_8K=1                       (no 8192 check this batch — the 08 dump at 4096 is the baseline)
	/// </summary>
	public partial class CoastalFragmentTool : Node
	{
		private static readonly int[] DefaultSeeds = { 1063685222, 999999937 };

		/// <summary>⚠ Task 01's pool, verbatim — the curve's identity.</summary>
		private static readonly int[] CalibrationSeeds = { 1063685222, 20260819, 777001, 424242, 90210, 31337 };

		/// <summary>⭐ THE LADDER — set from the probe (chat2/09 report §1): light → heavy, amplitude the only axis.</summary>
		private static readonly float[] DefaultLadder = { 0.06f, 0.15f, 0.30f, 0.50f };

		private static readonly float[] ProbeFreqs = { 12f, 20f, 32f };
		private static readonly float[] ProbeAmps = { 0.03f, 0.06f, 0.12f, 0.20f, 0.32f, 0.5f };

		private const float DefaultStretch = 2f;
		private const float DefaultSpeckFrac = 2.5e-7f;     // ≈ 4 cells at 4096 — true noise only
		private const int DefaultMapSize = 4096;
		private const int DefaultCalibSize = 2048;

		public override void _Ready()
		{
			try { Run(); }
			catch (Exception e)
			{
				GD.PrintErr("==================================================================");
				GD.PrintErr($"  REFUSED: {e.Message}");
				GD.PrintErr(e.StackTrace);
				GD.PrintErr("==================================================================");
				GetTree().Quit(2);
			}
		}

		private sealed class HemiStats
		{
			public int All, Big; public long Min, Med, Max; public double Mean; public int[] Hist; public long[] Largest = Array.Empty<long>();
		}

		private sealed class Row
		{
			public int Level; public float Amp; public int Seed;
			public HemiStats N, S; public long MainlandCells; public int SpecksReverted;
			public bool Ok; public ulong Ms;
		}

		private void Run()
		{
			ToolingPaths.Configure(OS.GetUserDataDir());

			int task        = EnvInt("ISLA_TASK", 9);
			string descr    = EnvStr("ISLA_BATCH", "coastal_fragment");
			int mapSize     = EnvInt("ISLA_MAPSIZE", DefaultMapSize);
			int calibSize   = EnvInt("ISLA_CALIB_SIZE", DefaultCalibSize);
			int[] seeds     = EnvSeeds("ISLA_SEEDS", DefaultSeeds);
			float stretch   = EnvFloat("ISLA_STRETCH", DefaultStretch);
			float[] ladder  = EnvFloats("ISLA_FRAG_LEVELS", DefaultLadder);
			float freq      = EnvFloat("ISLA_FRAG_FREQ", CoastalFragment.DefaultFreqPerMapWidth);
			float speckFrac = EnvFloat("ISLA_SPECK_FRAC", DefaultSpeckFrac);
			bool probe      = EnvStr("ISLA_PROBE", "0") == "1";
			bool bitesOnly  = EnvStr("ISLA_FRAG_BITES", CoastalFragment.DefaultBitesOnly ? "1" : "0") == "1";
			float[] probeFreqs = EnvFloats("ISLA_PROBE_FREQS", ProbeFreqs);
			float[] probeAmps  = EnvFloats("ISLA_PROBE_AMPS", ProbeAmps);
			bool skipRaw    = EnvStr("ISLA_SKIP_RAW", "0") == "1";
			string p1Source = EnvStr("ISLA_PHASE1_SOURCE", "02_pass1_port");
			string t08Source = EnvStr("ISLA_T08_SOURCE", "08_southern_stretch_explore");
			string t08Level = EnvStr("ISLA_T08_LEVEL", "stretch_3");     // the 08 rung with stretch 2

			string batchRoot = ToolingPaths.BatchRoot(task, descr);
			DirAccess.MakeDirRecursiveAbsolute(batchRoot);
			string scratch = ToolingPaths.BatchScratch(batchRoot);
			DirAccess.MakeDirRecursiveAbsolute(scratch);

			var anchors = CurveAnchors.Default;
			float sea = 0.15f;
			long big = Cells(RegionPass.ThresholdMidFrac, mapSize);
			long speckCells = Cells(speckFrac, mapSize);

