#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <esp_log.h>

#include "eos.h"
#include "net.h"
#include "at_cmd.h"
#include "cell.h"

static const char *TAG = "EOS CELL USSD";

extern char *at_cmd_buf;

void eos_cell_ussd_handler(unsigned char _mtype, EOSMessage *msg, uint16_t len) {
    unsigned char mtype;
    unsigned char *buffer = msg->buffer;
    int rv;

    if (len < 1) return;

    mtype = buffer[0] & ~EOS_CELL_MTYPE_MASK;
    buffer++;
    len--;

    switch (mtype) {
        case EOS_CELL_MTYPE_USSD_REQUEST: {
            if (len > EOS_CELL_USSD_SIZE_REQ) break;

            rv = snprintf(at_cmd_buf, AT_SIZE_CMD_BUF, "AT+CUSD=1,\"%.*s\",15\r", len, buffer);
            if ((rv < 0) || (rv >= AT_SIZE_CMD_BUF)) break;

            rv = eos_modem_take(1000);
            if (rv) break;

            at_cmd(at_cmd_buf);
            rv = at_expect("^OK", "^ERROR", 1000);

            eos_modem_give();
            break;
        }

        case EOS_CELL_MTYPE_USSD_CANCEL: {
            rv = eos_modem_take(1000);
            if (rv) break;

            at_cmd("AT+CUSD=2\r");
            rv = at_expect("^OK", "^ERROR", 1000);

            eos_modem_give();
            break;
        }
    }
}

static void ussd_reply_handler(char *urc, regmatch_t m[]) {
    EOSMessage msg;
    uint16_t len;
    char *rbuf;
    size_t rlen;
    int rep, rv;

    sscanf(urc + m[1].rm_so, "%1d", &rep);

    eos_net_alloc(&msg);
    if (msg.size < 2) {
        eos_net_free(&msg);
        return;
    }
    msg.buffer[0] = EOS_CELL_MTYPE_USSD | EOS_CELL_MTYPE_USSD_REPLY;
    msg.buffer[1] = rep;
    len = 2;

    if (m[2].rm_so == -1) {
        rv = eos_net_send(EOS_NET_MTYPE_CELL, &msg, len);
        if (rv) ESP_LOGE(TAG, "NET SEND ERR:%d", rv);
        return;
    }

    rbuf = (char *)msg.buffer + len;
    rlen = m[2].rm_eo - m[2].rm_so - 2;
    if (msg.size < rlen + len + 1) {
        eos_net_free(&msg);
        return;
    }
    memcpy(rbuf, urc + m[2].rm_so + 2, rlen);
    rbuf[rlen] = '\0';

    rv = EOS_OK;
    do {
        char *end;

        end = strchr(rbuf, '"');
        if (end) {
            len += end - rbuf;
            break;
        } else {
            rlen = strlen(rbuf);
            rbuf[rlen] = '\n';
            rbuf += rlen + 1;
            len += rlen + 1;
        }
        rv = eos_modem_readln(rbuf, msg.size - len, 1000);
        if (rv) break;
    } while (1);

    if (rv) {
        ESP_LOGE(TAG, "ERROR");
        eos_net_free(&msg);
        return;
    }

    rv = eos_net_send(EOS_NET_MTYPE_CELL, &msg, len);
    if (rv) ESP_LOGE(TAG, "NET SEND ERR:%d", rv);
}

void eos_cell_ussd_init(void) {
    int rv;

    rv = at_urc_insert("^\\+CUSD: ([0-9])(,\".*)?", ussd_reply_handler, REG_EXTENDED);
    assert(rv == EOS_OK);
}