#!/usr/bin/env node
import { mkdir, readdir, readFile, writeFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { NodeIO } from "@gltf-transform/core";
import { Matrix4, Triangle, Vector3 } from "three";
import {
  buildPartyNavigationGraph,
  findNearestPartyNavigationSurface,
  findPartyNavigationPath,
} from "../../src/game/partyNavigation.ts";

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
const recipeDirectory = path.join(root, "scripts/runewaker-pipeline/recipes");
const gameplayReportFile = path.join(
  root,
  "scripts/runewaker-pipeline/RUNEWAKER_GAMEPLAY_CONTENT_REPORT.json",
);
const outputJson = path.join(
  root,
  "scripts/runewaker-pipeline/RUNEWAKER_NAVIGATION_GAP_REPORT.json",
);
const outputMarkdown = path.join(
  root,
  "scripts/runewaker-pipeline/RUNEWAKER_NAVIGATION_GAP_REPORT.md",
);
const weldTolerance = 0.001;
const reviewedFindings = {
  "cave-water-dragon": {
    disposition: "gated-wave-and-door-review",
    safeAutomaticLink: false,
    finding: "Template 104161 runs the ten-add water-elemental controller, creates a blocking door, and removes it only after the counter reaches ten. Lytfir is on a lower isolated surface, so a permanent link would bypass the preserved gate/drop sequence.",
    evidence: [
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01562.lua:1",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01562.lua:21",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01562.lua:42",
    ],
  },
  hoto: {
    disposition: "source-order-required-before-linking",
    safeAutomaticLink: false,
    finding: "The distance fallback crosses the same 6.65m vertical surface break three times. Preserved local configuration supplies boss anchors but no authoritative encounter order, so these heuristic legs cannot justify a link.",
    evidence: [
      "scripts/runewaker-pipeline/build-population.mjs:634",
      "scripts/runewaker-pipeline/recipes/hoto-population.json",
    ],
  },
  "ice-dwarf-kingdom": {
    disposition: "door-gated-room-review",
    safeAutomaticLink: false,
    finding: "Crasset's isolated surface is separated by a 1.64m/0.60m gap, but his preserved death hook creates an orb that finds and hides door 112321. A permanent bidirectional link would erase that gate state.",
    evidence: [
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01356.lua:16",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01356.lua:36",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01356.lua:46",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01356.lua:54",
    ],
  },
  "kalins-shrine": {
    disposition: "teleport-room-mechanic",
    safeAutomaticLink: false,
    finding: "The preserved server scripts register six Kalin locations as separate keeper rooms and advance with a group teleport. The vertical component gaps are therefore encounter state, not wall seams.",
    evidence: [
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:713",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:1298",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:1363",
    ],
  },
  "raksha-temple": {
    disposition: "missing-modular-environment-assembly",
    safeAutomaticLink: false,
    finding: "The environment recipe explicitly adds isolated source-anchor support pads because the single primary ROS does not cover the modular WDB combat anchors. Secondary environment pieces must be assembled before route authoring.",
    evidence: ["scripts/runewaker-pipeline/recipes/raksha-temple.json:16"],
  },
  "the-origin": {
    disposition: "missing-modular-environment-assembly",
    safeAutomaticLink: false,
    finding: "Both objectives and the entrance sit on isolated source-anchor support pads. The WDB contains many separately placed cathedral, slope, bridge, and connector ROS pieces that the primary-only environment package does not yet assemble.",
    evidence: ["scripts/runewaker-pipeline/recipes/the-origin.json:16"],
  },
  "treasure-trove": {
    disposition: "missing-modular-environment-plus-bridge-door-mechanics",
    safeAutomaticLink: false,
    finding: "Boss anchors are isolated support pads, while preserved Lua requires a boss-enabled drawbridge switch and a key-gated hold door. The modular environment and stateful bridge/door must precede navigation links.",
    evidence: [
      "scripts/runewaker-pipeline/recipes/treasure-trove.json:16",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01159.lua:1",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01159.lua:38",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/01159.lua:50",
    ],
  },
  "ystra-labyrinth-boss1": {
    disposition: "separate-authored-room-placements",
    safeAutomaticLink: false,
    finding: "The package intentionally clones three distinct WDB room placements hundreds of meters apart; the preserved travel catalog also treats the boss-room destinations separately. Connecting them through open space would invent geometry.",
    evidence: [
      "scripts/runewaker-pipeline/recipes/ystra-labyrinth-boss1.json:16",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:1423",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:1425",
      "../rom-pvt-server-backups/Runewaker/Resource/luascript/03246.lua:1426",
    ],
  },
};

