#include "samplering.h"

static const char * const hexstr = "0123456789ABCDEF";

uint32_t SampleRing::Up (const char * data, const uint32_t len) {
  for (unsigned n=0; n<len; n++) {
    const char c = data [n];
    switch (c) {
      case '$':
        rcvd_counter = 0;
        rcvd_status  = RCVD_DATA;
        break;
      case '\r':
      case '\n':
        CmdReceived ();
        rcvd_counter = 0;
        rcvd_status  = RCVD_IDLE;
        break;
      default:
        if (rcvd_status == RCVD_DATA) {
          rcvd_buffer [rcvd_counter] = c;
          rcvd_counter += 1u;
        }
        break;
    }
  }
  return len;
}
void SampleRing::CmdReceived() {
  if (rcvd_counter == 0u) return;
  unsigned result = 0u;
  for (unsigned n=0; n<rcvd_counter; n++) {
    const char c = rcvd_buffer [n];
    result *= 16;
    if ((c >= '0') and (c <= '9')) {
      result += (unsigned) (c - '0');
    } else if ((c >= 'A') and (c <= 'F')) {
      result += (unsigned) (c - 'A' + 10);
    } else if ((c >= 'a') and (c <= 'f')) {
      result += (unsigned) (c - 'a' + 10);
    } else {
      // chyba : nech byt
    }
  }
  CommandPass (result);
}
void SampleRing::CommandPass(const unsigned int cmd) {
  RcvdHeader header;
  header.common = cmd & 0xFFFF;
  const DESTINATION dest = static_cast<DESTINATION> (header.bits.destinat);
  switch (dest) {
    case DEST_CHA:
    case DEST_CHB:
      break;
    case DEST_BASE:
      ReloadTimer (header.bits.cmd_value);
      break;
    case DEST_TRIG: {
      const TRIGGER_CMD command = static_cast<TRIGGER_CMD> (header.bits.cmd_type);
      switch (command) {
        case TRIGGER_CMD_OFSET: m_settings.offset = header.bits.cmd_value; break;
        case TRIGGER_CMD_VALUE: m_settings.value  = header.bits.cmd_value; break;
        case TRIGGER_CMD_MODE: {
          TriggerModeUnion new_mode_union;
          new_mode_union.common = header.bits.cmd_value;
          const TRIGER_MODE  new_mode    = static_cast<TRIGER_MODE> (new_mode_union.bits.mode);
          if (m_settings.mode    != new_mode)    m_settings.mode    = new_mode;
          const ADC_CHANNELS new_channel = static_cast<ADC_CHANNELS>(new_mode_union.bits.channel);
          if (m_settings.channel != new_channel) m_settings.channel = new_channel;
          const bool         new_rising  = new_mode_union.bits.rissing ? true : false;
          if (m_settings.rising  != new_rising)  m_settings.rising  = new_rising;
        } break;
      }
    } break;
  }
}

void SampleRing::write(DATA_BLOCK const * data) {
  if (m_finished) return;
  unsigned t_head   = m_head;   // dočasné proměnné kvůli zrychlení
  unsigned t_lenght = m_lenght; // následujícího cyklu
  if (m_mode == TIME_BASE_TRIGERED) {
    for (unsigned n=0u; n<DATA_HALF_LEN; n++) {
      const DATA_BLOCK & sample = data [n];
      ring_buffer [t_head].common_data = sample.common_data;
      t_head   += 1u;
      t_head   &= RING_MSK;
      t_lenght += 1u;
      const bool compare = m_settings.rising != (sample.channels[m_settings.channel] > m_settings.value);
      if (compare and m_old_triger and !m_trigered) {   // TRIGERED
        if (t_lenght >= m_settings.offset) {
          t_lenght    = m_settings.offset;
          m_trigered  = true;
        }
      }
      m_old_triger  = !compare;
      if (t_lenght >= RING_LEN) {
        // zastavit odesílání dat, pokud není AUTO a není splněna podmínka trigeru
        if ((m_settings.mode != TRIGER_MODE_AUTO) and !m_trigered) continue;
        t_lenght    = RING_LEN;
        m_tail      = t_head;
        m_finished  = true;
        break;
      }
    }
  } else {
    const DATA_BLOCK & sample = data [0];
    ring_buffer [t_head].common_data = sample.common_data;
    t_head   += 1u;
    t_head   &= RING_MSK;
    t_lenght += 1u;
    m_finished = true;
  }
  m_head   = t_head;          // vrať zpátky hodnoty
  m_lenght = t_lenght;
}
bool SampleRing::read(DATA_BLOCK & sample) {
  if (!m_finished) return false;
  if (!m_lenght) {
    m_head = m_tail = m_lenght = 0u;
    m_trigered = false;
    m_finished = false;
    return false;
  }
  sample    = ring_buffer [m_tail];
  m_tail   += 1u;
  m_tail   &= RING_MSK;
  m_lenght -= 1u;
  return true;
}
uint32_t SampleRing::BlockSend (const char * buf, const uint32_t len) {
  uint32_t n, ofs = 0, req = len;
  for (;;) {
    // spodní vrstva může vrátit i nulu, pokud je FIFO plné
    n = BaseLayer::Down (buf + ofs, req);
    ofs += n;   // Posuneme ukazatel
    req -= n;   // Zmenšíme další požadavek
    if (!req) break;
  }
  return ofs;
}

void SampleRing::pass() {
  if (!m_finished) {
    return;
  }
  SendPrefix();
  DATA_BLOCK  data;
  while (read(data)) {
    SendData (data);
  }
  BlockSend("\r\n", 2);
}
static int to_str (char * buffer, const uint16_t data, const int len = 3) {
  unsigned val = data;
  for (int i=len-1; i>=0; --i) {
    buffer [i] = hexstr [val & 0xF];
    val >>= 4;
  }
  return len;
}
uint32_t SampleRing::SendPrefix() {
  const int buflen = 8;
  char buffer [buflen];
  int n = 0;
  buffer [n++] = '$';
  SendHeader sh;
  sh.bits.trig_flg = m_trigered ? 1 : 0;
  sh.bits.pack_len = m_lenght;
  n += to_str (buffer + n, sh.common, 4);
  buffer [n++] = '#';
  return BlockSend (buffer, n);
}
uint32_t SampleRing::SendData (const DATA_BLOCK & data) {
  const int buflen = 8;
  char buffer [buflen];
  int n = 0;
  n += to_str (buffer + n, data.channels[0]);
  n += to_str (buffer + n, data.channels[1]);
  return BlockSend (buffer, n);
}