/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 <https://www.gnu.org/licenses/>.
 *
 */

/**
 * queue.cpp - The G-code command queue
 */

#include "queue.h"
GCodeQueue queue;

#include "gcode.h"

#include "../lcd/marlinui.h"
#include "../sd/cardreader.h"
#include "../module/planner.h"
#include "../module/temperature.h"
#include "../MarlinCore.h"

#if ENABLED(PRINTER_EVENT_LEDS)
  #include "../feature/leds/printer_event_leds.h"
#endif

#if HAS_ETHERNET
  #include "../feature/ethernet.h"
#endif

#if ENABLED(BINARY_FILE_TRANSFER)
  #include "../feature/binary_stream.h"
#endif

#if ENABLED(POWER_LOSS_RECOVERY)
  #include "../feature/powerloss.h"
#endif

/**
 * GCode line number handling. Hosts may opt to include line numbers when
 * sending commands to Marlin, and lines will be checked for sequentiality.
 * M110 N<int> sets the current line number.
 */
long GCodeQueue::last_N[NUM_SERIAL];

/**
 * GCode Command Queue
 * A simple ring buffer of BUFSIZE command strings.
 *
 * Commands are copied into this buffer by the command injectors
 * (immediate, serial, sd card) and they are processed sequentially by
 * the main loop. The gcode.process_next_command method parses the next
 * command and hands off execution to individual handler functions.
 */
uint8_t GCodeQueue::length = 0,  // Count of commands in the queue
        GCodeQueue::index_r = 0, // Ring buffer read position
        GCodeQueue::index_w = 0; // Ring buffer write position

char GCodeQueue::command_buffer[BUFSIZE][MAX_CMD_SIZE];

/*
 * The port that the command was received on
 */
#if HAS_MULTI_SERIAL
  int16_t GCodeQueue::port[BUFSIZE];
#endif

/**
 * Serial command injection
 */

// Number of characters read in the current line of serial input
static int serial_count[NUM_SERIAL] = { 0 };

bool send_ok[BUFSIZE];

/**
 * Next Injected PROGMEM Command pointer. (nullptr == empty)
 * Internal commands are enqueued ahead of serial / SD commands.
 */
PGM_P GCodeQueue::injected_commands_P; // = nullptr

/**
 * Injected SRAM Commands
 */
char GCodeQueue::injected_commands[64]; // = { 0 }

GCodeQueue::GCodeQueue() {
  // Send "ok" after commands by default
  LOOP_L_N(i, COUNT(send_ok)) send_ok[i] = true;
}

/**
 * Check whether there are any commands yet to be executed
 */
bool GCodeQueue::has_commands_queued() {
  return queue.length || injected_commands_P || injected_commands[0];
}

/**
 * Clear the Marlin command queue
 */
void GCodeQueue::clear() {
  index_r = index_w = length = 0;
}

/**
 * Once a new command is in the ring buffer, call this to commit it
 */
void GCodeQueue::_commit_command(bool say_ok
  #if HAS_MULTI_SERIAL
    , int16_t p/*=-1*/
  #endif
) {
  send_ok[index_w] = say_ok;
  TERN_(HAS_MULTI_SERIAL, port[index_w] = p);
  TERN_(POWER_LOSS_RECOVERY, recovery.commit_sdpos(index_w));
  if (++index_w >= BUFSIZE) index_w = 0;
  length++;
}

/**
 * Copy a command from RAM into the main command buffer.
 * Return true if the command was successfully added.
 * Return false for a full buffer, or if the 'command' is a comment.
 */
bool GCodeQueue::_enqueue(const char* cmd, bool say_ok/*=false*/
  #if HAS_MULTI_SERIAL
    , int16_t pn/*=-1*/
  #endif
) {
  if (*cmd == ';' || length >= BUFSIZE) return false;
  strcpy(command_buffer[index_w], cmd);
  _commit_command(say_ok
    #if HAS_MULTI_SERIAL
      , pn
    #endif
  );
  return true;
}

#define ISEOL(C) ((C) == '\n' || (C) == '\r')

/**
 * Enqueue with Serial Echo
 * Return true if the command was consumed
 */
bool GCodeQueue::enqueue_one(const char* cmd) {