const readJson = async (file) => JSON.parse((await readFile(file, "utf8")).replace(/^\uFEFF/, ""));
const constantCase = (value) => String(value).replaceAll("-", "_").toUpperCase();

function generatedJson(source, name, suffix) {
  const marker = "export const " + name + " = ";
  const start = source.indexOf(marker);
  if (start < 0) throw new Error("Missing generated constant " + name + ".");
  const valueStart = start + marker.length;
  const valueEnd = source.indexOf(suffix, valueStart);
  if (valueEnd < 0) throw new Error("Missing type suffix for " + name + ".");
  return JSON.parse(source.slice(valueStart, valueEnd));
}

class DisjointSet {
  constructor(size) {
    this.parent = Int32Array.from({ length: size }, (_, index) => index);
    this.rank = new Uint8Array(size);
  }

  find(value) {
    let rootValue = value;
    while (this.parent[rootValue] !== rootValue) rootValue = this.parent[rootValue];
    while (this.parent[value] !== value) {
      const next = this.parent[value];
      this.parent[value] = rootValue;
      value = next;
    }
    return rootValue;
  }

  union(left, right) {
    let leftRoot = this.find(left);
    let rightRoot = this.find(right);
    if (leftRoot === rightRoot) return;
    if (this.rank[leftRoot] < this.rank[rightRoot]) [leftRoot, rightRoot] = [rightRoot, leftRoot];
    this.parent[rightRoot] = leftRoot;
    if (this.rank[leftRoot] === this.rank[rightRoot]) this.rank[leftRoot] += 1;
  }
}

function geometryFromPositions(positions) {
  return {
    getAttribute(name) {
      if (name !== "position") return undefined;
      return {
        itemSize: 3,
        count: positions.length / 3,
        getX: (index) => positions[index * 3],
        getY: (index) => positions[index * 3 + 1],
        getZ: (index) => positions[index * 3 + 2],
      };
    },
    getIndex() { return null; },
  };
}

async function navigationPositions(file) {
  const document = await new NodeIO().read(file);
  const positions = [];
  const vertex = new Vector3();
  for (const node of document.getRoot().listNodes()) {
    const mesh = node.getMesh();
    if (!mesh) continue;
    const world = new Matrix4().fromArray(node.getWorldMatrix());
    for (const primitive of mesh.listPrimitives()) {
      const source = primitive.getAttribute("POSITION")?.getArray();
      if (!source) continue;
      const sourceIndices = primitive.getIndices()?.getArray();
      const indices = sourceIndices
        ? Array.from(sourceIndices)
        : Array.from({ length: source.length / 3 }, (_, index) => index);
      for (const index of indices) {
        vertex.fromArray(source, index * 3).applyMatrix4(world);
        positions.push(vertex.x, vertex.y, vertex.z);
      }
    }
  }
  if (!positions.length || positions.length % 9 !== 0) {
    throw new Error("Navigation GLB contains no complete triangles.");
  }
  return positions;
}

function bucketCoordinate(value) {
  return Math.floor(value / weldTolerance);
}

function bucketKey(x, y, z) {
  return `${x},${y},${z}`;
}

function analyzeRawComponents(positions) {
  const sourceVertexCount = positions.length / 3;
  const sourceToWelded = new Int32Array(sourceVertexCount);
  const welded = [];
  const buckets = new Map();
  const toleranceSquared = weldTolerance * weldTolerance;

  for (let sourceId = 0; sourceId < sourceVertexCount; sourceId += 1) {
    const point = positions.slice(sourceId * 3, sourceId * 3 + 3);
    const bucket = point.map(bucketCoordinate);
    let bestId = -1;
    let bestDistanceSquared = Number.POSITIVE_INFINITY;
    for (let dx = -1; dx <= 1; dx += 1) {
      for (let dy = -1; dy <= 1; dy += 1) {
        for (let dz = -1; dz <= 1; dz += 1) {
          for (const candidateId of buckets.get(bucketKey(
            bucket[0] + dx,
            bucket[1] + dy,
            bucket[2] + dz,
          )) ?? []) {
            const candidate = welded[candidateId];
            const distanceSquared = (
              (candidate[0] - point[0]) ** 2
              + (candidate[1] - point[1]) ** 2
              + (candidate[2] - point[2]) ** 2
            );
            if (distanceSquared <= toleranceSquared && distanceSquared < bestDistanceSquared) {
              bestId = candidateId;
              bestDistanceSquared = distanceSquared;
            }
          }
        }
      }
    }
    if (bestId < 0) {
      bestId = welded.length;
      welded.push(point);
      const key = bucketKey(...bucket);
      const entries = buckets.get(key);
      if (entries) entries.push(bestId);
      else buckets.set(key, [bestId]);
    }
    sourceToWelded[sourceId] = bestId;
  }

