/*
 *  blue.c
 *  quack
 *
 *  Created by Michel DEPEIGE on 18/07/2021.
 *  Copyright (c) 2021 Michel DEPEIGE.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the Apache License, Version 2.0 (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 <string.h>

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_bt.h"
#include "esp_bt_defs.h"
#include "esp_gap_ble_api.h"
#include "esp_gatts_api.h"
#include "esp_gatt_defs.h"
#include "esp_bt_main.h"
#include "esp_bt_device.h"

#include "esp_hidd.h"
#include "esp_hidh.h"
#include "esp_hid_gap.h"

#include "adb.h"
#include "blue.h"
#include "gpio.h"
#include "led.h"
#include "m4848.h"

/* debug tag */
static const char *TAG = "blue";

/* globals */
TaskHandle_t t_adb2hid;
extern TaskHandle_t t_click;
static esp_hidd_dev_t *hid_dev = NULL;
extern QueueHandle_t q_qx, q_qy;

/* private functions */
static void blue_d_connect(void);
static void blue_d_disconnect(esp_hidd_event_data_t *dev);
static void blue_d_init(void);
static void blue_d_start(void);
void blue_h_callback(void *handler_args, esp_event_base_t base, int32_t id, void *event_data);
static void blue_h_init(void);
static esp_hid_report_item_t blue_h_ri_find(esp_hidh_dev_t *d, esp_hid_usage_t u, uint8_t t, uint8_t p);
static void	blue_handle_button(uint8_t buttons);
static esp_hid_raw_report_map_t	*blue_hid_rm_get(esp_hidh_dev_t *dev);
void blue_set_boot_protocol(esp_hidh_dev_t *dev);
static bool blue_support_boot(esp_hidh_dev_t *dev);

/* direct calls to bluedroid */
extern void BTA_HhSetProtoMode(uint8_t handle, uint8_t t_type);

/* Device specific functions blue_d_* */
static void blue_d_callback(void *handler_args, esp_event_base_t base, int32_t id, void *event_data)
{
	esp_hidd_event_t event = (esp_hidd_event_t)id;
	esp_hidd_event_data_t *param = (esp_hidd_event_data_t *)event_data;

	switch (event) {
		case ESP_HIDD_START_EVENT: {
			blue_d_start();
			break;
		}
		case ESP_HIDD_CONNECT_EVENT: {
			blue_d_connect();
			break;
		}
		case ESP_HIDD_PROTOCOL_MODE_EVENT: {
			ESP_LOGI(TAG, "PROTOCOL MODE[%u]: %s", param->protocol_mode.map_index, param->protocol_mode.protocol_mode ? "REPORT" : "BOOT");
			break;
		}
		case ESP_HIDD_CONTROL_EVENT: {
			ESP_LOGI(TAG, "CONTROL[%u]: %sSUSPEND", param->control.map_index, param->control.control ? "EXIT_" : "");
			break;
		}
		case ESP_HIDD_OUTPUT_EVENT: {
			ESP_LOGI(TAG, "OUTPUT[%u]: %8s ID: %2u, Len: %d, Data:", param->output.map_index, esp_hid_usage_str(param->output.usage), param->output.report_id, param->output.length);
			ESP_LOG_BUFFER_HEX(TAG, param->output.data, param->output.length);
			break;
		}
		case ESP_HIDD_FEATURE_EVENT: {
			ESP_LOGI(TAG, "FEATURE[%u]: %8s ID: %2u, Len: %d, Data:", param->feature.map_index, esp_hid_usage_str(param->feature.usage), param->feature.report_id, param->feature.length);
			ESP_LOG_BUFFER_HEX(TAG, param->feature.data, param->feature.length);
			break;
		}
		case ESP_HIDD_DISCONNECT_EVENT: {
			blue_d_disconnect(param);
			break;
		}
		case ESP_HIDD_STOP_EVENT: {
			ESP_LOGI(TAG, "STOP");
			break;
		}
		default:
			break;
	}
	return;
}

static void blue_d_connect() {
	ESP_LOGI(TAG, "Host connected");
	xTaskNotify(t_blue, LED_ON, eSetValueWithOverwrite);
}

static void blue_d_disconnect(esp_hidd_event_data_t *dev) {
	ESP_LOGI(TAG, "Host disconnected, reason: %s",
			 esp_hid_disconnect_reason_str(esp_hidd_dev_transport_get(dev->disconnect.dev), dev->disconnect.reason));
	esp_hid_ble_gap_adv_start();
	xTaskNotify(t_blue, LED_SLOW, eSetValueWithOverwrite);
}

static void blue_d_init() {
	esp_err_t	ret;

	ret = esp_hid_ble_gap_adv_init(ESP_HID_APPEARANCE_MOUSE, m4848_config.device_name);
	ESP_ERROR_CHECK( ret );

	if ((ret = esp_ble_gatts_register_callback(esp_hidd_gatts_event_handler)) != ESP_OK) {
		ESP_LOGE(TAG, "GATTS register callback failed: %d", ret);
		return;
	}

