app/src/main/java/dev/lowrespalmtree/comet/Gemtext.kt

@@ -1,6 +1,5 @@
 package dev.lowrespalmtree.comet
 
-import android.util.Log
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.launch
@@ -19,8 +18,6 @@ class PreTextLine(val text: String) : Line
 class BlockquoteLine(val text: String) : Line
 class ListItemLine(val text: String) : Line
 
-const val TAG = "Gemtext"
-
 fun parseData(
     inChannel: Channel<ByteArray>,
     charset: Charset,
@@ -30,7 +27,6 @@ fun parseData(
     scope.launch {
         var isPref = false
         var buffer = ByteArray(0)
-        Log.d(TAG, "parseData: start getting data from channel")
         for (data in inChannel) {
             buffer += data
             var nextLineFeed: Int = -1
@@ -45,7 +41,6 @@ fun parseData(
                 channel.send(line)
             }
         }
-        Log.d(TAG, "parseData: channel closed")
         channel.close()
     }
     return channel

app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt

@@ -11,12 +11,17 @@ import android.view.inputmethod.EditorInfo
 import android.view.inputmethod.InputMethodManager
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewModelScope
 import androidx.recyclerview.widget.LinearLayoutManager
 import dev.lowrespalmtree.comet.databinding.ActivityMainBinding
-import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.*
+import java.net.ConnectException
+import java.net.UnknownHostException
+import java.nio.charset.Charset
 
-@ExperimentalCoroutinesApi
 class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
     private lateinit var binding: ActivityMainBinding
     private lateinit var pageViewModel: PageViewModel
@@ -87,7 +92,10 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
         }
 
         when (uri.scheme) {
-            "gemini" -> pageViewModel.sendGeminiRequest(uri)
+            "gemini" -> {
+                currentUrl = uri.toString()
+                pageViewModel.sendGeminiRequest(uri)
+            }
             else -> openUnknownScheme(uri)
         }
     }
@@ -117,27 +125,17 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
         Log.d(TAG, "handleEvent: $event")
         if (!event.handled) {
             when (event) {
-                is PageViewModel.SuccessEvent -> {
-                    currentUrl = event.uri
-                    visitedUrls.add(event.uri)
-                }
-                is PageViewModel.RedirectEvent -> {
-                    openUrl(event.uri, base = currentUrl, redirections = event.redirects)
-                }
-                is PageViewModel.FailureEvent -> {
-                    var message = event.details
-                    if (!event.serverDetails.isNullOrEmpty())
-                        message += "\n\n" + "Server details: ${event.serverDetails}"
-                    alert(message, title = event.short)
-                }
+                is PageViewModel.SuccessEvent -> visitedUrls.add(event.uri)
+                is PageViewModel.RedirectEvent -> openUrl(event.uri, redirections = event.redirects)
+                is PageViewModel.FailureEvent -> alert(event.message)
             }
             event.handled = true
         }
     }
 
-    private fun alert(message: String, title: String? = null) {
+    private fun alert(message: String) {
         AlertDialog.Builder(this)
-            .setTitle(title ?: getString(R.string.error_alert_title))
+            .setTitle(R.string.error_alert_title)
             .setMessage(message)
             .create()
             .show()
@@ -151,6 +149,121 @@ class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
         }
     }
 
