import type { Ref } from "vue";
import type { ProjectFile } from "../../domain/project";
import type { Node } from "../../domain/phy";
import { longPressColumn, treeIndex, treeNodes } from "./logic";

export function usePhyTreeModel(project: () => ProjectFile, focus: Ref<string | null>) {
  function allNodes(nodes = project().phy.root): Node[] {
    return treeNodes(nodes);
  }

  function node(id: string): Node | undefined {
    return treeIndex(project().phy.root).nodes.get(id);
  }

  function parentId(id: string): string | null {
    return treeIndex(project().phy.root).selectableParent(id);
  }

  function isAncestor(candidate: string, id: string): boolean {
    let parent = parentId(id);
    while (parent) {
      if (parent === candidate) return true;
      parent = parentId(parent);
    }
    return false;
  }

  function selectedContainer(id: string): string | null {
    return treeIndex(project().phy.root).insertionContainer(id);
  }

  function groupForVariant(id: string): string | null {
    return treeIndex(project().phy.root).groupForVariant(id);
  }

  function parentLabel(id: string | null): string {
    if (!id) return "root";
    const item = node(id);
    if (item?.type === "variantGroup") return item.name;
    if (item?.type === "cluster") return item.name || "クラスター";
    const variant = allNodes()
      .flatMap((item) => (item.type === "variantGroup" ? item.children : []))
      .find((item) => item.id === id);
    return variant?.name || id;
  }

  function pressTargets(id: string): string[] {
    const ancestors: string[] = [];
    let parent = parentId(id);
    while (parent) {
      const group = allNodes().find(
        (item) => item.type === "variantGroup" && item.children.some((variant) => variant.id === parent),
      );
      if (group) {
        ancestors.push(group.id);
        parent = parentId(group.id);
      } else {
        ancestors.push(parent);
        parent = parentId(parent);
      }
      if (ancestors.at(-1) === focus.value) break;
    }
    return longPressColumn(id, ancestors, focus.value || undefined);
  }

  return {
    allNodes,
    node,
    parentId,
    isAncestor,
    selectedContainer,
    groupForVariant,
    parentLabel,
    pressTargets,
  };
}