  //SERIAL_ECHOPGM("enqueue_one(\"");
  //SERIAL_ECHO(cmd);
  //SERIAL_ECHOPGM("\") \n");

  if (*cmd == 0 || ISEOL(*cmd)) return true;

  if (_enqueue(cmd)) {
    SERIAL_ECHO_MSG(STR_ENQUEUEING, cmd, "\"");
    return true;
  }
  return false;
}

/**
 * Process the next "immediate" command from PROGMEM.
 * Return 'true' if any commands were processed.
 */
bool GCodeQueue::process_injected_command_P() {
  if (!injected_commands_P) return false;

  char c;
  size_t i = 0;
  while ((c = pgm_read_byte(&injected_commands_P[i])) && c != '\n') i++;

  // Extract current command and move pointer to next command
  char cmd[i + 1];
  memcpy_P(cmd, injected_commands_P, i);
  cmd[i] = '\0';
  injected_commands_P = c ? injected_commands_P + i + 1 : nullptr;

  // Execute command if non-blank
  if (i) {
    parser.parse(cmd);
    gcode.process_parsed_command();
  }
  return true;
}

/**
 * Process the next "immediate" command from SRAM.
 * Return 'true' if any commands were processed.
 */
bool GCodeQueue::process_injected_command() {
  if (injected_commands[0] == '\0') return false;

  char c;
  size_t i = 0;
  while ((c = injected_commands[i]) && c != '\n') i++;

  // Execute a non-blank command
  if (i) {
    injected_commands[i] = '\0';
    parser.parse(injected_commands);
    gcode.process_parsed_command();
  }

  // Copy the next command into place
  for (
    uint8_t d = 0, s = i + !!c;                     // dst, src
    (injected_commands[d] = injected_commands[s]);  // copy, exit if 0
    d++, s++                                        // next dst, src
  );

  return true;
}

/**
 * Enqueue and return only when commands are actually enqueued.
 * Never call this from a G-code handler!
 */
void GCodeQueue::enqueue_one_now(const char* cmd) { while (!enqueue_one(cmd)) idle(); }

/**
 * Attempt to enqueue a single G-code command
 * and return 'true' if successful.
 */
bool GCodeQueue::enqueue_one_P(PGM_P const pgcode) {
  size_t i = 0;
  PGM_P p = pgcode;
  char c;
  while ((c = pgm_read_byte(&p[i])) && c != '\n') i++;
  char cmd[i + 1];
  memcpy_P(cmd, p, i);
  cmd[i] = '\0';
  return _enqueue(cmd);
}

/**
 * Enqueue from program memory and return only when commands are actually enqueued
 * Never call this from a G-code handler!
 */
void GCodeQueue::enqueue_now_P(PGM_P const pgcode) {
  size_t i = 0;
  PGM_P p = pgcode;
  for (;;) {
    char c;
    while ((c = pgm_read_byte(&p[i])) && c != '\n') i++;
    char cmd[i + 1];
    memcpy_P(cmd, p, i);
    cmd[i] = '\0';
    enqueue_one_now(cmd);
    if (!c) break;
    p += i + 1;
  }
}

/**
 * Send an "ok" message to the host, indicating
 * that a command was successfully processed.
 *
 * If ADVANCED_OK is enabled also include:
 *   N<int>  Line number of the command, if any
 *   P<int>  Planner space remaining
 *   B<int>  Block queue space remaining
 */
void GCodeQueue::ok_to_send() {
  #if HAS_MULTI_SERIAL
    const int16_t pn = command_port();
    if (pn < 0) return;
    PORT_REDIRECT(pn);                    // Reply to the serial port that sent the command
  #endif
  if (!send_ok[index_r]) return;
  SERIAL_ECHOPGM(STR_OK);
  #if ENABLED(ADVANCED_OK)
    char* p = command_buffer[index_r];
    if (*p == 'N') {
      SERIAL_ECHO(' ');
      SERIAL_ECHO(*p++);
      while (NUMERIC_SIGNED(*p))
        SERIAL_ECHO(*p++);
    }
    SERIAL_ECHOPAIR_P(SP_P_STR, int(planner.moves_free()),
                      SP_B_STR, int(BUFSIZE - length));
  #endif
  SERIAL_EOL();
}

