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

namespace IslaApocalypse.Tools
{
	/// <summary>
	/// ⭐ THE REGION-LABELING BATCH (chat2/07) — the general region layer on the current terrain, the
	/// island tag fixed by construction, and the tunable speck revert swept.
	///
	/// ═══ WHAT IT PRODUCES — a fixed budget: 4 plates + the count/size table ═══
	///
	///   PLATES (4 fields, each grayscale + .f32 + relief + the LABELED-REGIONS overlay + the tag overlay):
	///     {plate}_threshold_low / _mid / _high   three revert thresholds on ONE seed — the developer
	///                                            dials "where too-small-to-keep sits" by eye.
	///     {second}_threshold_mid                 the preset on a second seed — the table seed with the
	///                                            most NATURAL islands (offshore off), auto-picked or
	///                                            ISLA_SECOND_SEED — labeling + threshold are not
	///                                            seed-specific; the big organic masses tag correctly.
	///
	///   THE COUNT/SIZE TABLE (data): per seed, natural islands (offshore off), pre-revert islands, and
	///     post-revert islands at each threshold, with size min / median / mean / max and a log-spaced
	///     size histogram — the instrument the later southern-stretch step tunes against.
	///
	/// Every "current terrain" field = shelf ON + the chat2/06 organic preset (`density_mid`) + region
	/// labeling ON; the revert is the variable. 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/RegionLabelingTool.tscn
	///
	///   ISLA_TASK / ISLA_BATCH / ISLA_SKIP_RAW / ISLA_OUTPUT_DIR
	///   ISLA_MAPSIZE        plate + table size        (default 4096)
	///   ISLA_TABLE_SIZE     count-table size           (default = ISLA_MAPSIZE; a probe may drop it)
	///   ISLA_CALIB_SIZE     curve calibration size     (default 2048, task 01's)
	///   ISLA_TABLE_SEEDS    the table seeds            (default 8 below)
	///   ISLA_PLATE_SEED     the three-threshold seed   (default 1063685222)
	///   ISLA_SECOND_SEED    the second plate seed      (default 0 = auto: most natural islands)
	///   ISLA_THR_LOW / ISLA_THR_MID / ISLA_THR_HIGH    thresholds, fraction of map area (probe overrides)
	///   ISLA_TABLE_ONLY=1   probe: table only (no regressions, no plates)
	///   ISLA_PHASE1_SOURCE   the Phase-1 regression dump's batch (default "chat1/02_pass1_port")
	/// </summary>
	public partial class RegionLabelingTool : Node
	{
		private static readonly int[] DefaultTableSeeds =
		{
			1063685222, 20260821, 8675309, 123456789, 271828182, 999999937, 90210, 424242,
		};

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

		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 Level { public string Label; public float Frac; }

		private sealed class Row
		{
			public string Level; public int Seed; public long ThresholdCells;
			public int Natural, NaturalN, NaturalS;                    // offshore OFF, revert OFF
			public int Pre, PreN, PreS;                                // offshore ON, revert OFF
			public int Post, PostN, PostS;                             // offshore ON, revert at this level
			public int RevertedComps; public long RevertedCells;
			public long PreMin, PreMed, PreMax, PostMin, PostMed, PostMax; public double PreMean, PostMean;
			public int[] PreHist, PostHist;
			public long MainlandCells; public bool Ok; public ulong Ms;
		}

		private void Run()
		{
			ToolingPaths.Configure(OS.GetUserDataDir());
			// ⭐ rivers/01: batches are namespaced by chat. The default is this tool's AUTHORING chat,
			// so re-running it reproduces its own batch in place; ISLA_CHAT redirects a run to another
			// chat's namespace — which is what keeps an acceptance run from overwriting its own anchor.
			ToolingPaths.ConfigureChat(EnvStr(ToolingPaths.ChatVar, "chat2"));

