CmdArgsInterface.h

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#pragma once
#include "Parameter.h"
#include "ParamConstraint.h"
#include <unordered_map>
#include <vector>

#include "Version.h"

namespace Hazelnp
{
    /** The main class to interface with
    */
    class CmdArgsInterface
    {
    public:
        CmdArgsInterface();
        CmdArgsInterface(const int argc, const char* const* argv);

        ~CmdArgsInterface();

        //! Will parse command line arguments
        void Parse(const int argc, const char* const* argv);

        //! Will return argv[0], the name of the executable.
        const std::string& GetExecutableName() const;

        //! Will return the value given a key
        const Value& operator[](const std::string& key) const;

        //! Will check wether a parameter exists given a key, or not
        bool HasParam(const std::string& key) const;

        // Abbreviations
        //! Will register an abbreviation (like -f for --force)
        void RegisterAbbreviation(const std::string& abbrev, const std::string& target);

        //! Will return the long form of an abbreviation (like --force for -f)  
        //! Returns "" if no match is found
        const std::string& GetAbbreviation(const std::string& abbrev) const;

        //! Will check wether or not an abbreviation is registered
        bool HasAbbreviation(const std::string& abbrev) const;

        //! Will delete the abbreviation for a given parameter.  
        //! IMPORTANT: This parameter is the abbreviation! Not the long form!
        void ClearAbbreviation(const std::string& abbrevation);

        //! Will delete all abbreviations
        void ClearAbbreviations();

        //! Will register a constraint for a parameter.
        //! IMPORTANT: Any parameter can only have ONE constraint. Applying a new one will overwrite the old one!
        //! Construct the ParamConstraint struct yourself to combine Require, TypeSafety and Incompatibilities! You can also use the ParamConstraint constructor!
        void RegisterConstraint(const std::string& key, const ParamConstraint& constraint);

        //! Will return the constraint information for a specific parameter
        ParamConstraint GetConstraint(const std::string& parameter) const;

        //! Will the constraint of a specific parameter
        void ClearConstraint(const std::string& parameter);

        //! Will delete all constraints
        void ClearConstraints();

        //! Sets whether to crash the application, and print to stderr, when an exception is 
        //! raised whilst parsing, or not.
        void SetCrashOnFail(bool crashOnFail);

        //! Gets whether the application crashes on an exception whilst parsing, and prints to stderr.
        bool GetCrashOnFail() const;

        //! Sets whether the CmdArgsInterface should automatically catch the --help parameter, print the parameter documentation to stdout, and exit or not.
        void SetCatchHelp(bool catchHelp);

        //! Retruns whether the CmdArgsInterface should automatically catch the --help parameter, print the parameter documentation to stdout, and exit or not.
        bool GetCatchHelp() const;

        //! Sets a brief description of the application to be automatically added to the documentation.
        void SetBriefDescription(const std::string& description);

        //! Returns the brief description of the application to be automatically added to the documentation.
        const std::string& GetBriefDescription();

        //! Willl register a short description for a parameter.  
        //! Will overwrite existing descriptions for that parameter.
        void RegisterDescription(const std::string& parameter, const std::string& description);

        //! Will return a short description for a parameter, if it exists.  
        //! Empty string if it does not exist.
        const std::string& GetDescription(const std::string& parameter) const;

        //! Returns whether or not a given parameter has a registered description
        bool HasDescription(const std::string& parameter) const;

        //! Will delete the description of a parameter if it exists.
        void ClearDescription(const std::string& parameter);

        //! Will delete all parameter descriptions
        void ClearDescriptions();

        //! Will generate a text-based documentation suited to show the user, for example on --help.
        std::string GenerateDocumentation() const;

    private:
        //! Will translate the c-like args to an std::vector
        void PopulateRawArgs(const int argc, const char* const* argv);

        //! Will replace all args matching an abbreviation with their long form (like -f for --force)
        void ExpandAbbreviations();

        //! Will parse the next parameter. Returns the index of the next parameter.
        std::size_t ParseNextParameter(const std::size_t parIndex, Parameter*& out_Par);

        //! Will convert a vector of string-values to an actual Value
        Value* ParseValue(const std::vector<std::string>& values, const ParamConstraint* constraint = nullptr);

        //! Will apply the loaded constraints on the loaded values, exluding types.
        void ApplyConstraints();

        //! Will return a pointer to a paramConstraint given a key. If there is no, it returns nullptr
        const ParamConstraint* GetConstraintForKey(const std::string& key) const;

        std::string executableName; //! The path of the executable. Always argv[0]
        std::unordered_map<std::string, Parameter*> parameters;

        //! These are abbreviations. Like, -f for --force.
        std::unordered_map<std::string, std::string> parameterAbreviations;

        //! Parameter constraints, mapped to keys
        std::unordered_map<std::string, ParamConstraint> parameterConstraints;

        //! Raw argv
        std::vector<std::string> rawArgs;

        //! Short descriptions for parameters
        //! First member is the abbreviation
        std::unordered_map<std::string, std::string> parameterDescriptions;

        //! A brief description of the application to be added to the generated documentation. Optional.
        std::string briefDescription;

        //! If set to true, CmdArgsInterface will automatically catch the --help parameter, print the parameter documentation to stdout and exit.
        bool catchHelp = true;

        //! If set to true, CmdArgsInterface will crash the application with output to stderr when an exception is thrown whilst parsing.
        bool crashOnFail = true;
    };
}