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

namespace IslaApocalypse.Tools
{
	/// <summary>
	/// ⭐ THE OFFSHORE-ISLANDS BATCH — chat2/06: ORGANIC-ONLY, TUNED FOR COVERAGE, SOUTH-WEIGHTED,
	/// NO FORCED COUNT. (chat2/05's version of this tool — faithful / floor_only / hybrid / dense —
	/// is in git history at 3b96e06; the forced floor it batched was reverted out on look.)
	///
	/// ⚠ Since chat2/07 the island tag is set BY THE REGION LAYER (every non-mainland land component,
	/// natural islets included), so this tool's counts now include natural islands; the chat2/06 batch
	/// of record (offshore-pass islands only) was produced at e8571b2.
	///
	/// ═══ WHAT IT PRODUCES — a fixed budget: 4 plates + a count table + a diagnosis ═══
	///
	///   PLATES (4, at ISLA_MAPSIZE, grayscale + .f32 + relief + tags overlay):
	///     {plate}_density_low / _mid / _high   three densities on ONE seed — the developer picks the
	///                                          look by eye (more islands vs slop), apples to apples.
	///     {bulge}_density_mid                  the preset on the southern-bulge seed — the table seed
	///                                          whose south was SPARSEST at density_mid (auto-picked,
	///                                          or ISLA_BULGE_SEED) — the south fix is not seed-specific.
	///
	///   THE COUNT TABLE (data, not plates): per seed, north / south island counts across ~12 seeds for
	///     each of the 3 density levels, with min / mean / max per hemisphere per level, the guard
	///     ledger and the island sizes. This is how "a few south / a couple north, consistently" is
	///     READ — as statistics of the tuning, never as a floor.
	///
	///   THE DIAGNOSIS (data): per hemisphere over the calibration seed pool — valid-zone area, which
	///     gate binds, noise peaks clearing the threshold — measured BEFORE any knob moved (§2 of the
	///     task). → <see cref="OffshoreDiagnosis"/>.
	///
	/// ═══ THE CURVE IS THE TAGGED CURVE, UNCHANGED ═══
	///
	/// `continuous_restored` (tag terrain-curve-v1), calibrated on task 01's pool at the iteration
	/// size WITH OFFSHORE OFF — islands are additive land on top of a curve that does not know they
	/// exist. Oracle a1 / a3 / a4 prove offshore-off is bit-identical to Phase 1, task 03 and the
	/// tag's own 04 gallery dump.
	///
	/// ═══ RUNNING IT ═══
	///
	///   xvfb-run -a Godot_v4.7.2-stable_mono_linux.x86_64 \
	///     --path ~/celerNexus/islaApocalypse-v2 res://Tools/Scenes/OffshoreIslandsTool.tscn
	///
	///   ISLA_TASK / ISLA_BATCH / ISLA_SKIP_RAW / ISLA_OUTPUT_DIR
	///   ISLA_MAPSIZE        plate + table size        (default 4096 — islands need pixels to read)
	///   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) — also the diagnosis size
	///   ISLA_TABLE_SEEDS    the count-table seeds      (default 12 below)
	///   ISLA_PLATE_SEED     the three-density seed     (default 1063685222)
	///   ISLA_BULGE_SEED     the south-bulge seed       (default 0 = auto: sparsest south at density_mid)
	///   ISLA_DENS_LOW / ISLA_DENS_MID / ISLA_DENS_HIGH / ISLA_SOUTH_WEIGHT     the tuning (probe overrides)
	///   ISLA_OFF_MINAREA / ISLA_OFF_MINSEP / ISLA_OFF_MAXAREA                  the guards   (probe overrides)
	///   ISLA_OFF_FREQ / ISLA_OFF_CORE / ISLA_OFF_SHARP / ISLA_OFF_CREST        the shape    (probe overrides)
	///   ISLA_TABLE_ONLY=1   probe: diagnosis + count 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 OffshoreIslandsTool : Node
	{
		/// <summary>
		/// The count-table pool: chat2/05's six hybrid seeds + task 01's calibration pool (minus the
		/// shared anchor) + one more. Twelve draws; the anchor first.
		/// </summary>
		private static readonly int[] DefaultTableSeeds =
		{
			1063685222, 20260821, 8675309, 123456789, 271828182, 999999937,
			20260819, 777001, 424242, 90210, 31337, 55555,
		};

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

		private const int DefaultMapSize = 4096;
		private const int DefaultCalibSize = 2048;

		/// <summary>The consistency targets the table is read against: "a couple north, a few south".</summary>
		private const int TargetNorth = 2, TargetSouth = 3;