			int task        = EnvInt("ISLA_TASK", 7);
			string descr    = EnvStr("ISLA_BATCH", "region_labeling");
			int mapSize     = EnvInt("ISLA_MAPSIZE", DefaultMapSize);
			int tableSize   = EnvInt("ISLA_TABLE_SIZE", mapSize);
			int calibSize   = EnvInt("ISLA_CALIB_SIZE", DefaultCalibSize);
			int[] tableSeeds = EnvSeeds("ISLA_TABLE_SEEDS", DefaultTableSeeds);
			int plateSeed   = EnvInt("ISLA_PLATE_SEED", 1063685222);
			int secondEnv   = EnvInt("ISLA_SECOND_SEED", 0);
			string p1Source = EnvStr("ISLA_PHASE1_SOURCE", "chat1/02_pass1_port");
			bool skipRaw    = EnvStr("ISLA_SKIP_RAW", "0") == "1";
			bool tableOnly  = EnvStr("ISLA_TABLE_ONLY", "0") == "1";

			var levels = new List<Level>
			{
				new() { Label = "threshold_low",  Frac = EnvFloat("ISLA_THR_LOW",  RegionPass.ThresholdLowFrac) },
				new() { Label = "threshold_mid",  Frac = EnvFloat("ISLA_THR_MID",  RegionPass.ThresholdMidFrac) },
				new() { Label = "threshold_high", Frac = EnvFloat("ISLA_THR_HIGH", RegionPass.ThresholdHighFrac) },
			};
			Level mid = levels[1];

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

			var anchors = CurveAnchors.Default;
			float sea = 0.15f;

			GD.Print("==================================================================");
			GD.Print("  REGION LABELING (chat2/07) — label all land, fix the tag, tunable speck revert");
			GD.Print("==================================================================");
			GD.Print($"MapSize   : {mapSize} (plates)   table at {tableSize}   curve calibrated at {calibSize} (offshore OFF)");
			GD.Print($"table     : {string.Join(", ", tableSeeds)}");
			GD.Print($"plate seed: {plateSeed}   second seed: {(secondEnv > 0 ? secondEnv.ToString() : "auto (most natural islands)")}");
			foreach (var l in levels) GD.Print($"  {l.Label,-15} {l.Frac:G3} of map area = {Cells(l.Frac, mapSize):N0} cells at {mapSize} ({Cells(l.Frac, tableSize):N0} at {tableSize})");
			GD.Print($"terrain   : shelf ON + offshore {OffshoreSettings.Organic().Describe()}");
			GD.Print($"contract  : classify field · land 8-connected · mainland = centre component · id/size/centroid/hemisphere(centroid)/isMainland");
			GD.Print($"batch     : {batchRoot}{(tableOnly ? "   ⚠ ISLA_TABLE_ONLY — a probe, not the batch of record" : "")}");
			GD.Print("==================================================================");

			// ═══ 0. THE CURVE ═══
			GD.Print($"\n--- 0. CURVE (task-01 pool at {calibSize}, offshore off) ---");
			var (knots, calibration) = CalibrateCurve(calibSize, sea, anchors);
			GD.Print($"  {knots}");
			GD.Print($"  {calibration.Describe()}");

			TerrainGenConfig Cfg(int size, int seed, string label, bool offshoreOn, bool revertOn, float frac)
			{
				// ⭐ rivers/01 — FAMILY-OFF PINNED, not defaulted. This tool is chat-2 shaping DEVELOPMENT:
				// it was authored and judged before the shape family existed, and its regression checks
				// hold pass 1 against the FAMILY-OFF `02_pass1_port` dump. The re-baseline flipped the
				// bare defaults family-ON, so without this pin every config here would silently acquire
				// stretch + fragmentation and every anchor check would fail for a configuration reason.
				// → TerrainGenConfig.WithFamilyOff().
				var c = BaseConfig(size, seed, knots, anchors, calibration, label).WithFamilyOff();
				// …then this tool's own axes, AFTER the pin (the pin would otherwise clear them).
				if (offshoreOn) { c.CoastShelf = true; c.Offshore = OffshoreSettings.Organic(); }
				c.RegionLabeling = true;
				c.SpeckRevert = revertOn;
				c.MinLandComponentFrac = frac;
				return c;
			}

