import { readdir, readFile } from 'node:fs/promises'
import { existsSync } from 'node:fs'
import { join, extname, resolve } from 'node:path'
import type { Resource } from './types.js'
import { pathToFileURL } from 'node:url'

/**
 * Load all resource definitions from collections/, questions/, dashboards/ subdirs.
 * Supports .ts/.js files that default-export a Resource, and .sql/.mongodb + .meta.json pairs.
 */
export async function loadResources(baseDir: string = '.'): Promise<Resource[]> {
  const resources: Resource[] = []
  const root = resolve(baseDir)

  const subdirs = ['collections', 'questions', 'dashboards', 'snippets']

  for (const subdir of subdirs) {
    const dir = join(root, subdir)
    if (!existsSync(dir)) continue

    const files = await readdir(dir)
    for (const file of files) {
      const ext = extname(file)
      if (ext === '.ts' || ext === '.js') {
        const filePath = join(dir, file)
        const mod = await import(pathToFileURL(filePath).href)
        const resource = mod.default as Resource
        if (resource && resource.kind) {
          resources.push(resource)
        }
      } else if (ext === '.sql' || ext === '.mongodb') {
        const baseName = file.replace(/\.(sql|mongodb)$/, '')
        const metaPath = join(dir, `${baseName}.meta.json`)
        if (existsSync(metaPath)) {
          const content = await readFile(join(dir, file), 'utf-8')
          const meta = JSON.parse(await readFile(metaPath, 'utf-8'))
          if (subdir === 'snippets') {
            resources.push({
              kind: 'snippet',
              content,
              ...meta,
            })
          } else {
            resources.push({
              kind: 'question',
              type: 'native',
              query: content,
              ...meta,
            })
          }
        }
      }
    }
  }

  return resources
}