/**
 * Send a "Resend: nnn" message to the host to
 * indicate that a command needs to be re-sent.
 */
void GCodeQueue::flush_and_request_resend() {
  const int16_t pn = command_port();
  #if HAS_MULTI_SERIAL
    if (pn < 0) return;
    PORT_REDIRECT(pn);                    // Reply to the serial port that sent the command
  #endif
  SERIAL_FLUSH();
  SERIAL_ECHOPGM(STR_RESEND);
  SERIAL_ECHOLN(last_N[pn] + 1);
  ok_to_send();
}

inline bool serial_data_available() {
  byte data_available = 0;
  if (MYSERIAL0.available()) data_available++;
  #ifdef SERIAL_PORT_2
    const bool port2_open = TERN1(HAS_ETHERNET, ethernet.have_telnet_client);
    if (port2_open && MYSERIAL1.available()) data_available++;
  #endif
  return data_available > 0;
}

inline int read_serial(const uint8_t index) {
  switch (index) {
    case 0: return MYSERIAL0.read();
    case 1: {
      #if HAS_MULTI_SERIAL
        const bool port2_open = TERN1(HAS_ETHERNET, ethernet.have_telnet_client);
        if (port2_open) return MYSERIAL1.read();
      #endif
    }
    default: return -1;
  }
}

void GCodeQueue::gcode_line_error(PGM_P const err, const int8_t pn) {
  PORT_REDIRECT(pn);                      // Reply to the serial port that sent the command
  SERIAL_ERROR_START();
  serialprintPGM(err);
  SERIAL_ECHOLN(last_N[pn]);
  while (read_serial(pn) != -1);          // Clear out the RX buffer
  flush_and_request_resend();
  serial_count[pn] = 0;
}

FORCE_INLINE bool is_M29(const char * const cmd) {  // matches "M29" & "M29 ", but not "M290", etc
  const char * const m29 = strstr_P(cmd, PSTR("M29"));
  return m29 && !NUMERIC(m29[3]);
}

#define PS_NORMAL 0
#define PS_EOL    1
#define PS_QUOTED 2
#define PS_PAREN  3
#define PS_ESC    4

inline void process_stream_char(const char c, uint8_t &sis, char (&buff)[MAX_CMD_SIZE], int &ind) {

  if (sis == PS_EOL) return;    // EOL comment or overflow

  #if ENABLED(PAREN_COMMENTS)
    else if (sis == PS_PAREN) { // Inline comment
      if (c == ')') sis = PS_NORMAL;
      return;
    }
  #endif

  else if (sis >= PS_ESC)       // End escaped char
    sis -= PS_ESC;

  else if (c == '\\') {         // Start escaped char
    sis += PS_ESC;
    if (sis == PS_ESC) return;  // Keep if quoting
  }

  #if ENABLED(GCODE_QUOTED_STRINGS)

    else if (sis == PS_QUOTED) {
      if (c == '"') sis = PS_NORMAL; // End quoted string
    }
    else if (c == '"')          // Start quoted string
      sis = PS_QUOTED;

  #endif

  else if (c == ';') {          // Start end-of-line comment
    sis = PS_EOL;
    return;
  }

  #if ENABLED(PAREN_COMMENTS)
    else if (c == '(') {        // Start inline comment
      sis = PS_PAREN;
      return;
    }
  #endif

  // Backspace erases previous characters
  if (c == 0x08) {
    if (ind) buff[--ind] = '\0';
  }
  else {
    buff[ind++] = c;
    if (ind >= MAX_CMD_SIZE - 1)
      sis = PS_EOL;             // Skip the rest on overflow
  }
}

/**
 * Handle a line being completed. For an empty line
 * keep sensor readings going and watchdog alive.
 */
inline bool process_line_done(uint8_t &sis, char (&buff)[MAX_CMD_SIZE], int &ind) {
  sis = PS_NORMAL;                    // "Normal" Serial Input State
  buff[ind] = '\0';                   // Of course, I'm a Terminator.
  const bool is_empty = (ind == 0);   // An empty line?
  if (is_empty)
    thermalManager.manage_heater();   // Keep sensors satisfied
  else
    ind = 0;                          // Start a new line
  return is_empty;                    // Inform the caller
}

