/**
 * NEURON IIoT System for Industry 4.0
 * Copyright (C) 2020-2022 EMQ Technologies Co., Ltd All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 **/
#include <stdlib.h>

#include <neuron.h>

#include "errcodes.h"

#include "modbus_point.h"
#include "modbus_req.h"
#include "modbus_stack.h"

static neu_plugin_t *driver_open(void);

static int driver_close(neu_plugin_t *plugin);
static int driver_init(neu_plugin_t *plugin, bool load);
static int driver_uninit(neu_plugin_t *plugin);
static int driver_start(neu_plugin_t *plugin);
static int driver_stop(neu_plugin_t *plugin);
static int driver_config(neu_plugin_t *plugin, const char *config);
static int driver_request(neu_plugin_t *plugin, neu_reqresp_head_t *head,
                          void *data);
static int driver_connect(neu_plugin_t *plugin);

static int driver_validate_tag(neu_plugin_t *plugin, neu_datatag_t *tag);
static int driver_group_timer(neu_plugin_t *plugin, neu_plugin_group_t *group);
static int driver_write(neu_plugin_t *plugin, void *req, neu_datatag_t *tag,
                        neu_value_u value);
static int driver_write_tags(neu_plugin_t *plugin, void *req, UT_array *tags);
static int driver_test_read_tag(neu_plugin_t *plugin, void *req,
                                neu_datatag_t tag);

static const neu_plugin_intf_funs_t plugin_intf_funs = {
    .open        = driver_open,
    .close       = driver_close,
    .init        = driver_init,
    .uninit      = driver_uninit,
    .start       = driver_start,
    .stop        = driver_stop,
    .setting     = driver_config,
    .request     = driver_request,
    .try_connect = driver_connect,

    .driver.validate_tag  = driver_validate_tag,
    .driver.group_timer   = driver_group_timer,
    .driver.group_sync    = driver_group_timer,
    .driver.write_tag     = driver_write,
    .driver.tag_validator = NULL,
    .driver.write_tags    = driver_write_tags,
    .driver.test_read_tag = driver_test_read_tag,
    .driver.add_tags      = NULL,
    .driver.load_tags     = NULL,
    .driver.del_tags      = NULL,
    .driver.directory     = NULL,
    .driver.fup_open      = NULL,
    .driver.fup_data      = NULL,
    .driver.fdown_open    = NULL,
    .driver.fdown_data    = NULL,
};

const neu_plugin_module_t neu_plugin_module = {
    .version     = NEURON_PLUGIN_VER_1_0,
    .schema      = "modbus-tcp",
    .module_name = "Modbus TCP",
    .module_descr =
        "This plugin is used to connect devices using the modbus TCP protocol "
        "Users can choose to connect as a client or a server. Support TCP and "
        "UDP communication methods.",
    .module_descr_zh =
        "该插件用于连接使用 modbus tcp 协议的设备。"
        "用户可选择作为客户端连接，或是服务端连接,支持 TCP 和 UDP 通信方式。",
    .intf_funs = &plugin_intf_funs,
    .kind      = NEU_PLUGIN_KIND_SYSTEM,
    .type      = NEU_NA_TYPE_DRIVER,
    .display   = true,
    .single    = false,
};

static neu_plugin_t *driver_open(void)
{
    neu_plugin_t *plugin = calloc(1, sizeof(neu_plugin_t));

    neu_plugin_common_init(&plugin->common);

    return plugin;
}

static int driver_close(neu_plugin_t *plugin)
{
    free(plugin);

    return 0;
}

static int driver_init(neu_plugin_t *plugin, bool load)
{
    (void) load;
    plugin->protocol = MODBUS_PROTOCOL_TCP;
    plugin->events   = neu_event_new(plugin->common.name);
    plugin->stack    = modbus_stack_create((void *) plugin, MODBUS_PROTOCOL_TCP,
                                        modbus_send_msg, modbus_value_handle,
                                        modbus_write_resp);

