// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "nvs.h"
#include "nvs_flash.h"
#include "esp_system.h"
#include "esp_log.h"

#include "esp_bt.h"
#include "bt_app_core.h"
#include "bt_app_av.h"
#include "esp_bt_main.h"
#include "esp_bt_device.h"
#include "esp_gap_bt_api.h"
#include "esp_a2dp_api.h"
#include "esp_avrc_api.h"
#include "driver/i2s.h"

/* device name */
#define LOCAL_DEVICE_NAME    "ESP_SPEAKER"

/* event for stack up */
enum {
    BT_APP_EVT_STACK_UP = 0,
};

/********************************
 * STATIC FUNCTION DECLARATIONS
 *******************************/

/* GAP callback function */
static void bt_app_gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param);
/* handler for bluetooth stack enabled events */
static void bt_av_hdl_stack_evt(uint16_t event, void *p_param);

/*******************************
 * STATIC FUNCTION DEFINITIONS
 ******************************/

static void bt_app_gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t *param)
{
    switch (event) {
    /* when authentication completed, this event comes */
    case ESP_BT_GAP_AUTH_CMPL_EVT: {
        if (param->auth_cmpl.stat == ESP_BT_STATUS_SUCCESS) {
            ESP_LOGI(BT_AV_TAG, "authentication success: %s", param->auth_cmpl.device_name);
            esp_log_buffer_hex(BT_AV_TAG, param->auth_cmpl.bda, ESP_BD_ADDR_LEN);
        } else {
            ESP_LOGE(BT_AV_TAG, "authentication failed, status: %d", param->auth_cmpl.stat);
        }
        break;
    }

#if (CONFIG_BT_SSP_ENABLED == true)
    /* when Security Simple Pairing user confirmation requested, this event comes */
    case ESP_BT_GAP_CFM_REQ_EVT:
        ESP_LOGI(BT_AV_TAG, "ESP_BT_GAP_CFM_REQ_EVT Please compare the numeric value: %d", param->cfm_req.num_val);
        esp_bt_gap_ssp_confirm_reply(param->cfm_req.bda, true);
        break;
    /* when Security Simple Pairing passkey notified, this event comes */
    case ESP_BT_GAP_KEY_NOTIF_EVT:
        ESP_LOGI(BT_AV_TAG, "ESP_BT_GAP_KEY_NOTIF_EVT passkey: %d", param->key_notif.passkey);
        break;
    /* when Security Simple Pairing passkey requested, this event comes */
    case ESP_BT_GAP_KEY_REQ_EVT:
        ESP_LOGI(BT_AV_TAG, "ESP_BT_GAP_KEY_REQ_EVT Please enter passkey!");
        break;
#endif

    /* when GAP mode changed, this event comes */
    case ESP_BT_GAP_MODE_CHG_EVT:
        ESP_LOGI(BT_AV_TAG, "ESP_BT_GAP_MODE_CHG_EVT mode: %d", param->mode_chg.mode);
        break;
    /* others */
    default: {
        ESP_LOGI(BT_AV_TAG, "event: %d", event);
        break;
    }
    }
}

static void bt_av_hdl_stack_evt(uint16_t event, void *p_param)
{
    ESP_LOGD(BT_AV_TAG, "%s event: %d", __func__, event);

    switch (event) {
    /* when do the stack up, this event comes */
    case BT_APP_EVT_STACK_UP: {
        esp_bt_dev_set_device_name(LOCAL_DEVICE_NAME);
        esp_bt_gap_register_callback(bt_app_gap_cb);

        assert(esp_avrc_ct_init() == ESP_OK);
        esp_avrc_ct_register_callback(bt_app_rc_ct_cb);
        assert(esp_avrc_tg_init() == ESP_OK);
        esp_avrc_tg_register_callback(bt_app_rc_tg_cb);

        esp_avrc_rn_evt_cap_mask_t evt_set = {0};
        esp_avrc_rn_evt_bit_mask_operation(ESP_AVRC_BIT_MASK_OP_SET, &evt_set, ESP_AVRC_RN_VOLUME_CHANGE);
        assert(esp_avrc_tg_set_rn_evt_cap(&evt_set) == ESP_OK);

        assert(esp_a2d_sink_init() == ESP_OK);
        esp_a2d_register_callback(&bt_app_a2d_cb);
        esp_a2d_sink_register_data_callback(bt_app_a2d_data_cb);

