LibrusLogin.kt

import java.util.regex.Pattern

import java.net.CookieManager
import java.net.CookiePolicy

import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.JavaNetCookieJar
import okhttp3.RequestBody
import okhttp3.MediaType

import org.json.JSONObject

fun login(username: String, password: String): String {
    val jsonMediaType = MediaType.parse("application/json; charset=utf-8")

    val patternCSRF = Pattern.compile("<meta name=\"csrf-token\" content=\"(.*?)\">")

    val cookieManager = CookieManager()
    cookieManager.setCookiePolicy(CookiePolicy.ACCEPT_ALL)

    val client = OkHttpClient.Builder()
            .cookieJar(JavaNetCookieJar(cookieManager))
            .followRedirects(false)
            .build()

    val cookieRequest = Request.Builder()
            .url("https://portal.librus.pl/oauth2/authorize?" +
                    "client_id=wmSyUMo8llDAs4y9tJVYY92oyZ6h4lAt7KCuy0Gv&" +
                    "redirect_uri=http://localhost/bar&response_type=code")
            .build()

    client.newCall(cookieRequest).execute()

    val csrfRequest = Request.Builder()
            .url("https://portal.librus.pl/rodzina/login")
            .build()

    val response = client.newCall(csrfRequest).execute()

    val matcher = patternCSRF.matcher(response.body()!!.string())
    matcher.find()
    val csrf = matcher.group(1)

    val loginFormBodyJson = JSONObject()
            .put("email", username)
            .put("password", password)

    val loginFormBody = RequestBody.create(jsonMediaType, loginFormBodyJson.toString())

    val portalLoginRequest = Request.Builder()
            .addHeader("X-CSRF-TOKEN", csrf)
            .url("https://portal.librus.pl/rodzina/login/action")
            .post(loginFormBody)
            .build()

    client.newCall(portalLoginRequest).execute()

    val codeRequest = Request.Builder()
            .url("https://portal.librus.pl/oauth2/authorize?" +
                    "client_id=wmSyUMo8llDAs4y9tJVYY92oyZ6h4lAt7KCuy0Gv&" +
                    "redirect_uri=http://localhost/bar&response_type=code")
            .build()

    val codeResponse = client.newCall(codeRequest).execute()

    return codeResponse.header("Location")!!.split("code=")[1]
}