/*
  system.c - Handles system level commands and real-time processes
  Part of Grbl

  Copyright (c) 2014-2016 Sungeun K. Jeon for Gnea Research LLC

  Grbl 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.

  Grbl 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 Grbl.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "grbl.h"

void system_init() {
    CONTROL_DDR &= ~(CONTROL_MASK); // Configure as input pins
#ifdef DISABLE_CONTROL_PIN_PULL_UP
    CONTROL_PORT &= ~(CONTROL_MASK); // Normal low operation. Requires external pull-down.
#else
    CONTROL_PORT |= CONTROL_MASK; // Enable internal pull-up resistors. Normal high operation.
#endif
    CONTROL_PCMSK |= CONTROL_MASK; // Enable specific pins of the Pin Change Interrupt
    PCICR |= (1 << CONTROL_INT);   // Enable Pin Change Interrupt
}

// Returns control pin state as a uint8 bitfield. Each bit indicates the input pin state, where
// triggered is 1 and not triggered is 0. Invert mask is applied. Bitfield organization is
// defined by the CONTROL_PIN_INDEX in the header file.
uint8_t system_control_get_state() {
    uint8_t control_state = 0;
    uint8_t pin = (CONTROL_PIN & CONTROL_MASK) ^ CONTROL_MASK;
#ifdef INVERT_CONTROL_PIN_MASK
    pin ^= INVERT_CONTROL_PIN_MASK;
#endif
    if (pin) {
#ifdef ENABLE_SAFETY_DOOR_INPUT_PIN
        if (bit_istrue(pin, (1 << CONTROL_SAFETY_DOOR_BIT))) {
            control_state |= CONTROL_PIN_INDEX_SAFETY_DOOR;
        }
#else
        if (bit_istrue(pin, (1 << CONTROL_FEED_HOLD_BIT))) {
            control_state |= CONTROL_PIN_INDEX_FEED_HOLD;
        }
#endif
        if (bit_istrue(pin, (1 << CONTROL_RESET_BIT))) {
            control_state |= CONTROL_PIN_INDEX_RESET;
        }
        if (bit_istrue(pin, (1 << CONTROL_CYCLE_START_BIT))) {
            control_state |= CONTROL_PIN_INDEX_CYCLE_START;
        }
    }
    return (control_state);
}

// Pin change interrupt for pin-out commands, i.e. cycle start, feed hold, and reset. Sets
// only the realtime command execute variable to have the main program execute these when
// its ready. This works exactly like the character-based realtime commands when picked off
// directly from the incoming serial data stream.
ISR(CONTROL_INT_vect) {
    uint8_t pin = system_control_get_state();
    if (pin) {
        if (bit_istrue(pin, CONTROL_PIN_INDEX_RESET)) {
            mc_reset();
        }
        if (bit_istrue(pin, CONTROL_PIN_INDEX_CYCLE_START)) {
            bit_true(sys_rt_exec_state, EXEC_CYCLE_START);
        }
#ifndef ENABLE_SAFETY_DOOR_INPUT_PIN
        if (bit_istrue(pin, CONTROL_PIN_INDEX_FEED_HOLD)) {
            bit_true(sys_rt_exec_state, EXEC_FEED_HOLD);
#else
        if (bit_istrue(pin, CONTROL_PIN_INDEX_SAFETY_DOOR)) {
            bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
#endif
        }
    }
}

// Returns if safety door is ajar(T) or closed(F), based on pin state.
uint8_t system_check_safety_door_ajar() {
#ifdef ENABLE_SAFETY_DOOR_INPUT_PIN
    return (system_control_get_state() & CONTROL_PIN_INDEX_SAFETY_DOOR);
#else
    return (false); // Input pin not enabled, so just return that it's closed.
#endif
}

// Executes user startup script, if stored.
void system_execute_startup(char *line) {
    uint8_t n;
    for (n = 0; n < N_STARTUP_LINE; n++) {
        if (!(settings_read_startup_line(n, line))) {
            line[0] = 0;
            report_execute_startup_message(line, STATUS_SETTING_READ_FAIL);
        } else {
            if (line[0] != 0) {
                uint8_t status_code = gc_execute_line(line);
                report_execute_startup_message(line, status_code);
            }
        }
    }
}