		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 Row
		{
			public string Level; public int Seed;
			public int CountN, CountS, PreN, PreS, SpecksN, SpecksS, ClustersN, ClustersS, BlobsN, BlobsS;
			public long Lifted, SizeMin, SizeMed, SizeMax; public double SizeMean;
			public float HMaxBefore, HMaxAfter;
			public bool Ok; public ulong Ms;
		}

		private sealed class Level
		{
			public string Label; public OffshoreSettings Settings;
		}

		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", 6);
			string descr    = EnvStr("ISLA_BATCH", "offshore_organic_tune");
			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 bulgeSeedEnv = EnvInt("ISLA_BULGE_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";

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

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

			// ═══ THE THREE DENSITY LEVELS — the preset of record is `mid` ═══
			OffshoreSettings LevelSettings(float density)
			{
				var o = OffshoreSettings.Organic();
				o.Density           = density;
				o.SouthWeight       = EnvFloat("ISLA_SOUTH_WEIGHT", o.SouthWeight);
				o.MinIslandAreaFrac = EnvFloat("ISLA_OFF_MINAREA", o.MinIslandAreaFrac);
				o.MinSeparationFrac = EnvFloat("ISLA_OFF_MINSEP",  o.MinSeparationFrac);
				o.MaxIslandAreaFrac = EnvFloat("ISLA_OFF_MAXAREA", o.MaxIslandAreaFrac);
				o.FreqPerMapWidth   = EnvFloat("ISLA_OFF_FREQ",    o.FreqPerMapWidth);
				o.CoreFraction      = EnvFloat("ISLA_OFF_CORE",    o.CoreFraction);
				o.EdgeSharpness     = EnvFloat("ISLA_OFF_SHARP",   o.EdgeSharpness);
				o.CrestM            = EnvFloat("ISLA_OFF_CREST",   o.CrestM);
				return o;
			}
			var levels = new List<Level>
			{
				new() { Label = "density_low",  Settings = LevelSettings(EnvFloat("ISLA_DENS_LOW",  OffshoreSettings.OrganicDensityLow)) },
				new() { Label = "density_mid",  Settings = LevelSettings(EnvFloat("ISLA_DENS_MID",  OffshoreSettings.OrganicDensityMid)) },
				new() { Label = "density_high", Settings = LevelSettings(EnvFloat("ISLA_DENS_HIGH", OffshoreSettings.OrganicDensityHigh)) },
			};
			Level mid = levels[1];

			GD.Print("==================================================================");
			GD.Print("  OFFSHORE ISLANDS (chat2/06) — organic-only, tuned for coverage, south-weighted, no forced count");
			GD.Print("==================================================================");
			GD.Print($"MapSize   : {mapSize} (plates)   table at {tableSize}   curve calibrated at {calibSize} (offshore OFF)   diagnosis at {calibSize}");
			GD.Print($"table     : {string.Join(", ", tableSeeds)}");
			GD.Print($"plate seed: {plateSeed}   bulge seed: {(bulgeSeedEnv > 0 ? bulgeSeedEnv.ToString() : "auto (sparsest south at density_mid)")}");
			foreach (var l in levels) GD.Print($"  {l.Label,-13} {l.Settings.Describe()}");
			GD.Print($"hemisphere: NORTH = rows [0, {mapSize / 2})   SOUTH = rows [{mapSize / 2}, {mapSize})   (y runs south)");
			GD.Print($"batch     : {batchRoot}{(tableOnly ? "   ⚠ ISLA_TABLE_ONLY — a probe, not the batch of record" : "")}");
			GD.Print("==================================================================");

			// ═══ 0. THE CURVE — continuous_restored, calibrated with offshore off ═══
			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()}");

			// ═══ 1. REGRESSIONS — the things that must not have moved ═══
			var hard = new List<ShapingOracle.Check>();
			if (!tableOnly)
			{
				GD.Print($"\n--- 1. REGRESSIONS at {calibSize}, seed {plateSeed} ---");
				var offCfg = BaseConfig(calibSize, plateSeed, knots, anchors, calibration, "off");
				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 == Phase-1 .f32 dump",
					pOff.Height, ShapingOracle.LoadAnchor("a1", "ISLA_PHASE1_SOURCE", p1Dump, calibSize), calibSize, p1Dump));

				// ⚑ RETIRED at rivers/01 — a3, `continuous_restored` == `03_mountain_restore`.
				//   A curve-development intermediate: it proved the chat2/03 climb restoration against
				//   chat2/02. Both are upstream of the locked shape, and `terrain-shape-v1` (a10) now
				//   asserts the whole chain end-to-end — subsuming it.
				// 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.

