import { readFileSync, readdirSync, statSync } from 'fs'
import { join } from 'path'
import { describe, it, expect } from 'vitest'

const ROOT = join(import.meta.dirname, '../..')

function collectSourceFiles(dir: string, acc: string[] = []): string[] {
  for (const name of readdirSync(dir)) {
    const full = join(dir, name)
    const st = statSync(full)
    if (st.isDirectory()) {
      if (name === 'node_modules' || name === 'out') continue
      collectSourceFiles(full, acc)
    } else if (/\.(ts|tsx)$/.test(name)) {
      acc.push(full)
    }
  }
  return acc
}

function extractNamedImports(content: string): { from: string; names: string[] }[] {
  const results: { from: string; names: string[] }[] = []
  const re = /import\s+(?:type\s+)?\{([^}]+)\}\s+from\s+['"]([^'"]+)['"]/g
  let m: RegExpExecArray | null
  while ((m = re.exec(content)) !== null) {
    const names = m[1]
      .split(',')
      .map((part) => part.trim())
      .filter(Boolean)
      .map((part) => part.split(/\s+as\s+/)[0]!.trim())
    results.push({ from: m[2]!, names })
  }
  return results
}

describe('release gate: import hygiene', () => {
  it('UT-RELEASE-01: no duplicate named imports from the same module', () => {
    const files = collectSourceFiles(join(ROOT, 'src'))
    const offenders: string[] = []

    for (const file of files) {
      const blocks = extractNamedImports(readFileSync(file, 'utf8'))
      const seen = new Map<string, Set<string>>()
      for (const { from, names } of blocks) {
        if (!seen.has(from)) seen.set(from, new Set())
        const bucket = seen.get(from)!
        for (const name of names) {
          if (bucket.has(name)) {
            offenders.push(`${file}: duplicate import { ${name} } from '${from}'`)
          }
          bucket.add(name)
        }
      }
    }

    expect(offenders, offenders.join('\n')).toEqual([])
  })
})