using Godot;
using Godot.Collections; // Required for Godot's built-in JSON parser

namespace IslaApocalypse.Core // Change this if your namespace is different
{
	public static class ConfigManager
	{
		// Default Fallbacks
		// public static int WorldSeed = 1063685222;
		public static int WorldSeed = (int)GD.Randi(); // if 0 also randomizes
		public static int MapSize = 8192;
		public static float CraterRadius = 400f;
		public static float DensityMultiplier = 1.0f; // <-- Replaces TownCount
		public static int ChunkRadius = 24; // Default chunk size, can be overridden by config

		// Iteration toggle: skip the ~25-min A* road pass entirely. The blueprint is
		// still exported (road sections present but empty) — an iteration artifact,
		// not a shippable world. Default false.
		public static bool SkipRoads = false;

		// Sea-level model (D-033, terrain-water task 04): "flat" = one scalar sea
		// level everywhere (SeaLevelValue); "field" = the legacy latitude Lerp
		// (0.26 north .. 0.15 south). Generator-only — the runtime never computes
		// sea level. Default: flat 0.15.
		public static string SeaLevelModel = "flat";
		public static float SeaLevelValue = 0.15f;

		// Height-redistribution curve (tasks 05–10, graduation M-7): "v5" is the
		// task-09 gate's winner — the BALANCED terraced ascent with corner easing and
		// modulated shelves; "off" is the raw legacy profile. "v1"–"v4" and the
		// taste-batch tri-state ("v5-compact" lost, "v5-balanced" became plain "v5")
		// are retired. Default: v5.
		public static string TerrainCurve = "v5";

		// Terrain detail passes (task 10): "v1" = shelf micro-relief + shelf-edge
		// variation as one judged unit (requires the curve; no-op when it is off);
		// "off" disables both. ShelfReliefAmp is the micro-relief amplitude in metres
		// of OUTPUT height. ShelfEdgeVariation is the shelf-edge warp amplitude in
		// metres of INPUT height — how far the shelf/riser boundary contour is
		// displaced, not an elevation change; it is clamped at load time to the
		// largest shift the curve's bands can absorb. Defaults: v1, 3 m, 12 m.
		public static string TerrainDetail = "v1";
		public static float ShelfReliefAmp = 3.0f;
		public static float ShelfEdgeVariation = 12.0f;

		// Island falloff shaping (task 11).
		//
		// CoastProfile: "wide" adds the submarine shelf — the height curve is identity
		// at and below sea, so it never reached the seabed, which still dropped ~6.7x
		// steeper than the land it meets. "steep" is the pre-task-11 seabed, kept for
		// A/B. The shelf cannot move the waterline, so biomes and water are identical
		// either way. Default: wide.
		//
		// IslandAxisX/Y: the falloff axis ratios (pre-task-11: 1.15 / 0.90). NOTE,
		// measured: the island is already Trench-clamped in x at ~90% of the map
		// width, so AxisX is a weak lever — aspect responds almost entirely to AxisY.
		// These MOVE THE COASTLINE and therefore move biomes, by design.
		//
		// OffshoreIslandDensity: fraction of the ocean noise field above the islet
		// threshold. 0 disables the layer. Islets never touch the Trench and are held
		// off the mainland by a depth moat.
		public static string CoastProfile = "wide";
		public static float IslandAxisX = 1.30f;
		public static float IslandAxisY = 0.78f;
		public static float OffshoreIslandDensity = 0.02f;

		// The pre-task-11 axis ratios, so "steep"/legacy runs can restore them exactly.
		public const float LEGACY_AXIS_X = 1.15f;
		public const float LEGACY_AXIS_Y = 0.90f;

		public static void LoadConfig()
		{
			string path = "res://ServerConfig.json";

			if (!FileAccess.FileExists(path))
			{
				GD.PrintErr("[ConfigManager] ServerConfig.json not found! Defaulting to 8K.");
				return;
			}

			// Read the file
			using var file = FileAccess.Open(path, FileAccess.ModeFlags.Read);
			string content = file.GetAsText();
			
			// Parse the JSON
			var json = new Json();
			var error = json.Parse(content);
			if (error != Error.Ok)
			{
				GD.PrintErr($"[ConfigManager] JSON Parse Error: {json.GetErrorMessage()}");
				return;
			}

			var data = (Dictionary)json.Data;

			// Extract the Seed
			if (data.ContainsKey("WorldSeed"))
			{
				WorldSeed = (int)data["WorldSeed"];
			}

			// Extract the MapProfile and run your Switch/Case logic!
			string profile = "8K";
			if (data.ContainsKey("MapProfile"))
			{
				profile = (string)data["MapProfile"];
			}

			// Extract the TownDensity and run your Switch/Case logic!
			string townDensity = "Normal";
			if (data.ContainsKey("TownDensity"))
			{
				townDensity = (string)data["TownDensity"];
			}
			// Extract the ChunkRadius
			if (data.ContainsKey("ChunkRadius"))            {
				ChunkRadius = (int)data["ChunkRadius"];
			}

			// Extract the SkipRoads iteration toggle
			if (data.ContainsKey("SkipRoads"))
			{
				SkipRoads = (bool)data["SkipRoads"];
			}