				// Shelf ON, islets OFF: land must be bit-identical (the shelf touches only sea).
				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.HMaxAfterOffshore(p1Shelf));
				foreach (var c in hard) GD.Print("  " + c);

				// ⭐ a4 — offshore OFF at the 04 gallery's size == the terrain-curve-v1 tag's OWN output.
				// The literal "offshore-off is bit-identical to terrain-curve-v1", at full size.
				// ⚑ RETIRED at rivers/01 — a4, offshore-OFF at 8192 == `04_seed_gallery` (`terrain-curve-v1`).
				//   The PRE-FAMILY committed curve. The locked shape is family-ON, so this dump is a
				//   baseline the generator is deliberately no longer on; `a10` replaced it as the 8192
				//   acceptance. (It also cost an 8192 generation on every run of this tool.)
				// 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. THE DIAGNOSIS — measure the south before touching a knob ═══
			GD.Print($"\n--- 2. DIAGNOSIS (calibration pool at {calibSize}, shelf on, {mid.Label} thresholds) ---");
			var diag = new List<OffshoreDiagnosis.Report>();
			foreach (int s in CalibrationSeeds)
			{
				var dCfg = BaseConfig(calibSize, s, knots, anchors, calibration, "shelf_only");
				dCfg.CoastShelf = true;
				Pass1Result pShelf = Topography.Generate(dCfg);
				var rep = OffshoreDiagnosis.Run(pShelf.Height, pShelf.PreTrenchFalloff, calibSize, s, sea, mid.Settings, dCfg.Scale);
				diag.Add(rep);
				GD.Print($"  seed {s,-11} N: zone {rep.North.Zone,9:N0} ({rep.North.ZoneShareOfSea,6:P1}) peaks in zone {rep.North.PeaksInZone,3} > thr {rep.North.PeaksInZoneOverThr,3}   " +
						 $"S: zone {rep.South.Zone,9:N0} ({rep.South.ZoneShareOfSea,6:P1}) peaks in zone {rep.South.PeaksInZone,3} > thr {rep.South.PeaksInZoneOverThr,3}   " +
						 $"sole-blocked N d/f/t {rep.North.SoleDepth:N0}/{rep.North.SoleFalloff:N0}/{rep.North.SoleTrench:N0}  S {rep.South.SoleDepth:N0}/{rep.South.SoleFalloff:N0}/{rep.South.SoleTrench:N0}");
			}
			var (poolN, poolS) = OffshoreDiagnosis.Pool(diag);
			string interpretation = OffshoreDiagnosis.Interpret(poolN, poolS);
			GD.Print("  " + interpretation);

			// ═══ 3. THE COUNT TABLE — ~12 seeds × 3 levels ═══
			GD.Print($"\n--- 3. COUNT TABLE at {tableSize} ---");
			var rows = new List<Row>();
			var perFieldChecks = new List<ShapingOracle.Check>();
			bool notesShown = false;
			foreach (int seed in tableSeeds)
			{
				Pass1Result p1Off = Topography.Generate(BaseConfig(tableSize, seed, knots, anchors, calibration, "off"));
				foreach (var lv in levels)
				{
					var cfg = BaseConfig(tableSize, seed, knots, anchors, calibration, lv.Label);
					cfg.CoastShelf = true; cfg.Offshore = lv.Settings.Clone();
					Pass1Result p1 = Topography.Generate(cfg);
					Pass2Result p2 = Shaping.Shape(p1, cfg);
					if (!notesShown) { foreach (string n in p1.Notes) GD.Print("    " + n); notesShown = true; }