// Directs and executes one line of formatted input from protocol_process. While mostly
// incoming streaming g-code blocks, this also executes Grbl internal commands, such as
// settings, initiating the homing cycle, and toggling switch states. This differs from
// the realtime command module by being susceptible to when Grbl is ready to execute the
// next line during a cycle, so for switches like block delete, the switch only effects
// the lines that are processed afterward, not necessarily real-time during a cycle,
// since there are motions already stored in the buffer. However, this 'lag' should not
// be an issue, since these commands are not typically used during a cycle.
uint8_t system_execute_line(char *line) {
    uint8_t char_counter = 1;
    uint8_t helper_var = 0; // Helper variable
    float   parameter, value;
    switch (line[char_counter]) {
    case 0: report_grbl_help(); break;
    case 'J': // Jogging
        // Execute only if in IDLE or JOG states.
        if (sys.state != STATE_IDLE && sys.state != STATE_JOG) {
            return (STATUS_IDLE_ERROR);
        }
        if (line[2] != '=') {
            return (STATUS_INVALID_STATEMENT);
        }
        return (gc_execute_line(line)); // NOTE: $J= is ignored inside g-code parser and used to detect jog motions.
        break;
    case '$':
    case 'G':
    case 'C':
    case 'X':
        if (line[2] != 0) {
            return (STATUS_INVALID_STATEMENT);
        }
        switch (line[1]) {
        case '$': // Prints Grbl settings
            if (sys.state & (STATE_CYCLE | STATE_HOLD)) {
                return (STATUS_IDLE_ERROR);
            } // Block during cycle. Takes too long to print.
            else {
                report_grbl_settings();
            }
            break;
        case 'G': // Prints gcode parser state
            // TODO: Move this to realtime commands for GUIs to request this data during suspend-state.
            report_gcode_modes();
            break;
        case 'C': // Set check g-code mode [IDLE/CHECK]
            // Perform reset when toggling off. Check g-code mode should only work if Grbl
            // is idle and ready, regardless of alarm locks. This is mainly to keep things
            // simple and consistent.
            if (sys.state == STATE_CHECK_MODE) {
                mc_reset();
                report_feedback_message(MESSAGE_DISABLED);
            } else {
                if (sys.state) {
                    return (STATUS_IDLE_ERROR);
                } // Requires no alarm mode.
                sys.state = STATE_CHECK_MODE;
                report_feedback_message(MESSAGE_ENABLED);
            }
            break;
        case 'X': // Disable alarm lock [ALARM]
            if (sys.state == STATE_ALARM) {
                // Block if safety door is ajar.
                if (system_check_safety_door_ajar()) {
                    return (STATUS_CHECK_DOOR);
                }
                report_feedback_message(MESSAGE_ALARM_UNLOCK);
                sys.state = STATE_IDLE;
                // Don't run startup script. Prevents stored moves in startup from causing accidents.
            } // Otherwise, no effect.
            break;
        }
        break;
    default:
        // Block any system command that requires the state as IDLE/ALARM. (i.e. EEPROM, homing)
        if (!(sys.state == STATE_IDLE || sys.state == STATE_ALARM)) {
            return (STATUS_IDLE_ERROR);
        }
        switch (line[1]) {
        case '#': // Print Grbl NGC parameters
            if (line[2] != 0) {
                return (STATUS_INVALID_STATEMENT);
            } else {
                report_ngc_parameters();
            }
            break;
        case 'H': // Perform homing cycle [IDLE/ALARM]
            if (bit_isfalse(settings.flags, BITFLAG_HOMING_ENABLE)) {
                return (STATUS_SETTING_DISABLED);
            }
            if (system_check_safety_door_ajar()) {
                return (STATUS_CHECK_DOOR);
            } // Block if safety door is ajar.
            sys.state = STATE_HOMING; // Set system state variable
            if (line[2] == 0) {
                mc_homing_cycle(HOMING_CYCLE_ALL);
#ifdef HOMING_SINGLE_AXIS_COMMANDS
            } else if (line[3] == 0) {
                switch (line[2]) {
                case 'X': mc_homing_cycle(HOMING_CYCLE_X); break;
                case 'Y': mc_homing_cycle(HOMING_CYCLE_Y); break;
                case 'Z': mc_homing_cycle(HOMING_CYCLE_Z); break;
                default: return (STATUS_INVALID_STATEMENT);
                }
#endif
            } else {
                return (STATUS_INVALID_STATEMENT);
            }
            if (!sys.abort) {           // Execute startup scripts after successful homing.