  const sets = new DisjointSet(welded.length);
  const triangles = [];
  for (let sourceId = 0; sourceId < sourceVertexCount; sourceId += 3) {
    const vertices = [
      sourceToWelded[sourceId],
      sourceToWelded[sourceId + 1],
      sourceToWelded[sourceId + 2],
    ];
    sets.union(vertices[0], vertices[1]);
    sets.union(vertices[1], vertices[2]);
    triangles.push({ vertices, sourceId: sourceId / 3 });
  }

  const componentByRoot = new Map();
  for (let vertexId = 0; vertexId < welded.length; vertexId += 1) {
    const rootId = sets.find(vertexId);
    let component = componentByRoot.get(rootId);
    if (!component) {
      component = { sourceId: rootId, vertices: [], triangles: [], bounds: null };
      componentByRoot.set(rootId, component);
    }
    component.vertices.push(vertexId);
  }
  for (const triangle of triangles) {
    componentByRoot.get(sets.find(triangle.vertices[0])).triangles.push(triangle);
  }
  const components = [...componentByRoot.values()].sort((left, right) => (
    right.vertices.length - left.vertices.length || left.sourceId - right.sourceId
  ));
  components.forEach((component, componentId) => {
    component.id = componentId;
    const points = component.vertices.map((vertexId) => welded[vertexId]);
    component.bounds = {
      min: [0, 1, 2].map((axis) => Math.min(...points.map((point) => point[axis]))),
      max: [0, 1, 2].map((axis) => Math.max(...points.map((point) => point[axis]))),
    };
  });

  const triangle = new Triangle();
  const target = new Vector3();
  const closest = new Vector3();
  const nearest = (point) => {
    target.fromArray(point);
    let result = null;
    for (const component of components) {
      for (const entry of component.triangles) {
        triangle.a.fromArray(welded[entry.vertices[0]]);
        triangle.b.fromArray(welded[entry.vertices[1]]);
        triangle.c.fromArray(welded[entry.vertices[2]]);
        triangle.closestPointToPoint(target, closest);
        const distance = target.distanceTo(closest);
        if (!result || distance < result.distance) {
          result = {
            componentId: component.id,
            componentVertices: component.vertices.length,
            componentTriangles: component.triangles.length,
            distance,
            position: closest.toArray(),
            triangleId: entry.sourceId,
          };
        }
      }
    }
    return result;
  };

  const componentGap = (leftId, rightId) => {
    if (leftId === rightId) {
      return { distance: 0, horizontalDistance: 0, verticalDistance: 0, left: null, right: null };
    }
    let left = components[leftId];
    let right = components[rightId];
    let swapped = false;
    if (left.vertices.length > right.vertices.length) {
      [left, right] = [right, left];
      swapped = true;
    }
    let result = null;
    for (const leftVertexId of left.vertices) {
      const leftPoint = welded[leftVertexId];
      for (const rightVertexId of right.vertices) {
        const rightPoint = welded[rightVertexId];
        const dx = rightPoint[0] - leftPoint[0];
        const dy = rightPoint[1] - leftPoint[1];
        const dz = rightPoint[2] - leftPoint[2];
        const distance = Math.hypot(dx, dy, dz);
        if (result && result.distance <= distance) continue;
        result = {
          distance,
          horizontalDistance: Math.hypot(dx, dz),
          verticalDistance: Math.abs(dy),
          left: swapped ? rightPoint : leftPoint,
          right: swapped ? leftPoint : rightPoint,
        };
      }
    }
    return result;
  };

  return { components, nearest, componentGap, welded };
}

function triangleComponents(graph) {
  const nodes = graph.triangleNodes ?? [];
  const componentIds = new Int32Array(nodes.length);
  componentIds.fill(-1);
  let nextComponent = 0;
  for (const node of nodes) {
    if (componentIds[node.id] >= 0) continue;
    const pending = [node.id];
    componentIds[node.id] = nextComponent;
    while (pending.length) {
      const triangleId = pending.pop();
      for (const edge of nodes[triangleId].neighbors) {
        if (componentIds[edge.to] >= 0) continue;
        componentIds[edge.to] = nextComponent;
        pending.push(edge.to);
      }
    }
    nextComponent += 1;
  }
  return { componentIds, count: nextComponent };
}