					var comps = OffshoreAnalysis.Components(p1.IsIsland, p1.Height, sea, tableSize);
					var (cn, cs) = OffshoreAnalysis.CountByHemisphere(comps);
					var (szMin, szMed, szMean, szMax, _) = OffshoreAnalysis.SizeSummary(comps, 0);
					var checks = new List<ShapingOracle.Check>
					{
						ShapingOracle.MoatIntact(p1, comps),
						ShapingOracle.MainlandUnmoved(p1Off, p1, sea),
						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, CountN = cn, CountS = cs,
						Lifted = p1.OffshoreLiftedCells, HMaxBefore = p1.HMaxSeedBeforeOffshore, HMaxAfter = p1.HMaxSeed,
						SizeMin = szMin, SizeMed = szMed, SizeMean = szMean, SizeMax = szMax, Ok = ok, Ms = p1.ElapsedMs,
					};
					ReadGuardLedger(p1, row);
					rows.Add(row);
					GD.Print($"  {lv.Label,-13} seed {seed,-11} N {cn,2} S {cs,2}  (pre-guard N {row.PreN,2} S {row.PreS,2}; specks {row.SpecksN + row.SpecksS,2} clusters {row.ClustersN + row.ClustersS,2} blobs {row.BlobsN + row.BlobsS,2})  " +
							 $"size med {szMed,5} max {szMax,6}  {(ok ? "ok" : "⚠ CHECK FAILED")}  {p1.ElapsedMs} ms");
				}
			}
			var stats = LevelStats(levels, rows);
			GD.Print("\n  per level (min / mean / max):");
			foreach (var st in stats)
				GD.Print($"  {st.Label,-13} N {st.MinN} / {st.MeanN:F1} / {st.MaxN}   S {st.MinS} / {st.MeanS:F1} / {st.MaxS}   " +
						 $"seeds with N≥{TargetNorth} & S≥{TargetSouth}: {st.MeetBoth}/{st.Seeds}   S≥N: {st.SouthAtLeastNorth}/{st.Seeds}   " +
						 $"guards: specks {st.Specks} clusters {st.Clusters} blobs {st.Blobs}");

			// ═══ 4. THE PLATES — exactly four ═══
			int bulgeSeed = bulgeSeedEnv > 0 ? bulgeSeedEnv : PickBulgeSeed(rows, mid.Label, plateSeed);
			GD.Print($"\n  southern-bulge seed: {bulgeSeed}{(bulgeSeedEnv > 0 ? " (ISLA_BULGE_SEED)" : " (auto: sparsest south at density_mid among the table seeds)")}");
			var plates = new List<(int seed, Level level)> { (plateSeed, levels[0]), (plateSeed, levels[1]), (plateSeed, levels[2]), (bulgeSeed, mid) };
			var plateRows = new List<Row>();
			if (!tableOnly)
			{
				GD.Print($"\n--- 4. PLATES at {mapSize} ---");
				foreach (var (seed, lv) in plates)
				{
					var cfg = BaseConfig(mapSize, seed, knots, anchors, calibration, lv.Label);
					cfg.CoastShelf = true; cfg.Offshore = lv.Settings.Clone();
					Pass1Result p1 = Topography.Generate(cfg);
					Pass2Result p2 = Shaping.Shape(p1, cfg);
					var comps = OffshoreAnalysis.Components(p1.IsIsland, p1.Height, sea, mapSize);
					var (cn, cs) = OffshoreAnalysis.CountByHemisphere(comps);
					var moat = ShapingOracle.MoatIntact(p1, comps); moat.Name += $" [plate {lv.Label} {seed}]";
					var tag = ShapingOracle.TagCoastlineConsistent(p2, sea); tag.Name += $" [plate {lv.Label} {seed}]";
					perFieldChecks.Add(moat); perFieldChecks.Add(tag);
					WritePlate(batchRoot, p1, p2, sea, anchors, skipRaw, cn, cs);
					var row = new Row { Level = lv.Label, Seed = seed, CountN = cn, CountS = cs, Lifted = p1.OffshoreLiftedCells, Ok = moat.Passed && tag.Passed };
					ReadGuardLedger(p1, row);
					plateRows.Add(row);
					GD.Print($"  plate {seed}_{lv.Label}: N {cn} S {cs}  lifted {p1.OffshoreLiftedCells:N0}  {(row.Ok ? "ok" : "⚠ CHECK FAILED")}  {p1.ElapsedMs} ms");
					foreach (string n in p1.Notes) if (n.Contains("guards") || n.Contains("islands:")) GD.Print("    " + n);
				}
			}

			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);

			// ═══ 5. THE DATA FILES + INDEX ═══
			WriteCountTable(batchRoot, tableSize, levels, rows, stats);
			WriteDiagnosis(batchRoot, calibSize, mid, diag, poolN, poolS, interpretation);
			WriteIndex(batchRoot, mapSize, tableSize, calibSize, plateSeed, bulgeSeed, tableSeeds, levels, rows, stats, plateRows,
				diag, poolN, poolS, interpretation, 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);
		}

