// Heavily inspired by https://github.com/openid/AppAuth-Android/blob/master/library/java/net/openid/appauth/AuthorizationManagementActivity.java

package expo.modules.criiptoverify
import android.app.Activity
import android.os.Bundle
import androidx.browser.customtabs.CustomTabsIntent
import androidx.appcompat.app.AppCompatActivity
import android.util.Log
import android.content.Context
import android.content.Intent
import android.net.Uri

private const val TAG = "CriiptoVerifyActivity"
private const val KEY_AUTHORIZE_URL = "authorizeUrl"
private const val KEY_REDIRECT_URI = "redirectUri"
private const val KEY_AUTHORIZATION_STARTED = "authorizationStarted"
class CriiptoVerifyActivity : AppCompatActivity() {
  var authorizationStarted : Boolean = false
  var authorizeUrl : String? = null
  var redirectUri : String? = null 
  var intermediateResponse : Uri? = null

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState);

    if (savedInstanceState == null) {
      var extras = getIntent()?.getExtras()
      if (extras == null) {
        var data = getIntent()?.getData()
        Log.v(TAG, "CriiptoVerifyActivity.onCreate with no extras (data: " + data.toString());
        if (data != null) {
          intermediateResponse = data
        }
        return
      }
      extractState(extras);
    } else {
      Log.v(TAG, "CriiptoVerifyActivity.onCreate with saved instance state"); 
      extractState(savedInstanceState);
    }
  }

  override fun onResume() {
    super.onResume()

    /**
     * Detected intermediate response/redirect from MitID app
     * kill this activity so we can resume to the primary activity with the browser
     */
    if (intermediateResponse != null) {
      Log.v(TAG, "CriiptoVerifyActivity.onResume: intermediate response" + getIntent().getData().toString())
      finish()
      return
    }

    /**
     * Start new browser flow
     */
    if (!authorizationStarted) {
      Log.v(TAG, "CriiptoVerifyActivity.onResume: start authorization")
      val intent = createCustomTabsIntent().apply {
        data = Uri.parse(authorizeUrl)
      }

      startActivity(intent)
      authorizationStarted = true
      return
    }

    /**
     * User dismissed browser
     */
    if (getIntent().getData() == null) {
      setResult(Activity.RESULT_OK, Intent())
      finish()
      return
    }
  }

  override fun onNewIntent(intent: Intent?) {
    super.onNewIntent(intent)
    val data = intent?.getData()

    Log.v(TAG, "CriiptoVerifyActivity.onNewIntent "+data.toString())

    if (data != null && data.isHierarchical) {
      if (data.getQueryParameter("error") != null || data.getQueryParameter("code") != null) {
        var resultIntent = Intent().apply {
          setData(data)
        }
        setResult(Activity.RESULT_OK, resultIntent)
        finish()
      }
    }
  }

  private fun createCustomTabsIntent(): Intent {
    val builder = CustomTabsIntent.Builder()
    
    return builder.build().intent.apply {
      addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
    }
  }


  override fun onSaveInstanceState(outState: Bundle) {
    super.onSaveInstanceState(outState)
    outState.apply {
      putString(KEY_AUTHORIZE_URL, authorizeUrl)
      putString(KEY_REDIRECT_URI, redirectUri)
      putBoolean(KEY_AUTHORIZATION_STARTED, authorizationStarted)
    } 
  }

  private fun extractState(state: Bundle) {
    authorizeUrl = state.getString(KEY_AUTHORIZE_URL, null)
    redirectUri = state.getString(KEY_REDIRECT_URI, null)
    authorizationStarted = state.getBoolean(KEY_AUTHORIZATION_STARTED, false)
  }

  companion object {
    fun createStartIntent(context: Context, params: StartParams) : Intent {
      return createBaseIntent(context).apply {
        putExtra(KEY_AUTHORIZE_URL, params.authorizeUrl);
        putExtra(KEY_REDIRECT_URI, params.redirectUri);
      }
    }
  
    private fun createBaseIntent(context: Context) : Intent {
      return Intent(context, CriiptoVerifyActivity::class.java).apply {
        addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
        addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
      }
    }
  }
}