package expo.modules.systemui

import android.content.Context
import android.content.SharedPreferences
import android.content.res.Configuration
import android.graphics.Color
import android.graphics.drawable.ColorDrawable
import androidx.appcompat.app.AppCompatDelegate
import expo.modules.kotlin.exception.Exceptions
import expo.modules.kotlin.functions.Queues
import expo.modules.kotlin.modules.Module
import expo.modules.kotlin.modules.ModuleDefinition

const val PREFERENCE_KEY = "expoRootBackgroundColor"

class SystemUIModule : Module() {
  private val context: Context
    get() = appContext.reactContext ?: throw Exceptions.ReactContextLost()
  private val prefs: SharedPreferences
    get() = context.getSharedPreferences("expo_ui_preferences", Context.MODE_PRIVATE)
      ?: throw Exceptions.ReactContextLost()

  private val systemBackgroundColor
    get() = when (AppCompatDelegate.getDefaultNightMode()) {
      AppCompatDelegate.MODE_NIGHT_YES -> Color.BLACK
      AppCompatDelegate.MODE_NIGHT_NO -> Color.WHITE
      AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM -> {
        when (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) {
          Configuration.UI_MODE_NIGHT_YES -> Color.BLACK
          Configuration.UI_MODE_NIGHT_NO -> Color.WHITE
          else -> Color.WHITE
        }
      }
      else -> Color.WHITE
    }

  override fun definition() = ModuleDefinition {
    Name("ExpoSystemUI")

    AsyncFunction("setBackgroundColorAsync") { color: Int? ->
      color?.let {
        prefs.edit()
          .putInt(PREFERENCE_KEY, it)
          .apply()
      } ?: prefs.edit()
        .remove(PREFERENCE_KEY)
        .apply()
      setBackgroundColor(color ?: systemBackgroundColor)
    }.runOnQueue(Queues.MAIN)

    AsyncFunction<String?>("getBackgroundColorAsync") {
      val background = appContext.throwingActivity.window.decorView.background
      return@AsyncFunction if (background is ColorDrawable) {
        colorToHex((background.mutate() as ColorDrawable).color)
      } else {
        null
      }
    }
  }

  private fun setBackgroundColor(color: Int) {
    val rootView = appContext.throwingActivity.window?.decorView
    val colorInt = Color.parseColor(colorToHex(color))
    rootView?.setBackgroundColor(colorInt)
  }

  companion object {
    fun colorToHex(color: Int): String {
      return String.format("#%02x%02x%02x", Color.red(color), Color.green(color), Color.blue(color))
    }
  }
}