		// ---- the table's statistics -------------------------------------------

		private sealed class LevelStat
		{
			public string Label; public int Seeds;
			public int MinN, MaxN, MinS, MaxS; public double MeanN, MeanS;
			public int MeetBoth, SouthAtLeastNorth, Specks, Clusters, Blobs;
			public long SizeMed, SizeMax;
		}

		private static List<LevelStat> LevelStats(List<Level> levels, List<Row> rows)
		{
			var outp = new List<LevelStat>();
			foreach (var lv in levels)
			{
				var st = new LevelStat { Label = lv.Label, MinN = int.MaxValue, MinS = int.MaxValue };
				double sumN = 0, sumS = 0; var meds = new List<long>();
				foreach (var r in rows)
				{
					if (r.Level != lv.Label) continue;
					st.Seeds++;
					st.MinN = Math.Min(st.MinN, r.CountN); st.MaxN = Math.Max(st.MaxN, r.CountN); sumN += r.CountN;
					st.MinS = Math.Min(st.MinS, r.CountS); st.MaxS = Math.Max(st.MaxS, r.CountS); sumS += r.CountS;
					if (r.CountN >= TargetNorth && r.CountS >= TargetSouth) st.MeetBoth++;
					if (r.CountS >= r.CountN) st.SouthAtLeastNorth++;
					st.Specks += r.SpecksN + r.SpecksS; st.Clusters += r.ClustersN + r.ClustersS; st.Blobs += r.BlobsN + r.BlobsS;
					meds.Add(r.SizeMed); st.SizeMax = Math.Max(st.SizeMax, r.SizeMax);
				}
				if (st.Seeds == 0) { st.MinN = st.MinS = 0; }
				else { st.MeanN = sumN / st.Seeds; st.MeanS = sumS / st.Seeds; meds.Sort(); st.SizeMed = meds[meds.Count / 2]; }
				outp.Add(st);
			}
			return outp;
		}

		/// <summary>The table seed whose SOUTH count at the preset level is lowest (ties → lower total, then first in the pool), excluding the plate seed.</summary>
		private static int PickBulgeSeed(List<Row> rows, string midLabel, int plateSeed)
		{
			int best = 0, bestS = int.MaxValue, bestTotal = int.MaxValue;
			foreach (var r in rows)
			{
				if (r.Level != midLabel || r.Seed == plateSeed) continue;
				int total = r.CountN + r.CountS;
				if (r.CountS < bestS || (r.CountS == bestS && total < bestTotal)) { best = r.Seed; bestS = r.CountS; bestTotal = total; }
			}
			return best == 0 ? plateSeed : best;
		}

		/// <summary>Copy the pass's guard ledger into a table row (the pass reports it; the tool does not recompute it).</summary>
		private static void ReadGuardLedger(Pass1Result p1, Row row)
		{
			var l = p1.OffshoreLedger;
			if (l == null) return;
			row.PreN = l.PreGuardNorth; row.PreS = l.PreGuardSouth;
			row.SpecksN = l.SpecksNorth; row.SpecksS = l.SpecksSouth;
			row.ClustersN = l.ClustersNorth; row.ClustersS = l.ClustersSouth;
			row.BlobsN = l.BlobsNorth; row.BlobsS = l.BlobsSouth;
		}

		// ---- the curve, measured exactly as tasks 03/04/05 did ----------------

		private static (CurveKnots, ClimbCalibration, Dictionary<int, Pass1Result>) 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, pass1);
		}

		/// <remarks>
		/// ⭐ rivers/01 — FAMILY-OFF PINNED, not defaulted. This tool is chat-2 shaping DEVELOPMENT
		/// (chat2/05–06): authored and judged before the shape family existed, and its regressions hold
		/// pass 1 against the FAMILY-OFF `02_pass1_port` dump. The re-baseline flipped the bare defaults
		/// family-ON, so without <see cref="TerrainGenConfig.WithFamilyOff"/> every config here would
		/// silently acquire stretch + fragmentation and the anchor checks would fail for a configuration
		/// reason, not a regression. The variants re-enable offshore explicitly, after the pin.
		/// </remarks>
		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,
		}.WithFamilyOff();   // ⭐ shelf / islets / speck / stretch / frag / erosion all OFF — pinned