			GD.Print("==================================================================");
			GD.Print("  COASTAL FRAGMENTATION (chat2/09) — break more pieces off the edges, N + S");
			GD.Print("==================================================================");
			GD.Print($"MapSize   : {mapSize} (plates)   calibration / probe at {calibSize}");
			GD.Print($"seeds     : {string.Join(", ", seeds)}");
			GD.Print($"fixed     : stretch {stretch:G3} (band {SouthernStretch.DefaultBandStartFrac:F2}/{SouthernStretch.DefaultBandFeatherFrac:F2}, sinker stretched) · frag freq {freq:G3}/map · window {CoastalFragment.DefaultBandCentre:F2} ± {CoastalFragment.DefaultBandHalfWidth:F2} · speck revert < {speckCells} cells ({speckFrac:G2})");
			GD.Print($"ladder    : FragmentAmp {string.Join(", ", ladder)}   noise {(bitesOnly ? "BITES ONLY [0,1]" : "zero-mean [-1,1]")}   (\"big\" island = ≥ {big:N0} cells at {mapSize})");
			GD.Print($"batch     : {batchRoot}{(probe ? "   ⚠ ISLA_PROBE — numbers only" : "")}");
			GD.Print("==================================================================");

			GD.Print($"\n--- 0. CURVE (task-01 pool at {calibSize}, offshore off) ---");
			var (knots, calibration) = CalibrateCurve(calibSize, sea, anchors);
			GD.Print($"  {knots}");
			float highRaw = knots.K2;     // the top of the preserved lowland (30 m output) — "above the toe+red band"

			TerrainGenConfig Cfg(int size, int seed, string label, float amp, float fq, float st, bool revert)
			{
				return new TerrainGenConfig
				{
					MapSize = size, Seed = seed, VariantLabel = label,
					Curve = true, ShelfDetail = false, CurveMode = CurveModeKind.Continuous,
					Knots = knots, Anchors = anchors, ClimbCalibration = calibration, LowlandCeilingM = 30f,
					CoastShelf = false, Offshore = new OffshoreSettings(),
					RegionLabeling = true, SpeckRevert = revert, MinLandComponentFrac = speckFrac,
					SouthStretch = st,
					FragmentAmp = amp, FragmentFreqPerMapWidth = fq, FragmentBitesOnly = bitesOnly,
				};
			}

			// ═══ PROBE ═══
			if (probe)
			{
				GD.Print($"\n--- PROBE at {calibSize}: frequency × amplitude, stretch {stretch:G3} ---");
				long bigC = Cells(RegionPass.ThresholdMidFrac, calibSize);
				var sb = new StringBuilder();
				sb.AppendLine($"# chat2/09 probe — fragmentation frequency × amplitude at {calibSize}, stretch {stretch:G3}, noise {(bitesOnly ? "bites only" : "zero-mean")}");
				sb.AppendLine();
				sb.AppendLine($"\"big\" = ≥ {bigC} cells at {calibSize}. Speck revert < {Cells(speckFrac, calibSize)} cells. Offshore off.");
				sb.AppendLine();
				sb.AppendLine("| seed | freq | amp | N islands all / big | N size med / max | S islands all / big | S size med / max | mainland cells | mainland Δ vs amp 0 |");
				sb.AppendLine("|---|---|---|---|---|---|---|---|---|");
				foreach (int seed in seeds)
				{
					var base0 = Topography.Generate(Cfg(calibSize, seed, "amp0", 0f, freq, stretch, true));
					long main0 = base0.Regions.Mainland.SizeCells;
					var (n0, s0) = Stats(base0.Regions, bigC);
					sb.AppendLine($"| `{seed}` | — | 0 | {n0.All} / {n0.Big} | {n0.Med} / {n0.Max} | {s0.All} / {s0.Big} | {s0.Med} / {s0.Max} | {main0:N0} | 0 |");
					GD.Print($"  seed {seed} amp 0: N {n0.All}/{n0.Big} med {n0.Med} max {n0.Max}  S {s0.All}/{s0.Big} med {s0.Med} max {s0.Max}  mainland {main0:N0}");
					foreach (float fq in probeFreqs)
						foreach (float amp in probeAmps)
						{
							var p = Topography.Generate(Cfg(calibSize, seed, "probe", amp, fq, stretch, true));
							var (n, s) = Stats(p.Regions, bigC);
							long main = p.Regions.Mainland.SizeCells;
							sb.AppendLine($"| `{seed}` | {fq:G3} | {amp:G3} | {n.All} / {n.Big} | {n.Med} / {n.Max} | {s.All} / {s.Big} | {s.Med} / {s.Max} | {main:N0} | {main - main0:+#,0;-#,0;0} |");
							GD.Print($"  seed {seed} freq {fq,4:G3} amp {amp,5:G3}: N {n.All,3}/{n.Big,3} med {n.Med,6} max {n.Max,7}  S {s.All,3}/{s.Big,3} med {s.Med,6} max {s.Max,7}  mainland {main:N0} ({main - main0:+#,0;-#,0;0})");
						}
				}
				WriteText(Path.Combine(scratch, bitesOnly ? "frag_probe_bites_only.md" : "frag_probe.md"), sb.ToString());
				GD.Print($"\n  probe written: {Path.Combine(scratch, "frag_probe.md")}");
				GetTree().Quit(0);
				return;
			}

