/*
 * Copyright (C) 2021 BlueKitchen GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 * 4. Any redistribution, use, or modification is done solely for
 *    personal benefit and not for any commercial purpose or for
 *    monetary gain.
 *
 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Please inquire about commercial licensing options at 
 * contact@bluekitchen-gmbh.com
 *
 */

#define BTSTACK_FILE__ "hids_client.c"

#include "btstack_config.h"

#include <stdint.h>
#include <string.h>

#include "ble/gatt-service/hids_client.h"

#include "btstack_memory.h"
#include "ble/att_db.h"
#include "ble/core.h"
#include "ble/gatt_client.h"
#include "ble/sm.h"
#include "bluetooth_gatt.h"
#include "btstack_debug.h"
#include "btstack_event.h"
#include "btstack_run_loop.h"
#include "gap.h"

static btstack_linked_list_t clients;
static uint16_t hids_cid_counter = 0;

static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static uint16_t hids_get_next_cid(void){
    if (hids_cid_counter == 0xffff) {
        hids_cid_counter = 1;
    } else {
        hids_cid_counter++;
    }
    return hids_cid_counter;
}

static hids_client_t * hids_create_client(hci_con_handle_t con_handle, uint16_t cid){
    hids_client_t * client = btstack_memory_hids_client_get();
    if (!client){
        log_error("Not enough memory to create client");
        return NULL;
    }
    client->state = HIDS_CLIENT_STATE_IDLE;
    client->cid = cid;
    client->con_handle = con_handle;
    
    client->num_instances = 0;
    btstack_linked_list_add(&clients, (btstack_linked_item_t *) client);
    return client;
}

static void hids_finalize_client(hids_client_t * client){
    btstack_linked_list_remove(&clients, (btstack_linked_item_t *) client);
    btstack_memory_hids_client_free(client); 
}

static hids_client_t * hids_get_client_for_con_handle(hci_con_handle_t con_handle){
    btstack_linked_list_iterator_t it;    
    btstack_linked_list_iterator_init(&it, &clients);
    while (btstack_linked_list_iterator_has_next(&it)){
        hids_client_t * client = (hids_client_t *)btstack_linked_list_iterator_next(&it);
        if (client->con_handle != con_handle) continue;
        return client;
    }
    return NULL;
}

static hids_client_t * hids_get_client_for_cid(uint16_t hids_cid){
    btstack_linked_list_iterator_t it;    
    btstack_linked_list_iterator_init(&it, &clients);
    while (btstack_linked_list_iterator_has_next(&it)){
        hids_client_t * client = (hids_client_t *)btstack_linked_list_iterator_next(&it);
        if (client->cid != hids_cid) continue;
        return client;
    }
    return NULL;
}

static void hids_emit_connection_established(hids_client_t * client, uint8_t status){
    uint8_t event[7];
    int pos = 0;
    event[pos++] = HCI_EVENT_GATTSERVICE_META;
    event[pos++] = sizeof(event) - 2;
    event[pos++] = GATTSERVICE_SUBEVENT_HID_SERVICE_CONNECTED;
    little_endian_store_16(event, pos, client->cid);
    pos += 2;
    event[pos++] = status;
    event[pos++] = client->num_instances;
    (*client->client_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event));
}


static void hids_run_for_client(hids_client_t * client){
    uint8_t att_status;
    
    switch (client->state){
        case HIDS_CLIENT_STATE_W2_QUERY_SERVICE:
            client->state = HIDS_CLIENT_STATE_W4_SERVICE_RESULT;
            att_status = gatt_client_discover_primary_services_by_uuid16(handle_gatt_client_event, client->con_handle, ORG_BLUETOOTH_SERVICE_HUMAN_INTERFACE_DEVICE);
            // TODO handle status
            UNUSED(att_status);
            break;
        
        case HIDS_CLIENT_STATE_W2_QUERY_CHARACTERISTIC:
            break;

        case HIDS_CLIENT_STATE_CONNECTED:
            break;
        default:
            break;
    }
}

static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    UNUSED(packet_type);
    UNUSED(channel);     
    UNUSED(size);

    hids_client_t * client;
    uint8_t att_status;

    switch(hci_event_packet_get_type(packet)){
        case GATT_EVENT_SERVICE_QUERY_RESULT:
            client = hids_get_client_for_con_handle(gatt_event_service_query_result_get_handle(packet));
            btstack_assert(client != NULL);

            break;

        case GATT_EVENT_QUERY_COMPLETE:
            client = hids_get_client_for_con_handle(gatt_event_query_complete_get_handle(packet));
            btstack_assert(client != NULL);
            
            att_status = gatt_event_query_complete_get_att_status(packet);
            
            switch (client->state){
                case HIDS_CLIENT_STATE_W4_SERVICE_RESULT:

                    break;
                default:
                    break;
            }
            break;

        default:
            break;
    }
}

uint8_t hids_client_connect(hci_con_handle_t con_handle, btstack_packet_handler_t packet_handler, uint16_t * hids_cid){
    btstack_assert(packet_handler != NULL);
    
    hids_client_t * client = hids_get_client_for_con_handle(con_handle);
    if (client != NULL){
        return ERROR_CODE_COMMAND_DISALLOWED;
    }

    uint16_t cid = hids_get_next_cid();
    if (hids_cid != NULL) {
        *hids_cid = cid;
    }

    client = hids_create_client(con_handle, cid);
    if (client == NULL) {
        return BTSTACK_MEMORY_ALLOC_FAILED;
    }

    client->client_handler = packet_handler; 
    client->state = HIDS_CLIENT_STATE_W2_QUERY_SERVICE;

    hids_run_for_client(client);
    return ERROR_CODE_SUCCESS;
}

uint8_t hids_client_disconnect(uint16_t hids_cid){
    hids_client_t * client = hids_get_client_for_cid(hids_cid);
    if (client == NULL){
        return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
    }
    // finalize connection
    hids_finalize_client(client);
    return ERROR_CODE_SUCCESS;
}

void hids_client_init(void){}

void hids_client_deinit(void){}