#include <stdint.h>

#include "host/ble_att.h"
#include "host/ble_gatt.h"
#include "host/ble_hs_mbuf.h"
#include "os/os_mbuf.h"
#include "esp_log.h"

#include "gatt_svcs.h"
#include "BLE_UUID.h"

static struct char_pres_format current_char_pres_format = {
  .format = FORMAT_UINT32,
  .exponent = -3,
  .unit = AMPERE_UNIT_UUID,
  .namespc = 1,
  .descrH = NSP_DESC_MAIN & 0xff,
  .descrL = (NSP_DESC_MAIN>>8) & 0xff,
};

static struct char_pres_format raw_voltage_char_pres_format = {
  .format = FORMAT_UINT32,
  .exponent = -3,
  .unit = VOLTS_UNIT_UUID,
  .namespc = 1,
  .descrH = NSP_DESC_MAIN & 0xff,
  .descrL = (NSP_DESC_MAIN>>8) & 0xff,
};

static struct char_pres_format refrsh_rate_char_pres_format = {
  .format = FORMAT_UINT32,
  .exponent = -3,
  .unit = SECONDS_UNIT_UUID,
  .namespc = 1,
  .descrH = NSP_DESC_MAIN & 0xff,
  .descrL = (NSP_DESC_MAIN>>8) & 0xff,
};

static int
gatt_svr_chr_write(struct os_mbuf *om, uint16_t min_len, uint16_t max_len,
                   void *dst, uint16_t *len)
{
    uint16_t om_len;
    int rc;

    om_len = OS_MBUF_PKTLEN(om);
    if (om_len < min_len || om_len > max_len) {
        return BLE_ATT_ERR_INVALID_ATTR_VALUE_LEN;
    }

    rc = ble_hs_mbuf_to_flat(om, dst, max_len, len);
    if (rc != 0) {
        return BLE_ATT_ERR_UNLIKELY;
    }

    return 0;
}

int gatt_char_access_cs(uint16_t conn_handle, uint16_t attr_handle, struct ble_gatt_access_ctxt* ctxt, void* arg){
  int rc = 0;

  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_READ_CHR:
      ;
      uint16_t* handles = arg;
  
      int id = -1;
      for(int i = 0; i < EC_CHRS_NUM; i++) if(handles[i] == attr_handle) id = i;
      uint32_t data = id;
      rc = os_mbuf_append(ctxt->om, &data, sizeof(data));
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      rc = os_mbuf_append(ctxt->om, &current_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
    break;
  }

  return rc ? BLE_ATT_ERR_INSUFFICIENT_RES : 0;
}

int gatt_char_access_ev(uint16_t conn_handle, uint16_t attr_handle, struct ble_gatt_access_ctxt* ctxt, void* arg){
  int rc = 0;

  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_READ_CHR:
      ;
      uint16_t* handles = arg;
  
      int id = -1;
      for(int i = 0; i < EV_CHRS_NUM; i++) if(handles[i] == attr_handle) id = i;
      uint32_t data = id;
      rc = os_mbuf_append(ctxt->om, &data, sizeof(data));
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      rc = os_mbuf_append(ctxt->om, &raw_voltage_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
    break;
  }

  return rc ? BLE_ATT_ERR_INSUFFICIENT_RES : 0;
}

int gatt_char_access_sampling_rate(uint16_t conn_handle, uint16_t attr_handle, struct ble_gatt_access_ctxt* ctxt, void* arg){
  int rc = 0;

  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_WRITE_CHR:
      ;
      uint32_t data;
      rc = gatt_svr_chr_write(ctxt->om, sizeof(data), sizeof(data), &data, NULL);
      ESP_LOGI("BLE", "Refresh rate : %lu", data);
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      rc = os_mbuf_append(ctxt->om, &refrsh_rate_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
    break;
  }

  return rc ? BLE_ATT_ERR_INSUFFICIENT_RES : 0;
}