			// ═══ 1. REGRESSIONS ═══
			GD.Print($"\n--- 1. REGRESSIONS ---");
			var hard = new List<ShapingOracle.Check>();
			{
				var offCfg = Cfg(calibSize, seeds[0], "off", 0f, freq, 0f, false);
				Pass1Result p1 = Topography.Generate(offCfg);
				var curveOff = offCfg.Clone(); curveOff.Curve = false;
				string p1Dump = Path.Combine(ToolingPaths.BatchesRoot, p1Source, $"{seeds[0]}_full", "height.f32");
				hard.Add(ShapingOracle.DumpRegression("a1", "curve OFF, stretch OFF, frag OFF == Phase-1 .f32 dump (the curve is untouched)", Shaping.Shape(p1, curveOff).Height, HeightField.Load(p1Dump, calibSize), calibSize, p1Dump));

				// ⭐ a8 — frag OFF at the fixed stretch, revert OFF == the task-08 stretch-2 field (its dump at the plate size).
				foreach (int seed in seeds)
				{
					string t08Dump = Path.Combine(ToolingPaths.BatchesRoot, t08Source, $"{seed}_{t08Level}", "height.f32");
					if (File.Exists(t08Dump) && mapSize == 4096)
					{
						var c8 = Cfg(mapSize, seed, "t08", 0f, freq, stretch, false);
						Pass2Result q8 = Shaping.Shape(Topography.Generate(c8), c8);
						hard.Add(ShapingOracle.DumpRegression("a8", $"frag OFF, stretch {stretch:G3}, revert OFF == task-08 {t08Level} dump (the baseline) [{seed}]", q8.Height, HeightField.Load(t08Dump, mapSize), mapSize, t08Dump));
					}
					else GD.Print($"  a8 [{seed}]: ⚠ skipped — {(mapSize != 4096 ? "map size is not 4096" : $"no 08 dump at {t08Dump}")}");
				}
				foreach (var c in hard) GD.Print("  " + c);
			}

			// ═══ 2. THE LADDER — 4 amplitudes × 2 seeds ═══
			GD.Print($"\n--- 2. THE LADDER at {mapSize} ---");
			var rows = new List<Row>();
			var baseline = new Dictionary<int, Row>();
			var perField = new List<ShapingOracle.Check>();
			foreach (int seed in seeds)
			{
				var c0 = Cfg(mapSize, seed, "frag_0", 0f, freq, stretch, true);
				Pass1Result p0 = Topography.Generate(c0);
				baseline[seed] = MakeRow(0, 0f, seed, p0, big, true, p0.ElapsedMs);
				var b = baseline[seed];
				GD.Print($"  seed {seed} baseline (amp 0, stretch {stretch:G3}): N {b.N.All}/{b.N.Big} S {b.S.All}/{b.S.Big} mainland {b.MainlandCells:N0}");

