"use strict";

(function (global) {
  function buildGraph(nodes = [], opts = {}) {
    const idOf = opts.idOf || (n => n?.id);
    const edgesOf = opts.edgesOf || ((n) => [...(n?.parents || []), ...(n?.children || [])]);
    const byId = new Map(nodes.filter(Boolean).map(n => [idOf(n), n]).filter(([id]) => id));
    const graph = new Map([...byId.keys()].map(id => [id, new Set()]));
    const connect = (a, b) => {
      if (!a || !b || a === b || !graph.has(a) || !graph.has(b)) return;
      graph.get(a).add(b);
      graph.get(b).add(a);
    };
    for (const node of byId.values()) {
      const id = idOf(node);
      for (const next of edgesOf(node, byId)) connect(id, next);
    }
    return { graph, byId };
  }

  function connectedComponents(nodes = [], opts = {}) {
    const { graph, byId } = buildGraph(nodes, opts);
    const sort = opts.sort || null;
    const nodeList = [...byId.values()].sort(sort || (() => 0));
    const seen = new Set();
    const comps = [];
    for (const node of nodeList) {
      const start = opts.idOf ? opts.idOf(node) : node.id;
      if (!start || seen.has(start)) continue;
      const stack = [start];
      const comp = [];
      seen.add(start);
      while (stack.length) {
        const id = stack.pop();
        const item = byId.get(id);
        if (item) comp.push(item);
        for (const next of graph.get(id) || []) {
          if (seen.has(next)) continue;
          seen.add(next);
          stack.push(next);
        }
      }
      if (!opts.filter || opts.filter(comp)) comps.push(sort ? comp.sort(sort) : comp);
    }
    return comps;
  }



  function addParentEdge(childId, parentId, known, parentsByChild, childrenByParent) {
    if (!childId || !parentId || childId === parentId || !known?.has?.(childId) || !known.has(parentId)) return false;
    if (!parentsByChild.has(childId)) parentsByChild.set(childId, new Set());
    if (!childrenByParent.has(parentId)) childrenByParent.set(parentId, new Set());
    parentsByChild.get(childId).add(parentId);
    childrenByParent.get(parentId).add(childId);
    return true;
  }

  function buildRelationIndex(family = {}) {
    const known = new Set(Object.keys(family || {}));
    const parentsByChild = new Map();
    const childrenByParent = new Map();
    const addParent = (childId, parentId) => addParentEdge(childId, parentId, known, parentsByChild, childrenByParent);
    for (const n of Object.values(family || {})) {
      if (!n?.id) continue;
      for (const parentId of n.parents || []) addParent(n.id, parentId);
      for (const childId of n.children || []) addParent(childId, n.id);
    }
    return { parentsByChild, childrenByParent };
  }

  function relationAllowsParentChild(family = {}, childId, parentId) {
    const child = family?.[childId];
    const parent = family?.[parentId];
    if (!child || !parent) return false;
    const childListsParent = Array.isArray(child.parents) && child.parents.includes(parentId);
    const parentListsChild = Array.isArray(parent.children) && parent.children.includes(childId);
    return childListsParent || parentListsChild;
  }



  global.TarinaiFamilyGraph = {
    connectedComponents,
    addParentEdge,
    buildRelationIndex,
    relationAllowsParentChild,
  };
})(typeof window !== "undefined" ? window : globalThis);