package com.microsoft.clarity.reactnative

import com.facebook.react.bridge.Arguments
import com.facebook.react.bridge.ReactApplicationContext
import com.facebook.react.bridge.ReactContextBaseJavaModule
import com.facebook.react.bridge.ReactMethod
import com.facebook.react.modules.core.DeviceEventManagerModule
import com.microsoft.clarity.Clarity

internal class ClarityEmitter(private val reactContext: ReactApplicationContext) :
  ReactContextBaseJavaModule(reactContext) {

  private var listenerCount = 0
  private var registeredOnSessionStartedCallback = false

  override fun getName(): String {
    return NAME
  }

  @ReactMethod
  fun addListener(eventName: String) {
    listenerCount += 1

    registerOnSessionStartedCallback()
  }

  @ReactMethod
  fun removeListeners(count: Int) {
    listenerCount -= count
  }

  private fun registerOnSessionStartedCallback() {
    // `setOnSessionStartedCallback` should be called:
    //   - once to maintain the same callback.
    //   - only when there are listeners so that they can receive the first invocation from the SDK.
    if (registeredOnSessionStartedCallback) return

    registeredOnSessionStartedCallback = Clarity.setOnSessionStartedCallback { sessionId ->
      if (listenerCount <= 0) return@setOnSessionStartedCallback

      val params = Arguments.createMap().apply {
        putString(CLARITY_SESSION_ID_PARAMETER, sessionId)
      }

      reactContext.getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter::class.java)
        .emit(CLARITY_EVENT_SESSION_STARTED, params)
    }
  }

  companion object {
    const val NAME = "ClarityEmitter"
    const val CLARITY_EVENT_SESSION_STARTED = "sessionStarted"
    const val CLARITY_SESSION_ID_PARAMETER = "sessionId"
  }
}