#!/usr/bin/python
# -*- coding: utf-8 -*-
import os
import shutil
import zipfile

# 步骤:
# 找到源apk文件
# 遍历channel.txt中的所有渠道
# 创建新的渠道包文件,并复制源文件内容到新创建的渠道包文件
# 在新的渠道包文件中/META-INF/目录下创建标识渠道的空文件


def get_original_apk(path):
    for f in os.listdir(path):
        if f.endswith(".apk"):
            return f


def multi_channel_pkg():
    # 获取源apk,前缀及后缀
    original_apk = get_original_apk(".")

    if original_apk is None:
        return

    index = original_apk.find(".apk")
    original_apk_name = os.path.splitext(original_apk)[0:index]
    apk_name_prefix = original_apk_name[0]
    apk_name_suffix = original_apk_name[1]

    if os.path.exists("./output"):
        shutil.rmtree("./output")

    os.mkdir("./output")

    # 遍历渠道文件
    with open("./channel.txt") as f:
        for line in f:
            channel_name = line.strip("\n")

            # 拷贝源apk内容到渠道apk
            dest_apk = "./output/{}-{}{}".format(apk_name_prefix, channel_name, apk_name_suffix)
            shutil.copy(original_apk, dest_apk)

            # 创建空的渠道文件
            f_empty_channel = open(channel_name, 'w')
            f_empty_channel.close()

            # 往渠道apk中添加空的渠道文件
            dest_channel_path = "./META-INF/" + channel_name
            f = zipfile.ZipFile(dest_apk, 'a')
            f.write(channel_name, dest_channel_path)
            f.close()

            # 删除本地空的渠道文件
            os.remove(channel_name)


multi_channel_pkg()

public static void pack(String outputDir, File originalApkFile, File channelFile) {
    List<String> channels = getAllChannels(channelFile);
    for (String channel : channels) {
        packOneApk(outputDir, originalApkFile, channel);
    }
}

public static String readPackChannel(File channelApkFile) {
    String channel = "";
    try {
        RandomAccessFile raf = new RandomAccessFile(channelApkFile, "r");
        //read magic words
        long index = raf.length() - MAGIC.length;
        raf.seek(index);
        byte magic[] = new byte[MAGIC.length];
        raf.read(magic);
        if (!isEqual(magic, MAGIC)) {
            return channel;
        }

        //read channel length
        index -= 2;
        raf.seek(index);
        short channelLength = raf.readShort();
        if (channelLength <= 0) {
            return channel;
        }

        //read channel
        index -= channelLength;
        raf.seek(index);
        byte channelByte[] = new byte[channelLength];
        raf.read(channelByte);
        channel = new String(channelByte, Charset.forName("UTF-8"));
    } catch (IOException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }

    return channel;
}

private static void packOneApk(String outputDir, File originalApkFile, String channel) {
    writeComment(outputDir, originalApkFile, channel);
}

private static void writeComment(String outputDir, File originalApkFile, String channel) {
    try {
        String originalApkFileName = originalApkFile.getName();
        int index = originalApkFileName.indexOf(".apk");
        if (index == -1) {
            return;
        }

        String apkPrefix = originalApkFileName.substring(0, index - 1);
        String destApkFileName = apkPrefix + "-" + channel + ".apk";
        File destApkFile = new File(outputDir, destApkFileName);
        boolean success = destApkFile.createNewFile();
        if (!success) {
            return;
        }

        copyFile(originalApkFile, destApkFile);
        //comment length is 2 bytes
        //comment format: channel + channel.length(2 bytes) + magic
        RandomAccessFile raf = new RandomAccessFile(destApkFileName, "rw");
        raf.seek(destApkFile.length() - 2);
        writeShort((short) (channel.getBytes("UTF-8").length + 2 + MAGIC.length), raf);
        raf.write(channel.getBytes("UTF-8"));
        writeShort((short)channel.getBytes("UTF-8").length, raf);
        raf.write(MAGIC);
        raf.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private static void copyFile(File originalApkFile, File destApkFile) {
    BufferedInputStream bis = null;
    BufferedOutputStream bos = null;
    try {
        bis = new BufferedInputStream(new FileInputStream(originalApkFile));
        bos = new BufferedOutputStream(new FileOutputStream(destApkFile));
        byte buffer[] = new byte[1024];
        int length;
        while ((length = bis.read(buffer)) != -1) {
            bos.write(buffer, 0, length);
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (bos != null) {
                bos.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            if (bis != null) {
                bis.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}