const { withMainActivity } = require('expo/config-plugins')

// Why: edge-to-edge picks the navigation bar's light or dark look (and the contrast scrim drawn
// behind it) once, from the phone's theme at launch (#34246). MainActivity handles uiMode itself,
// so Orca's own theme choice and later phone switches never reach the bar, leaving a white scrim
// under a dark app. AppCompat reports both through onConfigurationChanged with the resolved uiMode.
const MARKER = 'orca: navigation bar theme'

const CLASS_HEADER = 'class MainActivity : ReactActivity() {'
const IMPORTS = [
  'android.content.res.Configuration',
  'androidx.core.view.WindowInsetsControllerCompat'
]

const INIT_BLOCK = `
  // ${MARKER}, generated by plugins/android-navigation-bar-theme.js.
  init {
    addOnConfigurationChangedListener { config ->
      val dark = config.uiMode and Configuration.UI_MODE_NIGHT_MASK == Configuration.UI_MODE_NIGHT_YES
      WindowInsetsControllerCompat(window, window.decorView).isAppearanceLightNavigationBars = !dark
    }
  }
`

function patchMainActivity(contents) {
  if (contents.includes(MARKER)) {
    return contents
  }
  if (!contents.includes(CLASS_HEADER)) {
    throw new Error(
      "android-navigation-bar-theme: Expo's MainActivity template changed; update the plugin before building."
    )
  }
  const imports = IMPORTS.filter((name) => !contents.includes(`import ${name}\n`))
    .map((name) => `import ${name}\n`)
    .join('')
  return contents
    .replace(/^(package [^\n]+\n)/, `$1${imports}`)
    .replace(CLASS_HEADER, `${CLASS_HEADER}\n${INIT_BLOCK}`)
}

module.exports = function withAndroidNavigationBarTheme(config) {
  return withMainActivity(config, (cfg) => {
    if (cfg.modResults.language !== 'kt') {
      throw new Error(
        `android-navigation-bar-theme: expected a Kotlin MainActivity, got ${cfg.modResults.language}`
      )
    }
    cfg.modResults.contents = patchMainActivity(cfg.modResults.contents)
    return cfg
  })
}