    plog_notice(plugin, "%s init success", plugin->common.name);
    return 0;
}

static int driver_uninit(neu_plugin_t *plugin)
{
    plog_notice(plugin, "%s uninit start", plugin->common.name);
    if (plugin->conn != NULL) {
        neu_conn_destory(plugin->conn);
    }

    if (plugin->stack) {
        modbus_stack_destroy(plugin->stack);
    }

    // Repair: Release the corresponding IP memory according to the current
    // mode.
    if (plugin->is_server) {
        if (plugin->param.params.tcp_server.ip != NULL) {
            free(plugin->param.params.tcp_server.ip);
            plugin->param.params.tcp_server.ip = NULL;
        }
    } else {
        if (plugin->param.params.tcp_client.ip != NULL) {
            free(plugin->param.params.tcp_client.ip);
            plugin->param.params.tcp_client.ip = NULL;
        }
    }
    // Fix: Release the backup IP memory.
    if (plugin->param_backup.params.tcp_client.ip != NULL) {
        free(plugin->param_backup.params.tcp_client.ip);
        plugin->param_backup.params.tcp_client.ip = NULL;
    }

    neu_event_close(plugin->events);

    plog_notice(plugin, "%s uninit success", plugin->common.name);

    return 0;
}

static int driver_start(neu_plugin_t *plugin)
{
    neu_conn_start(plugin->conn);
    plog_notice(plugin, "%s start success", plugin->common.name);
    return 0;
}

static int driver_stop(neu_plugin_t *plugin)
{
    neu_conn_stop(plugin->conn);
    plog_notice(plugin, "%s stop success", plugin->common.name);
    return 0;
}

static int driver_config(neu_plugin_t *plugin, const char *config)
{
    int              ret       = 0;
    char *           err_param = NULL;
    neu_json_elem_t  port      = { .name = "port", .t = NEU_JSON_INT };
    neu_json_elem_t  timeout   = { .name = "timeout", .t = NEU_JSON_INT };
    neu_json_elem_t  host      = { .name      = "host",
                             .t         = NEU_JSON_STR,
                             .v.val_str = NULL };
    neu_json_elem_t  interval  = { .name = "interval", .t = NEU_JSON_INT };
    neu_json_elem_t  mode  = { .name = "connection_mode", .t = NEU_JSON_INT };
    neu_conn_param_t param = { 0 };
    neu_json_elem_t  max_retries = { .name = "max_retries", .t = NEU_JSON_INT };
    neu_json_elem_t  retry_interval = { .name = "retry_interval",
                                       .t    = NEU_JSON_INT };
    neu_json_elem_t  check_header   = { .name = "check_header",
                                     .t    = NEU_JSON_INT };

    neu_json_elem_t degradation   = { .name = "device_degrade",
                                    .t    = NEU_JSON_INT };
    neu_json_elem_t degrade_cycle = { .name = "degrade_cycle",
                                      .t    = NEU_JSON_INT };
    neu_json_elem_t degrade_time  = { .name = "degrade_time",
                                     .t    = NEU_JSON_INT };

    neu_json_elem_t endianess    = { .name = "endianess", .t = NEU_JSON_INT };
    neu_json_elem_t address_base = { .name = "address_base",
                                     .t    = NEU_JSON_INT };
    neu_json_elem_t endianess_64 = { .name = "endianess_64",
                                     .t    = NEU_JSON_INT };

    neu_json_elem_t  backup_ip   = { .name      = "backup_host",
                                  .t         = NEU_JSON_STR,
                                  .v.val_str = NULL };
    neu_json_elem_t  backup_port = { .name = "backup_port", .t = NEU_JSON_INT };
    neu_conn_param_t param_backup = { 0 };
    bool             backup       = false;

    ret = neu_parse_param((char *) config, &err_param, 5, &port, &host, &mode,
                          &timeout, &interval);

    if (ret != 0) {
        plog_error(plugin, "config: %s, decode error: %s", config, err_param);
        free(err_param);
        if (host.v.val_str != NULL) {
            free(host.v.val_str);
        }
        return -1;
    }

    if (timeout.v.val_int <= 0) {
        plog_error(plugin, "config: %s, set timeout error: %s", config,
                   err_param);
        free(err_param);
        return -1;
    }

