/*
 *
 *    Copyright (c) 2017 Nest Labs, Inc.
 *    All rights reserved.
 *
 *    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.
 */

/**
 *    @file
 *      Support functions for parsing command-line arguments.
 *
 */

#ifndef NLARGPARSER_H_
#define NLARGPARSER_H_

#include <Weave/Core/WeaveCore.h>

#if WEAVE_CONFIG_ENABLE_ARG_PARSER

#include <stdlib.h>

namespace nl {
namespace ArgParser {

struct OptionSet;

/**
 * A function that can be called to handle a set of command line options.
 */
typedef bool (*OptionHandlerFunct)(const char *progName, OptionSet *optSet, int id, const char *name, const char *arg);


/**
 * A function that can be called to handle any remaining, non-option command line arguments.
 */
typedef bool (*NonOptionArgHandlerFunct)(const char *progName, int argc, char *argv[]);


/**
 * Defines the argument requirements for a command line option.
 */
enum OptionArgumentType
{
    kNoArgument         = 0,
    kArgumentRequired   = 1,
    kArgumentOptional   = 2,
};

/**
 * Defines a command line option.
 */
struct OptionDef
{
    const char *Name;                   /**< Long name for the option */
    OptionArgumentType ArgType;         /**< An enumerated value specifying whether the option takes an argument */
    uint16_t Id;                        /**< An integer id for the option.  If the value falls in the range of
                                             graphical ASCII characters the value is also used as the short name
                                             for the option. */
};

/**
 * Defines a group of logically-related and reusable command line options.
 */
struct OptionSet
{
    OptionHandlerFunct OptionHandler;   /**< Pointer to function for processing individual options */
    OptionDef *OptionDefs;              /**< NULL terminated list of option definitions structures. */
    const char *HelpGroupName;          /**< Group name under which options appear in help output */
    const char *OptionHelp;             /**< Help text describing options */
};

/**
 * An OptionSet where the handler is a virtual function.
 */
class OptionSetBase : public OptionSet
{
public:
    OptionSetBase();
    virtual bool HandleOption(const char *progName, OptionSet *optSet, int id, const char *name, const char *arg) = 0;

private:
    static bool CallHandleFunct(const char *progName, OptionSet *optSet, int id, const char *name, const char *arg);
};

extern bool ParseArgs(const char *progName, int argc, char *argv[], OptionSet *optSets[]);
extern bool ParseArgs(const char *progName, int argc, char *argv[], OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler);
extern bool ParseArgs(const char *progName, int argc, char *argv[], OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler, bool ignoreUnknown);

extern bool ParseArgsFromString(const char *progName, const char *argStr, OptionSet *optSets[]);
extern bool ParseArgsFromString(const char *progName, const char *argStr, OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler);
extern bool ParseArgsFromString(const char *progName, const char *argStr, OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler, bool ignoreUnknown);

extern bool ParseArgsFromEnvVar(const char *progName, const char *varName, OptionSet *optSets[]);
extern bool ParseArgsFromEnvVar(const char *progName, const char *varName, OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler);
extern bool ParseArgsFromEnvVar(const char *progName, const char *varName, OptionSet *optSets[], NonOptionArgHandlerFunct nonOptArgHandler, bool ignoreUnknown);

extern void PrintOptionHelp(OptionSet *optionSets[], FILE *s);

extern void (*PrintArgError)(const char *msg, ...);
extern void DefaultPrintArgError(const char *msg, ...);

// Utility functions for parsing common argument value types.
extern bool ParseBoolean(const char *str, bool& output);
extern bool ParseInt(const char *str, uint8_t& output);
extern bool ParseInt(const char *str, uint16_t& output);
extern bool ParseInt(const char *str, int32_t& output);
extern bool ParseInt(const char *str, uint32_t& output);
extern bool ParseInt(const char *str, uint64_t& output);
extern bool ParseInt(const char *str, int32_t& output, int base);
extern bool ParseInt(const char *str, uint32_t& output, int base);
extern bool ParseInt(const char *str, uint64_t& output, int base);
extern bool ParseIPAddress(const char *str, nl::Inet::IPAddress& output);
extern bool ParseNodeId(const char *str, uint64_t& nodeId);
extern bool ParseFabricId(const char *str, uint64_t& fabricId, bool allowReserved = false);
extern bool ParseSubnetId(const char *str, uint16_t& subnetId);
extern bool ParseHexString(const char *hexStr, uint32_t strLen, uint8_t *outBuf, uint32_t outBufSize, uint32_t& outDataLen);

extern OptionSet **gActiveOptionSets;


/**
 * Common OptionSet for handling informational options (--help, --version).
 *
 */
class HelpOptions : public OptionSetBase
{
public:
    const char *AppName;            /**< The name of the command-line application. */
    const char *AppUsage;           /**< A short string depicting the application's command-line syntax. */
    const char *AppVersion;             const char *AppDesc;            /**< A description of the application's purpose/behavior. */

    HelpOptions(const char *appName, const char *appUsage, const char *appVersion);
    HelpOptions(const char *appName, const char *appUsage, const char *appVersion, const char *appDesc);

    void PrintBriefUsage(FILE *s);
    void PrintLongUsage(OptionSet *optSets[], FILE *s);
    void PrintVersion(FILE *s);

    virtual bool HandleOption(const char *progName, OptionSet *optSet, int id, const char *name, const char *arg);
};


} // namespace ArgParser
} // namespace nl

#endif // WEAVE_CONFIG_ENABLE_ARG_PARSER

#endif // NLARGPARSER_H_