			// ═══ 1. REGRESSIONS ═══
			var hard = new List<ShapingOracle.Check>();
			if (!tableOnly)
			{
				GD.Print($"\n--- 1. REGRESSIONS at {calibSize}, seed {plateSeed} ---");
				var offCfg = Cfg(calibSize, plateSeed, "off", offshoreOn: false, revertOn: false, mid.Frac);
				Pass1Result p1 = Topography.Generate(offCfg);

				var curveOff = offCfg.Clone(); curveOff.Curve = false;
				Pass2Result pOff = Shaping.Shape(p1, curveOff);
				// ⭐ a1 KEPT at rivers/01 — the family-off pass-1 guard (config pinned family-off). ⚠ loud.
				string p1Dump = Path.Combine(ToolingPaths.BatchesRoot, p1Source, $"{plateSeed}_full", "height.f32");
				hard.Add(ShapingOracle.DumpRegression("a1", "curve OFF, offshore OFF, revert OFF (labeling on) == Phase-1 .f32 dump",
					pOff.Height, ShapingOracle.LoadAnchor("a1", "ISLA_PHASE1_SOURCE", p1Dump, calibSize), calibSize, p1Dump));

				// ⚑ RETIRED at rivers/01 — a3 and a3r, both against `03_mountain_restore`.
				//   A curve-development intermediate, subsumed by the `terrain-shape-v1` acceptance (a10).
				//   a3r was informational only, and its subject — how many natural specks the revert takes —
				//   is now reported by the region ledger every run, with the revert ON by default.
				// The dump is NOT deleted (file-safety; regenerable, and the record of what was judged);
				// its `INDEX.md` is marked superseded. → XX_Human/output/rivers/01_*.report.md §A4.

				var shelfCfg = offCfg.Clone(); shelfCfg.CoastShelf = true; shelfCfg.VariantLabel = "shelf_only";
				Pass1Result p1Shelf = Topography.Generate(shelfCfg);
				var j0 = ShapingOracle.MainlandUnmoved(p1, p1Shelf, sea);
				j0.Name = "shelf alone: every land cell bit-identical (shelf is below-sea only)";
				hard.Add(j0);
				hard.Add(ShapingOracle.CentreIsLand(p1));
				foreach (var c in hard) GD.Print("  " + c);

				// ⚑ RETIRED at rivers/01 — a4 (`04_seed_gallery`) and a6 (`06_offshore_organic_tune`).
				//   a4 held the PRE-FAMILY committed curve; the locked shape is family-ON, and a10 is the
				//   8192 acceptance now. a6 held the ORGANIC ISLET layer — the DROPPED mechanism (→ D-063):
				//   islands are organic-only, made by the stretch + fragmentation and identified here, never
				//   placed. An oracle pinning islet output is an oracle defending a design that was reversed.
				// The dump is NOT deleted (file-safety; regenerable, and the record of what was judged);
				// its `INDEX.md` is marked superseded. → XX_Human/output/rivers/01_*.report.md §A4.
			}

			// ═══ 2. DETERMINISM ═══
			GD.Print($"\n--- 2. DETERMINISM at {tableSize}, seed {plateSeed}, {mid.Label} ---");
			var perFieldChecks = new List<ShapingOracle.Check>();
			{
				var cA = Cfg(tableSize, plateSeed, mid.Label, true, true, mid.Frac);
				var cB = Cfg(tableSize, plateSeed, mid.Label, true, true, mid.Frac);
				var det = ShapingOracle.LabelsDeterministic(Topography.Generate(cA), Topography.Generate(cB));
				det.Name += $" [{plateSeed}]";
				perFieldChecks.Add(det); GD.Print("  " + det);
			}

			// ═══ 3. THE COUNT/SIZE TABLE ═══
			GD.Print($"\n--- 3. COUNT/SIZE TABLE at {tableSize} ---");
			var rows = new List<Row>();
			var naturalCount = new Dictionary<int, int>();
			bool notesShown = false;
			foreach (int seed in tableSeeds)
			{
				// natural: offshore OFF, revert OFF
				Pass1Result pNat = Topography.Generate(Cfg(tableSize, seed, "natural", false, false, mid.Frac));
				var (natN, natS) = RegionLabeling.IslandsByHemisphere(pNat.Regions);
				naturalCount[seed] = pNat.Regions.IslandCount;
				// pre: offshore ON, revert OFF
				var cPre = Cfg(tableSize, seed, "pre", true, false, mid.Frac);
				Pass1Result pPre = Topography.Generate(cPre);
				{
					var cj = ShapingOracle.MainlandUnmoved(pNat, pPre, sea); cj.Name += $" [offshore on vs off, {seed}]"; perFieldChecks.Add(cj);
					var cm = ShapingOracle.CentreIsLand(pPre); cm.Name += $" [pre {seed}]"; perFieldChecks.Add(cm);
				}
				if (!notesShown) { foreach (string n in pPre.Notes) GD.Print("    " + n); }
				GD.Print($"  seed {seed,-11} natural islands {pNat.Regions.IslandCount,3} (N {natN} / S {natS})   pre-revert {pPre.Regions.IslandCount,3} (N {pPre.RegionLedger.PostNorth} / S {pPre.RegionLedger.PostSouth})  mainland {pPre.Regions.Mainland.SizeCells:N0} cells");