				for (int li = 0; li < ladder.Length; li++)
				{
					float amp = ladder[li];
					string label = $"frag_{li + 1}";
					var cfg = Cfg(mapSize, seed, label, amp, freq, stretch, true);
					Pass1Result p1 = Topography.Generate(cfg);
					Pass2Result p2 = Shaping.Shape(p1, cfg);
					var checks = new List<ShapingOracle.Check>
					{
						ShapingOracle.InteriorLocked(p0, p1, cfg.FragmentBandCentre, cfg.FragmentBandHalfWidth),
						ShapingOracle.HighGroundReport(p0, p1, highRaw, $"K2 ({highRaw:F3} raw, the top of the preserved lowland)"),
						ShapingOracle.CentreIsLand(p1),
						ShapingOracle.TagCoastlineConsistent(p2, sea),
						ShapingOracle.ClassifyFidelity(p1, p2),
					};
					foreach (var c in checks) { c.Name += $" [{label} = {amp:G3}, {seed}]"; perField.Add(c); }
					bool ok = checks.TrueForAll(c => c.Passed);
					var row = MakeRow(li + 1, amp, seed, p1, big, ok, p1.ElapsedMs);
					rows.Add(row);
					WriteField(batchRoot, p1, p2, sea, anchors, skipRaw, amp);
					GD.Print($"  {label,-7} amp {amp,5:G3}  seed {seed,-11} N {row.N.All,3}/{row.N.Big,3} med {row.N.Med,6} max {row.N.Max,7}   S {row.S.All,3}/{row.S.Big,3} med {row.S.Med,6} max {row.S.Max,7}   mainland {row.MainlandCells:N0} ({row.MainlandCells - b.MainlandCells:+#,0;-#,0;0})  specks {row.SpecksReverted}  {(ok ? "ok" : "⚠ CHECK FAILED")}  {p1.ElapsedMs} ms");
				}
			}

			// determinism
			{
				float amp = ladder[1];
				var a = Topography.Generate(Cfg(mapSize, seeds[0], "det", amp, freq, stretch, true));
				var bb = Topography.Generate(Cfg(mapSize, seeds[0], "det", amp, freq, stretch, true));
				var det = ShapingOracle.LabelsDeterministic(a, bb); det.Name += $" [amp {amp:G3}, {seeds[0]}]";
				var bits = ShapingOracle.NorthLocked("o2", $"two generations bit-identical everywhere [amp {amp:G3}, {seeds[0]}]", a.Height, bb.Height, mapSize, mapSize);
				perField.Add(det); perField.Add(bits); GD.Print("  " + det); GD.Print("  " + bits);
			}

			bool allOk = hard.TrueForAll(c => c.Passed) && perField.TrueForAll(c => c.Passed);
			GD.Print($"\n  ORACLE: {(allOk ? "ALL HARD CHECKS PASS" : "*** FAILURES ***")}");
			foreach (var c in perField) if (!c.Passed) GD.PrintErr("  " + c);

			WriteTable(batchRoot, mapSize, ladder, seeds, rows, baseline, big, stretch, freq, speckCells);
			WriteIndex(batchRoot, mapSize, calibSize, ladder, seeds, rows, baseline, big, stretch, freq, speckCells, hard, perField, allOk);

			GD.Print("\n==================================================================");
			GD.Print($"  DONE — {batchRoot}");
			GD.Print($"  ORACLE {(allOk ? "HARD CHECKS ALL PASS" : "*** FAILURES — see the table ***")}");
			GD.Print("==================================================================");
			GetTree().Quit(allOk ? 0 : 3);
		}

		// ---- the instrument --------------------------------------------------

		private static long Cells(float frac, int size) => Math.Max(1L, (long)Math.Round(frac * (double)size * size));

		private static (HemiStats north, HemiStats south) Stats(RegionLabels l, long big)
		{
			var n = new List<long>(); var s = new List<long>();
			foreach (var r in l.Regions)
			{
				if (r.IsMainland) continue;
				if (r.Hemisphere == RegionLabeling.HemiSouth) s.Add(r.SizeCells); else n.Add(r.SizeCells);
			}
			return (Make(n, big), Make(s, big));
		}