	ESP_ERROR_CHECK(esp_hidd_dev_init(&m4848_config, ESP_HID_TRANSPORT_BLE, blue_d_callback, &hid_dev));
	xTaskCreate(blue_adb2hid, "ADB2BT", 2 * 1024, NULL, tskIDLE_PRIORITY + 1, &t_adb2hid);
}

/*
 * Called when the ESP HIS stack is started
 * Start advertising our Bluetooth stuff
 */

static void blue_d_start()
{
	ESP_LOGD(TAG, "Bluetooth stack started");
	xTaskNotify(t_blue, LED_SLOW, eSetValueWithOverwrite);
	esp_hid_ble_gap_adv_start();
}

/*
 * Called by the ADB stack from adb_task_host on mouse activity
 * Convert the 16bit ADB data to a 3 bytes HID INPUT REPORT matching the m4848
 */

void	blue_adb2hid(void *pvParameters) {
	uint16_t data = 0;
	uint8_t buffer[3] = {0, 0, 0};
	int8_t move = 0;
	unsigned int tmp;

	ESP_LOGD(TAG, "ADB2BT started on core %d", xPortGetCoreID());

	while (true) {
		xTaskNotifyWait(0, 0, &tmp, portMAX_DELAY);
		data = (uint16_t)tmp;

		if (! esp_hidd_dev_connected(hid_dev))
			continue;

		/* button pressed */
		if (! (data & ADB_CMP_B1) || (! (data & ADB_CMP_B2)))
			buffer[0] = (1<<0);
		else
			buffer[0] = 0;

		/*
		 * cast negative signed 7 bits to signed 8 bits
		 * then apply a slight acceleration (x^1.2)
		 */

		move = (data & ADB_CMP_MX) >> 0;
		if (move & 0x40) {
			move &= ~0x40;
			move |= 0x80;
			move += 64;
			move *= -1;
			buffer[1] = m4848_accel[move];
			buffer[1] = buffer[1] * -1;
		}
		else {
			buffer[1] = m4848_accel[move];
		}

		move = (data & ADB_CMP_MY) >> 8;
		if (move & 0x40) {
			move &= ~0x40;
			move |= 0x80;
			move += 64;
			move *= -1;
			buffer[2] = m4848_accel[move];
			buffer[2] = buffer[2] * -1;
		}
		else {
			buffer[2] = m4848_accel[move];
		}

		esp_hidd_dev_input_set(hid_dev, 1, 0, buffer, 3);
	}
}

/* Host specific functions blue_h_* */
void blue_h_callback(void *handler_args, esp_event_base_t base, int32_t id, void *event_data)
{
	esp_hidh_event_t event = (esp_hidh_event_t)id;
	esp_hidh_event_data_t *param = (esp_hidh_event_data_t *)event_data;

	const uint8_t *bda = NULL;

	/* union described in include/esp_hidh.h */
	switch (event) {
		case ESP_HIDH_OPEN_EVENT: {
			esp_hidh_dev_dump(param->open.dev, stdout);
			blue_h_open(param);
			break;
		}
		case ESP_HIDH_BATTERY_EVENT: {
			bda = esp_hidh_dev_bda_get(param->battery.dev);
			ESP_LOGI(TAG, ESP_BD_ADDR_STR " battery: %d%%", ESP_BD_ADDR_HEX(bda), param->battery.level);
			break;
		}
		case ESP_HIDH_INPUT_EVENT: {
			//ESP_LOG_BUFFER_HEX(TAG, param->input.data, param->input.length);
			xTaskNotify(t_yellow, LED_ONCE, eSetValueWithOverwrite);
			blue_h_input(param->input.dev, param->input.data, param->input.length);
			break;
					   }
		case ESP_HIDH_FEATURE_EVENT: {
			bda = esp_hidh_dev_bda_get(param->feature.dev);
							 ESP_LOGI(TAG, ESP_BD_ADDR_STR " FEATURE: %8s, MAP: %2u, ID: %3u, Len: %d", ESP_BD_ADDR_HEX(bda), esp_hid_usage_str(param->feature.usage), param->feature.map_index, param->feature.report_id, param->feature.length);
							 ESP_LOG_BUFFER_HEX(TAG, param->feature.data, param->feature.length);
							 break;
						 }
		case ESP_HIDH_CLOSE_EVENT: {
			blue_h_close(param);
			break;
		}
		default:
			ESP_LOGI(TAG, "Unknwown event: %d", event);
	}
}