				foreach (var lv in levels)
				{
					var cfg = Cfg(tableSize, seed, lv.Label, true, true, lv.Frac);
					Pass1Result p1 = Topography.Generate(cfg);
					Pass2Result p2 = Shaping.Shape(p1, cfg);
					if (!notesShown) { foreach (string n in p1.Notes) if (n.StartsWith("[Regions]")) GD.Print("    " + n); notesShown = true; }
					var led = p1.RegionLedger;
					long thr = led.ThresholdCells;
					var comps = OffshoreAnalysis.Components(p1.IsIsland, p1.Height, sea, tableSize);
					var checks = new List<ShapingOracle.Check>
					{
						ShapingOracle.CentreIsLand(p1),
						ShapingOracle.RevertGuards(pPre, p1, sea, thr),
						ShapingOracle.MoatIntact(p1, comps),
						ShapingOracle.TagCoastlineConsistent(p2, sea),
						ShapingOracle.HMaxAfterOffshore(p1),
						ShapingOracle.ClassifyFidelity(p1, p2),
					};
					foreach (var c in checks) { c.Name += $" [{lv.Label} {seed}]"; perFieldChecks.Add(c); }
					bool ok = checks.TrueForAll(c => c.Passed);
					var row = new Row
					{
						Level = lv.Label, Seed = seed, ThresholdCells = thr,
						Natural = pNat.Regions.IslandCount, NaturalN = natN, NaturalS = natS,
						Pre = led.PreIslands, PreN = led.PreNorth, PreS = led.PreSouth,
						Post = led.PostIslands, PostN = led.PostNorth, PostS = led.PostSouth,
						RevertedComps = led.RevertedComponents, RevertedCells = led.RevertedCells,
						PreMin = led.PreMin, PreMed = led.PreMedian, PreMean = led.PreMean, PreMax = led.PreMax,
						PostMin = led.PostMin, PostMed = led.PostMedian, PostMean = led.PostMean, PostMax = led.PostMax,
						PreHist = led.PreHistogram, PostHist = led.PostHistogram,
						MainlandCells = p1.Regions.Mainland.SizeCells, Ok = ok, Ms = p1.ElapsedMs,
					};
					rows.Add(row);
					GD.Print($"  {lv.Label,-15} seed {seed,-11} thr {thr,5}  pre {row.Pre,3} → post {row.Post,3} (N {row.PostN,2} / S {row.PostS,2})  reverted {row.RevertedComps,3} comps / {row.RevertedCells,7:N0} cells  " +
							 $"post size min {row.PostMin,5} med {row.PostMed,5} max {row.PostMax,6}  {(ok ? "ok" : "⚠ CHECK FAILED")}  {p1.ElapsedMs} ms");
				}
			}