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

		private static void WritePlate(string batchRoot, Pass1Result p1, Pass2Result p2, float sea,
			CurveAnchors anchors, bool skipRaw, int countN, int countS)
		{
			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 tag overlay — the one artifact that shows the DATA this pass set.
			TagOverlayRenderer.SavePng(p2.Height, p2.IsIsland, p2.IslandHemisphere, p2.MapSize, sea,
				countN, countS, Path.Combine(dir, "tags.png"));
		}

		private static string CountTableMarkdown(List<Level> levels, List<Row> rows, List<LevelStat> stats)
		{
			var sb = new StringBuilder();
			sb.AppendLine("| Level | Seed | **N** | **S** | total | pre-guard N / S | specks | clusters | blobs | size cells min / median / mean / max | lifted cells | HMaxSeed before → after | oracle | ms |");
			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.CountN}** | **{r.CountS}** | {r.CountN + r.CountS} | {r.PreN} / {r.PreS} | " +
								  $"{r.SpecksN + r.SpecksS} | {r.ClustersN + r.ClustersS} | {r.BlobsN + r.BlobsS} | " +
								  $"{r.SizeMin} / {r.SizeMed} / {r.SizeMean:F0} / {r.SizeMax} | {r.Lifted:N0} | " +
								  $"{r.HMaxBefore:F4} → {r.HMaxAfter:F4}{(r.HMaxBefore != r.HMaxAfter ? " ⚠" : "")} | {(r.Ok ? "pass" : "**FAIL**")} | {r.Ms} |");
				}
			sb.AppendLine();
			sb.AppendLine("**Per level — the consistency read (min / mean / max over the seeds):**");
			sb.AppendLine();
			sb.AppendLine($"| Level | density N / S | seeds | **N min / mean / max** | **S min / mean / max** | seeds with N ≥ {TargetNorth} & S ≥ {TargetSouth} | seeds with S ≥ N | specks / clusters / blobs reverted | median island (cells) | largest island (cells) |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|---|---|");
			foreach (var st in stats)
			{
				var lv = levels.Find(l => l.Label == st.Label);
				sb.AppendLine($"| `{st.Label}` | {lv.Settings.Density:F4} / {lv.Settings.DensitySouth:F4} | {st.Seeds} | **{st.MinN} / {st.MeanN:F1} / {st.MaxN}** | **{st.MinS} / {st.MeanS:F1} / {st.MaxS}** | " +
							  $"**{st.MeetBoth} / {st.Seeds}** | {st.SouthAtLeastNorth} / {st.Seeds} | {st.Specks} / {st.Clusters} / {st.Blobs} | {st.SizeMed} | {st.SizeMax} |");
			}
			return sb.ToString();
		}

		private static void WriteCountTable(string batchRoot, int tableSize, List<Level> levels, List<Row> rows, List<LevelStat> stats)
		{
			var sb = new StringBuilder();
			sb.AppendLine($"# The count table — {rows.Count / Math.Max(1, levels.Count)} seeds × {levels.Count} density levels at {tableSize}");
			sb.AppendLine();
			sb.AppendLine("Tagged 8-connected island components per hemisphere (centroid), after the guards. **No count is forced**;");
			sb.AppendLine("this is the statistical outcome of the tuning. NORTH = rows [0, N/2), SOUTH = rows [N/2, N); y runs south.");
			sb.AppendLine();
			sb.Append(CountTableMarkdown(levels, rows, stats));
			WriteText(Path.Combine(batchRoot, "count_table.md"), sb.ToString());

			var csv = new StringBuilder();
			csv.AppendLine("level,seed,density_n,density_s,north,south,total,preguard_n,preguard_s,specks,clusters,blobs,size_min,size_median,size_mean,size_max,lifted_cells,hmax_before,hmax_after,oracle,ms");
			foreach (var r in rows)
			{
				var lv = levels.Find(l => l.Label == r.Level);
				csv.AppendLine(string.Join(",", r.Level, r.Seed, lv.Settings.Density.ToString("F5", System.Globalization.CultureInfo.InvariantCulture),
					lv.Settings.DensitySouth.ToString("F5", System.Globalization.CultureInfo.InvariantCulture),
					r.CountN, r.CountS, r.CountN + r.CountS, r.PreN, r.PreS, r.SpecksN + r.SpecksS, r.ClustersN + r.ClustersS, r.BlobsN + r.BlobsS,
					r.SizeMin, r.SizeMed, r.SizeMean.ToString("F1", System.Globalization.CultureInfo.InvariantCulture), r.SizeMax, r.Lifted,
					r.HMaxBefore.ToString("G9", System.Globalization.CultureInfo.InvariantCulture), r.HMaxAfter.ToString("G9", System.Globalization.CultureInfo.InvariantCulture),
					r.Ok ? "pass" : "FAIL", r.Ms));
			}
			WriteText(Path.Combine(batchRoot, "count_table.csv"), csv.ToString());
		}

