import { join, resolve } from 'node:path'
import { debounce } from 'perfect-debounce'
import type { Plugin } from 'vite'
import { generateRouteTypes } from '../../typed-routes/generateRouteTypes'
import { getRouterRootFromOneOptions } from '../../utils/getRouterRootFromOneOptions'
import type { One } from '../types'

export function generateFileSystemRouteTypesPlugin(options: One.PluginOptions): Plugin {
  return {
    name: `one-generate-fs-route-types`,
    enforce: 'post',
    apply: 'serve',

    configureServer(server) {
      const appDir = join(process.cwd(), getRouterRootFromOneOptions(options))
      // Generate routes.d.ts inside the app directory to keep it organized
      const outFile = join(appDir, 'routes.d.ts')

      const routerRoot = getRouterRootFromOneOptions(options)
      const typedRoutesGeneration =
        options.router?.experimental?.typedRoutesGeneration || undefined

      // on change ./app stuff lets reload this to pick up any route changes
      const fileWatcherChangeListener = debounce(async (type: string, path: string) => {
        if (type === 'add' || type === 'delete' || type === 'change') {
          // resolve to absolute path since watcher may emit relative paths
          const absolutePath = resolve(path)
          // skip routes.d.ts itself to avoid infinite loop
          if (absolutePath === outFile) {
            return
          }
          if (absolutePath.startsWith(appDir)) {
            // generate
            generateRouteTypes(
              outFile,
              routerRoot,
              options.router?.ignoredRouteFiles,
              typedRoutesGeneration
            )
          }
        }
      }, 100)

      server.watcher.addListener('all', fileWatcherChangeListener)

      return () => {
        // once on startup:

        generateRouteTypes(
          outFile,
          routerRoot,
          options.router?.ignoredRouteFiles,
          typedRoutesGeneration
        )
      }
    },
  } satisfies Plugin
}