#include <stdint.h>

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

#include "gatt_svcs.h"
#include "BLE_UUID.h"
#include "configuration.h"
#include "power_profiler.h"

static struct char_pres_format current_char_pres_format = {
  .format = FORMAT_UINT32,
  .exponent = -6,
  .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 struct char_pres_format zero_cali_nsamp_char_pres_format = {
  .format = FORMAT_UINT32,
  .exponent = 0,
  .unit = UNITLESS_UNIT_UUID,
  .namespc = 1,
  .descrH = NSP_DESC_MAIN & 0xff,
  .descrL = (NSP_DESC_MAIN>>8) & 0xff,
};

static struct char_pres_format auto_range_char_pres_format = {
  .format = FORMAT_BOOL,
  .exponent = 0,
  .unit = UNITLESS_UNIT_UUID,
  .namespc = 1,
  .descrH = NSP_DESC_MAIN & 0xff,
  .descrL = (NSP_DESC_MAIN>>8) & 0xff,
};

static struct char_pres_format current_range_char_pres_format = {
  .format = FORMAT_INT32,
  .exponent = 0,
  .unit = UNITLESS_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:
      ;
      struct ble_context *c_ctxt = arg;
      uint16_t id = c_ctxt->handle;
  
      uint32_t data = c_ctxt->meas->amperes[id];
      rc = os_mbuf_append(ctxt->om, &data, sizeof(data));
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      ;
      if(arg == NULL) // characteristic presentation format
        rc = os_mbuf_append(ctxt->om, &current_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
      else{
        struct ble_context *c_ctxt = arg;
        uint16_t handle = c_ctxt->handle;

        unsigned int gain = c_ctxt->meas_ctxt->inputs[handle].gain;
        rc = os_mbuf_append(ctxt->om, &gain, sizeof(gain));
      }
    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:
      ;
      struct ble_context *c_ctxt = arg;
      uint16_t id = c_ctxt->handle;
  
      uint32_t data = c_ctxt->meas->raw_volt[id];
      rc = os_mbuf_append(ctxt->om, &data, sizeof(data));
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      if(arg == NULL) // characteristic presentation format
        rc = os_mbuf_append(ctxt->om, &raw_voltage_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
      else{
        struct ble_context *c_ctxt = arg;
        uint16_t handle = c_ctxt->handle;

        unsigned int gain = c_ctxt->meas_ctxt->inputs[handle].gain;
        rc = os_mbuf_append(ctxt->om, &gain, sizeof(gain));
      }
    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;

  struct ble_context *c_ctxt = arg;
  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_READ_CHR:
      ;
      rc = os_mbuf_append(ctxt->om, &c_ctxt->conf->refresh_delay, sizeof(c_ctxt->conf->refresh_delay));
    break;
    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);
      c_ctxt->conf->refresh_delay = data;
      save_configuration_to_nvs(c_ctxt->conf);
    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;
}

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


  struct ble_context* c_ctxt = arg;
  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_WRITE_CHR:
    {
      switch (c_ctxt->handle){
        case ZEROS_CALI_ID:
          start_zero_cali(c_ctxt->meas_ctxt, c_ctxt->conf->zero_cali_nsamp, c_ctxt->conf->offsets);
          save_configuration_to_nvs(c_ctxt->conf);
        break;
        case ZEROS_CALI_RESET:
          for(int i = 0; i < INPUTS_NUM; i++)
            c_ctxt->conf->offsets[i] = 0;
          save_configuration_to_nvs(c_ctxt->conf);
          ESP_LOGI(TAG, "offset zeroed %lu %lu %lu", c_ctxt->conf->offsets[0], c_ctxt->conf->offsets[1], c_ctxt->conf->offsets[2]);
        break;
        case ZEROS_CALI_NSAMP_ID:
          ;
          uint32_t data;
          rc = gatt_svr_chr_write(ctxt->om, sizeof(data), sizeof(data), &data, NULL);
          c_ctxt->conf->zero_cali_nsamp = data;
          save_configuration_to_nvs(c_ctxt->conf);
        break;
      }
    }
    break;
    case BLE_GATT_ACCESS_OP_READ_CHR:
      ;
      rc = os_mbuf_append(ctxt->om, &c_ctxt->conf->zero_cali_nsamp, sizeof(c_ctxt->conf->zero_cali_nsamp));
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
      ;
      rc = os_mbuf_append(ctxt->om, &zero_cali_nsamp_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
    break;
  }

  return rc ? BLE_ATT_ERR_INSUFFICIENT_RES : 0;
}

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

  struct ble_context* c_ctxt = arg;
  switch(ctxt->op){
    case BLE_GATT_ACCESS_OP_WRITE_CHR:
    {
      switch (c_ctxt->handle){
        case AUTO_RANGE_ID:
          ;
          uint8_t state;
          rc = gatt_svr_chr_write(ctxt->om, sizeof(state), sizeof(state), &state, NULL);
          c_ctxt->conf->auto_range = state;
          save_configuration_to_nvs(c_ctxt->conf);
        break;
        case CURRENT_RANGE_ID:
          ;
          int data;
          rc = gatt_svr_chr_write(ctxt->om, sizeof(data), sizeof(data), &data, NULL);
          ESP_LOGI(TAG, "new range %d", data);
          c_ctxt->conf->range = data;
          activate_range(c_ctxt->conf->ranges, data, c_ctxt->conf->ranges_num - 1);
          save_configuration_to_nvs(c_ctxt->conf);
        break;
      }
    }
    break;
    case BLE_GATT_ACCESS_OP_READ_CHR:
    {
      switch (c_ctxt->handle){
        case AUTO_RANGE_ID:
          ;
          rc = os_mbuf_append(ctxt->om, &c_ctxt->conf->auto_range, sizeof(c_ctxt->conf->auto_range));
        break;
        case CURRENT_RANGE_ID:
          rc = os_mbuf_append(ctxt->om, &c_ctxt->conf->range, sizeof(c_ctxt->conf->range));
          ;
        break;
      }
    }
    break;
    case BLE_GATT_ACCESS_OP_READ_DSC:
    {
      switch (c_ctxt->handle){
        case AUTO_RANGE_ID:
          ;
          rc = os_mbuf_append(ctxt->om, &auto_range_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
        break;
        case CURRENT_RANGE_ID:
          ;
          rc = os_mbuf_append(ctxt->om, &current_range_char_pres_format, CHAR_PRESENTATION_FORMAT_SIZE);
        break;
      }
    }
    break;
  }

  return rc ? BLE_ATT_ERR_INSUFFICIENT_RES : 0;
}

int gatt_char_access_csf(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:
      ;
      struct ble_context *c_ctxt = arg;
  
      uint32_t data = c_ctxt->meas->amperes_f;
      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;
}