// API location: io.trtc.tuikit.atomicxcore.api.login.LoginStore
 LoginStore.shared.login(
     activity,       // Activity context
     sdkAppID,       // Int, SDK application ID
     userID,         // String, User ID
     userSig,        // String, User signature
     object : CompletionHandler {
         override fun onSuccess() {
             // Login success
         }
         override fun onFailure(code: Int, desc: String) {
             // Login failed
         }
     }
 )

import android.os.Bundle
import android.view.ViewGroup
import android.widget.FrameLayout
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowCompat
import androidx.core.view.WindowInsetsCompat
import androidx.core.view.updatePadding
import io.trtc.tuikit.atomicxcore.api.CompletionHandler
import io.trtc.tuikit.atomicxcore.api.login.LoginStore
import io.trtc.tuikit.chat.uikit.pages.ChatPageView

class ChatPageDemoActivity : AppCompatActivity() {
    private val sdkAppID: Int = 0           // TODO
    private val senderUserID = ""           // TODO
    private val senderUserSig = ""          // TODO
    private val receiverUserID = ""         // TODO
    private val conversationID: String get() = "c2c_${receiverUserID}"
    private var chatPageView: ChatPageView? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        WindowCompat.setDecorFitsSystemWindows(window, false)
        LoginStore.shared.login(this, sdkAppID, senderUserID, senderUserSig, object : CompletionHandler {
            override fun onSuccess() = showChatPage()
            override fun onFailure(code: Int, desc: String) {}
        })
    }
    private fun showChatPage() {
        val container = FrameLayout(this).apply {
            layoutParams = ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.MATCH_PARENT
            )
        }
        ViewCompat.setOnApplyWindowInsetsListener(container) { view, insets ->
            val bars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            view.updatePadding(top = bars.top, bottom = bars.bottom)
            insets
        }
        setContentView(container)
        val page = ChatPageView(this)
        container.addView(page)
        page.setup(
            conversationID = conversationID,
            onUserClick = { /* Handle user avatar click */ }
        )
        chatPageView = page
    }
    override fun onDestroy() {
        chatPageView?.release()
        super.onDestroy()
    }
}