PDFReaderReaderModule/src/main/java/com/kdanmobile/reader/ReaderModel.kt

package com.kdanmobile.reader

import android.annotation.SuppressLint
import android.arch.lifecycle.ViewModel
import android.os.Handler
import android.os.Message
import android.util.Log
import com.kdanmobile.kmpdfkit.manager.KMPDFFactory
import com.kdanmobile.kmpdfkit.manager.controller.KMPDFDocumentController
import java.util.*

object ReaderModel {
    private const val TAG = "ReaderModel"

    private var filename: String? = null
    var password: String = ""
        private set

    var kmpdfFactory: KMPDFFactory? = null
        private set

    @SuppressLint("StaticFieldLeak")
    var kmpdfDocumentController: KMPDFDocumentController? = null
        private set

    private var shouldDestroy = false

    @SuppressLint("HandlerLeak")
    private val handler = object : Handler() {
        override fun handleMessage(msg: Message) {
            super.handleMessage(msg)
            when (msg.what) {
                10 -> if (shouldDestroy && set.isEmpty()) {
                    destroy()
                }
            }
        }
    }

    private val set = HashSet<String>()

    var onPdfChangedListener: OnPdfChangedListener? = null

    @Synchronized
    fun initKMPDFFactory(kmpdfFactory: KMPDFFactory?, filename: String?, password: String = "") {
        Log.d(TAG, "initKMPDFFactory $filename $password")
        if (this.filename != filename || this.password != password) {
            val items = set.toList()
            destroy()
            set.addAll(items)
        }
        if (null == this.kmpdfFactory) {
            shouldDestroy = false
            this.kmpdfFactory = kmpdfFactory
            this.filename = filename
            this.password = password
        }
    }

    fun initKMPDFDocumentController() {
        Log.d(TAG, "initKMPDFDocumentController")
        kmpdfDocumentController = kmpdfFactory?.getController(KMPDFFactory.ControllerType.DOCUMENT) as KMPDFDocumentController
    }

    @Synchronized
    fun destroy() {
        Log.d(TAG, "destroy")
        filename = null
        password = ""
        kmpdfFactory?.destroy()
        kmpdfFactory = null
        kmpdfDocumentController = null
        shouldDestroy = false
        set.clear()
    }

    fun onViewModelCreate(viewModel: ViewModel) {
        Log.d(TAG, "onViewModelCreate ($viewModel)")
        set.add(viewModel.toString())
        printSet()
    }

    fun onViewModelCleared(viewModel: ViewModel) {
        Log.d(TAG, "onViewModelCleared ($viewModel)")
        set.remove(viewModel.toString())

        if (set.isEmpty()) {
            shouldDestroy = true
            handler.sendEmptyMessageDelayed(10, 2000)
        }
        printSet()
    }

    private fun printSet() {
        Log.d(TAG, "======================================================================")
        var count = 0
        set.forEach {
            Log.d(TAG, " [${count++}] $it")
        }
    }
}