import fs from 'fs';
import { unified } from 'unified';
import remarkParse from 'remark-parse';
import remarkFrontmatter from 'remark-frontmatter';
import remarkGfm from 'remark-gfm';

import remarkDirective from 'remark-directive';

export interface LintResult {
  ruleId: string;
  message: string;
}

export async function lintFile(filePath: string): Promise<LintResult[]> {
  const content = fs.readFileSync(filePath, 'utf-8');
  const results: LintResult[] = [];

  const processor = unified()
    .use(remarkParse)
    .use(remarkFrontmatter, ['yaml'])
    .use(remarkGfm)
    .use(remarkDirective);

  const tree = processor.parse(content);
  // We will pass the tree to rules here later.
  const { checkFrontmatter } = await import('./rules/frontmatter.js');
  results.push(...checkFrontmatter(tree as any));

  const { checkToc } = await import('./rules/toc.js');
  results.push(...checkToc(tree as any));

  const { checkStructure } = await import('./rules/structure.js');
  results.push(...checkStructure(tree as any));

  const { checkCallouts } = await import('./rules/callouts.js');
  results.push(...checkCallouts(tree as any));

  const { checkCodeBlocks } = await import('./rules/codeblocks.js');
  results.push(...checkCodeBlocks(tree as any));


  // Placeholder logic
  if (content.length === 0) {
    results.push({ ruleId: 'empty-file', message: 'File is empty' });
  }

  return results;
}