Detect MIDI port

4 files changed, 95 insertions, 7 deletions

diff --git a/MIDI.cpp b/MIDI.cpp
index 278e810..d4f5928 100644
--- a/MIDI.cpp
+++ b/MIDI.cpp
@@ -1,6 +1,14 @@
 #include "MIDI.h"
 
+#include <unordered_set>
+#include <string>
+
+namespace {
+  std::unordered_set<std::string> supported_devices{"AudioBox 22 VSL", "CH345", "M2"};
+}
+
 MIDI::MIDI():
+  m_client{},
   seq_handle{},
   in_port{},
   npfd{},
@@ -17,7 +25,9 @@ MIDI::MIDI():
     throw std::runtime_error("MIDI client name couldn't be set");
   }
 
-  if (0 > ((in_port = snd_seq_create_simple_port(seq_handle, "24:0",
+  detect_port();
+
+  if (0 > ((in_port = snd_seq_create_simple_port(seq_handle, fmt::format("{}:0", m_client).c_str(),
                     SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE | SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ,
                     SND_SEQ_PORT_TYPE_APPLICATION))))
   {
@@ -29,7 +39,7 @@ MIDI::MIDI():
   if (1) {
     snd_seq_addr_t sender, dest;
     snd_seq_port_subscribe_t *subs;
-    sender.client = 24;
+    sender.client = m_client;
     sender.port = 0;
     dest.client = snd_seq_client_id(seq_handle);
     dest.port = in_port;
@@ -45,7 +55,7 @@ MIDI::MIDI():
       throw std::runtime_error("MIDI port couldn't be connected");
     }
   } else {
-    if (0 > snd_seq_connect_from(seq_handle, in_port, 24, 0))
+    if (0 > snd_seq_connect_from(seq_handle, in_port, m_client, 0))
     {
       throw std::runtime_error("MIDI port couldn't be connected");
     }
@@ -75,6 +85,50 @@ MIDI::MIDI():
   }
 }
 
+void MIDI::detect_port(void)
+{
+  bool found{};
+
+  snd_seq_client_info_t *cinfo;
+  snd_seq_port_info_t *pinfo;
+
+  snd_seq_client_info_alloca(&cinfo);
+  snd_seq_port_info_alloca(&pinfo);
+
+  snd_seq_client_info_set_client(cinfo, -1);
+  while (snd_seq_query_next_client(seq_handle, cinfo) >= 0) {
+    int client = snd_seq_client_info_get_client(cinfo);
+
+    snd_seq_port_info_set_client(pinfo, client);
+    snd_seq_port_info_set_port(pinfo, -1);
+    while (snd_seq_query_next_port(seq_handle, pinfo) >= 0) {
+      /* port must understand MIDI messages */
+      if (!(snd_seq_port_info_get_type(pinfo)
+            & SND_SEQ_PORT_TYPE_MIDI_GENERIC))
+              continue;
+      /* we need both WRITE and SUBS_WRITE */
+      if ((snd_seq_port_info_get_capability(pinfo)
+           & (SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE))
+          != (SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE))
+              continue;
+      if (supported_devices.contains(std::string{snd_seq_client_info_get_name(cinfo)})) {
+        m_client = snd_seq_port_info_get_client(pinfo);
+        found = true;
+      }
+      //std::cout << fmt::format("DEBUG: {}", get_midi_port()) << std::endl;
+      //printf("%3d:%-3d  %-32.32s %s\n",
+      //       snd_seq_port_info_get_client(pinfo),
+      //       snd_seq_port_info_get_port(pinfo),
+      //       snd_seq_client_info_get_name(cinfo),
+      //       snd_seq_port_info_get_name(pinfo));
+    }
+  }
+
+  if (!found) {
+    throw std::runtime_error("No MIDI device found");
+  }
+}
+
 MIDI::~MIDI()
 {
   snd_midi_event_free(midi_event_parser);
diff --git a/MIDI.h b/MIDI.h
index ee01f5b..46d7482 100644
--- a/MIDI.h
+++ b/MIDI.h
@@ -34,6 +34,9 @@ public:
   void wait_for_event();
 
 private:
+  void detect_port(void);
+
+  int m_client;
   snd_seq_t *seq_handle;
   int in_port;
   int npfd;
diff --git a/StatusLED.cpp b/StatusLED.cpp
index c3544a5..3013ddb 100644
--- a/StatusLED.cpp
+++ b/StatusLED.cpp
@@ -1,10 +1,32 @@
 #include "StatusLED.h"
 
-StatusLED::StatusLED()
+namespace fs = std::filesystem;
+
+StatusLED::StatusLED(): m_mode{Mode::OK}, m_bpm{60}
 {
 }
 
 void StatusLED::addLED(const LED& led)
 {
-  m_leds.push_back(led);
+  if (fs::exists(led.green) && fs::exists(led.red)) {
+    m_leds.push_back(led);
+  }
+}
+
+void StatusLED::setMode(Mode mode)
+{
+  m_mode = mode;
+}
+
+void StatusLED::setBPM(int bpm)
+{
+  m_bpm = bpm;
+}
+
+void StatusLED::initLED(const LED& led)
+{
+}
+
+void StatusLED::updateLED(const LED& led)
+{
 }
diff --git a/StatusLED.h b/StatusLED.h
index 39b19f5..b1c0f23 100644
--- a/StatusLED.h
+++ b/StatusLED.h
@@ -5,6 +5,7 @@
 
 struct LED
 {
+  // the root to the whole LED interface, e.g. "/sys/class/leds/ACT"
   std::filesystem::path green;
   std::filesystem::path red;
 };
@@ -14,15 +15,23 @@ class StatusLED
 public:
   enum class Mode
   {
-    OK, // green
-    Error // red
+    OK,     // green
+    OKBeat, // green with heartbeat
+    Error,  // red
   };
 
   StatusLED();
 
   void addLED(const LED& led);
 
+  void setMode(Mode mode);
+  void setBPM(int bpm);
+
 private:
+  void initLED(const LED& led);
+  void updateLED(const LED& led);
+
   std::vector<LED> m_leds; // on best effort base, those will all show the same status
   Mode m_mode;
+  int m_bpm;
 };