LottieSample/src/main/kotlin/com/airbnb/lottie/samples/PlayerViewModel.kt

package com.airbnb.lottie.samples

import android.app.Application
import android.arch.lifecycle.AndroidViewModel
import android.arch.lifecycle.MutableLiveData
import android.net.Uri
import android.os.Handler
import android.os.Looper
import com.airbnb.lottie.LottieComposition
import com.airbnb.lottie.LottieCompositionFactory
import com.airbnb.lottie.LottieTask
import com.airbnb.lottie.samples.model.CompositionArgs
import java.io.FileInputStream
import java.io.FileNotFoundException

class PlayerViewModel(application: Application) : AndroidViewModel(application) {

    private val handler = Handler(Looper.getMainLooper())

    val composition = MutableLiveData<LottieComposition>()
    val error = MutableLiveData<Throwable>()

    fun fetchAnimation(args: CompositionArgs) {
        val url = args.url ?: args.animationData?.lottieLink

        val task = when {
            url != null -> LottieCompositionFactory.fromUrl(getApplication(), url)
            args.fileUri != null -> taskForUri(args.fileUri)
            args.asset != null -> LottieCompositionFactory.fromAsset(getApplication(), args.asset)
            else -> throw IllegalArgumentException("Don't know how to fetch animation for $args")
        }
        registerTask(task)
    }

    private fun taskForUri(uri: Uri): LottieTask<LottieComposition> {
        val fis = try {
            when (uri.scheme) {
                "file" -> FileInputStream(uri.path)
                "content" -> getApplication<LottieApplication>().contentResolver.openInputStream(uri)
                else -> return LottieTask() { throw IllegalArgumentException("Unknown scheme ${uri.scheme}") }
            }
        } catch (e: FileNotFoundException) {
            return LottieTask() { throw e }
        }

        return LottieCompositionFactory.fromJsonInputStream(fis, uri.toString())
    }

    private fun registerTask(task: LottieTask<LottieComposition>) {
        task
                .addListener { composition.value = it }
                .addFailureListener { error.value = it }
    }
}