#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>

#include <main.h>
#include <usart.h>
#include <PontCoopScheduler.h>
#include <mbusComm.h>
#include <loopCtrl.h>
#include <show.h>
#include <logger.h>
#include <frontend.h>

#include <mbus/mbus-protocol.h>



static const uint8_t MBUS_QUERY_CMD = 0x5b;

typedef enum {
    MBCR_SUCCESS = 0,
    MBCR_ERROR_TIMEOUT,
    MBCR_ERROR_LOOP_FAILURE,
    MBCR_ERROR_TX_REG_UNACCESSIBLE,
    MBCR_ERROR_OUT_OF_MEMORY__FRAME,
    MBCR_ERROR_OUT_OF_MEMORY__USERDATA,
    MBCR_ERROR_STATE_ENGINE__START1,
    MBCR_ERROR_STATE_ENGINE__LENGTH1,
    MBCR_ERROR_STATE_ENGINE__LENGTH2,
    MBCR_ERROR_STATE_ENGINE__START2,
    MBCR_ERROR_STATE_ENGINE__INVALID_CHKSUM,
    MBCR_ERROR_STATE_ENGINE__STOP,
    MBCR_ERROR_STATE_ENGINE__ILLEGAL_STATE,
    MBCR_ERROR_STATE_ENGINE__UNKNOWN
} e_mbusCommResult;

typedef enum {
    MBCS_IDLE,
    MBCS_SEND,
    MBCS_SEND_CONT,
    MBCS_SENDING_DONE,
    MBCS_ENABLE_FRONTEND,
    MBCS_START1,
    MBCS_LENGTH1,
    MBCS_LENGTH2,
    MBCS_START2,
    MBCS_C_FIELD,
    MBCS_A_FIELD,
    MBCS_CI_FIELD,
    MBCS_USERDATA,
    MBCS_CHKSUM,
    MBCS_STOP,
    MBCS_DONE,
    MBCS_TIMEOUT,
    MBCS_DISABLE_FRONTEND,
    MBCS_ERROR
} e_mbusCommState;

typedef struct {
  uint8_t start1;
  uint8_t length1;
  uint8_t length2;
  uint8_t start2;
  uint8_t l;
  uint8_t c;
  uint8_t a;
  uint8_t ci;
  uint8_t *userdata;
  uint8_t chksum;
  uint8_t stop;
} t_longframe;

typedef struct {
    e_mbusCommState state;
    uint8_t retryCnt;
    uint8_t cmd;
    uint8_t addr;
    uint8_t sendBuf[5];
    uint8_t receiveCnt;
    uint8_t receivedOctet;
    bool receiving;
    e_mbusCommResult result;
    t_longframe frame;
    t_mbusDevice *device;
} t_mbusCommHandle;


static t_mbusCommHandle mbusCommHandle = { .state = MBCS_IDLE, .retryCnt = 0, .cmd = 0, .addr = 0, .receiveCnt = 0, .receivedOctet = 0, .receiving = false };



static void parseAndPrintFrame(t_mbusCommHandle *mbusCommHandle) {
    t_longframe *frame = &(mbusCommHandle->frame);

    mbus_frame reply;
    memset(&reply, 0, sizeof(reply));

    //mbus_parse(&reply, buf, len);
    reply.start1 = frame->start1;
    reply.length1 = frame->length1;
    reply.length2 = frame->length2;
    reply.start2 = frame->start2;
    reply.control = frame->c;
    reply.address = frame->a;
    reply.control_information = frame->ci;
    memcpy(reply.data, frame->userdata, frame->length1 - 3);
    reply.checksum = frame->chksum;
    reply.stop = frame->stop;
    reply.type = MBUS_FRAME_TYPE_LONG;
    reply.data_size = frame->length1 - 3;

    mbus_frame_data frame_data;
    memset(&frame_data, 0, sizeof(frame_data));