+    class PageViewModel : ViewModel() {
+        private var requestJob: Job? = null
+        val state: MutableLiveData<State> by lazy { MutableLiveData<State>(State.IDLE) }
+        private var linesList = ArrayList<Line>()
+        val lines: MutableLiveData<List<Line>> by lazy { MutableLiveData<List<Line>>() }
+        val event: MutableLiveData<Event> by lazy { MutableLiveData<Event>() }
+
+        enum class State {
+            IDLE, CONNECTING, RECEIVING
+        }
+
+        abstract class Event(var handled: Boolean = false)
+        data class SuccessEvent(val uri: String) : Event()
+        data class RedirectEvent(val uri: String, val redirects: Int) : Event()
+        data class FailureEvent(val message: String) : Event()
+
+        /**
+         * Perform a request against this URI.
+         *
+         * The URI must be valid, absolute and with a gemini scheme.
+         */
+        fun sendGeminiRequest(uri: Uri, redirects: Int = 0) {
+            Log.d(TAG, "sendRequest: URI \"$uri\"")
+            state.postValue(State.CONNECTING)
+            requestJob?.apply { if (isActive) cancel() }
+            requestJob = viewModelScope.launch(Dispatchers.IO) {
+                val response = try {
+                    val request = Request(uri)
+                    val socket = request.connect()
+                    val channel = request.proceed(socket, this)
+                    Response.from(channel, viewModelScope)
+                } catch (e: Exception) {
+                    Log.e(TAG, "sendGeminiRequest coroutine: ${e.stackTraceToString()}")
+                    // If we got cancelled, die silently.
+                    if (!isActive)
+                        return@launch
+                    signalError(
+                        when (e) {
+                            is UnknownHostException -> "Unknown host \"${uri.authority}\"."
+                            is ConnectException -> "Can't connect to this server: ${e.message}."
+                            else -> "Oops, something failed!"
+                        }
+                    )
+                    return@launch
+                }
+                if (!isActive)
+                    return@launch
+                if (response == null) {
+                    signalError("Can't parse server response.")
+                    return@launch
+                }
+
+                Log.i(TAG, "sendRequest: got ${response.code} with meta \"${response.meta}\"")
+                when (response.code.getCategory()) {
+                    Response.Code.Category.SUCCESS -> handleRequestSuccess(response, uri)
+                    Response.Code.Category.REDIRECT -> handleRedirect(response, redirects = redirects + 1)
+                    Response.Code.Category.SERVER_ERROR -> handleError(response)
+                    else -> signalError("Can't handle code ${response.code}.")
+                }
+            }
+        }
+
+        private fun signalError(message: String) {
+            event.postValue(FailureEvent(message))
+            state.postValue(State.IDLE)
+        }
+
+        private suspend fun handleRequestSuccess(response: Response, uri: Uri) {
+            state.postValue(State.RECEIVING)
+
+            linesList.clear()
+            lines.postValue(linesList)
+            val charset = Charset.defaultCharset()
+            var mainTitle: String? = null
+            var lastUpdate = System.currentTimeMillis()
+            for (line in parseData(response.data, charset, viewModelScope)) {
+                linesList.add(line)
+                if (mainTitle == null && line is TitleLine && line.level == 1)
+                    mainTitle = line.text
+                val time = System.currentTimeMillis()
+                if (time - lastUpdate >= 100) {  // Throttle to 100ms the recycler view updates…
+                    lines.postValue(linesList)
+                    lastUpdate = time
+                }
+            }
+            lines.postValue(linesList)
+
+            // We record the history entry here: it's nice because we have the main title available
+            // and we're already in a coroutine for database access.
+            History.record(uri.toString(), mainTitle)
+            event.postValue(SuccessEvent(uri.toString()))
+            state.postValue(State.IDLE)
+        }
+
+        private fun handleRedirect(response: Response, redirects: Int) {
+            event.postValue(RedirectEvent(response.meta, redirects))
+        }
+
+        private fun handleError(response: Response) {
+            event.postValue(FailureEvent(when (response.code) {
+                Response.Code.TEMPORARY_FAILURE -> "40: the server encountered a temporary failure."
+                Response.Code.SERVER_UNAVAILABLE -> "41: the server is currently unavailable."
+                Response.Code.CGI_ERROR -> "42: a CGI script encountered an error."
+                Response.Code.PROXY_ERROR -> "43: the server failed to proxy the request."
+                Response.Code.SLOW_DOWN -> "44: slow down!"
+                Response.Code.PERMANENT_FAILURE -> "50: this request failed and similar requests will likely fail as well."
+                Response.Code.NOT_FOUND -> "51: this page can't be found."
+                Response.Code.GONE -> "52: this page is gone."
+                Response.Code.PROXY_REQUEST_REFUSED -> "53: the server refused to proxy the request."
+                Response.Code.BAD_REQUEST -> "59: bad request."
+                else -> "${response.code}: unknown error code."
+            }))
+        }
+    }
+
     companion object {
         const val TAG = "MainActivity"
     }

app/src/main/java/dev/lowrespalmtree/comet/Request.kt

@@ -7,7 +7,6 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.launch
 import java.io.BufferedInputStream
-import java.net.InetSocketAddress
 import java.net.SocketTimeoutException
 import java.security.cert.X509Certificate
 import javax.net.ssl.SSLContext
@@ -21,9 +20,8 @@ class Request(private val uri: Uri) {
         Log.d(TAG, "connect")
         val context = SSLContext.getInstance("TLSv1.2")
         context.init(null, arrayOf(TrustManager()), null)
-        val socket = context.socketFactory.createSocket() as SSLSocket
+        val socket = context.socketFactory.createSocket(uri.host, port) as SSLSocket
         socket.soTimeout = 10000
-        socket.connect(InetSocketAddress(uri.host, port), 10000)
         socket.startHandshake()
         return socket
     }
@@ -41,11 +39,13 @@ class Request(private val uri: Uri) {
                     try {
                         @Suppress("BlockingMethodInNonBlockingContext")  // what u gonna do
                         while ((bis.read(buffer).also { numRead = it }) >= 0) {
+                            Log.d(TAG, "proceed coroutine: received $numRead bytes")
                             val received = buffer.sliceArray(0 until numRead)
                             channel.send(received)
                         }
                     } catch (e: SocketTimeoutException) {
-                        Log.i(TAG, "proceed coroutine: socket timeout.")
+                        Log.i(TAG, "Socket timeout.")
+                        channel.cancel()
                     }
                 }
             }
@@ -56,10 +56,9 @@ class Request(private val uri: Uri) {
     }
 
