import android.content.Context
import android.os.Handler
import android.os.Looper
import android.webkit.CookieManager
import android.webkit.WebSettings
import android.webkit.WebView
import android.webkit.WebViewClient
import okhttp3.Interceptor
import okhttp3.Request
import okhttp3.Response
import okhttp3.ResponseBody
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import java.io.IOException
import java.util.concurrent.CountDownLatch

interface AntiDDOSCookiesStorage {
    fun saveCookie(cookie: String)
    fun loadCookie(): String?
}

class AntiDdosInterceptor(private val context: Context, private val cookiesStorage: AntiDDOSCookiesStorage) : Interceptor {
    companion object {
        const val TARGET_STRING = "SomeLongString"
    }

    override fun intercept(chain: Interceptor.Chain): Response {
        val originalRequest = chain.request()
        var savedCookies = cookiesStorage.loadCookie()

        if (savedCookies == null) {
            val bodyFromWebView = loadPageWithWebView(originalRequest.url.toString())
            savedCookies = cookiesStorage.loadCookie()

            if (bodyFromWebView != null && bodyFromWebView.contains(TARGET_STRING)) {
                return chain.proceed(originalRequest)
                    .newBuilder()
                    .body(ResponseBody.create("text/html".toMediaTypeOrNull(), bodyFromWebView))
                    .build()
            }
        }

        val requestWithCookies = originalRequest.newBuilder()
            .header("Cookie", savedCookies ?: "")
            .build()

        var response = chain.proceed(requestWithCookies)
        val responseBodyString = response.body?.string() ?: ""

        if (!responseBodyString.contains(TARGET_STRING)) {
            // If TARGET_STRING is not found, repeat the process
            response.close()
            val bodyFromWebView = loadPageWithWebView(originalRequest.url.toString())
            savedCookies = cookiesStorage.loadCookie()
            val newRequestWithCookies = originalRequest.newBuilder()
                .header("Cookie", savedCookies ?: "")
                .build()
            response = chain.proceed(newRequestWithCookies)

            if (bodyFromWebView != null && bodyFromWebView.contains(TARGET_STRING)) {
                return response.newBuilder()
                    .body(ResponseBody.create("text/html".toMediaTypeOrNull(), bodyFromWebView))
                    .build()
            }
        }

        return response.newBuilder()
            .body(ResponseBody.create("text/html".toMediaTypeOrNull(), responseBodyString))
            .build()
    }

    private fun loadPageWithWebView(url: String): String? {
        val latch = CountDownLatch(1)
        val result = StringBuilder()

        Handler(Looper.getMainLooper()).post {
            val webView = WebView(context)
            val webSettings: WebSettings = webView.settings
            webSettings.javaScriptEnabled = true
            webView.webViewClient = object : WebViewClient() {
                override fun onPageFinished(view: WebView?, url: String?) {
                    view?.evaluateJavascript("(function() { return document.documentElement.outerHTML; })();") { html ->
                        val cookieManager = CookieManager.getInstance()
                        val cookies = cookieManager.getCookie(url)
                        cookiesStorage.saveCookie(cookies)
                        result.append(html)
                        latch.countDown()
                    }
                }
            }

            webView.loadUrl(url)
        }

        try {
            latch.await()
        } catch (e: InterruptedException) {
            e.printStackTrace()
        }

        return result.toString()
    }
}