// Part of dump1090, a Mode S message decoder for RTLSDR devices.
//
// sdr_hackrf.h: HackRF One support (header)
//
// Copyright (c) 2019 FlightAware LLC
//
// This file is free software: you may copy, redistribute and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation, either version 2 of the License, or (at your
// option) any later version.
//
// This file is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "dump1090.h"
#include "sdr_hackrf.h"

#include <libhackrf/hackrf.h>
#include <inttypes.h>

static struct {
    hackrf_device *device;
    uint64_t freq;
    int enable_amp;
    int lna_gain;
    int vga_gain;
    int rate;
    int ppm;

    iq_convert_fn converter;
    struct converter_state *converter_state;
} HackRF;

void hackRFInitConfig()
{
    HackRF.device = NULL;
    HackRF.freq = 1090000000;
    HackRF.enable_amp = 0;
    HackRF.lna_gain = 32;
    HackRF.vga_gain = 50;
    HackRF.rate = 2400000;
    HackRF.ppm = 0;
    HackRF.converter = NULL;
    HackRF.converter_state = NULL;
}

bool hackRFHandleOption(int argc, char **argv, int *jptr)
{
    int j = *jptr;
    bool more = (j+1 < argc);
    if (!strcmp(argv[j], "--lna-gain") && more) {
        HackRF.lna_gain = atoi(argv[++j]);

        if (HackRF.lna_gain % 8 != 0) {
            fprintf(stderr, "Error: --lna-gain must be multiple of 8\n");
            return false;
        }

        if (HackRF.lna_gain > 40 || HackRF.lna_gain < 0) {
            fprintf(stderr, "Error: --lna-gain range is 0 - 42\n");
            return false;
        }
    } else if (!strcmp(argv[j], "--vga-gain") && more) {
        HackRF.vga_gain = atoi(argv[++j]);

        if (HackRF.vga_gain % 2 != 0) {
            fprintf(stderr, "Error: --vga-gain must be multiple of 2\n");
            return false;
        }

        if (HackRF.vga_gain > 62 || HackRF.vga_gain < 0) {
            fprintf(stderr, "Error: --vga-gain range is 0 - 62\n");
            return false;
        }

    } else if (!strcmp(argv[j], "--ppm") && more) {
        HackRF.ppm = atoi(argv[++j]);
    } else if (!strcmp(argv[j], "--samplerate") && more) {
        HackRF.rate = atoi(argv[++j]);
    } else if (!strcmp(argv[j], "--enable-amp")) {
        HackRF.enable_amp = 1;
    } else {
        return false;
    }

    *jptr = j;

    return true;
}

void hackRFShowHelp()
{
    printf("      HackRF-specific options (use with --device-type hackrf)\n");
    printf("\n");
    printf("--enable-amp             enable amplifier)\n");
    printf("--lna-gain               set LNA gain (Range 0-40 in 8dB steps))\n");
    printf("--vga-gain               set VGA gain (Range 0-62 in 2dB steps))\n");
    printf("--samplerate             set sample rate)\n");
    printf("--ppm                    ppm correction)\n");
    printf("\n");
}

static void show_config()
{
    fprintf(stderr, "freq : %ld\n", HackRF.freq);
    fprintf(stderr, "lna_gain : %d\n", HackRF.lna_gain);
    fprintf(stderr, "vga_gain : %d\n", HackRF.vga_gain);
    fprintf(stderr, "samplerate : %d\n", HackRF.rate);
    fprintf(stderr, "ppm : %d\n", HackRF.ppm);
}

bool hackRFOpen()
{
    if (HackRF.device) {
        return true;
    }

    // Calculate sample rate and frequency deviation if ppm is specified
    if (HackRF.ppm != 0) {
        HackRF.rate = (uint32_t)((double)HackRF.rate * (1000000 - HackRF.ppm)/1000000+0.5);
        HackRF.freq = HackRF.freq * (1000000 - HackRF.ppm)/1000000;
    }

    int status;

    status = hackrf_init();
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_init failed with code %d\n", status);
        return false;
    }

    status = hackrf_open(&HackRF.device);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_open failed with code %d\n", status);
        hackrf_exit();
        return false;
    }

    status = hackrf_set_freq(HackRF.device, HackRF.freq);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_set_freq failed with code %d\n", status);
        hackrf_close(HackRF.device);
        hackrf_exit();
        return false;
    }

    status = hackrf_set_sample_rate(HackRF.device, HackRF.rate);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_set_sample_rate failed with code %d\n", status);
        hackrf_close(HackRF.device);
        hackrf_exit();
        return false;
    }

    status = hackrf_set_amp_enable(HackRF.device, HackRF.enable_amp);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_set_amp_enable failed with code %d\n", status);
        hackrf_close(HackRF.device);
        hackrf_exit();
        return false;
    }

    status = hackrf_set_lna_gain(HackRF.device, HackRF.lna_gain);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_set_lna_gain failed with code %d\n", status);
        hackrf_close(HackRF.device);
        hackrf_exit();
        return false;
    }

    status = hackrf_set_vga_gain(HackRF.device, HackRF.vga_gain);
    if (status != 0) {
        fprintf(stderr, "HackRF: hackrf_set_vga_gain failed with code %d\n", status);
        hackrf_close(HackRF.device);
        hackrf_exit();
        return false;
    }

    show_config();

