/*
 Itay Marom
 Cisco Systems, Inc.
*/

/*
Copyright (c) 2015-2015 Cisco Systems, Inc.

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.
*/

#ifndef __TREX_RPC_CMD_API_H__
#define __TREX_RPC_CMD_API_H__

#include <string>
#include <vector>
#include <json/json.h>
#include <trex_rpc_exception_api.h>

/**
 * describe different types of rc for run()
 */
typedef enum trex_rpc_cmd_rc_ {
    TREX_RPC_CMD_OK,
    TREX_RPC_CMD_PARSE_ERR,
    TREX_RPC_CMD_EXECUTE_ERR,
    TREX_RPC_CMD_INTERNAL_ERR
} trex_rpc_cmd_rc_e;

/**
 * simple exception for RPC command processing
 * 
 * @author imarom (23-Aug-15)
 */
class TrexRpcCommandException : TrexRpcException {
public:
    TrexRpcCommandException(trex_rpc_cmd_rc_e rc) : m_rc(rc) {

    }

    trex_rpc_cmd_rc_e get_rc() {
        return m_rc;

    }

protected:
    trex_rpc_cmd_rc_e m_rc;
};

/**
 * interface for RPC command
 * 
 * @author imarom (13-Aug-15)
 */
class TrexRpcCommand {
public:

    /**
     * method name and params
     */
    TrexRpcCommand(const std::string &method_name, int param_count) : m_name(method_name), m_param_count(param_count) {

    }

    /**
     * entry point for executing RPC command
     * 
     */
    trex_rpc_cmd_rc_e run(const Json::Value &params, Json::Value &result);

    const std::string &get_name() {
        return m_name;
    }

    virtual ~TrexRpcCommand() {}

protected:

    /**
     * different types of fields
     */
    enum field_type_e {
        FIELD_TYPE_BYTE,
        FIELD_TYPE_UINT16,
        FIELD_TYPE_INT,
        FIELD_TYPE_DOUBLE,
        FIELD_TYPE_BOOL,
        FIELD_TYPE_STR,
        FIELD_TYPE_OBJ,
        FIELD_TYPE_ARRAY
    };

    /**
     * implemented by the dervied class
     * 
     */
    virtual trex_rpc_cmd_rc_e _run(const Json::Value &params, Json::Value &result) = 0;

    /**
     * check param count
     */
    void check_param_count(const Json::Value &params, int expected, Json::Value &result);

    /**
     * parse functions
     * 
     */
    uint8_t  parse_byte(const Json::Value &parent, const std::string &name, Json::Value &result);
    uint16_t parse_uint16(const Json::Value &parent, const std::string &name, Json::Value &result);
    int      parse_int(const Json::Value &parent, const std::string &name, Json::Value &result);
    double   parse_double(const Json::Value &parent, const std::string &name, Json::Value &result);
    bool     parse_bool(const Json::Value &parent, const std::string &name, Json::Value &result);
    const std::string  parse_string(const Json::Value &parent, const std::string &name, Json::Value &result);
    const Json::Value & parse_object(const Json::Value &parent, const std::string &name, Json::Value &result);
    const Json::Value & parse_array(const Json::Value &parent, const std::string &name, Json::Value &result);

    uint8_t  parse_byte(const Json::Value &parent, int index, Json::Value &result);
    uint16_t parse_uint16(const Json::Value &parent, int index, Json::Value &result);
    int      parse_int(const Json::Value &parent, int index, Json::Value &result);
    double   parse_double(const Json::Value &parent, int index, Json::Value &result);
    bool     parse_bool(const Json::Value &parent, int index, Json::Value &result);
    const std::string  parse_string(const Json::Value &parent, int index, Json::Value &result);
    const Json::Value & parse_object(const Json::Value &parent, int index, Json::Value &result);
    const Json::Value & parse_array(const Json::Value &parent, int index, Json::Value &result);

    /**
     * parse a field from choices 
     * 
     */
    template<typename T> T parse_choice(const Json::Value &params, const std::string &name, std::initializer_list<T> choices, Json::Value &result) {
        const Json::Value &field = params[name];

        if (field == Json::Value::null) {
            std::stringstream ss;
            ss << "field '" << name << "' is missing";
            generate_parse_err(result, ss.str());
        }

        for (auto x : choices) {
            if (field == x) {
                return (x);
            }
        }

        std::stringstream ss;

        ss << "field '" << name << "' can only be one of [";
        for (auto x : choices) {
            ss << "'" << x << "' ,";
        }

        std::string s = ss.str();
        s.pop_back();
        s.pop_back();
        s += "]";
        generate_parse_err(result, s);
    }

    /**
     * check field type
     * 
     */
    void check_field_type(const Json::Value &parent, const std::string &name, field_type_e type, Json::Value &result);
    void check_field_type(const Json::Value &parent, int index, field_type_e type, Json::Value &result);
    void check_field_type_common(const Json::Value &field, const std::string &name, field_type_e type, Json::Value &result);

    /**
     * error generating functions
     * 
     */
    void generate_parse_err(Json::Value &result, const std::string &msg);


    /**
     * method execute error
     * 
     */
    void generate_execute_err(Json::Value &result, const std::string &msg);

    /**
     * internal error
     * 
     */
    void generate_internal_err(Json::Value &result, const std::string &msg);


    /**
     * translate enum to string
     * 
     */
    const char * type_to_str(field_type_e type);

    /**
     * translate JSON values to string
     * 
     */
    const char * json_type_to_name(const Json::Value &value);

    /* RPC command name */
    std::string   m_name;
    int           m_param_count;
};

#endif /* __TREX_RPC_CMD_API_H__ */