     @SuppressLint("CustomX509TrustManager")
-    class TrustManager : X509TrustManager {
+    class TrustManager: X509TrustManager {
         @SuppressLint("TrustAllX509TrustManager")
-        override fun checkClientTrusted(chain: Array<out X509Certificate>?, authType: String?) {
-        }
+        override fun checkClientTrusted(chain: Array<out X509Certificate>?, authType: String?) {}
 
         override fun checkServerTrusted(chain: Array<out X509Certificate>?, authType: String?) {
             Log.d(TAG, "cool cert, please continue")

app/src/main/java/dev/lowrespalmtree/comet/Response.kt

@@ -3,7 +3,7 @@ package dev.lowrespalmtree.comet
 import android.util.Log
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.channels.ClosedReceiveChannelException
+import kotlinx.coroutines.channels.consumeEach
 import kotlinx.coroutines.launch
 import java.nio.ByteBuffer
 import java.nio.charset.Charset
@@ -51,56 +51,44 @@ class Response(val code: Code, val meta: String, val data: Channel<ByteArray>) {
 
     companion object {
         private const val TAG = "Response"
-        private const val MAX_META_LEN = 1024
-        private const val MAX_HEADER_LEN = 2 + 1 + MAX_META_LEN + 2
 
         /** Return a response object from the incoming server data, served through the channel. */
         suspend fun from(channel: Channel<ByteArray>, scope: CoroutineScope): Response? {
             var received = 0
             val headerBuffer = ByteBuffer.allocate(1024)
-            var lfIndex: Int
-            // While we don't have a response object (i.e. no header parsed), keep reading.
-            while (true) {
-                val data = try {
-                    channel.receive()
-                } catch (e: ClosedReceiveChannelException) {
-                    Log.i(TAG, "companion from: channel closed during initial receive")
-                    return null
-                }
-                if (received + data.size > MAX_HEADER_LEN) {
-                    Log.i(TAG, "companion from: received too much data for a valid header")
-                    return null
-                }
+            for (data in channel) {
                 // Push some data into our buffer.
                 headerBuffer.put(data)
                 received += data.size
                 // Check if there is enough data to parse a Gemini header from it (e.g. has \r\n).
-                lfIndex = headerBuffer.array().indexOf(0x0D)  // \r
+                val lfIndex = headerBuffer.array().indexOf(0x0D)  // \r
                 if (lfIndex == -1)
                     continue
                 if (headerBuffer.array()[lfIndex + 1] != (0x0A.toByte()))  // \n
                     continue
-                break
-            }
-            // We have our header! Parse it to create our Response object.
-            val bytes = headerBuffer.array()
-            val headerData = bytes.sliceArray(0 until lfIndex)
-            val (code, meta) = parseHeader(headerData)
-                ?: return null .also { Log.i(TAG, "companion from: can't parse header") }
-            val response = Response(code, meta, Channel())
-            scope.launch {
-                // If we got too much data from the channel: push the trailing data first.
-                val trailingIndex = lfIndex + 2
-                if (trailingIndex < received) {
-                    val trailingData = bytes.sliceArray(trailingIndex until received)
-                    response.data.send(trailingData)
+                // We have our header! Parse it to create our Response object.
+                val bytes = headerBuffer.array()
+                val headerData = bytes.sliceArray(0 until lfIndex)
+                val (code, meta) = parseHeader(headerData)
+                    ?: return null.also { Log.e(TAG, "Failed to parse header") }
+                val responseChannel = Channel<ByteArray>()
+                val response = Response(code, meta, responseChannel)
+                scope.launch {
+                    // If we got too much data from the channel: push the trailing data first.
+                    val trailingIndex = lfIndex + 2
+                    if (trailingIndex < received) {
+                        val trailingData = bytes.sliceArray(trailingIndex until received)
+                        responseChannel.send(trailingData)
+                    }
+                    // Forward all incoming data to the Response channel.
+                    channel.consumeEach { responseChannel.send(it) }
+                    responseChannel.close()
                 }
-                // Forward all incoming data to the Response channel.
-                for (data in channel)
-                    response.data.send(data)
-                response.data.close()
+                // Return the response here; this stops consuming the channel from this for-loop so
+                // that the coroutine above can take care of it.
+                return response
             }
-            return response
+            return null
         }
 
         /** Return the code and meta from this header if it could be parsed correctly. */