void blue_h_close(esp_hidh_event_data_t *p) {
	const uint8_t *bda = NULL;

	configASSERT(p != NULL);
	bda = esp_hidh_dev_bda_get(p->close.dev);
	ESP_LOGI(TAG, "closed connection with device " ESP_BD_ADDR_STR, ESP_BD_ADDR_HEX(bda));
	esp_hidh_dev_free(p->close.dev);

	xTaskNotify(t_blue, LED_SLOW, eSetValueWithOverwrite);
}

static void	blue_handle_button(uint8_t buttons) {
	static bool	status = BLUE_BUTTON_N;	// Keep state

	buttons = buttons & (BLUE_BUTTON_1 | BLUE_BUTTON_2 | BLUE_BUTTON_3);

	if (status && buttons)
		return ;
	if (status == BLUE_BUTTON_N && buttons == BLUE_BUTTON_N)
		return ;

	/* release button */
	if (status && buttons == BLUE_BUTTON_N) {
		xTaskNotify(t_click, 0, eSetValueWithOverwrite);
		status = 0;
		ESP_LOGD(TAG, "button released");
		return ;
	}

	/* press button */
	if (status == BLUE_BUTTON_N && buttons) {
		xTaskNotify(t_click, 1, eSetValueWithOverwrite);
		status = 1;
		ESP_LOGD(TAG, "button pressed");
		return ;
	}

}

static void blue_h_init(void) {
	esp_hidh_config_t config = {
		.callback = blue_h_callback,
		.event_stack_size = 4096
	};

	ESP_ERROR_CHECK(esp_hidh_init(&config));

	xTaskCreatePinnedToCore(blue_scan, "blue_scan", 6 * 1024, NULL, 2, NULL, 0);
}

/*
 * Bluetooth common init: init module and various stuff
 * Host or Device specific inits go in blue_d_init() or blue_h_init()
 */
void blue_init(void)
{
	esp_err_t	ret;

	ret = nvs_flash_init();
	if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
		ESP_ERROR_CHECK(nvs_flash_erase());
		ret = nvs_flash_init();
	}

	ESP_LOGD(TAG, "Starting Bluetooth init on core %d", xPortGetCoreID());
	ESP_ERROR_CHECK(ret);
	/* ESP_BT_MODE_CLASSIC_BT doesn't work, it freezes esp_hidh_init */
	ESP_ERROR_CHECK(esp_hid_gap_init(ESP_BT_MODE_BTDM));
	ESP_ERROR_CHECK(esp_ble_gattc_register_callback(esp_hidh_gattc_event_handler));

	esp_log_level_set("event", ESP_LOG_INFO);
	/* complains about wrong data len on BOOT mode and CCONTROL */
	esp_log_level_set("BT_HIDH", ESP_LOG_ERROR);

    /*
     * at this point, everything but bluetooth is started.
     * put green steady, start blinking blue and keep scanning until a device is found
     */

    xTaskNotify(t_green, LED_ON, eSetValueWithOverwrite);
    xTaskNotify(t_blue, LED_FAST, eSetValueWithOverwrite);

	if (adb_is_host())
		blue_d_init();
	else
		blue_h_init();
}

/*
 * data follows HID Mouse boot protocol format
 *
 * Byte | Bits | Description
 * -----+------+---------------------------------------------------------------
 * 0    | 0    | Button 1 (left)
 * 0    | 1    | Button 2 (right)
 * 0    | 2    | Button 3 (middle)
 * 0    | 3-7  | Device specific, usually unused (0)
 * 1    | 0-7  | X Displacement
 * 2    | 0-7  | Y Displacement
 * 3+   | 0-7  | Device specific, usually 3 is scroll wheel, usually unused (0)
 */

void blue_h_input(esp_hidh_dev_t *dev, uint8_t *data, uint16_t length) {
	uint8_t buttons;
	uint8_t	i;
	int8_t x, y;

	buttons = data[0];

