ariane/app/src/main/java/oppen/tva/io/GeminiDatasource.kt

package oppen.tva.io

import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import java.io.*
import java.net.URI
import java.security.SecureRandom
import javax.net.ssl.*

const val GEMINI_SCHEME = "gemini"

class GeminiDatasource: Datasource{

    override fun request(uri: URI, onUpdate: (state: TvaState) -> Unit) {

        //Any inputted uri starting with a colon is an app-specific command, eg. :prefs :settings
        if(uri.toString().startsWith(":")){
            onUpdate(TvaState.AppQuery(uri))
            return
        }

        when (uri.scheme) {
            GEMINI_SCHEME -> {
                //Indicate app should show progress indicator
                onUpdate(TvaState.Requesting(uri))

                GlobalScope.launch {
                    geminiRequest(uri, onUpdate)
                }

            }
            else -> onUpdate(TvaState.NotGeminiRequest(uri))
        }
    }

    /**
     *
     * This was largely copied from https://framagit.org/waweic/gemini-client/-/blob/master/app/src/main/java/rocks/ism/decentral/geminiclient/GeminiConnection.kt
     *
     */
    private fun geminiRequest(uri: URI, onUpdate: (state: TvaState) -> Unit){
        val port = if(uri.port == -1) 1965 else uri.port

        val sslContext = SSLContext.getInstance("TLSv1.2")
        sslContext.init(null, DummyTrustManager.get(), SecureRandom())

        val factory: SSLSocketFactory = sslContext.socketFactory
        val socket: SSLSocket = factory.createSocket(uri.host, port) as SSLSocket
        socket.enabledProtocols = arrayOf("TLSv1.2")

        socket.startHandshake()

        // OUT >>>>>>>>>>>>>>>>>>>>>>>>>>
        val outputStreamWriter = OutputStreamWriter(socket.outputStream)
        val bufferedWriter = BufferedWriter(outputStreamWriter)
        val outWriter = PrintWriter(bufferedWriter)

        outWriter.print(uri.toString() + "\r\n")
        outWriter.flush()

        if (outWriter.checkError()) {
            onUpdate(TvaState.GeminiPrintWriterError)
            outWriter.close()
            return
        }

        // IN <<<<<<<<<<<<<<<<<<<<<<<<<<<
        val lines = mutableListOf<String>()
        socket.inputStream.reader().use { inputStreamReader ->
            BufferedReader(inputStreamReader).use { reader ->
                lines.addAll(reader.readLines())
            }
        }

        val header = lines.firstOrNull() ?: ""
        lines.removeAt(0)

        println("Tva: header: $header")

        lines.forEach {
            println("Tva: line: $it")
        }

        println("Tva: ends -----------------")

        outputStreamWriter.close()
        bufferedWriter.close()
        outWriter.close()
        onUpdate(TvaState.GeminiResponse(uri, header, lines))
    }
}