/**
 * Get all commands waiting on the serial port and queue them.
 * Exit when the buffer is full or when no more characters are
 * left on the serial port.
 */
void GCodeQueue::get_serial_commands() {
  static char serial_line_buffer[NUM_SERIAL][MAX_CMD_SIZE];

  static uint8_t serial_input_state[NUM_SERIAL] = { PS_NORMAL };

  #if ENABLED(BINARY_FILE_TRANSFER)
    if (card.flag.binary_mode) {
      /**
       * For binary stream file transfer, use serial_line_buffer as the working
       * receive buffer (which limits the packet size to MAX_CMD_SIZE).
       * The receive buffer also limits the packet size for reliable transmission.
       */
      binaryStream[card.transfer_port_index].receive(serial_line_buffer[card.transfer_port_index]);
      return;
    }
  #endif

  // If the command buffer is empty for too long,
  // send "wait" to indicate Marlin is still waiting.
  #if NO_TIMEOUTS > 0
    static millis_t last_command_time = 0;
    const millis_t ms = millis();
    if (length == 0 && !serial_data_available() && ELAPSED(ms, last_command_time + NO_TIMEOUTS)) {
      SERIAL_ECHOLNPGM(STR_WAIT);
      last_command_time = ms;
    }
  #endif

  /**
   * Loop while serial characters are incoming and the queue is not full
   */
  while (length < BUFSIZE && serial_data_available()) {
    LOOP_L_N(i, NUM_SERIAL) {

      const int c = read_serial(i);
      if (c < 0) continue;

      const char serial_char = c;

      if (ISEOL(serial_char)) {

        // Reset our state, continue if the line was empty
        if (process_line_done(serial_input_state[i], serial_line_buffer[i], serial_count[i]))
          continue;

        char* command = serial_line_buffer[i];

        while (*command == ' ') command++;                   // Skip leading spaces
        char *npos = (*command == 'N') ? command : nullptr;  // Require the N parameter to start the line

        if (npos) {

          const bool M110 = !!strstr_P(command, PSTR("M110"));

          if (M110) {
            char* n2pos = strchr(command + 4, 'N');
            if (n2pos) npos = n2pos;
          }

          const long gcode_N = strtol(npos + 1, nullptr, 10);

          if (gcode_N != last_N[i] + 1 && !M110)
            return gcode_line_error(PSTR(STR_ERR_LINE_NO), i);

          char *apos = strrchr(command, '*');
          if (apos) {
            uint8_t checksum = 0, count = uint8_t(apos - command);
            while (count) checksum ^= command[--count];
            if (strtol(apos + 1, nullptr, 10) != checksum)
              return gcode_line_error(PSTR(STR_ERR_CHECKSUM_MISMATCH), i);
          }
          else
            return gcode_line_error(PSTR(STR_ERR_NO_CHECKSUM), i);

          last_N[i] = gcode_N;
        }
        #if ENABLED(SDSUPPORT)
          // Pronterface "M29" and "M29 " has no line number
          else if (card.flag.saving && !is_M29(command))
            return gcode_line_error(PSTR(STR_ERR_NO_CHECKSUM), i);
        #endif

        //
        // Movement commands give an alert when the machine is stopped
        //

        if (IsStopped()) {
          char* gpos = strchr(command, 'G');
          if (gpos) {
            switch (strtol(gpos + 1, nullptr, 10)) {
              case 0: case 1:
              #if ENABLED(ARC_SUPPORT)
                case 2: case 3:
              #endif
              #if ENABLED(BEZIER_CURVE_SUPPORT)
                case 5:
              #endif
                PORT_REDIRECT(i);                      // Reply to the serial port that sent the command
                SERIAL_ECHOLNPGM(STR_ERR_STOPPED);
                LCD_MESSAGEPGM(MSG_STOPPED);
                break;
            }
          }
        }