			// Extract the sea-level model
			if (data.ContainsKey("SeaLevelModel"))
			{
				string model = (string)data["SeaLevelModel"];
				if (model == "flat" || model == "field")
					SeaLevelModel = model;
				else
					GD.PrintErr($"[ConfigManager] Unknown SeaLevelModel '{model}'. Keeping '{SeaLevelModel}'.");
			}
			if (data.ContainsKey("SeaLevelValue"))
			{
				SeaLevelValue = (float)data["SeaLevelValue"];
			}

			// Extract the terrain-curve gate
			if (data.ContainsKey("TerrainCurve"))
			{
				string curve = (string)data["TerrainCurve"];
				if (curve == "off" || curve == "v5")
					TerrainCurve = curve;
				else if (curve == "v5-balanced")
					GD.PrintErr($"[ConfigManager] TerrainCurve 'v5-balanced' won the task-09 gate and is now plain \"v5\". Keeping '{TerrainCurve}'.");
				else if (curve == "v5-compact")
					GD.PrintErr($"[ConfigManager] TerrainCurve 'v5-compact' was retired by the task-09 verdict (BALANCED won). Keeping '{TerrainCurve}' — use \"v5\" or \"off\".");
				else if (curve == "v1" || curve == "v2" || curve == "v3" || curve == "v4")
					GD.PrintErr($"[ConfigManager] TerrainCurve '{curve}' was retired by a later recalibration (v5, tasks 09/10). Keeping '{TerrainCurve}' — use \"v5\" or \"off\".");
				else
					GD.PrintErr($"[ConfigManager] Unknown TerrainCurve '{curve}'. Keeping '{TerrainCurve}'.");
			}

			// Extract the terrain-detail gate + relief amplitude
			if (data.ContainsKey("TerrainDetail"))
			{
				string detail = (string)data["TerrainDetail"];
				if (detail == "off" || detail == "v1")
					TerrainDetail = detail;
				else
					GD.PrintErr($"[ConfigManager] Unknown TerrainDetail '{detail}'. Keeping '{TerrainDetail}'.");
			}
			if (data.ContainsKey("ShelfReliefAmp"))
			{
				ShelfReliefAmp = (float)data["ShelfReliefAmp"];
			}
			if (data.ContainsKey("ShelfEdgeVariation"))
			{
				ShelfEdgeVariation = (float)data["ShelfEdgeVariation"];
			}

			// Extract the island-falloff dials (task 11)
			if (data.ContainsKey("CoastProfile"))
			{
				string coast = (string)data["CoastProfile"];
				if (coast == "steep" || coast == "wide")
					CoastProfile = coast;
				else
					GD.PrintErr($"[ConfigManager] Unknown CoastProfile '{coast}'. Keeping '{CoastProfile}'.");
			}
			if (data.ContainsKey("IslandAxisX")) IslandAxisX = (float)data["IslandAxisX"];
			if (data.ContainsKey("IslandAxisY")) IslandAxisY = (float)data["IslandAxisY"];
			if (data.ContainsKey("OffshoreIslandDensity")) OffshoreIslandDensity = (float)data["OffshoreIslandDensity"];

			// The axis ratios divide map extents; a zero or negative one is a divide-by-
			// zero that would silently produce an all-ocean map. Refuse it loudly.
			if (IslandAxisX <= 0.01f || IslandAxisY <= 0.01f)
			{
				GD.PrintErr($"[ConfigManager] IslandAxisX/Y must be > 0.01 (got {IslandAxisX}/{IslandAxisY}). Restoring legacy {LEGACY_AXIS_X}/{LEGACY_AXIS_Y}.");
				IslandAxisX = LEGACY_AXIS_X;
				IslandAxisY = LEGACY_AXIS_Y;
			}
			OffshoreIslandDensity = Mathf.Clamp(OffshoreIslandDensity, 0f, 0.5f);

			switch (profile)
			{
				case "4K":
					MapSize = 4096;
					CraterRadius = 400f; // Scaled down crater
					break;
				case "6K":
					MapSize = 6144;
					CraterRadius = 600f;
					break;
				case "8K":
					MapSize = 8192;
					CraterRadius = 800f; // Your original crater size spread over an 8K map
					break;
				case "10K":
					MapSize = 10240;
					CraterRadius = 1000f;
					break;
				default:
					GD.PrintErr($"[ConfigManager] Unknown MapProfile '{profile}'. Defaulting to 8K.");
					MapSize = 8192;
					CraterRadius = 800f;
					break;
			}

			switch (townDensity)
			{
				case "Sparse":
					DensityMultiplier = 0.5f;
					break;
				case "Normal":
					DensityMultiplier = 1.0f;
					break;
				case "Dense":
					DensityMultiplier = 2.0f;
					break;
				default:
					GD.PrintErr($"[ConfigManager] Unknown TownDensity '{townDensity}'. Defaulting to Normal.");
					DensityMultiplier = 1.0f;
					break;
			}
			
			GD.Print($"[ConfigManager] Successfully loaded {profile} Profile. MapSize set to {MapSize}.");
		}
	}
}