/**
 * scripts/generate-docs/lib/stats.ts
 * Counts the moving parts that should appear in the stats bar on index.html.
 * Numbers are derived from the filesystem so they can never go stale.
 */
import { readFileSync } from 'node:fs';
import { sync as globSync } from 'glob';
import { join } from 'node:path';
import { parseAllSkills } from './skill-parser';

const REPO_ROOT = join(__dirname, '..', '..', '..');

export interface Stats {
  skills: number;
  baSkills: number;
  agents: number;
  hooks: number;
  cliCommands: number;
  /**
   * Audit-rule ranges per code prefix, rendered as `PREFIX-001..0NN`.
   * Derived by scanning every BA SKILL.md body for `PREFIX-NNN` occurrences,
   * so the documented ranges can never drift from the shipped rules.
   * Usage in docs-src markdown / templates: `{{stats.rules.UC}}` → `UC-001..021`.
   */
  rules: Record<string, string>;
}

function count(glob: string): number {
  return globSync(glob.replace(/\\/g, '/'), { cwd: REPO_ROOT }).length;
}

function collectRuleRanges(): Record<string, string> {
  const files = globSync('templates/skills/business-analyse/**/SKILL.md', {
    cwd: REPO_ROOT,
    absolute: true,
    ignore: '**/node_modules/**',
  });
  const maxByPrefix = new Map<string, number>();
  const pattern = /\b([A-Z]{2,6})-(\d{3})\b/g;
  for (const file of files) {
    const content = readFileSync(file, 'utf-8');
    for (const m of content.matchAll(pattern)) {
      const prefix = m[1];
      const num = parseInt(m[2], 10);
      if (num > (maxByPrefix.get(prefix) ?? 0)) maxByPrefix.set(prefix, num);
    }
  }
  const out: Record<string, string> = {};
  for (const [prefix, max] of maxByPrefix) {
    out[prefix] = `${prefix}-001..${String(max).padStart(3, '0')}`;
  }
  return out;
}

export function collectStats(): Stats {
  const skills = parseAllSkills();
  return {
    skills: skills.length,
    baSkills: skills.filter((s) => s.phase === 'business-analyse').length,
    agents: count('templates/agents/*.md'),
    hooks: count('templates/hooks/*.{sh,js,mjs,cjs}'),
    // CLI commands = TypeScript files in src/commands/ excluding the barrel index.ts
    cliCommands: globSync('src/commands/*.ts', { cwd: REPO_ROOT })
      .filter((f) => !/[\\/]index\.ts$/.test(f)).length,
    rules: collectRuleRanges(),
  };
}