Blog Images Replacement

image-fetch.main.kts

@file:DependsOn("com.squareup.okhttp3:okhttp:4.9.0")

import okhttp3.*
import okhttp3.internal.closeQuietly
import okio.IOException
import java.io.File
import java.util.concurrent.CountDownLatch
import java.util.concurrent.atomic.AtomicInteger

// Please specify the post directory, static-host blog usually puts all posts in one dir like "./_post"
val dirPath = "xxx/_posts"
// Please specify the regex to filter your images, you can use an easy one or take from https://stackoverflow.com/questions/44227270/regex-to-parse-image-link-in-markdown
val regexString = "http://xxx.com/blog/.+(?=\\?imageslim)"

val inputDir = File(dirPath)
val outputDir = File(inputDir.parent, "fetched_images")
outputDir.mkdir()
var fileCount = 0
val allImages = mutableListOf<String>()
inputDir.walk().forEach {
    if (it.extension == "md") {
        println("processing ${it.name}")
        allImages.addAll(extractImages(it))
        fileCount++
    }
}
println("processed $fileCount files")
println("adding ${allImages.size} image download tasks")
val countDown = CountDownLatch(allImages.size)
var successDownloaded = AtomicInteger(0)
val client = OkHttpClient()
allImages.forEach {
    val fileName = it.split("/").last()
    downloadImage(client, it, fileName)
}
countDown.await()
println("Done, successfully downloaded ${successDownloaded.get()}")
System.exit(0)


fun extractImages(mdFile: File): List<String> {
    val content = mdFile.bufferedReader().use { it.readText() }
    val regex = Regex(regexString)
    return regex.findAll(content).map { it.value }.toList()
}


fun downloadImage(client: OkHttpClient, url: String, fileName: String) {
    val req = Request.Builder().url(url).build()
    client.newCall(req).enqueue(object : Callback {

        override fun onFailure(call: Call, e: IOException) {
            println("onFailure: $fileName")
            countDown.countDown()
        }

        override fun onResponse(call: Call, response: Response) {
            val inputStream = response.body!!.byteStream()
            val output = File(outputDir, fileName)
            output.createNewFile()
            output.outputStream().use { inputStream.copyTo(it) }
            successDownloaded.incrementAndGet()
            println("onSuccess: $fileName")
            response.closeQuietly()
            countDown.countDown()
        }

    })
}