		private static string DiagnosisMarkdown(int calibSize, Level mid, List<OffshoreDiagnosis.Report> diag,
			HemisphereDiagnosis poolN, HemisphereDiagnosis poolS, string interpretation)
		{
			var sb = new StringBuilder();
			sb.AppendLine($"Measured on the calibration pool at {calibSize} (shelf on, offshore off — the field the islet layer sees), with the");
			sb.AppendLine($"`{mid.Label}` thresholds (density N {mid.Settings.Density:F4} / S {mid.Settings.DensitySouth:F4}). *Zone* = cells with zone weight > 0");
			sb.AppendLine("(pass the falloff test + moat + outer bound); *peaks* = strict 8-neighbour local maxima of the islet noise field on sea cells;");
			sb.AppendLine("*sole blocker* = sea cells that fail exactly one gate (loosen that gate and they join the zone); *lost > thr* = over-threshold");
			sb.AppendLine("peaks outside the zone, with the gate(s) that excluded them.");
			sb.AppendLine();
			sb.AppendLine(OffshoreDiagnosis.TableHeader());
			foreach (var r in diag)
			{
				sb.AppendLine(OffshoreDiagnosis.TableRow(r, r.North));
				sb.AppendLine(OffshoreDiagnosis.TableRow(r, r.South));
			}
			var poolRep = new OffshoreDiagnosis.Report { Seed = 0 };
			sb.AppendLine(OffshoreDiagnosis.TableRow(poolRep, poolN).Replace("| `0` |", "| **pool** |"));
			sb.AppendLine(OffshoreDiagnosis.TableRow(poolRep, poolS).Replace("| `0` |", "| **pool** |"));
			sb.AppendLine();
			sb.AppendLine($"**Reading:** {interpretation}");
			return sb.ToString();
		}

		private static void WriteDiagnosis(string batchRoot, int calibSize, Level mid, List<OffshoreDiagnosis.Report> diag,
			HemisphereDiagnosis poolN, HemisphereDiagnosis poolS, string interpretation)
		{
			var sb = new StringBuilder();
			sb.AppendLine("# The south diagnosis — zone area, gates and peaks per hemisphere");
			sb.AppendLine();
			sb.Append(DiagnosisMarkdown(calibSize, mid, diag, poolN, poolS, interpretation));
			WriteText(Path.Combine(batchRoot, "diagnosis.md"), sb.ToString());
		}

