package ren.misaka.dshapp

import android.app.Notification
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.os.SystemClock
import android.text.format.Formatter
import java.util.UUID

internal class DownloadNotifications(context: Context, private val name: String, headers: Map<String, String>) {
    private val context = context.applicationContext
    private val tag = UUID.randomUUID().toString()
    private val progress = DownloadProgress(headers)

    @Synchronized fun update(bytes: Int = 0) {
        if (progress.finished) return
        progress.add(bytes)
        if (!progress.shouldUpdate(SystemClock.elapsedRealtime())) return
        post(null)
    }

    @Synchronized fun finish(status: String) {
        if (progress.finish()) post(status)
    }

    private fun post(status: String?) {
        runCatching {
            val manager = context.getSystemService(NotificationManager::class.java)
            manager.createNotificationChannel(NotificationChannel(CHANNEL, "下载", NotificationManager.IMPORTANCE_LOW).apply {
                lockscreenVisibility = Notification.VISIBILITY_PRIVATE
                setShowBadge(false)
            })
            val percent = progress.percent
            val size = Formatter.formatShortFileSize(context, progress.written)
            val text = status ?: (if (percent == null) "正在下载 · 已写入 $size" else "正在下载 · $percent% · 已写入 $size")
            val notification = Notification.Builder(context, CHANNEL)
                .setSmallIcon(android.R.drawable.stat_sys_download)
                .setContentTitle(name).setContentText(text)
                .setVisibility(Notification.VISIBILITY_PRIVATE)
                .setOnlyAlertOnce(true).setOngoing(status == null)
                .setProgress(if (status == null) 100 else 0, if (status == null) percent ?: 0 else 0, status == null && percent == null)
                .build()
            manager.notify(tag, 0, notification)
        }.onFailure {
            if (status != null) runCatching {
                context.getSystemService(NotificationManager::class.java).cancel(tag, 0)
            }
        }
    }

    companion object {
        private const val CHANNEL = "downloads"
    }
}