    ret = neu_parse_param((char *) config, &err_param, 2, &max_retries,
                          &retry_interval);
    if (ret != 0) {
        free(err_param);
        max_retries.v.val_int    = 0;
        retry_interval.v.val_int = 0;
    }

    ret = neu_parse_param((char *) config, &err_param, 1, &check_header);
    if (ret != 0) {
        free(err_param);
        check_header.v.val_int = 0;
    }

    ret = neu_parse_param((char *) config, &err_param, 3, &degradation,
                          &degrade_cycle, &degrade_time);
    if (ret != 0) {
        free(err_param);
        degradation.v.val_int   = 0;
        degrade_cycle.v.val_int = 2;
        degrade_time.v.val_int  = 600;
    }

    ret = neu_parse_param((char *) config, &err_param, 1, &endianess);
    if (ret != 0) {
        free(err_param);
        endianess.v.val_int = MODBUS_ABCD;
    }

    ret = neu_parse_param((char *) config, &err_param, 1, &address_base);
    if (ret != 0) {
        free(err_param);
        address_base.v.val_int = base_1;
    }

    ret = neu_parse_param((char *) config, &err_param, 2, &backup_ip,
                          &backup_port);
    if (ret != 0) {
        free(err_param);
    } else {
        backup = true;
    }

    ret = neu_parse_param((char *) config, &err_param, 1, &endianess_64);
    if (ret != 0) {
        free(err_param);
        endianess_64.v.val_int = MODBUS_LL;
    }

    param.log              = plugin->common.log;
    param_backup.log       = plugin->common.log;
    plugin->interval       = interval.v.val_int;
    plugin->max_retries    = max_retries.v.val_int;
    plugin->retry_interval = retry_interval.v.val_int;
    plugin->check_header   = check_header.v.val_int;
    plugin->degradation    = degradation.v.val_int;
    plugin->degrade_cycle  = degrade_cycle.v.val_int;
    plugin->degrade_time   = degrade_time.v.val_int;
    plugin->endianess      = endianess.v.val_int;
    plugin->endianess_64   = endianess_64.v.val_int;
    plugin->address_base   = address_base.v.val_int;

    if (mode.v.val_int == 1) {
        param.type                 = NEU_CONN_TCP_SERVER;
        param.params.tcp_server.ip = strdup(
            host.v.val_str); // fix: Create a copy instead of direct assignment
        param.params.tcp_server.port         = port.v.val_int;
        param.params.tcp_server.start_listen = modbus_tcp_server_listen;
        param.params.tcp_server.stop_listen  = modbus_tcp_server_stop;
        param.params.tcp_server.timeout      = timeout.v.val_int;
        param.params.tcp_server.max_link     = 1;
        backup                               = false;

        // Fix: Release previous memory when switching to Server mode. Note: Due
        // to union sharing memory, it is necessary to determine how to release
        // based on the previous mode.
        if (!plugin->is_server) {
            // before client to server
            if (plugin->param.params.tcp_client.ip != NULL) {
                free(plugin->param.params.tcp_client.ip);
                plugin->param.params.tcp_client.ip = NULL;
            }
        } else {
            // before server to server
            if (plugin->param.params.tcp_server.ip != NULL) {
                free(plugin->param.params.tcp_server.ip);
                plugin->param.params.tcp_server.ip = NULL;
            }
        }

        plugin->is_server = true;

        if (plugin->param_backup.params.tcp_client.ip != NULL) {
            free(plugin->param_backup.params.tcp_client.ip);
            plugin->param_backup.params.tcp_client.ip = NULL;
        }
    }
    if (mode.v.val_int == 0) {
        param.type = NEU_CONN_TCP_CLIENT;
        // Fix: Release memory based on the previous mode when switching to
        // Client mode
        if (plugin->is_server) {
            // before server to client
            if (plugin->param.params.tcp_server.ip != NULL) {
                free(plugin->param.params.tcp_server.ip);
                plugin->param.params.tcp_server.ip = NULL;
            }
        } else {
            // before client to client
            if (plugin->param.params.tcp_client.ip != NULL) {
                free(plugin->param.params.tcp_client.ip);
                plugin->param.params.tcp_client.ip = NULL;
            }
        }
        plugin->is_server = false;

