import { access } from "node:fs/promises";
import path from "node:path";
import {
  readTextFileIfSmall,
  relative,
  repositoryRoot,
  walkFiles,
} from "./repository-files.mjs";

const requiredDocuments = [
  "AGENTS.md",
  "docs/README.md",
  "docs/agent-playbook.md",
  "docs/implementation-plan.md",
  "docs/quality-gates.md",
  "docs/decisions.md",
];

const failures = [];

for (const required of requiredDocuments) {
  try {
    await access(path.join(repositoryRoot, required));
  } catch {
    failures.push(`missing required document: ${required}`);
  }
}

const markdownFiles = (await walkFiles()).filter((file) => file.endsWith(".md"));
const markdownLink = /!?\[[^\]]*\]\(([^)]+)\)/g;

for (const markdownFile of markdownFiles) {
  const content = await readTextFileIfSmall(markdownFile);
  if (content === null) continue;

  for (const match of content.matchAll(markdownLink)) {
    let target = match[1].trim();
    if (target.startsWith("<") && target.endsWith(">")) {
      target = target.slice(1, -1);
    }
    target = target.split(/\s+["']/u, 1)[0];
    if (
      target === "" ||
      target.startsWith("#") ||
      /^[a-z][a-z\d+.-]*:/iu.test(target)
    ) {
      continue;
    }

    const pathPart = target.split("#", 1)[0].split("?", 1)[0];
    const decodedPath = decodeURIComponent(pathPart);
    const resolved = path.resolve(path.dirname(markdownFile), decodedPath);
    try {
      await access(resolved);
    } catch {
      failures.push(`${relative(markdownFile)} -> ${target}`);
    }
  }
}

if (failures.length > 0) {
  console.error("Documentation verification failed:");
  for (const failure of failures) console.error(`- ${failure}`);
  process.exitCode = 1;
} else {
  console.log(`Documentation verification passed (${markdownFiles.length} Markdown files).`);
}