		private static HemiStats Make(List<long> sizes, long big)
		{
			sizes.Sort();
			var h = new HemiStats { All = sizes.Count, Hist = new int[RegionLabeling.HistogramEdges.Length + 1] };
			if (sizes.Count == 0) return h;
			double sum = 0;
			foreach (long v in sizes) { h.Hist[RegionLabeling.HistogramBin(v)]++; if (v >= big) h.Big++; sum += v; }
			h.Min = sizes[0]; h.Med = sizes[sizes.Count / 2]; h.Max = sizes[^1]; h.Mean = sum / sizes.Count;
			int k = Math.Min(3, sizes.Count); h.Largest = new long[k];
			for (int i = 0; i < k; i++) h.Largest[i] = sizes[sizes.Count - 1 - i];
			return h;
		}

		private static Row MakeRow(int level, float amp, int seed, Pass1Result p1, long big, bool ok, ulong ms)
		{
			var (n, s) = Stats(p1.Regions, big);
			return new Row
			{
				Level = level, Amp = amp, Seed = seed, N = n, S = s, MainlandCells = p1.Regions.Mainland.SizeCells,
				SpecksReverted = p1.RegionLedger?.RevertedComponents ?? 0, Ok = ok, Ms = ms,
			};
		}

		// ---- the curve --------------------------------------------------------

		private static (CurveKnots, ClimbCalibration) CalibrateCurve(int calibSize, float sea, CurveAnchors anchors)
		{
			var rawPool = new LandHistogram(sea);
			var pass1 = new Dictionary<int, Pass1Result>();
			foreach (int s in CalibrationSeeds)
			{
				var p1 = Topography.Generate(new TerrainGenConfig { MapSize = calibSize, Seed = s });
				pass1[s] = p1;
				rawPool.Accumulate(p1.Height, calibSize);
			}
			var knots = new CurveKnots(2, "v2_balanced",
				rawPool.Quantile(CurveKnots.Percentiles[0]), rawPool.Quantile(CurveKnots.Percentiles[1]),
				rawPool.Quantile(CurveKnots.Percentiles[2]), rawPool.Quantile(CurveKnots.Percentiles[3]),
				rawPool.Quantile(CurveKnots.Percentiles[4]), rawPool.Quantile(CurveKnots.Percentiles[5]));
			float ceilingRaw = knots.K2;
			var rawAbove = new LandHistogram(sea);
			var outAbove = new LandHistogram(sea);
			foreach (int s in CalibrationSeeds)
			{
				var scfg = new TerrainGenConfig
				{
					MapSize = calibSize, Seed = s, Curve = true, ShelfDetail = true,
					CurveMode = CurveModeKind.Staircase, Knots = knots, Anchors = anchors, VariantLabel = "staircase",
				};
				Pass2Result st = Shaping.Shape(pass1[s], scfg);
				rawAbove.AccumulateWhere(pass1[s].Height, pass1[s].Height, calibSize, ceilingRaw);
				outAbove.AccumulateWhere(st.Height,       pass1[s].Height, calibSize, ceilingRaw);
			}
			var pcts = ClimbCalibration.DefaultPercentiles;
			var rawQ = new float[pcts.Length]; var outQ = new float[pcts.Length];
			for (int i = 0; i < pcts.Length; i++) { rawQ[i] = rawAbove.Quantile(pcts[i]); outQ[i] = outAbove.Quantile(pcts[i]); }
			var cal = ClimbCalibration.FromPercentiles(pcts, rawQ, outQ, ceilingRaw,
				HeightCurve.EffectiveSpikeMax(pass1[CalibrationSeeds[0]].HMaxSeed, knots, anchors),
				anchors.RedCeil, anchors.PeakCap, mountainLift: 1.0f, peakSharpness: 1.0f);
			return (knots, cal);
		}