    int r = mbus_frame_data_parse(&reply, &frame_data);
    if (r == 0) {
        mbus_data_variable *data_var = &(frame_data.data_var);
        logMsg("papf sts: %02x", data_var->header.status);
        if ((data_var->header.status & 0x01)) {
            errMsg("papf sts: Application Busy");
        }
        if ((data_var->header.status & 0x02)) {
            errMsg("papf sts: Any Application Error");
        }
        if ((data_var->header.status & 0x04)) {
            errMsg("papf sts: Power Low");
        }
        if ((data_var->header.status & 0x08)) {
            errMsg("papf sts: Permanent Error");
        }
        if ((data_var->header.status & 0x10)) {
            errMsg("papf sts: Temporary Error");
        }
        if ((data_var->header.status & 0x20)) {
            errMsg("papf sts: Specific to manufacturer Error 1");
        }
        if ((data_var->header.status & 0x40)) {
            errMsg("papf sts: Specific to manufacturer Error 2");
        }
        if ((data_var->header.status & 0x80)) {
            errMsg("papf sts: Specific to manufacturer Error 3");
        }
        mbus_data_record *record;
        int i;
        for (record = data_var->record, i = 0;
             record;
             record = record->next, i++) {
            for (uint8_t j = 0; j < MBUSDEVICE_NUM_OF_CONSIDEREDFIELDS; j++) {
                if ((mbusCommHandle->device->consideredField[j].index == i) &&
                    (strlen(mbusCommHandle->device->consideredField[j].label) > 0)) {
                   coloredMsg(LOG_YELLOW, "papf txt: I:%d, L:%s, U:%s V:%s", 
                              i,
                              mbusCommHandle->device->consideredField[j].label,
                              mbus_data_record_unit(record),
                              mbus_data_record_value(record));
                }
            }
        }
        mbus_data_record_free(data_var->record);
    } else {
        errMsg("papf err: unable to parse frame");
    }
}


static void handleRequestEngine(void *handle);
static void timeoutHandler(void *handle) {
    errMsg("mbc timeout");
    t_mbusCommHandle *localMbusCommHandle = (t_mbusCommHandle*) handle;
    localMbusCommHandle->state = MBCS_TIMEOUT;
    localMbusCommHandle->receiving = false;
    handleRequestEngine(handle);
}

static void receiveNext(t_mbusCommHandle *localMbusCommHandle) {
    localMbusCommHandle->receiving = true;
    HAL_UART_Receive_IT(&mbusUart, &(localMbusCommHandle->receivedOctet), 1);
}

static void handleRequestEngine(void *handle) {
    t_mbusCommHandle *localMbusCommHandle = (t_mbusCommHandle*) handle;

    static uint8_t userdataIdx = 0;
    static uint8_t calculatedChksum = 0;

    switch (localMbusCommHandle->state) {
        case MBCS_IDLE:
        logMsg("hre state IDLE");
        break;

        case MBCS_SEND:
        logMsg("hre state SEND");
        localMbusCommHandle->sendBuf[0] = 0x10;
        localMbusCommHandle->sendBuf[1] = localMbusCommHandle->cmd;
        localMbusCommHandle->sendBuf[2] = localMbusCommHandle->addr;
        localMbusCommHandle->sendBuf[3] = localMbusCommHandle->cmd + localMbusCommHandle->addr; // checksum
        localMbusCommHandle->sendBuf[4] = 0x16;
        localMbusCommHandle->state = MBCS_SEND_CONT;
        // no break !!

        case MBCS_SEND_CONT:
        logMsg("hre state SEND_CONT");
        show(LED_RED, OFF);
        if (! loopActive) {
            logMsg("hre enabling loop, try %d", localMbusCommHandle->retryCnt);
            localMbusCommHandle->retryCnt++;
            loopEnable();
            schAdd(handleRequestEngine, handle, 10, 0); // give 10ms to settled the loop
        } else {
            localMbusCommHandle->retryCnt = 0;
            HAL_UART_Transmit_IT(&mbusUart, localMbusCommHandle->sendBuf, 5);
            // transition from here to SENDING_DONE is initiate by mbusCommTxCpltCallback
            // interrupt callback
            localMbusCommHandle->state = MBCS_SENDING_DONE;
        }
        break;

