import fs from 'node:fs/promises'
import path from 'node:path'

import { discoverVideoResources } from '../discovery/index.ts'
import { generateVideoResourceMeta } from './generate-video-resource-meta.ts'

export async function updateComponentMeta(projectRoot: string, checkOnly = false): Promise<void> {
  const resources = await discoverVideoResources(projectRoot)
  const generated = await generateVideoResourceMeta({ projectRoot, resources })
  const currentContents = await readOptionalFile(generated.filePath)

  if (checkOnly) {
    if (currentContents?.trimEnd() !== generated.contents.trimEnd()) {
      throw new Error('Generated video resource metadata is stale. Run pnpm run update-component-meta')
    }

    return
  }

  await fs.mkdir(path.dirname(generated.filePath), { recursive: true })
  const tempFilePath = `${generated.filePath}.tmp`
  await fs.writeFile(tempFilePath, `${generated.contents}\n`, 'utf8')
  await fs.rename(tempFilePath, generated.filePath)
}

async function readOptionalFile(filePath: string): Promise<string | undefined> {
  try {
    return await fs.readFile(filePath, 'utf8')
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === 'ENOENT') {
      return undefined
    }

    throw error
  }
}

if (import.meta.url === `file://${process.argv[1]}`) {
  const checkOnly = process.argv.includes('--check')
  const cwd = process.cwd()

  updateComponentMeta(cwd, checkOnly).catch((error: unknown) => {
    const message = error instanceof Error ? error.message : String(error)
    console.error(message)
    process.exitCode = 1
  })
}