		private static void WriteIndex(string batchRoot, int mapSize, int tableSize, int calibSize, int plateSeed, int bulgeSeed,
			int[] tableSeeds, List<Level> levels, List<Row> rows, List<LevelStat> stats, List<Row> plateRows,
			List<OffshoreDiagnosis.Report> diag, HemisphereDiagnosis poolN, HemisphereDiagnosis poolS, string interpretation,
			List<ShapingOracle.Check> hard, List<ShapingOracle.Check> perField, bool allOk, bool tableOnly)
		{
			var mid = levels[1];
			var sb = new StringBuilder();
			sb.AppendLine("# Batch 06 — offshore islands: organic-only, tuned for coverage, south-weighted, no forced count");
			sb.AppendLine();
			sb.AppendLine("The chat2/05 forced floor (seeded stamps, guaranteed ≥2 N / ≥4 S) is **reverted out** — it looked stamped.");
			sb.AppendLine("The **organic noise-field layer is the only island mechanism**; this batch tunes its **density** (the main");
			sb.AppendLine("knob) and a **south weight** so it yields *a few south / a couple north* **consistently across seeds, as a");
			sb.AppendLine("statistical outcome** — never a hard-coded count. Guards against slop: specks, clusters and blobs are");
			sb.AppendLine("reverted whole; every surviving island is a noise outline, small, low, crisp.");
			sb.AppendLine();
			if (tableOnly) sb.AppendLine("> ⚠ **ISLA_TABLE_ONLY** — a probe run: diagnosis + count table only, no regressions, no plates. Not the batch of record.\n");
			sb.AppendLine("## ⭐ Open this first");
			sb.AppendLine();
			sb.AppendLine($"1. **`{plateSeed}_density_mid/tags.png`** — the preset of record: grey mainland, cyan = island N, orange = island S.");
			sb.AppendLine("   No rings any more — nothing is seeded. Then its `relief.png` for the shape.");
			sb.AppendLine($"2. **`{plateSeed}_density_low/`** and **`{plateSeed}_density_high/`** beside it — the same seed, less and more density;");
			sb.AppendLine("   pick the look by eye (more islands vs slop).");
			sb.AppendLine($"3. **`{bulgeSeed}_density_mid/tags.png`** — the preset on the southern-bulge seed (the table seed whose south was");
			sb.AppendLine("   sparsest at `density_mid`): the south tuning is not seed-specific.");
			sb.AppendLine("4. Then the count table below — *does it consistently give a few south / a couple north?*");
			sb.AppendLine();
			sb.AppendLine($"**Hemisphere convention (from the code, not invented):** y runs SOUTH. NORTH = rows `[0, {mapSize / 2})`,");
			sb.AppendLine($"SOUTH = rows `[{mapSize / 2}, {mapSize})`. Component hemisphere is by centroid; the tag per cell is by row.");
			sb.AppendLine();
			sb.AppendLine("## The four plates");
			sb.AppendLine();
			sb.AppendLine("| Plate | N | S | total | pre-guard N / S | specks / clusters / blobs | lifted cells | oracle |");
			sb.AppendLine("|---|---|---|---|---|---|---|---|");
			foreach (var r in plateRows)
				sb.AppendLine($"| `{r.Seed}_{r.Level}/` | **{r.CountN}** | **{r.CountS}** | {r.CountN + r.CountS} | {r.PreN} / {r.PreS} | {r.SpecksN + r.SpecksS} / {r.ClustersN + r.ClustersS} / {r.BlobsN + r.BlobsS} | {r.Lifted:N0} | {(r.Ok ? "pass" : "**FAIL**")} |");
			if (plateRows.Count == 0) sb.AppendLine("| *(no plates — probe run)* | | | | | | | |");
			sb.AppendLine();
			sb.AppendLine($"## ⭐ The count table — {tableSeeds.Length} seeds × 3 levels at {tableSize} (the consistency evidence)");
			sb.AppendLine();
			sb.Append(CountTableMarkdown(levels, rows, stats));
			sb.AppendLine();
			sb.AppendLine("Also as plain data: `count_table.md` / `count_table.csv`.");
			sb.AppendLine();
			sb.AppendLine("## The levels — density and south weight");
			sb.AppendLine();
			sb.AppendLine("| Level | settings |");
			sb.AppendLine("|---|---|");
			foreach (var lv in levels) sb.AppendLine($"| `{lv.Label}`{(lv == mid ? " ⭐ preset of record" : "")} | {lv.Settings.Describe()} |");
			sb.AppendLine();
			sb.AppendLine("The coast shelf is ON for every field (strength 0.775, scale 100 m, BitDecrement-clamped); invisible on these");
			sb.AppendLine("hypsometric plates — ported faithfully, judged when water renders. Moat / falloff test / outer bound unchanged from chat2/05.");
			sb.AppendLine();
			sb.AppendLine("## The south diagnosis — measured before tuning");
			sb.AppendLine();
			sb.Append(DiagnosisMarkdown(calibSize, mid, diag, poolN, poolS, interpretation));
			sb.AppendLine();
			sb.AppendLine("Also as `diagnosis.md`.");
			sb.AppendLine();
			sb.AppendLine("## ⚠ The palette is PROVISIONAL");
			sb.AppendLine();
			sb.AppendLine("`ProvisionalEven`, flagged. Grayscale + `tags.png` are the honest instruments here.");
			sb.AppendLine();
			sb.AppendLine("## The oracle");
			sb.AppendLine();
			sb.AppendLine("Regressions (offshore OFF must be bit-identical to Phase 1, task 03 and the `terrain-curve-v1` gallery dump):");
			sb.AppendLine();
			sb.AppendLine(hard.Count == 0 ? "*(skipped — probe run)*\n" : ShapingOracle.ToMarkdownTable(hard));
			sb.AppendLine("Per field (moat i · mainland unmoved j · tag/coastline k · HMaxSeed l · classify b):");
			sb.AppendLine();
			sb.AppendLine(ShapingOracle.ToMarkdownTable(perField));
			sb.AppendLine($"**{(allOk ? "ALL HARD CHECKS PASS" : "⚠⚠ FAILURES — do not judge this batch")}**");
			sb.AppendLine();
			sb.AppendLine("## Disposability");
			sb.AppendLine();
			sb.AppendLine("| Artifact | Keep? |");
			sb.AppendLine("|---|---|");
			sb.AppendLine("| `tags.png`, `relief.png`, `INDEX.md`, `count_table.md` / `.csv`, `diagnosis.md` | **keep** |");
			sb.AppendLine("| `grayscale.png` | ♻ regenerable from the `.f32` |");
			sb.AppendLine("| `height.f32` | ♻ regenerable from seed + code — large, clear freely |");
			sb.AppendLine("| `scratch/` | persistent by rule; never cleaned |");
			sb.AppendLine();
			sb.AppendLine($"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;
		}
	}
}