/*
 * test_audio_routing.c
 *
 * External test program for the looper application.
 * Connects to JACK, sends a test tone to the application's audio_in ports,
 * captures the output from audio_out ports, and verifies that audio is flowing.
 *
 * Compile with:
 *   gcc -o test_audio_routing test_audio_routing.c -ljack -lm
 *
 * Run after the looper application is running and JACK is active.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <jack/jack.h>
#include <unistd.h>

#define TEST_DURATION_SECONDS 2
#define SAMPLE_RATE 48000
#define NUM_CHANNELS 2   // test first two channels

static jack_client_t *client = NULL;
static jack_port_t *test_out_ports[NUM_CHANNELS];
static jack_port_t *test_in_ports[NUM_CHANNELS];
static float *captured_output[NUM_CHANNELS];
static jack_nframes_t captured_frames = 0;
static volatile int running = 1;

/* Generate a sine wave sample */
static float sine_sample(jack_nframes_t frame, float freq, float sample_rate) {
    return sinf(2.0f * M_PI * freq * frame / sample_rate);
}

/* Process callback: generate test tone on output ports, capture input ports */
static int process(jack_nframes_t nframes, void *arg) {
    (void)arg;

    /* Generate test tone on each output port */
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        jack_default_audio_sample_t *out =
            (jack_default_audio_sample_t *)jack_port_get_buffer(test_out_ports[ch], nframes);
        for (jack_nframes_t i = 0; i < nframes; i++) {
            /* 440 Hz sine wave, amplitude 0.5 */
            out[i] = 0.5f * sine_sample(captured_frames + i, 440.0f, SAMPLE_RATE);
        }
    }

    /* Capture input ports */
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        jack_default_audio_sample_t *in =
            (jack_default_audio_sample_t *)jack_port_get_buffer(test_in_ports[ch], nframes);
        /* Append to captured buffer */
        if (captured_output[ch]) {
            memcpy(captured_output[ch] + captured_frames, in, nframes * sizeof(float));
        }
    }
    captured_frames += nframes;

    return 0;
}

/* Shutdown callback */
static void shutdown(void *arg) {
    (void)arg;
    running = 0;
}

int main(void) {
    jack_status_t status;
    const char *client_name = "test_audio_routing";

    client = jack_client_open(client_name, JackNullOption, &status, NULL);
    if (!client) {
        fprintf(stderr, "Failed to open JACK client, status = 0x%2.0x\n", status);
        return 1;
    }

    /* Register ports */
    char port_name[64];
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        snprintf(port_name, sizeof(port_name), "test_out_%d", ch);
        test_out_ports[ch] = jack_port_register(client, port_name,
                                                JACK_DEFAULT_AUDIO_TYPE,
                                                JackPortIsOutput, 0);
        if (!test_out_ports[ch]) {
            fprintf(stderr, "Failed to register output port %d\n", ch);
            jack_client_close(client);
            return 1;
        }

        snprintf(port_name, sizeof(port_name), "test_in_%d", ch);
        test_in_ports[ch] = jack_port_register(client, port_name,
                                               JACK_DEFAULT_AUDIO_TYPE,
                                               JackPortIsInput, 0);
        if (!test_in_ports[ch]) {
            fprintf(stderr, "Failed to register input port %d\n", ch);
            jack_client_close(client);
            return 1;
        }
    }

    /* Set process callback */
    jack_set_process_callback(client, process, NULL);
    jack_on_shutdown(client, shutdown, NULL);

    /* Allocate capture buffers */
    jack_nframes_t sample_rate = jack_get_sample_rate(client);
    jack_nframes_t total_frames = sample_rate * TEST_DURATION_SECONDS;
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        captured_output[ch] = (float *)calloc(total_frames, sizeof(float));
        if (!captured_output[ch]) {
            fprintf(stderr, "Memory allocation failed\n");
            jack_client_close(client);
            return 1;
        }
    }

    /* Activate client */
    if (jack_activate(client) != 0) {
        fprintf(stderr, "Failed to activate JACK client\n");
        jack_client_close(client);
        return 1;
    }

    /* Connect to the looper application's ports */
    const char *app_client_name = "looper";  /* adjust if your app uses a different name */
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        char src_port[128], dst_port[128];
        snprintf(src_port, sizeof(src_port), "%s:test_out_%d", client_name, ch);
        snprintf(dst_port, sizeof(dst_port), "%s:audio_in_%d", app_client_name, ch);
        if (jack_connect(client, src_port, dst_port) != 0) {
            fprintf(stderr, "Warning: could not connect %s -> %s\n", src_port, dst_port);
        }

        snprintf(src_port, sizeof(src_port), "%s:audio_out_%d", app_client_name, ch);
        snprintf(dst_port, sizeof(dst_port), "%s:test_in_%d", client_name, ch);
        if (jack_connect(client, src_port, dst_port) != 0) {
            fprintf(stderr, "Warning: could not connect %s -> %s\n", src_port, dst_port);
        }
    }

    /* Run for the test duration */
    printf("Running test for %d seconds...\n", TEST_DURATION_SECONDS);
    sleep(TEST_DURATION_SECONDS);

    /* Deactivate and close */
    jack_deactivate(client);
    jack_client_close(client);

    /* Analyze captured output */
    int pass = 1;
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        float max_val = 0.0f;
        for (jack_nframes_t i = 0; i < total_frames; i++) {
            float abs_val = fabsf(captured_output[ch][i]);
            if (abs_val > max_val) max_val = abs_val;
        }
        printf("Channel %d: max output amplitude = %f\n", ch, max_val);
        if (max_val < 0.001f) {
            printf("FAIL: Channel %d output is near zero (no audio flowing)\n", ch);
            pass = 0;
        }
    }

    /* Cleanup */
    for (int ch = 0; ch < NUM_CHANNELS; ch++) {
        free(captured_output[ch]);
    }

    if (pass) {
        printf("PASS: Audio routing is working correctly.\n");
        return 0;
    } else {
        printf("FAIL: Audio routing test failed.\n");
        return 1;
    }
}