import { execSync } from "node:child_process";
import fs from "node:fs";
import path from "node:path";

// Get staged files from git
const stagedFiles = execSync("git diff --cached --name-only --diff-filter=ACMR")
  .toString()
  .split("\n")
  .filter(Boolean);

// Filter to only new or modified posts
const postFiles = stagedFiles.filter(
  (file) =>
    file.startsWith("content/posts/") &&
    file.endsWith(".md") &&
    !file.endsWith("_index.md"),
);

if (postFiles.length === 0) {
  process.exit(0);
}

let hasError = false;

for (const file of postFiles) {
  const basename = path.basename(file, ".md");

  // 1. Slug validation (kebab-case: lowercase letters, numbers, and hyphens)
  if (!/^[a-z0-9-]+$/.test(basename)) {
    console.error(`[ERROR] in ${file}:`);
    console.error(`   Filename must be kebab-case (e.g. 'my-cool-post.md').`);
    hasError = true;
  }

  // 2. Front-matter validation
  const content = fs.readFileSync(file, "utf8");

  // Zola uses +++ for TOML front-matter
  const frontMatterMatch = content.match(/^\+\+\+([\s\S]*?)\+\+\+/);

  if (!frontMatterMatch) {
    console.error(`[ERROR] in ${file}:`);
    console.error(`   Missing TOML front-matter (must be enclosed in +++).`);
    hasError = true;
    continue;
  }

  const frontMatter = frontMatterMatch[1];

  const hasTitle = /^title\s*=\s*".+"/m.test(frontMatter);
  const hasDate = /^date\s*=\s*\d{4}-\d{2}-\d{2}/m.test(frontMatter);

  if (!hasTitle) {
    console.error(`[ERROR] in ${file}:`);
    console.error(
      `   Missing 'title' field in front-matter (e.g. title = "My Post").`,
    );
    hasError = true;
  }

  if (!hasDate) {
    console.error(`[ERROR] in ${file}:`);
    console.error(
      `   Missing 'date' field in front-matter (e.g. date = 2024-01-01).`,
    );
    hasError = true;
  }
}

if (hasError) {
  console.error(
    "\n[FATAL] Commit rejected due to validation errors. Please fix the issues above and try again.\n",
  );
  process.exit(1);
} else {
  console.log("[SUCCESS] Post validation passed!");
}