	/*
	 * Do some checks before parsing data. We sould't get anything wrong in theory,
	 * but we sometimes to get shit from either mouse or bluetooth stack
	 *
	 * Stack issue: https://github.com/espressif/esp-idf/issues/6985
	 */

	if (length < 3) {
		xTaskNotify(t_red, LED_ONCE, eSetValueWithOverwrite);
		return;
	}
	if (buttons & BLUE_BUTTON_E) {
		xTaskNotify(t_red, LED_ONCE, eSetValueWithOverwrite);
		return;
	}

	/*
	 * we also want to ignore anything that contains scroll wheel & co for now
	 * statistically theses are corrupted packets
	 */

	for (i = 3; i < length; i++) {
		if (data[i]) {
			xTaskNotify(t_red, LED_ONCE, eSetValueWithOverwrite);
			return;
		}
	}

	blue_handle_button(buttons);

	/* quadrature use 7 bits x/y offsets, bluetooth BOOT uses 8 bits */
	x = data[1];
	y = data[2];

	/* reduce bluetooth movement speed as well before notifying */
	if (x != 0) {
		if (x == 1 || x == -1) {
			xQueueSendToBack(q_qx, &x, 0);
		}
		else {
			x /= 2;
			xQueueSendToBack(q_qx, &x, 0);
		}
	}
	if (y != 0) {
		if (y == 1 || y == -1) {
			xQueueSendToBack(q_qy, &y, 0);
		}
		else {
			y /= 2;
			xQueueSendToBack(q_qy, &y, 0);
		}
	}
}

void blue_h_open(esp_hidh_event_data_t *p) {
    const uint8_t *bda = NULL;

	configASSERT(p != NULL);
    bda = esp_hidh_dev_bda_get(p->open.dev);
    ESP_LOGI(TAG, "opened connection with " ESP_BD_ADDR_STR, ESP_BD_ADDR_HEX(bda));

	/* Dump various info on console */
	blue_hid_rm_get(p->open.dev);
	blue_set_boot_protocol(p->open.dev);
	if (blue_support_boot(p->open.dev) == false) {
		xTaskNotify(t_red, LED_ONCE, eSetValueWithOverwrite);
		ESP_LOGE(TAG, "Mouse does not support boot protocol !");
	}

    xTaskNotify(t_blue, LED_ON, eSetValueWithOverwrite);
    gpio_output_enable();
}

/* get specific report from report map matching specified usage + type + protocol */
static esp_hid_report_item_t blue_h_ri_find(esp_hidh_dev_t *d, esp_hid_usage_t u, uint8_t t, uint8_t p) {
	size_t num_reports = 0;
	esp_hid_report_item_t *reports;
	esp_hid_report_item_t search;

	configASSERT(d != NULL);
	configASSERT(p <= ESP_HID_REPORT_TYPE_FEATURE);
	configASSERT(t > 0);

	esp_hidh_dev_reports_get(d, &num_reports, &reports);
	memset(&search, 0, sizeof(esp_hid_report_item_t));

	for (uint8_t i = 0; i < num_reports; i++) {
		if (reports[i].protocol_mode == p && reports[i].report_type == t &&	reports[i].usage == u) {
			memcpy(&search, &reports[i], sizeof(esp_hid_report_item_t));
			break;
		}
	}

	free(reports);
	if (search.value_len == 0) {
		ESP_LOGW(TAG, "%s %s %s not found",
				 esp_hid_usage_str(u),
				 esp_hid_report_type_str(t),
				 esp_hid_protocol_mode_str(p));
	}
	else {
		ESP_LOGD(TAG, "%s %s %s is id %i size %i byte(s)",
				 esp_hid_usage_str(u),
				 esp_hid_report_type_str(t),
				 esp_hid_protocol_mode_str(p),
				 search.report_id,
				 search.value_len);
	}

	return search;
}

/* get report map raw pointer. Also dump it on JTAG */
static esp_hid_raw_report_map_t *blue_hid_rm_get(esp_hidh_dev_t *dev) {
	size_t num_maps = 0;
	esp_hid_raw_report_map_t *maps;

	configASSERT(dev != NULL);
	ESP_LOGI(TAG, BLUE_SNIP);
	esp_hidh_dev_report_maps_get(dev, &num_maps, &maps);
	ESP_LOG_BUFFER_HEX(TAG, maps[0].data, maps[0].len);
	ESP_LOGI(TAG, BLUE_SNIP);

