feat: add TUI client with FIFO communication and status display

engine/makefile

@@ -13,13 +13,17 @@ src/%.o: src/%.c
 
 integration: looper tests/integration.c
 	$(CC) $(CFLAGS) -o integration_test tests/integration.c -ljack -lm
+
+test_status_fifo: looper tests/test_status_fifo.c
+	$(CC) $(CFLAGS) -o test_status_fifo tests/test_status_fifo.c -ljack -lm
+
+test: integration test_status_fifo
+	./test_status_fifo
 	./integration_test
 
-test: integration
-
-.PHONY: clean integration test
+.PHONY: clean integration test_status_fifo test
 clean:
-	rm -f looper integration_test src/*.o
+	rm -f looper integration_test test_status_fifo src/*.o
 
 check:
 	cppcheck --enable=all --error-exitcode=1 --suppress=missingIncludeSystem --suppress=normalCheckLevelMaxBranches src/*.c --library=posix

engine/tests/makefile

@@ -0,0 +1,16 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -Wpedantic -std=c11 -I../src -I$(JACK_CFLAGS)
+LDFLAGS = -ljack -lpthread -lm
+
+all: test_status_fifo
+
+test_status_fifo: test_status_fifo.c ../src/looper.c ../src/channel.c ../src/midi.c ../src/queue.c ../src/pipe.c
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+test: test_status_fifo
+	./test_status_fifo
+
+.PHONY: all test clean
+
+clean:
+	rm -f test_status_fifo

engine/tests/test_status_fifo.c

@@ -6,33 +6,10 @@
 #include <fcntl.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/select.h>
 
 #define STATUS_FIFO "/tmp/looper_status"
-#define CMD_FIFO "/tmp/looper_cmd"
-
-static int write_cmd(const char *cmd) {
-    int fd = open(CMD_FIFO, O_WRONLY | O_NONBLOCK);
-    if (fd < 0) return -1;
-    size_t len = strlen(cmd);
-    int n = write(fd, cmd, len);
-    if (n == (int)len && cmd[len-1] != '\n')
-        write(fd, "\n", 1);
-    close(fd);
-    return (n >= 0) ? 0 : -1;
-}
-
-static int read_status_line(char *buf, size_t bufsize) {
-    int fd = open(STATUS_FIFO, O_RDONLY | O_NONBLOCK);
-    if (fd < 0) return -1;
-    FILE *f = fdopen(fd, "r");
-    if (!f) { close(fd); return -1; }
-    if (fgets(buf, bufsize, f) == NULL) {
-        fclose(f);
-        return -1;
-    }
-    fclose(f);
-    return 0;
-}
+#define CMD_FIFO    "/tmp/looper_cmd"
 
 static pid_t start_looper(void) {
     pid_t pid = fork();
@@ -47,33 +24,83 @@ static pid_t start_looper(void) {
     return pid;
 }
 
+/* Drain any stale data from the status FIFO */
+static void drain_fifo(void) {
+    int fd = open(STATUS_FIFO, O_RDONLY | O_NONBLOCK);
+    if (fd < 0) return;
+    char buf[4096];
+    while (read(fd, buf, sizeof(buf)) > 0);
+    close(fd);
+}
+
+/* Read the first status line with a timeout (milliseconds).
+ * Returns 0 on success, -1 on timeout/error. */
+static int read_status_line_timeout(char *buf, size_t bufsize, int timeout_ms) {
+    int fd = open(STATUS_FIFO, O_RDONLY | O_NONBLOCK);
+    if (fd < 0) return -1;
+
+    fd_set set;
+    struct timeval tv;
+    FD_ZERO(&set);
+    FD_SET(fd, &set);
+    tv.tv_sec  = timeout_ms / 1000;
+    tv.tv_usec = (timeout_ms % 1000) * 1000;
+
+    int ret = select(fd + 1, &set, NULL, NULL, &tv);
+    if (ret <= 0) {
+        close(fd);
+        return -1;
+    }
+
+    int n = read(fd, buf, bufsize - 1);
+    close(fd);
+    if (n <= 0) return -1;
+    buf[n] = '\0';
+
+    /* keep only the first line */
+    char *nl = strchr(buf, '\n');
+    if (nl) *nl = '\0';
+    return 0;
+}
+
 static int test_status_after_record(void) {
-    printf("Test: status FIFO reports recording state\n");
+    printf("Test: status FIFO reports RECORD state after record command\n");
     pid_t pid = start_looper();
     if (pid < 0) return 1;
-    usleep(200000);
-    if (write_cmd("record 0") != 0) {
-        fprintf(stderr, "  FAIL: cannot write record command\n");
-        kill(pid, SIGTERM); waitpid(pid, NULL, 0);
-        return 1;
-    }
-    usleep(500000);
-    char line[256];
-    if (read_status_line(line, sizeof(line)) != 0) {
-        fprintf(stderr, "  FAIL: cannot read status line\n");
+
+    /* Give looper time to start main loop and begin writing status */
+    usleep(1500000);
+    drain_fifo();
+
+    /* Send record 0 command via FIFO */
+    int fd_cmd = open(CMD_FIFO, O_WRONLY);
+    if (fd_cmd < 0) {
+        fprintf(stderr, "  FAIL: cannot open command FIFO\n");
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }
+    write(fd_cmd, "record 0\n", 9);
+    close(fd_cmd);
+
+    /* Keep reading status lines until we see RECORD or timeout (5 seconds) */
+    int found = 0;
     int ch, sc;
     char state[32];
-    if (sscanf(line, "CH=%d SC=%d STATE=%31s", &ch, &sc, state) != 3) {
-        fprintf(stderr, "  FAIL: malformed status line: %s\n", line);
-        kill(pid, SIGTERM); waitpid(pid, NULL, 0);
-        return 1;
+    char line[256];
+    for (int tries = 0; tries < 50; tries++) {
+        if (read_status_line_timeout(line, sizeof(line), 100) != 0) {
+            usleep(100000);
+            continue;
+        }
+        if (sscanf(line, "CH=%d SC=%d STATE=%31s", &ch, &sc, state) != 3)
+            continue;
+        if (ch == 0 && sc == 0 && strcmp(state, "RECORD") == 0) {
+            found = 1;
+            break;
+        }
     }
-    if (ch != 0 || sc != 0 || strcmp(state, "RECORD") != 0) {
-        fprintf(stderr, "  FAIL: expected CH=0 SC=0 STATE=RECORD, got: CH=%d SC=%d STATE=%s\n",
-                ch, sc, state);
+    if (!found) {
+        fprintf(stderr, "  FAIL: did not see STATE=RECORD for CH=0 SC=0 within 5 seconds\n");
         kill(pid, SIGTERM); waitpid(pid, NULL, 0);
         return 1;
     }