package org.jetbrains.dokka.base.resolvers.shared

import java.net.HttpURLConnection
import java.net.URL
import java.net.URLConnection

internal fun URL.doOpenConnectionToReadContent(timeout: Int = 10000, redirectsAllowed: Int = 16): URLConnection {
    val connection = this.openConnection().apply {
        connectTimeout = timeout
        readTimeout = timeout
    }

    when (connection) {
        is HttpURLConnection -> {
            return when (connection.responseCode) {
                in 200..299 -> {
                    connection
                }
                HttpURLConnection.HTTP_MOVED_PERM,
                HttpURLConnection.HTTP_MOVED_TEMP,
                HttpURLConnection.HTTP_SEE_OTHER -> {
                    if (redirectsAllowed > 0) {
                        val newUrl = connection.getHeaderField("Location")
                        URL(newUrl).doOpenConnectionToReadContent(timeout, redirectsAllowed - 1)
                    } else {
                        throw RuntimeException("Too many redirects")
                    }
                }
                else -> {
                    throw RuntimeException("Unhandled http code: ${connection.responseCode}")
                }
            }
        }
        else -> return connection
    }
}