#include <esp_log.h>
#include "mbiface.h"
#include "socket_server.h"
#include "tasks.h"
#include "modbus.h"
#include "fancontrol.h"
#include "settings.h"

static const char * TAG = "mb";

Tcpd_t g_mbifc_server = NULL;
ModbusSlave_t gModbus;

enum HoldingRegisters {
  H_MODE = 1,
  H_POWER,
  H_SUMMER,
  H_INITIAL_MODE,
  H_INITIAL_POWER,
  H_RECUP_MODE,
  H_RECUP_TIME,
  H_RECUP_TIME_MIN,
  H_RECUP_TIME_MAX,
  H_RECUP_FACTOR,
  H_RAMP_TIME,
  H_BLIND_TIME,
  H_MIN_POWER,
};

enum InputRegisters {
  I_RECUP_TIME_IN = 1,
  I_RECUP_TIME_OUT,
  I_T_VALIDITY,
  I_T_IN_INST,
  I_T_OUT_INST,
  I_T_INDOOR,
  I_T_OUTDOOR,
  I_T_INFLOW,
  I_T_EXHAUST,
  I_MODE_INST,
  I_MOTOR_RAMP,
  I_BLIND_RAMP,
};

/**
 * Socket read handler
 */
static esp_err_t read_fn(Tcpd_t serv, TcpdClient_t client, int sockfd)
{
    uint8_t buf[1024];
    uint8_t buf2[1024];
    int nbytes = read(sockfd, buf, sizeof(buf));
    if (nbytes <= 0) return ESP_FAIL;

    size_t resp_len = 0;
    ModbusError_t e = mb_handleRequest(&gModbus, buf, nbytes, buf2, 1024, &resp_len);
    if (e == 0) {
        tcpd_send(client, buf2, (ssize_t) resp_len);
    } else {
        ESP_LOGE(TAG, "Error %d, closing socket", e);
        tcpd_kick(client);
    }

    return ESP_OK;
}

ModbusException_t startOfAccess(ModbusSlave_t *pSlave, ModbusFunction_t function, uint8_t i) {
    return 0;
}

void endOfAccess(ModbusSlave_t *ms) {
    //
}

ModbusException_t ri(ModbusSlave_t *pSlave, uint16_t ref, uint16_t *pValue) {
    ESP_LOGD(TAG, "Read input %d", ref);
    uint16_t scratch = 0;

    switch (ref) {
        case I_RECUP_TIME_IN:
            *pValue = gState.real_recup_time_in;
            break;
        case I_RECUP_TIME_OUT:
            *pValue = gState.real_recup_time_out;
            break;
        case I_T_VALIDITY:
            scratch |= (int)gState.valid_t_actual_in;
            scratch |= (int)gState.valid_t_actual_out << 1;
            scratch |= (int)gState.valid_t_indoor << 2;
            scratch |= (int)gState.valid_t_outdoor << 3;
            scratch |= (int)gState.valid_t_inflow << 4;
            scratch |= (int)gState.valid_t_exhaust << 5;
            *pValue = scratch;
            break;
        case I_T_IN_INST:
            *pValue = gState.t_actual_in;
            break;
        case I_T_OUT_INST:
            *pValue = gState.t_actual_out;
            break;
        case I_T_INDOOR:
            *pValue = gState.t_indoor;
            break;
        case I_T_OUTDOOR:
            *pValue = gState.t_outdoor;
            break;
        case I_T_INFLOW:
            *pValue = gState.t_inflow;
            break;
        case I_T_EXHAUST:
            *pValue = gState.t_exhaust;
            break;
        case I_MODE_INST:
            *pValue = gState.instantaneous_vent_mode;
            break;
        case I_MOTOR_RAMP:
            *pValue = gState.ramp;
            break;
        case I_BLIND_RAMP:
            *pValue = gState.blind_position;
            break;

        default:
            return MB_EXCEPTION_ILLEGAL_DATA_ADDRESS;
    }

    return MB_EXCEPTION_OK;
}

ModbusException_t rh(ModbusSlave_t *pSlave, uint16_t ref, uint16_t *pValue) {
    ESP_LOGD(TAG, "Read holding %d", ref);

