UniqueNameSet.h

#pragma once

#include <set>
#include <map>

#include "ComplexName.h"

/**
 * \brief
 * A set which maps name prefixes (e.g. "func_static_") to the set of 
 * postfixes which are used in the current map.
 */
class UniqueNameSet
{
    // This maps name prefixes to a set of used postfixes
    // e.g. "func_static_" => ["1","3","4","5","05","10"]
    // Allows fairly quick lookup of used names and postfixes
    typedef std::map<std::string, PostfixSet> Names;
    Names _names;

public:

    /// Test if this set is empty
    bool empty() const
    {
        // Cycle through all prefixes and see if the postfixset is non-empty, break on first hit
        for (const auto& i : _names)
        {
            if (!i.second.empty())
            {
                return false;
            }
        }

        return true;
    }

    /**
     * \brief
     * Inserts the given full name into this set.
     *
     * Returns TRUE if the insertion was successful (i.e. the name didn't exist
     * yet).
     */
    bool insert(const ComplexName& name)
    {
        // Lookup the name in the map to see if we know this prefix already
        Names::iterator found = _names.find(name.getNameWithoutPostfix());

        if (found == _names.end())
		{
            // The name is not yet in the list, insert it afresh
            auto result = _names.insert(std::make_pair(name.getNameWithoutPostfix(), PostfixSet()));

            assert(result.second); // insert must succeed, we didn't find this just before

            // Overwrite the iterator
            found = result.first;
        }

        // The prefix is inserted at this point, add the postfix to the set
        auto result = found->second.insert(name.getPostfix());

        // Return the boolean of the insertion result, it is true on successful insertion
        return result.second;
    }

    /**
     * \brief
     * Removes the given full name from the set.
     *
     * Returns TRUE if the name was there in the first place.
     */
    bool erase(const ComplexName& name)
    {
        // Lookup the name in the map to see if we know this prefix already
        Names::iterator found = _names.find(name.getNameWithoutPostfix());

        if (found == _names.end())
		{
            return false; // Not found!
        }

        // The prefix has been found, remove the postfix from the set
        // Return true if the erase method removed any elements
        return found->second.erase(name.getPostfix()) > 0;
    }

    /**
     * \brief
     * Insert the given ComplexName into this set, changing its postfix if
     * necessary to ensure that is is unique.
     *
     * \return
     * The actual unique name that was used, which may be different from the
     * original ComplexName if there was a conflict.
     */
    std::string insertUnique(const ComplexName& name)
    {
        // Lookup the name in the map to see if we know this prefix
        Names::iterator found = _names.find(name.getNameWithoutPostfix());

        if (found == _names.end()) 
		{
            // The name is not yet in the list, we can add it with the given postfix
            auto result = _names.insert(std::make_pair(name.getNameWithoutPostfix(), PostfixSet()));

            assert(result.second); // insert must succeed, we didn't find this just before

            // Overwrite the iterator
            found = result.first;
        }

        // At this point, the "trunk" of the complex name is already in the list
        // The found iterator points to a valid prefix => PostFixSet mapping

        // Acquire a new unique postfix (if necessary) for this name to make it
        // unique
        PostfixSet& postfixSet = found->second;

        ComplexName uniqueName(name);

        std::string postfix = uniqueName.makePostfixUnique(postfixSet);
        postfixSet.insert(postfix);

        return uniqueName.getFullname();
    }

    /**
     * greebo: Returns true if the full name already exists in this set.
     */
    bool nameExists(const std::string& fullname) const
	{
        // Empty names never exist
        if (fullname.empty())
		{
            return false;
        }

        // Analyse the name (split it into parts) and pass the call to the specialised method
        return nameExists(ComplexName(fullname));
    }

    /**
     * greebo: Returns true if the complex name already exists in this set.
     */
    bool nameExists(const ComplexName& name) const
	{
        // Lookup the name in the map to see if we know this prefix
        Names::const_iterator found = _names.find(name.getNameWithoutPostfix());

        if (found != _names.end()) 
		{
            // We know the name "trunk", does the number exist?
            const PostfixSet& postfixSet = found->second;

            // If we know the number too, the full name exists
            return postfixSet.find(name.getPostfix()) != postfixSet.end();
        }

        // Prefix is not known, hence full name is not known
        return false;
    }

    /**
     * Copies all names from the <other> UniqueNameSet into this one.
     * This class will contain the union of both sets afterwards.
     * Duplicate names will be ignored.
     */
    void merge(const UniqueNameSet& other)
    {
        // cycle through all foreign names and import them
        for (const auto& i : other._names)
        {
            // Check if the prefix exists already in this set
            Names::iterator local = _names.find(i.first);

            if (local != _names.end())
			{
                // Prefix exists, merge the postfixes
                local->second.insert(i.second.begin(), i.second.end());
            }
            else
			{
                // Prefix doesn't exist yet, insert the whole string => PostfixSet pair
                _names.insert(i);
            }
        }
    }
};