        case MBCS_SENDING_DONE:
        logMsg("hre state SENDING_DONE");
        localMbusCommHandle->state = MBCS_ENABLE_FRONTEND;
        schAdd(handleRequestEngine, handle, 3, 0);
        break;

        case MBCS_ENABLE_FRONTEND:
        logMsg("hre state ENABLE_FRONTEND");
        frontendEnable();
        schAdd(timeoutHandler, handle, 2500, 0);
        calculatedChksum = 0;
        userdataIdx = 0;
        localMbusCommHandle->state = MBCS_START1;
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_START1:
        //logMsg("hre state START1");
        if (localMbusCommHandle->receivedOctet == 0x68) {
            localMbusCommHandle->frame.start1 = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->state = MBCS_LENGTH1;
        } else {
            errMsg("hre err: invalid start1 symbol %02x", localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__START1;
            localMbusCommHandle->state = MBCS_ERROR;
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_LENGTH1:
        //logMsg("hre state LENGTH1");
        if (localMbusCommHandle->receivedOctet <= 3) {
            errMsg("hre err: length to small %02x", localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__LENGTH1;
            localMbusCommHandle->state = MBCS_ERROR;
        } else {
            localMbusCommHandle->frame.length1 = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->frame.userdata = (uint8_t*) malloc(localMbusCommHandle->frame.length1 - 3);
            if (! localMbusCommHandle->frame.userdata) {
                errMsg("hre err: unable to allocate memory for userdata");
                localMbusCommHandle->result = MBCR_ERROR_OUT_OF_MEMORY__USERDATA;
                localMbusCommHandle->state = MBCS_ERROR;
            } else {
                localMbusCommHandle->state = MBCS_LENGTH2;
            }
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_LENGTH2:
        //logMsg("hre state LENGTH2");
        if (localMbusCommHandle->frame.length1 != localMbusCommHandle->receivedOctet) {
            errMsg("hre err: invalid length2 %02x vs. %02x", localMbusCommHandle->frame.length1, localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__LENGTH2;
            localMbusCommHandle->state = MBCS_ERROR;
        } else {
            localMbusCommHandle->frame.length2 = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->state = MBCS_START2;
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_START2:
        //logMsg("hre state START2");
        if (localMbusCommHandle->receivedOctet == 0x68) {
            localMbusCommHandle->frame.start2 = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->state = MBCS_C_FIELD;
        } else {
            errMsg("hre err: invalid start2 symbol %02x", localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__START2;
            localMbusCommHandle->state = MBCS_ERROR;
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_C_FIELD:
        //logMsg("hre state C_FIELD");
        localMbusCommHandle->frame.c = localMbusCommHandle->receivedOctet;
        calculatedChksum += localMbusCommHandle->receivedOctet;
        localMbusCommHandle->state = MBCS_A_FIELD;
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_A_FIELD:
        //logMsg("hre state A_FIELD");
        localMbusCommHandle->frame.a = localMbusCommHandle->receivedOctet;
        calculatedChksum += localMbusCommHandle->receivedOctet;
        localMbusCommHandle->state = MBCS_CI_FIELD;
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_CI_FIELD:
        //logMsg("hre state CI_FIELD");
        localMbusCommHandle->frame.ci = localMbusCommHandle->receivedOctet;
        calculatedChksum += localMbusCommHandle->receivedOctet;
        localMbusCommHandle->state = MBCS_USERDATA;
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_USERDATA:
        //logMsg("hre state USERDATA");
        localMbusCommHandle->frame.userdata[userdataIdx] = localMbusCommHandle->receivedOctet;
        calculatedChksum += localMbusCommHandle->receivedOctet;
        userdataIdx++;
        if (userdataIdx == (localMbusCommHandle->frame.length1 - 3)) {
            localMbusCommHandle->state = MBCS_CHKSUM;
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_CHKSUM:
        //logMsg("hre state CHKSUM");
        if (localMbusCommHandle->receivedOctet != calculatedChksum) {
            errMsg("hre err: invalid checksum %02x vs %02x", calculatedChksum, localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__INVALID_CHKSUM;
            localMbusCommHandle->state = MBCS_ERROR;
        } else {
            localMbusCommHandle->frame.chksum = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->state = MBCS_STOP;
        }
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_STOP:
        //logMsg("hre state STOP");
        if (localMbusCommHandle->receivedOctet == 0x16) {
            localMbusCommHandle->frame.stop = localMbusCommHandle->receivedOctet;
            localMbusCommHandle->state = MBCS_DONE;
            schAdd(handleRequestEngine, handle, 0, 0);
        } else {
            errMsg("hre err: invalid stop symbol %02x", localMbusCommHandle->receivedOctet);
            localMbusCommHandle->result = MBCR_ERROR_STATE_ENGINE__STOP;
            localMbusCommHandle->state = MBCS_ERROR;
            receiveNext(localMbusCommHandle);
        }
        break;