			// ═══ 4. THE PLATES ═══
			int secondSeed = secondEnv > 0 ? secondEnv : PickSecondSeed(naturalCount, tableSeeds, plateSeed);
			GD.Print($"\n  second seed: {secondSeed}{(secondEnv > 0 ? " (ISLA_SECOND_SEED)" : $" (auto: most natural islands among the table seeds — {naturalCount.GetValueOrDefault(secondSeed)})")}");
			var plateRows = new List<Row>();
			if (!tableOnly)
			{
				GD.Print($"\n--- 4. PLATES at {mapSize} ---");
				var plates = new List<(int seed, Level lv)> { (plateSeed, levels[0]), (plateSeed, levels[1]), (plateSeed, levels[2]), (secondSeed, mid) };
				foreach (var (seed, lv) in plates)
				{
					var cfg = Cfg(mapSize, seed, lv.Label, true, true, lv.Frac);
					Pass1Result p1 = Topography.Generate(cfg);
					Pass2Result p2 = Shaping.Shape(p1, cfg);
					var led = p1.RegionLedger;
					var cm = ShapingOracle.CentreIsLand(p1); cm.Name += $" [plate {lv.Label} {seed}]";
					var ck = ShapingOracle.TagCoastlineConsistent(p2, sea); ck.Name += $" [plate {lv.Label} {seed}]";
					perFieldChecks.Add(cm); perFieldChecks.Add(ck);
					WritePlate(batchRoot, p1, p2, sea, anchors, skipRaw);
					plateRows.Add(new Row
					{
						Level = lv.Label, Seed = seed, ThresholdCells = led.ThresholdCells,
						Pre = led.PreIslands, PreN = led.PreNorth, PreS = led.PreSouth, Post = led.PostIslands, PostN = led.PostNorth, PostS = led.PostSouth,
						RevertedComps = led.RevertedComponents, RevertedCells = led.RevertedCells,
						PostMin = led.PostMin, PostMed = led.PostMedian, PostMean = led.PostMean, PostMax = led.PostMax,
						MainlandCells = p1.Regions.Mainland.SizeCells, Ok = cm.Passed && ck.Passed, Ms = p1.ElapsedMs,
					});
					GD.Print($"  plate {seed}_{lv.Label}: pre {led.PreIslands} → post {led.PostIslands} (N {led.PostNorth} / S {led.PostSouth}), reverted {led.RevertedComponents} comps  {(cm.Passed && ck.Passed ? "ok" : "⚠ CHECK FAILED")}  {p1.ElapsedMs} ms");
				}
			}

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

			WriteTable(batchRoot, tableSize, levels, rows);
			WriteIndex(batchRoot, mapSize, tableSize, calibSize, plateSeed, secondSeed, tableSeeds, levels, rows, plateRows, hard, perFieldChecks, allOk, tableOnly);

			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);
		}

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

		private static int PickSecondSeed(Dictionary<int, int> natural, int[] seeds, int plateSeed)
		{
			int best = 0, bestN = -1;
			foreach (int s in seeds)
			{
				if (s == plateSeed) continue;
				int n = natural.GetValueOrDefault(s);
				if (n > bestN) { best = s; bestN = n; }
			}
			return best == 0 ? plateSeed : best;
		}

		// ---- the curve, measured exactly as tasks 03–06 did --------------------

		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(TerrainGenConfig.CalibrationPool(calibSize, s));   // family-off PINNED (rivers/01), not defaulted
				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)
			{
				// ⭐ rivers/01: family-off PINNED, like the pool it shapes. (The family acts in pass 1 and
				// `Shaping.Shape` never reads it, so this is inert today — pinned anyway so "the whole
				// calibration is family-off" is a total claim rather than a field-by-field one.)
				var scfg = new TerrainGenConfig
				{
					MapSize = calibSize, Seed = s, Curve = true, ShelfDetail = true,
					CurveMode = CurveModeKind.Staircase, Knots = knots, Anchors = anchors, VariantLabel = "staircase",
				}.WithFamilyOff();
				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);
		}

		private static TerrainGenConfig BaseConfig(int mapSize, int seed, CurveKnots k, CurveAnchors a,
			ClimbCalibration cal, string label) => new TerrainGenConfig
		{
			MapSize = mapSize, Seed = seed, VariantLabel = label,
			Curve = true, ShelfDetail = false, CurveMode = CurveModeKind.Continuous,
			Knots = k, Anchors = a, ClimbCalibration = cal, LowlandCeilingM = 30f,
			CoastShelf = false, Offshore = new OffshoreSettings(),   // OFF unless the variant turns it on
		};

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

		private static void WritePlate(string batchRoot, Pass1Result p1, Pass2Result p2, float sea, CurveAnchors anchors, bool skipRaw)
		{
			string dir = Path.Combine(batchRoot, $"{p2.Seed}_{p2.VariantLabel}");
			DirAccess.MakeDirRecursiveAbsolute(dir);

			GrayscaleRenderer.SavePng(p2.Height, p2.MapSize, Path.Combine(dir, "grayscale.png"));
			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()} {p2.Seed}")
				.SavePng(Path.Combine(dir, "relief.png"));