        #if DISABLED(EMERGENCY_PARSER)
          // Process critical commands early
          if (strcmp_P(command, PSTR("M108")) == 0) {
            wait_for_heatup = false;
            TERN_(HAS_LCD_MENU, wait_for_user = false);
          }
          if (strcmp_P(command, PSTR("M112")) == 0) kill(M112_KILL_STR, nullptr, true);
          if (strcmp_P(command, PSTR("M410")) == 0) quickstop_stepper();
        #endif

        #if defined(NO_TIMEOUTS) && NO_TIMEOUTS > 0
          last_command_time = ms;
        #endif

        // Add the command to the queue
        _enqueue(serial_line_buffer[i], true
          #if HAS_MULTI_SERIAL
            , i
          #endif
        );
      }
      else
        process_stream_char(serial_char, serial_input_state[i], serial_line_buffer[i], serial_count[i]);

    } // for NUM_SERIAL
  } // queue has space, serial has data
}

#if ENABLED(SDSUPPORT)

  /**
   * Get lines from the SD Card until the command buffer is full
   * or until the end of the file is reached. Because this method
   * always receives complete command-lines, they can go directly
   * into the main command queue.
   */
  inline void GCodeQueue::get_sdcard_commands() {
    static uint8_t sd_input_state = PS_NORMAL;

    if (!IS_SD_PRINTING()) return;

    int sd_count = 0;
    bool card_eof = card.eof();
    while (length < BUFSIZE && !card_eof) {
      const int16_t n = card.get();
      card_eof = card.eof();
      if (n < 0 && !card_eof) { SERIAL_ERROR_MSG(STR_SD_ERR_READ); continue; }

      const char sd_char = (char)n;
      const bool is_eol = ISEOL(sd_char);
      if (is_eol || card_eof) {

        // Reset stream state, terminate the buffer, and commit a non-empty command
        if (!is_eol && sd_count) ++sd_count;          // End of file with no newline
        if (!process_line_done(sd_input_state, command_buffer[index_w], sd_count)) {
          _commit_command(false);
          #if ENABLED(POWER_LOSS_RECOVERY)
            recovery.cmd_sdpos = card.getIndex();     // Prime for the NEXT _commit_command
          #endif
        }

        if (card_eof) card.fileHasFinished();         // Handle end of file reached
      }
      else
        process_stream_char(sd_char, sd_input_state, command_buffer[index_w], sd_count);

    }
  }

#endif // SDSUPPORT

/**
 * Add to the circular command queue the next command from:
 *  - The command-injection queues (injected_commands_P, injected_commands)
 *  - The active serial input (usually USB)
 *  - The SD card file being actively printed
 */
void GCodeQueue::get_available_commands() {

  get_serial_commands();

  TERN_(SDSUPPORT, get_sdcard_commands());
}

/**
 * Get the next command in the queue, optionally log it to SD, then dispatch it
 */
void GCodeQueue::advance() {

  // Process immediate commands
  if (process_injected_command_P() || process_injected_command()) return;

  // Return if the G-code buffer is empty
  if (!length) return;

  #if ENABLED(SDSUPPORT)

    if (card.flag.saving) {
      char* command = command_buffer[index_r];
      if (is_M29(command)) {
        // M29 closes the file
        card.closefile();
        SERIAL_ECHOLNPGM(STR_FILE_SAVED);

        #if !defined(__AVR__) || !defined(USBCON)
          #if ENABLED(SERIAL_STATS_DROPPED_RX)
            SERIAL_ECHOLNPAIR("Dropped bytes: ", MYSERIAL0.dropped());
          #endif
          #if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
            SERIAL_ECHOLNPAIR("Max RX Queue Size: ", MYSERIAL0.rxMaxEnqueued());
          #endif
        #endif

        ok_to_send();
      }
      else {
        // Write the string from the read buffer to SD
        card.write_command(command);
        if (card.flag.logging)
          gcode.process_next_command(); // The card is saving because it's logging
        else
          ok_to_send();
      }
    }
    else
      gcode.process_next_command();

  #else

    gcode.process_next_command();

  #endif // SDSUPPORT

  // The queue may be reset by a command handler or by code invoked by idle() within a handler
  --length;
  if (++index_r >= BUFSIZE) index_r = 0;

}