function endpointEvidence(point, graph, retainedTriangleComponents, raw) {
  const retained = findNearestPartyNavigationSurface(graph, point, Number.POSITIVE_INFINITY);
  const rawNearest = raw.nearest(point);
  return {
    point,
    retainedDistance: retained?.distance ?? null,
    retainedPosition: retained?.position ?? null,
    retainedTriangleId: retained?.triangleId ?? null,
    retainedTriangleComponent: retained
      ? retainedTriangleComponents.componentIds[retained.triangleId]
      : null,
    raw: rawNearest,
  };
}

function classifyLeg(from, to, reachable, environmentRecipe, componentGap) {
  if (reachable) return "mesh-reachable";
  const fromRaw = from.raw;
  const toRaw = to.raw;
  if (!fromRaw || !toRaw) return "missing-navigation-data";
  if (fromRaw.distance > 6 || toRaw.distance > 6) {
    return "objective-or-entrance-outside-all-navigation";
  }
  if (fromRaw.componentId !== toRaw.componentId) {
    const usesSupportPad = Boolean(environmentRecipe.source.sourceAnchorSupport)
      && (fromRaw.componentTriangles <= 2 || toRaw.componentTriangles <= 2);
    if (usesSupportPad) return "missing-primary-environment-geometry-source-support-pad";
    if (environmentRecipe.source.assemblyPlacementTranslations) {
      return "separate-authored-wdb-room-placements";
    }
    if (componentGap && componentGap.horizontalDistance <= 1 && componentGap.verticalDistance <= 0.5) {
      return "small-recast-surface-discontinuity-candidate";
    }
    return "separate-recast-surface-components";
  }
  if (from.retainedTriangleComponent !== to.retainedTriangleComponent) {
    return "retained-surface-edge-discontinuity";
  }
  if (from.retainedDistance > 3) return "entrance-or-prior-objective-outside-live-start-limit";
  if (to.retainedDistance > 6) return "objective-outside-live-approach-limit";
  return "unclassified-route-topology";
}

function rounded(value) {
  return Number.isFinite(value) ? Math.round(value * 1000) / 1000 : value;
}

function renderMarkdown(report) {
  const lines = [
    "# RuneWaker navigation gap analysis",
    "",
    "This diagnostic is offline-only. It measures source-authored entrance/objective positions",
    "against every raw Recast surface component and against the retained runtime surface.",
    "The current boss sequence is HealerMan's distance-from-entrance fallback, not a claimed",
    "source-authored order. It does not create links or infer doors/teleports.",
    "",
    `Unreachable heuristic legs analyzed: **${report.unreachableLegs}** across **${report.dungeons.length}** dungeons.`,
    "",
    "| Dungeon | Ordered leg | Geometry classification | From raw comp/dist | To raw comp/dist | Retained distances |",
    "| --- | --- | --- | --- | --- | --- |",
  ];
  for (const dungeon of report.dungeons) {
    for (const leg of dungeon.legs.filter((entry) => !entry.reachable)) {
      lines.push(`| ${dungeon.id} | ${leg.fromName} -> ${leg.toName} | ${leg.classification} | `
        + `${leg.from.raw.componentId}/${rounded(leg.from.raw.distance)}m | `
        + `${leg.to.raw.componentId}/${rounded(leg.to.raw.distance)}m | `
        + `${rounded(leg.from.retainedDistance)}m -> ${rounded(leg.to.retainedDistance)}m |`);
    }
  }
  lines.push("", "## Per-dungeon surface inventory", "");
  for (const dungeon of report.dungeons) {
    lines.push(`- ${dungeon.id}: ${dungeon.rawComponentCount} raw vertex-connected surfaces; `
      + `${dungeon.retainedTriangleComponentCount} shared-edge corridors inside the retained surface; `
      + `${dungeon.discardedRuntimeNodes} welded nodes discarded by largest-surface retention.`);
  }
  lines.push("", "## Reviewed dispositions", "");
  for (const dungeon of report.dungeons) {
    const finding = dungeon.reviewedFinding;
    lines.push(`### ${dungeon.id}`, "", `- Disposition: ${finding.disposition}.`,
      `- Safe automatic link: ${finding.safeAutomaticLink ? "yes" : "no"}.`,
      `- Finding: ${finding.finding}`,
      ...finding.evidence.map((entry) => `- Evidence: ${entry}`), "");
  }
  lines.push("");
  return lines.join("\n");
}

