/**
 * Action: page-labels-validation
 *
 * Validates shape labels on a single page and reports three categories of issues:
 *   1. empty_label     — shape has no label (or whitespace only)
 *   2. duplicate_label — two or more shapes share the same label
 *   3. long_label      — label exceeds MAX_LABEL_LENGTH characters
 *
 * Edges are excluded (connectors often have no label by design).
 */

import { parseDiagram } from "../../services/drawio-parser/parser.js";

const MAX_LABEL_LENGTH = 80;

export function run(filePath: string): Record<string, unknown> {
  const { shapes } = parseDiagram(filePath);

  const issues: Record<string, unknown>[] = [];

  // Track label → [ids] for duplicate detection
  const labelIndex = new Map<string, string[]>();

  for (const [id, shape] of shapes) {
    const label = shape.label?.trim() ?? "";

    // 1. Empty label
    if (label === "") {
      issues.push({ type: "empty_label", shapeId: id });
      continue; // skip further checks for unlabelled shapes
    }

    // 2. Long label
    if (label.length > MAX_LABEL_LENGTH) {
      issues.push({
        type: "long_label",
        shapeId: id,
        label,
        length: label.length,
        maxAllowed: MAX_LABEL_LENGTH,
      });
    }

    // Accumulate for duplicate check
    if (!labelIndex.has(label)) labelIndex.set(label, []);
    labelIndex.get(label)!.push(id);
  }

  // 3. Duplicate labels
  for (const [label, ids] of labelIndex) {
    if (ids.length > 1) {
      issues.push({
        type: "duplicate_label",
        label,
        shapeIds: ids,
        count: ids.length,
      });
    }
  }

  const empty     = issues.filter((i) => i["type"] === "empty_label").length;
  const duplicate = issues.filter((i) => i["type"] === "duplicate_label").length;
  const long      = issues.filter((i) => i["type"] === "long_label").length;

  return {
    action: "page-labels-validation",
    file: filePath,
    config: { maxLabelLength: MAX_LABEL_LENGTH },
    summary: {
      emptyLabels: empty,
      duplicateLabels: duplicate,
      longLabels: long,
      totalIssues: issues.length,
    },
    issues,
  };
}