        case MBCS_DONE:
        logMsg("hre state DONE");
        parseAndPrintFrame(localMbusCommHandle);
        if (localMbusCommHandle->frame.userdata != NULL) {
            free(localMbusCommHandle->frame.userdata);
            localMbusCommHandle->frame.userdata = NULL;
        }
        localMbusCommHandle->result = MBCR_SUCCESS;
        localMbusCommHandle->state = MBCS_DISABLE_FRONTEND;
        schDel(timeoutHandler, handle);
        schAdd(handleRequestEngine, handle, 0, 0);
        break;

        case MBCS_ERROR:
        errMsg("hre state ERROR");
        show(LED_RED, ON);
        errMsg("hre err: already error, read the rest (now: %02x) until timeout", localMbusCommHandle->receivedOctet);
        receiveNext(localMbusCommHandle);
        break;

        case MBCS_TIMEOUT:
        errMsg("hre state TIMEOUT");
        localMbusCommHandle->device->failures += 1;
        localMbusCommHandle->receiving = false;        
        if (localMbusCommHandle->frame.userdata != NULL) {
            free(localMbusCommHandle->frame.userdata);
            localMbusCommHandle->frame.userdata = NULL;
        }
        HAL_UART_AbortReceive(&mbusUart);
        uint8_t kitchenSink[16];
        memset(kitchenSink, 0, 16);
        HAL_StatusTypeDef r = HAL_UART_Receive(&mbusUart, kitchenSink, 16, 100);
        errMsg("hre abort, last receive result: %02x", r);
        // no break

        case MBCS_DISABLE_FRONTEND:
        logMsg("hre state DISABLE_FRONTEND");
        frontendDisable();
        localMbusCommHandle->state = MBCS_IDLE;
        break;
        

        default:
        localMbusCommHandle->state = MBCS_IDLE;
        break;
    }
}

void mbusCommTxCpltCallback(UART_HandleTypeDef *huart) {
    schAdd(handleRequestEngine, (void*) &mbusCommHandle, 0, 0);
}

void mbusCommRxCpltCallback(UART_HandleTypeDef *huart) {
    if (mbusCommHandle.receiving) {
        schAdd(handleRequestEngine, (void*) &mbusCommHandle, 0, 0);
        mbusCommHandle.receiving = false;
    } else {
        errMsg("mcrx: received 0x%02x but not expected", mbusCommHandle.receivedOctet);
    }
}

e_mbusCommRequestResult mbusCommRequest(t_mbusDevice *mbusDevice) {
    static uint32_t cnt = 0;
    e_mbusCommRequestResult res = MBCRR_BUSY;

    if (mbusCommHandle.state == MBCS_IDLE) {
        coloredMsg(LOG_BLUE, "*** NEW REQUEST %s R:%d F:%d C:%d ***", 
                   mbusDevice->deviceName, 
                   mbusDevice->requests, 
                   mbusDevice->failures, 
                   cnt);
        cnt++;

        mbusCommHandle.state = MBCS_SEND;
        mbusCommHandle.retryCnt = 0;
        mbusCommHandle.cmd = MBUS_QUERY_CMD;
        mbusCommHandle.addr = mbusDevice->address;
        mbusCommHandle.device = mbusDevice;
        mbusDevice->requests += 1;
        schAdd(handleRequestEngine, (void*) &mbusCommHandle, 0, 0);
        res = MBCRR_TRIGGERED;   
    }

    return res;
}