    switch (ref) {
        case H_MODE:
            *pValue = (int) gState.set_vent_mode;
            break;
        case H_POWER:
            *pValue = gState.set_power;
            break;
        case H_SUMMER:
            *pValue = (int) gSettings.summer_mode;
            break;
        case H_INITIAL_MODE:
            *pValue = (int) gSettings.initial_mode;
            break;
        case H_INITIAL_POWER:
            *pValue = gSettings.initial_power;
            break;
        case H_RECUP_MODE:
            *pValue = gSettings.recup_mode;
            break;
        case H_RECUP_TIME:
            *pValue = gSettings.recup_time;
            break;
        case H_RECUP_TIME_MIN:
            *pValue = gSettings.min_recup_time;
            break;
        case H_RECUP_TIME_MAX:
            *pValue = gSettings.max_recup_time;
            break;
        case H_RECUP_FACTOR:
            *pValue = gSettings.recup_factor;
            break;
        case H_RAMP_TIME:
            *pValue = gSettings.ramp_time;
            break;
        case H_BLIND_TIME:
            *pValue = gSettings.blind_time;
            break;
        case H_MIN_POWER:
            *pValue = gSettings.min_power;
            break;
        default:
            // inputs are mapped to the holding address space
            if (ref >= 100) {
                return ri(pSlave, ref - 100, pValue);
            }

            return MB_EXCEPTION_ILLEGAL_DATA_ADDRESS;
    }

    return MB_EXCEPTION_OK;
}

static bool is_valid_vent_mode(int value) {
    switch (value) {
        case VENT_MODE_OFF:
        case VENT_MODE_FREE:
        case VENT_MODE_OUT:
        case VENT_MODE_IN:
        case VENT_MODE_RECUP:
            return true;
        default:
            return false;
    }
}

ModbusException_t wh(ModbusSlave_t *pSlave, uint16_t ref, uint16_t value) {
    ESP_LOGD(TAG, "Write holding %d := %02x", ref, value);

    switch (ref) {
        case H_MODE:
            if (!is_valid_vent_mode(value)) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            fan_set_vent_mode(value);
            break;
        case H_POWER:
            if (value > 100) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            fan_set_power(value);
            break;
        case H_SUMMER:
            gSettings.summer_mode = (value != 0);
            settings_persist(SETTINGS_summer_mode);
            break;
        case H_INITIAL_MODE:
            if (!is_valid_vent_mode(value)) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.initial_mode = value;
            settings_persist(SETTINGS_initial_mode);
            break;
        case H_INITIAL_POWER:
            if (value > 100) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.initial_power = value;
            settings_persist(SETTINGS_initial_power);
            break;
        case H_RECUP_MODE:
            if (value == RECUP_MODE_TEMP || value == RECUP_MODE_TIME) {
                gSettings.recup_mode = value;
            } else {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            break;
        case H_RECUP_TIME:
            if (value == 0) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.recup_time = value;
            settings_persist(SETTINGS_recup_time);
            break;
        case H_RECUP_TIME_MIN:
            if (value == 0) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.min_recup_time = value;
            settings_persist(SETTINGS_min_recup_time);
            break;
        case H_RECUP_TIME_MAX:
            if (value == 0) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.max_recup_time = value;
            settings_persist(SETTINGS_max_recup_time);
            break;
        case H_RECUP_FACTOR:
            if (value > 100) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.recup_factor = value;
            settings_persist(SETTINGS_recup_factor);
            break;
        case H_RAMP_TIME:
            gSettings.ramp_time = value;
            settings_persist(SETTINGS_ramp_time);
            break;
        case H_BLIND_TIME:
            gSettings.blind_time = value;
            settings_persist(SETTINGS_blind_time);
            break;
        case H_MIN_POWER:
            if (value > 100) {
                return MB_EXCEPTION_ILLEGAL_DATA_VALUE;
            }
            gSettings.min_power = value;
            settings_persist(SETTINGS_min_power);
            break;
        default:
            return MB_EXCEPTION_ILLEGAL_DATA_ADDRESS;
    }

    return MB_EXCEPTION_OK;
}

void mbiface_setup()
{
    ESP_LOGI(TAG, "initing MB iface");
    gModbus.proto = MB_PROTO_TCP;
    gModbus.addr = 1;
    gModbus.startOfAccess = startOfAccess;
    gModbus.endOfAccess = endOfAccess;
    gModbus.readHolding = rh;
    gModbus.writeHolding = wh;
    gModbus.readInput = ri;

    tcpd_config_t server_config = TCPD_INIT_DEFAULT();
    server_config.max_clients = 1;
    server_config.task_prio = MBIFC_TASK_PRIO;
    server_config.task_stack = MBIFC_TASK_STACK;
    server_config.task_name = "MBIFC";
    server_config.port = 502;
    server_config.read_fn = read_fn;

    ESP_ERROR_CHECK(tcpd_init(&server_config, &g_mbifc_server));
}