        /* set discoverable and connectable mode, wait to be connected */
        esp_bt_gap_set_scan_mode(ESP_BT_CONNECTABLE, ESP_BT_GENERAL_DISCOVERABLE);
        break;
    }
    /* others */
    default:
        ESP_LOGE(BT_AV_TAG, "%s unhandled event: %d", __func__, event);
        break;
    }
}

/*******************************
 * MAIN ENTRY POINT
 ******************************/

void app_main(void)
{
    /* initialize NVS — it is used to store PHY calibration data */
    esp_err_t err = nvs_flash_init();
    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        err = nvs_flash_init();
    }
    ESP_ERROR_CHECK(err);

    /*
     * This example only uses the functions of Classical Bluetooth.
     * So release the controller memory for Bluetooth Low Energy.
     */
    ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_BLE));

    esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
    if ((err = esp_bt_controller_init(&bt_cfg)) != ESP_OK) {
        ESP_LOGE(BT_AV_TAG, "%s initialize controller failed: %s\n", __func__, esp_err_to_name(err));
        return;
    }
    if ((err = esp_bt_controller_enable(ESP_BT_MODE_CLASSIC_BT)) != ESP_OK) {
        ESP_LOGE(BT_AV_TAG, "%s enable controller failed: %s\n", __func__, esp_err_to_name(err));
        return;
    }
    if ((err = esp_bluedroid_init()) != ESP_OK) {
        ESP_LOGE(BT_AV_TAG, "%s initialize bluedroid failed: %s\n", __func__, esp_err_to_name(err));
        return;
    }
    if ((err = esp_bluedroid_enable()) != ESP_OK) {
        ESP_LOGE(BT_AV_TAG, "%s enable bluedroid failed: %s\n", __func__, esp_err_to_name(err));
        return;
    }

    /* I2S configuration parameters */
    i2s_config_t i2s_config = {
#ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
        .mode = I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN,
#else
        .mode = I2S_MODE_MASTER | I2S_MODE_TX,              /* only TX */
#endif
        .sample_rate = 44100,
        .bits_per_sample = 16,
        .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,       /* 2-channels */
        .communication_format = I2S_COMM_FORMAT_STAND_MSB,
        .dma_buf_count = 6,
        .dma_buf_len = 60,
        .intr_alloc_flags = 0,                              /* default interrupt priority */
        .tx_desc_auto_clear = true                          /* auto clear tx descriptor on underflow */
    };

    /* enable I2S */
    i2s_driver_install(0, &i2s_config, 0, NULL);
#ifdef CONFIG_EXAMPLE_A2DP_SINK_OUTPUT_INTERNAL_DAC
    i2s_set_dac_mode(I2S_DAC_CHANNEL_BOTH_EN);
    i2s_set_pin(0, NULL);
#else
    i2s_pin_config_t pin_config = {
        .bck_io_num = CONFIG_EXAMPLE_I2S_BCK_PIN,
        .ws_io_num = CONFIG_EXAMPLE_I2S_LRCK_PIN,
        .data_out_num = CONFIG_EXAMPLE_I2S_DATA_PIN,
        .data_in_num = -1                                   /* not used */
    };
    i2s_set_pin(0, &pin_config);
#endif

#if (CONFIG_BT_SSP_ENABLED == true)
    /* set default parameters for Secure Simple Pairing */
    esp_bt_sp_param_t param_type = ESP_BT_SP_IOCAP_MODE;
    esp_bt_io_cap_t iocap = ESP_BT_IO_CAP_IO;
    esp_bt_gap_set_security_param(param_type, &iocap, sizeof(uint8_t));
#endif

    /* set default parameters for Legacy Pairing (use fixed pin code 1234) */
    esp_bt_pin_type_t pin_type = ESP_BT_PIN_TYPE_FIXED;
    esp_bt_pin_code_t pin_code;
    pin_code[0] = '1';
    pin_code[1] = '2';
    pin_code[2] = '3';
    pin_code[3] = '4';
    esp_bt_gap_set_pin(pin_type, 4, pin_code);

    bt_app_task_start_up();
    /* bluetooth device name, connection mode and profile set up */
    bt_app_work_dispatch(bt_av_hdl_stack_evt, BT_APP_EVT_STACK_UP, NULL, 0, NULL);
}