const gameplayReport = await readJson(gameplayReportFile);
const blockedDungeonIds = new Set(
  gameplayReport.dungeons
    .filter((dungeon) => dungeon.objectiveRouteEvidence?.some((route) => !route.reachable))
    .map((dungeon) => dungeon.id),
);
const recipeNames = (await readdir(recipeDirectory))
  .filter((name) => name.endsWith("-population.json"))
  .sort();
const dungeons = [];

for (const recipeName of recipeNames) {
  const recipe = await readJson(path.join(recipeDirectory, recipeName));
  if (!blockedDungeonIds.has(recipe.dungeonId)) continue;
  const [environmentRecipe, environment, source, positions] = await Promise.all([
    readJson(path.resolve(root, recipe.files.environmentRecipe)),
    readJson(path.resolve(root, recipe.files.environmentMetadata)),
    readFile(path.resolve(root, recipe.files.generatedSource), "utf8"),
    navigationPositions(path.resolve(root, recipe.files.navigation)),
  ]);
  const bosses = generatedJson(
    source,
    constantCase(recipe.dungeonId) + "_BOSSES",
    " as const satisfies readonly DungeonBossObjective[];",
  );
  const graph = buildPartyNavigationGraph(geometryFromPositions(positions));
  const retainedTriangleComponents = triangleComponents(graph);
  const raw = analyzeRawComponents(positions);
  const legs = [];
  let origin = endpointEvidence(environment.entrance.footPosition, graph, retainedTriangleComponents, raw);
  let originName = "entrance";
  for (const boss of bosses) {
    const target = endpointEvidence(boss.position, graph, retainedTriangleComponents, raw);
    const approach = findNearestPartyNavigationSurface(graph, boss.position, 6);
    const pathResult = approach
      ? findPartyNavigationPath(graph, origin.point, approach.position, {
        maxStartSnapDistance: 3,
        maxEndSnapDistance: 6,
        simplifyTolerance: 0.01,
      })
      : null;
    const reachable = Boolean(pathResult?.length);
    const componentGap = origin.raw && target.raw
      ? raw.componentGap(origin.raw.componentId, target.raw.componentId)
      : null;
    legs.push({
      fromName: originName,
      toName: boss.name,
      objectiveId: boss.id,
      reachable,
      classification: classifyLeg(origin, target, reachable, environmentRecipe, componentGap),
      componentGap,
      from: origin,
      to: target,
      waypointCount: pathResult?.length ?? 0,
    });
    origin = approach
      ? endpointEvidence(approach.position, graph, retainedTriangleComponents, raw)
      : target;
    originName = boss.name;
  }
  dungeons.push({
    id: recipe.dungeonId,
    navigationFile: path.relative(root, path.resolve(root, recipe.files.navigation)).replaceAll("\\", "/"),
    rawComponentCount: raw.components.length,
    retainedTriangleComponentCount: retainedTriangleComponents.count,
    discardedRuntimeNodes: graph.discardedNodeCount,
    reviewedFinding: reviewedFindings[recipe.dungeonId] ?? {
      disposition: "manual-review-required",
      safeAutomaticLink: false,
      finding: "No reviewed source-backed navigation disposition is recorded.",
      evidence: [],
    },
    rawComponents: raw.components.map((component) => ({
      id: component.id,
      vertexCount: component.vertices.length,
      triangleCount: component.triangles.length,
      bounds: component.bounds,
    })),
    legs,
  });
}

const report = {
  schemaVersion: 1,
  generatedAt: new Date().toISOString(),
  methodology: {
    weldTolerance,
    liveStartSnapDistance: 3,
    liveObjectiveSnapDistance: 6,
    mutatesAssets: false,
  },
  unreachableLegs: dungeons.flatMap((dungeon) => dungeon.legs).filter((leg) => !leg.reachable).length,
  dungeons,
};
await mkdir(path.dirname(outputJson), { recursive: true });
await Promise.all([
  writeFile(outputJson, JSON.stringify(report, null, 2) + "\n"),
  writeFile(outputMarkdown, renderMarkdown(report)),
]);
console.log(`Analyzed ${report.unreachableLegs} unreachable RuneWaker objective route diagnostics.`);
console.log(path.relative(root, outputMarkdown));