		// ---- output -----------------------------------------------------------

		private static void WriteField(string batchRoot, Pass1Result p1, Pass2Result p2, float sea, CurveAnchors anchors, bool skipRaw, float amp)
		{
			string dir = Path.Combine(batchRoot, $"{p2.Seed}_{p2.VariantLabel}");
			DirAccess.MakeDirRecursiveAbsolute(dir);
			if (!skipRaw) HeightField.Save(p2.Height, p2.MapSize, Path.Combine(dir, "height.f32"));
			var look = new LookConfig
			{
				Name = "hillshade_even", Palette = ReliefPalette.Kind.ProvisionalEven,
				ZExaggeration = 18f, LightAzimuth = 315f, LightAltitude = 45f, HillshadeStrength = 0.30f, SeaLevel = sea,
			};
			Image map = ReliefRenderer.Render(p2.Height, p2.MapSize, look);
			LegendRenderer.WithLegend(map, look.Palette, sea, anchors.PeakCap, $"{p2.VariantLabel.ToUpperInvariant()} (AMP {amp:G3}) {p2.Seed}")
				.SavePng(Path.Combine(dir, "relief.png"));
			var led = p1.RegionLedger;
			RegionOverlayRenderer.SavePng(p1.Regions, led != null && led.RevertOn ? p1.RegionsPre : null, p1.MapSize,
				led?.RevertedComponents ?? 0, led?.ThresholdCells ?? 0, Path.Combine(dir, "regions.png"));
		}

		private static string HistRow(int[] h)
		{
			var sb = new StringBuilder();
			for (int i = 0; i < h.Length; i++) { if (i > 0) sb.Append(" · "); sb.Append(h[i]); }
			return sb.ToString();
		}

		private static string Largest(long[] l) => l.Length == 0 ? "—" : string.Join(" / ", Array.ConvertAll(l, v => v.ToString("N0")));

		private static string TableMarkdown(float[] ladder, int[] seeds, List<Row> rows, Dictionary<int, Row> baseline, long big)
		{
			var sb = new StringBuilder();
			var histHead = new StringBuilder();
			for (int i = 0; i <= RegionLabeling.HistogramEdges.Length; i++) { if (i > 0) histHead.Append(" · "); histHead.Append(RegionLabeling.HistogramLabel(i)); }
			sb.AppendLine($"| Level | amp | Seed | **N islands all / ≥ {big:N0}** | N size med / mean / max | N largest three | N histogram ({histHead}) | **S islands all / ≥ {big:N0}** | S size med / mean / max | S largest three | S histogram | mainland cells (Δ vs amp 0) | specks reverted | oracle |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|---|---|---|---|---|---|");
			foreach (int seed in seeds)
			{
				var b = baseline[seed];
				var all = new List<Row> { b }; all.AddRange(rows.FindAll(r => r.Seed == seed));
				foreach (var r in all)
					sb.AppendLine($"| {(r.Level == 0 ? "*baseline*" : $"`frag_{r.Level}`")} | {r.Amp:G3} | `{seed}` | **{r.N.All} / {r.N.Big}** | {r.N.Med} / {r.N.Mean:F0} / {r.N.Max} | {Largest(r.N.Largest)} | {HistRow(r.N.Hist)} | " +
								  $"**{r.S.All} / {r.S.Big}** | {r.S.Med} / {r.S.Mean:F0} / {r.S.Max} | {Largest(r.S.Largest)} | {HistRow(r.S.Hist)} | {r.MainlandCells:N0} ({r.MainlandCells - b.MainlandCells:+#,0;-#,0;0}) | {r.SpecksReverted} | {(r.Level == 0 ? "—" : r.Ok ? "pass" : "**FAIL**")} |");
			}
			return sb.ToString();
		}

		private static void WriteTable(string batchRoot, int mapSize, float[] ladder, int[] seeds, List<Row> rows, Dictionary<int, Row> baseline, long big,
			float stretch, float freq, long speckCells)
		{
			var sb = new StringBuilder();
			sb.AppendLine($"# The hemisphere-split count/size table — {ladder.Length} amplitudes × {seeds.Length} seeds at {mapSize}");
			sb.AppendLine();
			sb.AppendLine($"Fixed: stretch {stretch:G3}, fragmentation frequency {freq:G3}/map, window {CoastalFragment.DefaultBandCentre:F2} ± {CoastalFragment.DefaultBandHalfWidth:F2}, speck revert < {speckCells} cells. Offshore / shelf OFF.");
			sb.AppendLine("Islands = non-mainland 8-connected land components of the classify field; hemisphere by centroid. BOTH hemispheres are signals now.");
			sb.AppendLine();
			sb.Append(TableMarkdown(ladder, seeds, rows, baseline, big));
			WriteText(Path.Combine(batchRoot, "count_size_table.md"), sb.ToString());