                sys.state = STATE_IDLE; // Set to IDLE when complete.
                st_go_idle();           // Set steppers to the settings idle state before returning.
                if (line[2] == 0) {
                    system_execute_startup(line);
                }
            }
            break;
        case 'S': // Puts Grbl to sleep [IDLE/ALARM]
            if ((line[2] != 'L') || (line[3] != 'P') || (line[4] != 0)) {
                return (STATUS_INVALID_STATEMENT);
            }
            system_set_exec_state_flag(EXEC_SLEEP); // Set to execute sleep mode immediately
            break;
        case 'I': // Print or store build info. [IDLE/ALARM]
            if (line[++char_counter] == 0) {
                settings_read_build_info(line);
                report_build_info(line);
#ifdef ENABLE_BUILD_INFO_WRITE_COMMAND
            } else { // Store startup line [IDLE/ALARM]
                if (line[char_counter++] != '=') {
                    return (STATUS_INVALID_STATEMENT);
                }
                helper_var = char_counter; // Set helper variable as counter to start of user info line.
                do {
                    line[char_counter - helper_var] = line[char_counter];
                } while (line[char_counter++] != 0);
                settings_store_build_info(line);
#endif
            }
            break;
        case 'R': // Restore defaults [IDLE/ALARM]
            if ((line[2] != 'S') || (line[3] != 'T') || (line[4] != '=') || (line[6] != 0)) {
                return (STATUS_INVALID_STATEMENT);
            }
            switch (line[5]) {
#ifdef ENABLE_RESTORE_EEPROM_DEFAULT_SETTINGS
            case '$': settings_restore(SETTINGS_RESTORE_DEFAULTS); break;
#endif
#ifdef ENABLE_RESTORE_EEPROM_CLEAR_PARAMETERS
            case '#': settings_restore(SETTINGS_RESTORE_PARAMETERS); break;
#endif
#ifdef ENABLE_RESTORE_EEPROM_WIPE_ALL
            case '*': settings_restore(SETTINGS_RESTORE_ALL); break;
#endif
            default: return (STATUS_INVALID_STATEMENT);
            }
            report_feedback_message(MESSAGE_RESTORE_DEFAULTS);
            mc_reset(); // Force reset to ensure settings are initialized correctly.
            break;
        case 'N':                            // Startup lines. [IDLE/ALARM]
            if (line[++char_counter] == 0) { // Print startup lines
                for (helper_var = 0; helper_var < N_STARTUP_LINE; helper_var++) {
                    if (!(settings_read_startup_line(helper_var, line))) {
                        report_status_message(STATUS_SETTING_READ_FAIL);
                    } else {
                        report_startup_line(helper_var, line);
                    }
                }
                break;
            } else { // Store startup line [IDLE Only] Prevents motion during ALARM.
                if (sys.state != STATE_IDLE) {
                    return (STATUS_IDLE_ERROR);
                } // Store only when idle.
                helper_var = true; // Set helper_var to flag storing method.
                                   // No break. Continues into default: to read remaining command characters.
            }
        default: // Storing setting methods [IDLE/ALARM]
            if (!read_float(line, &char_counter, &parameter)) {
                return (STATUS_BAD_NUMBER_FORMAT);
            }
            if (line[char_counter++] != '=') {
                return (STATUS_INVALID_STATEMENT);
            }
            if (helper_var) { // Store startup line
                // Prepare sending gcode block to gcode parser by shifting all characters
                helper_var = char_counter; // Set helper variable as counter to start of gcode block
                do {
                    line[char_counter - helper_var] = line[char_counter];
                } while (line[char_counter++] != 0);
                // Execute gcode block to ensure block is valid.
                helper_var = gc_execute_line(line); // Set helper_var to returned status code.
                if (helper_var) {
                    return (helper_var);
                } else {
                    helper_var = trunc(parameter); // Set helper_var to int value of parameter
                    settings_store_startup_line(helper_var, line);
                }
            } else { // Store global setting.
                if (!read_float(line, &char_counter, &value)) {
                    return (STATUS_BAD_NUMBER_FORMAT);
                }
                if ((line[char_counter] != 0) || (parameter > 255)) {
                    return (STATUS_INVALID_STATEMENT);
                }
                return (settings_store_global_setting((uint8_t)parameter, value));
            }
        }
    }
    return (STATUS_OK); // If '$' command makes it to here, then everything's ok.
}