        param.params.tcp_client.ip      = strdup(host.v.val_str);
        param.params.tcp_client.port    = port.v.val_int;
        param.params.tcp_client.timeout = timeout.v.val_int;

        param_backup.type = NEU_CONN_TCP_CLIENT;
        if (backup_ip.v.val_str != NULL) {
            if (plugin->param_backup.params.tcp_client.ip != NULL) {
                free(plugin->param_backup.params.tcp_client.ip);
                plugin->param_backup.params.tcp_client.ip = NULL;
            }
            param_backup.params.tcp_client.ip = strdup(backup_ip.v.val_str);
        }
        param_backup.params.tcp_client.port    = backup_port.v.val_int;
        param_backup.params.tcp_client.timeout = timeout.v.val_int;
    }

    plugin->backup       = backup;
    plugin->param        = param;
    plugin->param_backup = param_backup;

    plog_notice(plugin,
                "config: host: %s, port: %" PRId64 ", mode: %" PRId64 "",
                host.v.val_str, port.v.val_int, mode.v.val_int);

    if (plugin->conn != NULL) {
        plugin->conn = neu_conn_reconfig(plugin->conn, &param);
    } else {
        plugin->common.link_state = NEU_NODE_LINK_STATE_DISCONNECTED;
        plugin->conn =
            neu_conn_new(&param, (void *) plugin, modbus_conn_connected,
                         modbus_conn_disconnected);
    }

    if (host.v.val_str != NULL) {
        free(host.v.val_str);
        host.v.val_str = NULL;
    }
    if (backup_ip.v.val_str != NULL) {
        free(backup_ip.v.val_str);
        backup_ip.v.val_str = NULL;
    }

    return 0;
}

static int driver_connect(neu_plugin_t *plugin)
{
    if (plugin->conn != NULL) {
        if (neu_conn_is_connected(plugin->conn)) {
            plugin->common.link_state = NEU_NODE_LINK_STATE_CONNECTED;
        } else {
            neu_conn_connect(plugin->conn);
            if (neu_conn_is_connected(plugin->conn)) {
                plugin->common.link_state = NEU_NODE_LINK_STATE_CONNECTED;
            }
        }
    }
    return 0;
}

static int driver_request(neu_plugin_t *plugin, neu_reqresp_head_t *head,
                          void *data)
{
    (void) plugin;
    (void) head;
    (void) data;
    return 0;
}

static int driver_validate_tag(neu_plugin_t *plugin, neu_datatag_t *tag)
{
    modbus_point_t point = { 0 };

    int ret = modbus_tag_to_point(tag, &point, plugin->address_base);
    if (ret == 0) {
        plog_notice(
            plugin,
            "validate tag success, name: %s, address: %s, type: %d, slave id: "
            "%d, start address: %d, n register: %d, area: %s",
            tag->name, tag->address, tag->type, point.slave_id,
            point.start_address, point.n_register,
            modbus_area_to_str(point.area));
    } else {
        plog_error(
            plugin,
            "validate tag error, name: %s, address: %s, type: %d, slave id: "
            "%d, start address: %d, n register: %d, area: %s",
            tag->name, tag->address, tag->type, point.slave_id,
            point.start_address, point.n_register,
            modbus_area_to_str(point.area));
    }
    return ret;
}

static int driver_group_timer(neu_plugin_t *plugin, neu_plugin_group_t *group)
{
    return modbus_group_timer(plugin, group, 0xfa);
}

static int driver_write(neu_plugin_t *plugin, void *req, neu_datatag_t *tag,
                        neu_value_u value)
{
    return modbus_write_tag(plugin, req, tag, value);
}

static int driver_write_tags(neu_plugin_t *plugin, void *req, UT_array *tags)
{
    return modbus_write_tags(plugin, req, tags);
}

static int driver_test_read_tag(neu_plugin_t *plugin, void *req,
                                neu_datatag_t tag)
{
    return modbus_test_read_tag(plugin, req, tag);
}