			var csv = new StringBuilder();
			csv.AppendLine("level,amp,seed,n_all,n_big,n_med,n_mean,n_max,n_largest,n_hist,s_all,s_big,s_med,s_mean,s_max,s_largest,s_hist,mainland_cells,specks_reverted,oracle,ms");
			var ic = System.Globalization.CultureInfo.InvariantCulture;
			foreach (int seed in seeds)
			{
				var all = new List<Row> { baseline[seed] }; all.AddRange(rows.FindAll(r => r.Seed == seed));
				foreach (var r in all)
					csv.AppendLine(string.Join(",", r.Level, r.Amp.ToString("G5", ic), r.Seed,
						r.N.All, r.N.Big, r.N.Med, r.N.Mean.ToString("F1", ic), r.N.Max, "\"" + Largest(r.N.Largest) + "\"", "\"" + HistRow(r.N.Hist) + "\"",
						r.S.All, r.S.Big, r.S.Med, r.S.Mean.ToString("F1", ic), r.S.Max, "\"" + Largest(r.S.Largest) + "\"", "\"" + HistRow(r.S.Hist) + "\"",
						r.MainlandCells, r.SpecksReverted, r.Ok ? "pass" : "FAIL", r.Ms));
			}
			WriteText(Path.Combine(batchRoot, "count_size_table.csv"), csv.ToString());
		}

		private static void WriteIndex(string batchRoot, int mapSize, int calibSize, float[] ladder, int[] seeds, List<Row> rows, Dictionary<int, Row> baseline, long big,
			float stretch, float freq, long speckCells, List<ShapingOracle.Check> hard, List<ShapingOracle.Check> perField, bool allOk)
		{
			int first = seeds.Length > 1 ? seeds[1] : seeds[0];
			var sb = new StringBuilder();
			sb.AppendLine("# Batch 09 — coastal fragmentation: break more pieces off the edges, N + S");
			sb.AppendLine();
			sb.AppendLine("**Options, not a setting.** At a FIXED stretch, a perimeter-wide band-limited fragmentation noise on the pre-power");
			sb.AppendLine("falloff — only inside the coastal window, zero-mean — is swept light → heavy. Thin necks of barely-land flip first");
			sb.AppendLine("(self-targeting: nothing detected, nothing stamped); the interior is bit-identical by construction (asserted). The");
			sb.AppendLine("region layer is the instrument; both hemispheres are fragmentation signals now.");
			sb.AppendLine();
			sb.AppendLine("## ⭐ Open this first");
			sb.AppendLine();
			sb.AppendLine($"1. **`{first}_frag_2/regions.png`** — a mid amplitude on the seed whose natural southern islands read fragmentation best; grey mainland, each island its own colour, dark red = a reverted speck (< {speckCells} cells).");
			sb.AppendLine($"2. Walk the ladder on that seed: `{first}_frag_1/` … `_frag_{ladder.Length}/` (`regions.png` beside `relief.png`); then the same on `{seeds[0]}`.");
			sb.AppendLine("3. Then the table: N and S count + size side by side, down the rows as amplitude climbs — look for counts rising while the largest pieces stay healthy.");
			sb.AppendLine();
			sb.AppendLine("## The fixed frame and the axis");
			sb.AppendLine();
			sb.AppendLine($"- **Fixed:** stretch `{stretch:G3}` (task 08's `stretch_3` rung; band {SouthernStretch.DefaultBandStartFrac:F2} / feather {SouthernStretch.DefaultBandFeatherFrac:F2}, sinker stretched — untouched this round) · fragmentation frequency `{freq:G3}` periods/map (the secondary dial, fixed) · window centre {CoastalFragment.DefaultBandCentre:F2} ± {CoastalFragment.DefaultBandHalfWidth:F2} (pre-power falloff) · speck revert < {speckCells} cells (true noise only) · offshore OFF · shelf OFF.");
			sb.AppendLine($"- **The axis — `FragmentAmp`:** {string.Join(" · ", Array.ConvertAll(ladder, v => v.ToString("G3")))} (levels 1–{ladder.Length}); baseline 0 = the task-08 stretch field, measured for Δ.");
			sb.AppendLine($"- \"big\" island = ≥ {big:N0} cells at {mapSize} (the 07 `threshold_mid`).");
			sb.AppendLine();
			sb.AppendLine($"## ⭐ The hemisphere-split count/size table — {ladder.Length} amplitudes × {seeds.Length} seeds at {mapSize}");
			sb.AppendLine();
			sb.Append(TableMarkdown(ladder, seeds, rows, baseline, big));
			sb.AppendLine();
			sb.AppendLine("Also as plain data: `count_size_table.md` / `.csv`. The probe that fixed the frequency and placed the ladder: `scratch/frag_probe.md`.");
			sb.AppendLine();
			sb.AppendLine("## ⚠ The palette is PROVISIONAL");
			sb.AppendLine();
			sb.AppendLine("`ProvisionalEven`, flagged. The individually-coloured scheme is only the `regions.png` overlay.");
			sb.AppendLine();
			sb.AppendLine("## The oracle (asymmetric: interior locked, coast free)");
			sb.AppendLine();
			sb.AppendLine("Regressions (the curve untouched; frag OFF at the fixed stretch bit-identical to the task-08 field):");
			sb.AppendLine();
			sb.AppendLine(ShapingOracle.ToMarkdownTable(hard));
			sb.AppendLine("Per field (interior locked r · high-ground report s (informational) · centre-is-land m · tag/coastline k · classify b · determinism o / o2):");
			sb.AppendLine();
			sb.AppendLine(ShapingOracle.ToMarkdownTable(perField));
			sb.AppendLine($"**{(allOk ? "ALL HARD CHECKS PASS" : "⚠⚠ FAILURES — do not judge this batch")}**");
			sb.AppendLine();
			sb.AppendLine("## Disposability");
			sb.AppendLine();
			sb.AppendLine("| Artifact | Keep? |");
			sb.AppendLine("|---|---|");
			sb.AppendLine("| `regions.png`, `relief.png`, `INDEX.md`, `count_size_table.md` / `.csv`, `scratch/frag_probe.md` | **keep** |");
			sb.AppendLine("| `height.f32` | ♻ regenerable from seed + code — large, clear freely |");
			sb.AppendLine("| `scratch/` | persistent by rule; never cleaned |");
			sb.AppendLine();
			sb.AppendLine($"Plates at {mapSize}, curve calibrated at {calibSize} with offshore off. {WorldScale.Describe()}.");
			WriteText(Path.Combine(batchRoot, "INDEX.md"), sb.ToString());
		}