void system_flag_wco_change() {
#ifdef FORCE_BUFFER_SYNC_DURING_WCO_CHANGE
    protocol_buffer_synchronize();
#endif
    sys.report_wco_counter = 0;
}

// Returns machine position of axis 'idx'. Must be sent a 'step' array.
// NOTE: If motor steps and machine position are not in the same coordinate frame, this function
//   serves as a central place to compute the transformation.
float system_convert_axis_steps_to_mpos(int32_t *steps, uint8_t idx) {
    float pos;
#ifdef COREXY
    if (idx == X_AXIS) {
        pos = (float)system_convert_corexy_to_x_axis_steps(steps) / settings.steps_per_mm[idx];
    } else if (idx == Y_AXIS) {
        pos = (float)system_convert_corexy_to_y_axis_steps(steps) / settings.steps_per_mm[idx];
    } else {
        pos = steps[idx] / settings.steps_per_mm[idx];
    }
#else
    pos = steps[idx] / settings.steps_per_mm[idx];
#endif
    return (pos);
}

void system_convert_array_steps_to_mpos(float *position, int32_t *steps) {
    uint8_t idx;
    for (idx = 0; idx < N_AXIS; idx++) {
        position[idx] = system_convert_axis_steps_to_mpos(steps, idx);
    }
    return;
}

// CoreXY calculation only. Returns x or y-axis "steps" based on CoreXY motor steps.
#ifdef COREXY
int32_t system_convert_corexy_to_x_axis_steps(int32_t *steps) {
    return ((steps[A_MOTOR] + steps[B_MOTOR]) / 2);
}

int32_t system_convert_corexy_to_y_axis_steps(int32_t *steps) {
    return ((steps[A_MOTOR] - steps[B_MOTOR]) / 2);
}
#endif

// Checks and reports if target array exceeds machine travel limits.
uint8_t system_check_travel_limits(float *target) {
    uint8_t idx;
    for (idx = 0; idx < N_AXIS; idx++) {
#ifdef HOMING_FORCE_SET_ORIGIN
        // When homing forced set origin is enabled, soft limits checks need to account for directionality.
        // NOTE: max_travel is stored as negative
        if (bit_istrue(settings.homing_dir_mask, bit(idx))) {
            if (target[idx] < 0 || target[idx] > -settings.max_travel[idx]) {
                return (true);
            }
        } else {
            if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) {
                return (true);
            }
        }
#else
        // NOTE: max_travel is stored as negative
        if (target[idx] > 0 || target[idx] < settings.max_travel[idx]) {
            return (true);
        }
#endif
    }
    return (false);
}

// Special handlers for setting and clearing Grbl's real-time execution flags.
void system_set_exec_state_flag(uint8_t mask) {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_state |= (mask);
    SREG = sreg;
}

void system_clear_exec_state_flag(uint8_t mask) {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_state &= ~(mask);
    SREG = sreg;
}

void system_set_exec_alarm(uint8_t code) {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_alarm = code;
    SREG = sreg;
}

void system_clear_exec_alarm() {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_alarm = 0;
    SREG = sreg;
}

void system_set_exec_motion_override_flag(uint8_t mask) {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_motion_override |= (mask);
    SREG = sreg;
}

void system_set_exec_accessory_override_flag(uint8_t mask) {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_accessory_override |= (mask);
    SREG = sreg;
}

void system_clear_exec_motion_overrides() {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_motion_override = 0;
    SREG = sreg;
}

void system_clear_exec_accessory_overrides() {
    uint8_t sreg = SREG;
    cli();
    sys_rt_exec_accessory_override = 0;
    SREG = sreg;
}