			// ⭐ The labeled-regions overlay — the point of this task.
			var led = p1.RegionLedger;
			RegionOverlayRenderer.SavePng(p1.Regions, led.RevertOn ? p1.RegionsPre : null, p1.MapSize,
				led.RevertedComponents, led.ThresholdCells, Path.Combine(dir, "regions.png"));

			// The hemisphere tag overlay (chat2/05's), now showing the tag by construction.
			var (n, s) = RegionLabeling.IslandsByHemisphere(p1.Regions);
			TagOverlayRenderer.SavePng(p2.Height, p2.IsIsland, p2.IslandHemisphere, p2.MapSize, sea, n, s, Path.Combine(dir, "tags.png"));
		}

		private static string HistRow(int[] h)
		{
			if (h == null) return "—";
			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 TableMarkdown(List<Level> levels, List<Row> rows, int tableSize)
		{
			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($"| Level | Seed | threshold (cells) | natural islands (offshore off) N / S | pre-revert islands N / S | **post-revert islands N / S** | reverted comps / cells | pre size min / med / mean / max | **post size min / med / mean / max** | post histogram ({histHead}) | mainland cells | oracle |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|---|---|---|---|");
			foreach (var lv in levels)
				foreach (var r in rows)
				{
					if (r.Level != lv.Label) continue;
					sb.AppendLine($"| `{r.Level}` | `{r.Seed}` | {r.ThresholdCells:N0} | {r.Natural} ({r.NaturalN} / {r.NaturalS}) | {r.Pre} ({r.PreN} / {r.PreS}) | **{r.Post} ({r.PostN} / {r.PostS})** | {r.RevertedComps} / {r.RevertedCells:N0} | " +
								  $"{r.PreMin} / {r.PreMed} / {r.PreMean:F0} / {r.PreMax} | **{r.PostMin} / {r.PostMed} / {r.PostMean:F0} / {r.PostMax}** | {HistRow(r.PostHist)} | {r.MainlandCells:N0} | {(r.Ok ? "pass" : "**FAIL**")} |");
				}
			sb.AppendLine();
			sb.AppendLine("**Per level (over the seeds):**");
			sb.AppendLine();
			sb.AppendLine("| Level | threshold | post islands min / mean / max | post N min / mean / max | post S min / mean / max | reverted comps (total) | reverted cells (total) | post median island (median over seeds) | smallest surviving island |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|---|");
			foreach (var lv in levels)
			{
				int cnt = 0, minP = int.MaxValue, maxP = 0, minN = int.MaxValue, maxN = 0, minS = int.MaxValue, maxS = 0; double sumP = 0, sumN = 0, sumS = 0;
				long revC = 0, revCells = 0, smallest = long.MaxValue; var meds = new List<long>(); long thr = 0;
				foreach (var r in rows)
				{
					if (r.Level != lv.Label) continue;
					cnt++; thr = r.ThresholdCells;
					minP = Math.Min(minP, r.Post); maxP = Math.Max(maxP, r.Post); sumP += r.Post;
					minN = Math.Min(minN, r.PostN); maxN = Math.Max(maxN, r.PostN); sumN += r.PostN;
					minS = Math.Min(minS, r.PostS); maxS = Math.Max(maxS, r.PostS); sumS += r.PostS;
					revC += r.RevertedComps; revCells += r.RevertedCells; meds.Add(r.PostMed);
					if (r.Post > 0) smallest = Math.Min(smallest, r.PostMin);
				}
				if (cnt == 0) continue;
				meds.Sort();
				sb.AppendLine($"| `{lv.Label}` | {lv.Frac:G3} = {thr:N0} cells | {minP} / {sumP / cnt:F1} / {maxP} | {minN} / {sumN / cnt:F1} / {maxN} | {minS} / {sumS / cnt:F1} / {maxS} | {revC} | {revCells:N0} | {meds[meds.Count / 2]} | {(smallest == long.MaxValue ? 0 : smallest)} |");
			}
			return sb.ToString();
		}