		private static void WriteText(string path, string text)
		{
			using var f = Godot.FileAccess.Open(path, Godot.FileAccess.ModeFlags.Write);
			if (f == null) { GD.PrintErr($"could not write {path}"); return; }
			f.StoreString(text);
		}

		// ---- env helpers --------------------------------------------------------

		private static string EnvStr(string k, string fallback)
		{
			string v = System.Environment.GetEnvironmentVariable(k);
			return string.IsNullOrWhiteSpace(v) ? fallback : v;
		}

		private static int EnvInt(string k, int fallback)
			=> int.TryParse(EnvStr(k, null) ?? "", out int v) ? v : fallback;

		private static float EnvFloat(string k, float fallback)
			=> float.TryParse(EnvStr(k, null) ?? "", System.Globalization.NumberStyles.Float,
				System.Globalization.CultureInfo.InvariantCulture, out float v) ? v : fallback;

		private static float[] EnvFloats(string k, float[] fallback)
		{
			string v = EnvStr(k, null);
			if (v == null) return fallback;
			var outp = new List<float>();
			foreach (string part in v.Split(',', StringSplitOptions.RemoveEmptyEntries))
				if (float.TryParse(part.Trim(), System.Globalization.NumberStyles.Float, System.Globalization.CultureInfo.InvariantCulture, out float f)) outp.Add(f);
			return outp.Count > 0 ? outp.ToArray() : fallback;
		}

		private static int[] EnvSeeds(string k, int[] fallback)
		{
			string v = EnvStr(k, null);
			if (v == null) return fallback;
			var outp = new List<int>();
			foreach (string part in v.Split(',', StringSplitOptions.RemoveEmptyEntries))
				if (int.TryParse(part.Trim(), out int s) && s > 0) outp.Add(s);
			return outp.Count > 0 ? outp.ToArray() : fallback;
		}
	}
}