AndroidCatVodSpider/app/src/main/java/com/github/catvod/utils/DownloadMT.kt

package com.github.catvod.utils

import com.github.catvod.crawler.SpiderDebug
import com.github.catvod.net.OkHttp
import com.github.catvod.utils.ProxyVideo.getMimeType
import com.github.catvod.utils.ProxyVideo.parseRange
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Deferred
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.async
import kotlinx.coroutines.awaitAll
import kotlinx.coroutines.runBlocking
import okhttp3.Response
import org.apache.commons.lang3.StringUtils
import java.io.InputStream
import java.io.SequenceInputStream
import java.util.Vector
import kotlin.math.min

object DownloadMT {
    private val THREAD_NUM: Int = Runtime.getRuntime().availableProcessors() * 2

    private val infos = mutableMapOf<String, Array<Any>>();

    fun proxyMultiThread(url: String, headers: Map<String, String>): Array<out Any?>? =
        runBlocking {
            proxyAsync(url, headers)
        }

    /**
     * 获取是否分片信息，顺带请求一个1MB块
     */
    @Throws(java.lang.Exception::class)
    fun getInfo(url: String?, headers: Map<String, String>): Array<Any> {
        val newHeaders: MutableMap<String, String> = java.util.HashMap(headers)
        newHeaders["Range"] = "bytes=0-" + (1024 * 1024 - 1)
        newHeaders["range"] = "bytes=0-" + (1024 * 1024 - 1)
        val info = ProxyVideo.proxy(url, newHeaders)
        return info
    }

    private suspend fun proxyAsync(url: String, headers: Map<String, String>): Array<out Any?>? {

        /*  val service = Executors.newFixedThreadPool(THREAD_NUM)*/
        SpiderDebug.log("--proxyMultiThread: THREAD_NUM: $THREAD_NUM")


        try {
            //缓存，避免每次都请求total等信息
            var info = infos[url]
            //第一次请求，请求是否支持range，顺带返回一个1MB块
            if (info == null) {
                infos.clear()
                info = CoroutineScope(Dispatchers.IO).async { getInfo(url, headers) }.await()
                infos[url] = info
            /*    //支持分片，先返回这个1MB块
                if (info[0] as Int == 206) {
                    return info
                }*/
            }

            val code = info[0] as Int
            SpiderDebug.log("-----------code:$code")

            if (code != 206) {
                return ProxyVideo.proxy(url, headers)
            }
            val resHeader = info[3] as MutableMap<String, String>
            val contentRange =
                if (StringUtils.isAllBlank(resHeader["Content-Range"])) resHeader["content-range"] else resHeader["Content-Range"]

            SpiderDebug.log("--contentRange:$contentRange")
            //文件总大小
            val total = StringUtils.split(contentRange, "/")[1]
            SpiderDebug.log("--文件总大小:$total")

            //如果文件太小，也不走代理
            /* if (total.toLong() < 1024 * 1024 * 100) {
                 return proxy(url, headers)
             }*/
            var range =
                if (StringUtils.isAllBlank(headers["range"])) headers["Range"] else headers["range"]
            if (StringUtils.isAllBlank(range)) range = "bytes=0-";
            SpiderDebug.log("---proxyMultiThread,Range:$range")
            val rangeObj = parseRange(
                range!!
            )
            //没有range,无需分割

            val partList = generatePart(rangeObj, total)

            // 存储执行结果的List
            val jobs = mutableListOf<Deferred<InputStream>>()
            val inputStreams = mutableListOf<InputStream>()
            for ((index, part) in partList.withIndex()) {


                val newRange = "bytes=" + part[0] + "-" + part[1]
                val headerNew: MutableMap<String, String> = HashMap(headers)

                headerNew["range"] = newRange
                headerNew["Range"] = newRange
                jobs += CoroutineScope(Dispatchers.IO).async {
                    val res = downloadRange(url, headerNew)
                    SpiderDebug.log(
                        ("---第" + index + "块下载完成" + ";Content-Range:" + (res?.headers())?.get(
                            "Content-Range"
                        ))
                    )
                    res?.body()!!.byteStream()
                }
            }
            inputStreams += jobs.awaitAll()

            var contentType: String? = ""


            //    SpiderDebug.log(" ++proxy res data:" + Json.toJson(response.body()));
            contentType = resHeader["Content-Type"]
            if (StringUtils.isAllBlank(contentType)) {
                contentType = resHeader["content-type"]
            }

            if (StringUtils.isAllBlank(contentType) && StringUtils.isNoneBlank(resHeader["Content-Disposition"])) {
                contentType = getMimeType(resHeader["Content-Disposition"])
            }


            /* respHeaders.put("Access-Control-Allow-Credentials", "true");
        respHeaders.put("Access-Control-Allow-Origin", "*");*/
            resHeader["Content-Length"] =
                (partList[THREAD_NUM - 1][1] - partList[0][0] + 1).toString()
            resHeader.remove("content-length")

            resHeader["Content-Range"] = String.format(
                "bytes %s-%s/%s", partList[0][0], partList[THREAD_NUM - 1][1], total
            )
            resHeader.remove("content-range")

            SpiderDebug.log("----proxy res contentType:$contentType")
            //   SpiderDebug.log("++proxy res body:" + response.body());
            SpiderDebug.log("----proxy res respHeaders:" + Json.toJson(resHeader))

            return arrayOf(
                206, contentType, SequenceInputStream(Vector(inputStreams).elements()), resHeader
            )


        } catch (e: Exception) {
            SpiderDebug.log("proxyMultiThread error:" + e.message)
            e.printStackTrace()
            return null
        }
    }

    fun generatePart(rangeObj: Map<String?, String>, total: String): List<LongArray> {
        val totalSize = total.toLong()
        //超过10GB，分块是80Mb，不然是16MB
        val partSize =
            if (totalSize > 8L * 1024L * 1024L * 1024L * 10L) 1024 * 1024 * 8 * 10L else 1024 * 1024 * 8 * 2L

        var start = rangeObj["start"]!!.toLong()
        var end =
            if (StringUtils.isAllBlank(rangeObj["end"])) start + partSize else rangeObj["end"]!!.toLong()


        end = min(end.toDouble(), (totalSize - 1).toDouble()).toLong()
        val length = end - start + 1

        val size = length / THREAD_NUM
        val partList: MutableList<LongArray> = ArrayList()
        for (i in 0..<THREAD_NUM) {
            val partEnd = min((start + size).toDouble(), end.toDouble()).toLong()

            partList.add(longArrayOf(start, partEnd))
            start = partEnd + 1
        }
        return partList
    }

    private fun downloadRange(
        url: String, headerNew: MutableMap<String, String>
    ): Response? = OkHttp.newCall(url, headerNew)
}