	/* looking at 4.2 SDK source, seems there is always only one map */
	configASSERT(num_maps == 1);
	return maps;
}

void blue_scan(void *pvParameters) {
    size_t len = 0;
    esp_hid_scan_result_t *mouse = NULL;
    esp_hid_scan_result_t *results = NULL;

    ESP_LOGI(TAG, "starting scan on core %d…", xPortGetCoreID());
    esp_hid_scan(BLUE_SCAN_DURATION, &len, &results);
    ESP_LOGI(TAG, "scan returned %u result(s)", len);
	xTaskNotify(t_blue, LED_SLOW, eSetValueWithOverwrite);

    if (len) {
        esp_hid_scan_result_t *r = results;

        while (r) {
            ESP_LOGI(TAG, "found %s %s device: " ESP_BD_ADDR_STR ", RSSI: %d, NAME: %s",
					 (r->transport == ESP_HID_TRANSPORT_BLE) ? "BLE" : "BT",
					 esp_hid_cod_major_str(r->bt.cod.major),
					 ESP_BD_ADDR_HEX(r->bda), r->rssi, r->name ? r->name : "");

			/* search for something that looks like Bluetooth Classic mouse */
            if (r->transport == ESP_HID_TRANSPORT_BT &&
				strcmp("PERIPHERAL", esp_hid_cod_major_str(r->bt.cod.major)) == 0
				&& (r->bt.cod.minor & ESP_HID_COD_MIN_MOUSE)) {
                    mouse = r;
            }
            r = r->next;
        }

        /* try to connect to the last candidate found */
        if (mouse)
            esp_hidh_dev_open(mouse->bda, mouse->transport, mouse->ble.addr_type);
        else
            ESP_LOGI(TAG, "devices found but no mouse detected");

        esp_hid_scan_results_free(results);
    }

    vTaskDelete(NULL);
}

void blue_set_boot_protocol(esp_hidh_dev_t *dev) {
	configASSERT(dev != NULL);

	/*
	 * /!\ Disclaimer /!\
	 * This is ugly. We are accessing directly bluedroid and need the hidden handle to do that
	 * Extract it from a private esp_hidh_dev_s struct and call BTA_HhSetProtoMode directly.
	 */

	struct decoy_dev_s {
		struct esp_hidh_dev_s   *next;

		esp_hid_device_config_t config;
		esp_hid_usage_t         usage;
		esp_hid_transport_t     transport;
		bool                    connected;
		bool                    opened;
		int                     status;

		size_t                  reports_len;
		void                    *reports;

		void                    *tmp;
		size_t                  tmp_len;

		xSemaphoreHandle        semaphore;

		esp_err_t               (*close)        (esp_hidh_dev_t *dev);
		esp_err_t               (*report_write) (esp_hidh_dev_t *dev, size_t map_index, size_t report_id, int report_type, uint8_t *data, size_t len);
		esp_err_t               (*report_read)  (esp_hidh_dev_t *dev, size_t map_index, size_t report_id, int report_type, size_t max_length, uint8_t *value, size_t *value_len);
		void                    (*dump)         (esp_hidh_dev_t *dev, FILE *fp);

		esp_bd_addr_t bda;

		struct {
			esp_bt_cod_t cod;
			int handle;
			uint8_t sub_class;
			uint8_t app_id;
			uint16_t attr_mask;
		} bt;
		TAILQ_ENTRY(esp_hidh_dev_s) devices;
	};

	struct decoy_dev_s *pass_that_handle;
	pass_that_handle = (struct decoy_dev_s *)dev;

	ESP_LOGI(TAG, "switching " ESP_BD_ADDR_STR " (%i) to protocol mode boot" ,
			 ESP_BD_ADDR_HEX(pass_that_handle->bda), pass_that_handle->bt.handle);

	//ESP_LOG_BUFFER_HEX(TAG, dev, sizeof(struct decoy_dev_s));
	/* bluedroid/bta/include/bta_hh_api.h */
	BTA_HhSetProtoMode(pass_that_handle->bt.handle, 0x01);
}

static bool blue_support_boot(esp_hidh_dev_t *dev) {
	esp_hid_report_item_t	mib;

	configASSERT(dev != NULL);
	mib = blue_h_ri_find(dev, ESP_HID_USAGE_MOUSE, ESP_HID_REPORT_TYPE_INPUT, ESP_HID_PROTOCOL_MODE_BOOT);
	if (mib.value_len == 0)
		return false;
	return true;
}