    HackRF.converter = init_converter(INPUT_UC8,
                                      Modes.sample_rate,
                                      Modes.dc_filter,
                                      &HackRF.converter_state);
    if (!HackRF.converter) {
        fprintf(stderr, "HackRF: can't initialize sample converter\n");
        return false;
    }

    return true;
}

static int handle_hackrf_samples(hackrf_transfer *transfer)
{
    struct mag_buf *outbuf;
    struct mag_buf *lastbuf;
    unsigned char *buf;
    int32_t len;
    uint32_t slen;
    unsigned next_free_buffer;
    unsigned free_bufs;
    unsigned block_duration;

    static int dropping = 0;
    static uint64_t sampleCounter = 0;

    sdrMonitor();

    // Lock the data buffer variables before accessing them
    pthread_mutex_lock(&Modes.data_mutex);
    if (Modes.exit) {
        pthread_mutex_unlock(&Modes.data_mutex);
        return -1;
    }

    next_free_buffer = (Modes.first_free_buffer + 1) % MODES_MAG_BUFFERS;
    outbuf = &Modes.mag_buffers[Modes.first_free_buffer];
    lastbuf = &Modes.mag_buffers[(Modes.first_free_buffer + MODES_MAG_BUFFERS - 1) % MODES_MAG_BUFFERS];
    free_bufs = (Modes.first_filled_buffer - next_free_buffer + MODES_MAG_BUFFERS) % MODES_MAG_BUFFERS;

    buf = transfer->buffer;
    len = transfer->buffer_length;

    // Values returned by HackRF need conversion from signed to unsigned
    for (int32_t i = 0; i < len; i++) {
        buf[i] ^= (uint8_t)0x80;
    }

    slen = len/2; // Drops any trailing odd sample, that's OK

    if (free_bufs == 0 || (dropping && free_bufs < MODES_MAG_BUFFERS/2)) {
        // FIFO is full. Drop this block.
        dropping = 1;
        outbuf->dropped += slen;
        sampleCounter += slen;
        pthread_mutex_unlock(&Modes.data_mutex);
        return -1;
    }

    dropping = 0;
    pthread_mutex_unlock(&Modes.data_mutex);

    // Compute the sample timestamp and system timestamp for the start of the block
    outbuf->sampleTimestamp = sampleCounter * 12e6 / Modes.sample_rate;
    sampleCounter += slen;

    // Get the approx system time for the start of this block
    block_duration = 1e3 * slen / Modes.sample_rate;
    outbuf->sysTimestamp = mstime() - block_duration;

    // Copy trailing data from last block (or reset if not valid)
    if (outbuf->dropped == 0) {
        memcpy(outbuf->data, lastbuf->data + lastbuf->length, Modes.trailing_samples * sizeof(uint16_t));
    } else {
        memset(outbuf->data, 0, Modes.trailing_samples * sizeof(uint16_t));
    }

    // Convert the new data
    outbuf->length = slen;
    HackRF.converter(buf, &outbuf->data[Modes.trailing_samples], slen, HackRF.converter_state, &outbuf->mean_level, &outbuf->mean_power);

    // Push the new data to the demodulation thread
    pthread_mutex_lock(&Modes.data_mutex);

    Modes.mag_buffers[next_free_buffer].dropped = 0;
    Modes.mag_buffers[next_free_buffer].length = 0;  // just in case
    Modes.first_free_buffer = next_free_buffer;

    pthread_cond_signal(&Modes.data_cond);
    pthread_mutex_unlock(&Modes.data_mutex);

    return 0;
}


void hackRFRun()
{
    if (!HackRF.device) {
        fprintf(stderr, "hackRFRun: HackRF.device = NULL\n");
        return;
    }

    int status = hackrf_start_rx(HackRF.device, &handle_hackrf_samples, NULL);

    if (status != 0) { 
        fprintf(stderr, "hackrf_start_rx failed"); 
        hackrf_close(HackRF.device); 
        hackrf_exit(); 
        exit (1); 
    }

    // hackrf_start_rx does not block so we need to wait until the streaming is finished
    // before returning from the hackRFRun function
    while (hackrf_is_streaming(HackRF.device) == HACKRF_TRUE) {
        struct timespec slp = { 0, 100 * 1000 * 1000};
        nanosleep(&slp, NULL);
    }

    fprintf(stderr, "HackRF stopped streaming %d\n", hackrf_is_streaming(HackRF.device));
}

void hackRFClose()
{
    if (HackRF.device) {
        hackrf_close(HackRF.device);
        hackrf_exit();
        HackRF.device = NULL;
    }
}