ultrasonic-app-subsonic-android/ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/EntryListFragment.kt

package org.moire.ultrasonic.fragment

import android.os.Bundle
import android.view.MenuItem
import android.view.View
import androidx.core.view.isVisible
import androidx.fragment.app.Fragment
import androidx.navigation.fragment.findNavController
import org.moire.ultrasonic.R
import org.moire.ultrasonic.adapters.FolderSelectorBinder
import org.moire.ultrasonic.domain.Artist
import org.moire.ultrasonic.domain.GenericEntry
import org.moire.ultrasonic.domain.Identifiable
import org.moire.ultrasonic.service.RxBus
import org.moire.ultrasonic.subsonic.DownloadHandler
import org.moire.ultrasonic.util.Constants
import org.moire.ultrasonic.util.Settings

/**
 * An extension of the MultiListFragment, with a few helper functions geared
 * towards the display of MusicDirectory.Entries.
 * @param T: The type of data which will be used (must extend GenericEntry)
 */
abstract class EntryListFragment<T : GenericEntry> : MultiListFragment<T>() {

    /**
     * Whether to show the folder selector
     */
    fun showFolderHeader(): Boolean {
        return listModel.showSelectFolderHeader(arguments) &&
            !listModel.isOffline() && !Settings.shouldUseId3Tags
    }

    override fun onContextMenuItemSelected(menuItem: MenuItem, item: T): Boolean {
        val isArtist = (item is Artist)

        return handleContextMenu(menuItem, item, isArtist, downloadHandler, this)
    }

    override fun onItemClick(item: T) {
        val bundle = Bundle()
        bundle.putString(Constants.INTENT_ID, item.id)
        bundle.putString(Constants.INTENT_NAME, item.name)
        bundle.putString(Constants.INTENT_PARENT_ID, item.id)
        bundle.putBoolean(Constants.INTENT_ARTIST, (item is Artist))
        findNavController().navigate(R.id.trackCollectionFragment, bundle)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        // Call a cheap function on ServerSettingsModel to make sure it is initialized by Koin,
        // because it can't be initialized from inside the callback
        serverSettingsModel.toString()

        RxBus.musicFolderChangedEventObservable.subscribe {
            if (!listModel.isOffline()) {
                val currentSetting = listModel.activeServer
                currentSetting.musicFolderId = it
                serverSettingsModel.updateItem(currentSetting)
            }
            listModel.refresh(refreshListView!!, arguments)
        }

        viewAdapter.register(
            FolderSelectorBinder(view.context)
        )
    }

    /**
     * What to do when the list has changed
     */
    override val defaultObserver: (List<T>) -> Unit = {
        emptyView.isVisible = it.isEmpty() && !(refreshListView?.isRefreshing?:false)

        if (showFolderHeader()) {
            val list = mutableListOf<Identifiable>(folderHeader)
            list.addAll(it)
            viewAdapter.submitList(list)
        } else {
            viewAdapter.submitList(it)
        }
    }

    /**
     * Get a folder header and update it on changes
     */
    private val folderHeader: FolderSelectorBinder.FolderHeader by lazy {
        val header = FolderSelectorBinder.FolderHeader(
            listModel.musicFolders.value!!,
            listModel.activeServer.musicFolderId
        )

        listModel.musicFolders.observe(
            viewLifecycleOwner,
            {
                header.folders = it
                viewAdapter.notifyItemChanged(0)
            }
        )

        header
    }

    companion object {
        @Suppress("LongMethod")
        internal fun handleContextMenu(
            menuItem: MenuItem,
            item: Identifiable,
            isArtist: Boolean,
            downloadHandler: DownloadHandler,
            fragment: Fragment
        ): Boolean {
            when (menuItem.itemId) {
                R.id.menu_play_now ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = false,
                        append = false,
                        autoPlay = true,
                        shuffle = false,
                        background = false,
                        playNext = false,
                        unpin = false,
                        isArtist = isArtist
                    )
                R.id.menu_play_next ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = false,
                        append = false,
                        autoPlay = true,
                        shuffle = true,
                        background = false,
                        playNext = true,
                        unpin = false,
                        isArtist = isArtist
                    )
                R.id.menu_play_last ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = false,
                        append = true,
                        autoPlay = false,
                        shuffle = false,
                        background = false,
                        playNext = false,
                        unpin = false,
                        isArtist = isArtist
                    )
                R.id.menu_pin ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = true,
                        append = true,
                        autoPlay = false,
                        shuffle = false,
                        background = false,
                        playNext = false,
                        unpin = false,
                        isArtist = isArtist
                    )
                R.id.menu_unpin ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = false,
                        append = false,
                        autoPlay = false,
                        shuffle = false,
                        background = false,
                        playNext = false,
                        unpin = true,
                        isArtist = isArtist
                    )
                R.id.menu_download ->
                    downloadHandler.downloadRecursively(
                        fragment,
                        item.id,
                        save = false,
                        append = false,
                        autoPlay = false,
                        shuffle = false,
                        background = true,
                        playNext = false,
                        unpin = false,
                        isArtist = isArtist
                    )
                else -> return false
            }
            return true
        }
    }
}