		private static void WriteTable(string batchRoot, int tableSize, List<Level> levels, List<Row> rows)
		{
			var sb = new StringBuilder();
			sb.AppendLine($"# The count/size table — {rows.Count / Math.Max(1, levels.Count)} seeds × {levels.Count} revert thresholds at {tableSize}");
			sb.AppendLine();
			sb.AppendLine("Islands = non-mainland 8-connected land components of the CLASSIFY field (mainland = the centre component).");
			sb.AppendLine("*natural* = offshore off, revert off; *pre-revert* = offshore `density_mid` on, revert off; *post-revert* = the same with");
			sb.AppendLine("the speck revert on at the level's threshold. Sizes in cells. Histogram bins are cells, log-spaced.");
			sb.AppendLine();
			sb.Append(TableMarkdown(levels, rows, tableSize));
			WriteText(Path.Combine(batchRoot, "count_size_table.md"), sb.ToString());

			var csv = new StringBuilder();
			csv.AppendLine("level,seed,threshold_cells,natural,natural_n,natural_s,pre,pre_n,pre_s,post,post_n,post_s,reverted_comps,reverted_cells,pre_min,pre_median,pre_mean,pre_max,post_min,post_median,post_mean,post_max,post_hist,mainland_cells,oracle,ms");
			var ic = System.Globalization.CultureInfo.InvariantCulture;
			foreach (var r in rows)
				csv.AppendLine(string.Join(",", r.Level, r.Seed, r.ThresholdCells, r.Natural, r.NaturalN, r.NaturalS, r.Pre, r.PreN, r.PreS, r.Post, r.PostN, r.PostS,
					r.RevertedComps, r.RevertedCells, r.PreMin, r.PreMed, r.PreMean.ToString("F1", ic), r.PreMax, r.PostMin, r.PostMed, r.PostMean.ToString("F1", ic), r.PostMax,
					"\"" + HistRow(r.PostHist) + "\"", r.MainlandCells, 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 tableSize, int calibSize, int plateSeed, int secondSeed,
			int[] tableSeeds, List<Level> levels, List<Row> rows, List<Row> plateRows,
			List<ShapingOracle.Check> hard, List<ShapingOracle.Check> perField, bool allOk, bool tableOnly)
		{
			var sb = new StringBuilder();
			sb.AppendLine("# Batch 07 — region labeling: label all land, fix the tag, tunable speck revert");
			sb.AppendLine();
			sb.AppendLine("The **region-labeling layer** (`Core.RegionLabeling`) flood-fills the CLASSIFY field's land into 8-connected");
			sb.AppendLine("components, names the **centre component** the mainland, and exposes id / size / centroid / hemisphere (by");
			sb.AppendLine("centroid) / isMainland. The **island tag is now a consequence of labeling** — every non-mainland component,");
			sb.AppendLine("natural detached masses included. The **speck revert** (origin-blind, lower-only, component-only, mainland never)");
			sb.AppendLine("lowers sub-threshold islands to their ring's seabed; the threshold is the dial swept here.");
			sb.AppendLine();
			if (tableOnly) sb.AppendLine("> ⚠ **ISLA_TABLE_ONLY** — a probe run: table only, no regressions, no plates. Not the batch of record.\n");
			sb.AppendLine("## ⭐ Open this first");
			sb.AppendLine();
			sb.AppendLine($"1. **`{plateSeed}_threshold_mid/regions.png`** — the labeled-regions overlay: grey = mainland (the centre component),");
			sb.AppendLine("   every island its own colour, dark red = where a reverted speck was. Then `relief.png` for the clean ocean.");
			sb.AppendLine($"2. **`{plateSeed}_threshold_low/`** and **`{plateSeed}_threshold_high/`** beside it — same seed, lower / higher cutoff.");
			sb.AppendLine($"3. **`{secondSeed}_threshold_mid/regions.png`** + `tags.png` — the second seed (most natural islands): the big organic");
			sb.AppendLine("   detached masses are labeled and TAGGED (cyan / orange), which task 06's overlay left grey.");
			sb.AppendLine("4. Then the count/size table — the instrument for the later southern-stretch step.");
			sb.AppendLine();
			sb.AppendLine("**The contract (verbatim):** field = classify (raw, uncurved) · land 8-connected (the complement of water's 4) ·");
			sb.AppendLine("component = maximal 8-connected set of land cells (classify ≥ sea) · mainland = the component containing the map");
			sb.AppendLine("centre (not merely the largest; the crater is NOT central) · per component: id, sizeCells, centroid, hemisphere");
			sb.AppendLine($"(by centroid), isMainland. NORTH = rows `[0, {mapSize / 2})`, SOUTH = rows `[{mapSize / 2}, {mapSize})`; y runs south.");
			sb.AppendLine();
			sb.AppendLine("## The four plates");
			sb.AppendLine();
			sb.AppendLine("| Plate | threshold (cells) | pre-revert islands N / S | **post-revert islands N / S** | reverted comps / cells | post size min / med / mean / max | mainland cells | oracle |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|");
			foreach (var r in plateRows)
				sb.AppendLine($"| `{r.Seed}_{r.Level}/` | {r.ThresholdCells:N0} | {r.Pre} ({r.PreN} / {r.PreS}) | **{r.Post} ({r.PostN} / {r.PostS})** | {r.RevertedComps} / {r.RevertedCells:N0} | {r.PostMin} / {r.PostMed} / {r.PostMean:F0} / {r.PostMax} | {r.MainlandCells:N0} | {(r.Ok ? "pass" : "**FAIL**")} |");
			if (plateRows.Count == 0) sb.AppendLine("| *(no plates — probe run)* | | | | | | | |");
			sb.AppendLine();
			sb.AppendLine($"## ⭐ The count/size table — {tableSeeds.Length} seeds × 3 thresholds at {tableSize}");
			sb.AppendLine();
			sb.Append(TableMarkdown(levels, rows, tableSize));
			sb.AppendLine();
			sb.AppendLine("Also as plain data: `count_size_table.md` / `.csv`.");
			sb.AppendLine();
			sb.AppendLine("## The levels");
			sb.AppendLine();
			sb.AppendLine("| Level | `MinLandComponentFrac` | cells at the plate size | cells at 8192 |");
			sb.AppendLine("|---|---|---|---|");
			foreach (var lv in levels) sb.AppendLine($"| `{lv.Label}`{(lv.Label == "threshold_mid" ? " ⭐ config default" : "")} | {lv.Frac:G3} | {Cells(lv.Frac, mapSize):N0} | {Cells(lv.Frac, 8192):N0} |");
			sb.AppendLine();
			sb.AppendLine($"Every field: coast shelf ON + offshore `{OffshoreSettings.Organic().Describe()}` + region labeling ON. The revert is the variable.");
			sb.AppendLine("The revert is **origin-blind**: it removes small natural nubs as well as offshore-pass dots (fewer / bigger, intended). An offshore");
			sb.AppendLine("island it removes leaves its submerged skirt (not this component — component-only) as a shoal.");
			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");
			sb.AppendLine();
			sb.AppendLine("Regressions (offshore OFF + revert OFF must be bit-identical to Phase 1, task 03 and the `terrain-curve-v1` gallery dump; labeling ON + revert OFF bit-identical to the task-06 dump):");
			sb.AppendLine();
			sb.AppendLine(hard.Count == 0 ? "*(skipped — probe run)*\n" : ShapingOracle.ToMarkdownTable(hard));
			sb.AppendLine("Per field (centre-is-land m · revert guards n · determinism o · moat i · mainland unmoved j · tag/coastline k · HMaxSeed l · classify b):");
			sb.AppendLine();
			sb.AppendLine(ShapingOracle.ToMarkdownTable(perField));
			sb.AppendLine($"**{(allOk ? "ALL HARD CHECKS PASS" : "⚠⚠ FAILURES — do not judge this batch")}**");
			sb.AppendLine();
			sb.AppendLine("## Disposability");
			sb.AppendLine();
			sb.AppendLine("| Artifact | Keep? |");
			sb.AppendLine("|---|---|");
			sb.AppendLine("| `regions.png`, `tags.png`, `relief.png`, `INDEX.md`, `count_size_table.md` / `.csv` | **keep** |");
			sb.AppendLine("| `grayscale.png` | ♻ regenerable from the `.f32` |");
			sb.AppendLine("| `height.f32` | ♻ regenerable from seed + code — large, clear freely |");
			sb.AppendLine("| `scratch/` | persistent by rule; never cleaned |");
			sb.AppendLine();
			sb.AppendLine($"Plates at {mapSize}, table at {tableSize}, 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 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;
		}
	}
}