#include <algorithm>

#include "mail.hpp"

namespace smtp::manage
{
    //
    //Constructors
    //
	Mail::Mail( file::Mail const& file_reader )
			: mFileReader( file_reader )
	{
		mMails = mFileReader.Read();
	}


    //
    //Public methods
    //
	MailsSet Mail::GetMailToSend() const
	{
		return mMails;
	}

	bool Mail::AddMailsToSend( MailsSet const& mails_to_add )
	{
        auto merged_mails = GetMergedMails( mails_to_add );

		auto result = mFileReader.Write( merged_mails );
        mMails = mFileReader.Read();
		return result;
	}

	bool Mail::DeleteMailToSend( MailsSet const& mail_to_send )
	{
		auto mails_to_delete = GetItersectionMails( mail_to_send );
		auto result_set_after_delete = GetMailsAfterDelete( mails_to_delete );
		auto result_of_delete = mFileReader.Write( result_set_after_delete );

		if( result_of_delete )
		{
			mMails = result_set_after_delete;
		}
		return result_of_delete;
	}

    //
    //Private methods
    //
	MailsSet Mail::GetMergedMails( MailsSet const& mails_to_add )
	{
        MailsSet result;
        auto sorted_mail_to_add = mails_to_add;
        sorted_mail_to_add.sort();
        mMails.sort();

        std::set_union( mMails.cbegin(), mMails.cend(),
                               sorted_mail_to_add.cbegin(), sorted_mail_to_add.cend(),
                               std::back_inserter( result ));
		return result;
	}

	MailsSet Mail::GetItersectionMails( MailsSet const& mail_to_send )
	{
		MailsSet result;

		auto sorted_mail_to_send = mail_to_send;
		sorted_mail_to_send.sort();
		mMails.sort();
		std::set_intersection( mMails.cbegin(), mMails.cend(),
							   sorted_mail_to_send.cbegin(), sorted_mail_to_send.cend(),
							   std::back_inserter( result ));
		return result;
	}

	MailsSet Mail::GetMailsAfterDelete( MailsSet const& result_set_after_delete )
	{
		auto result = mMails;
		for( const auto& element_to_delete: result_set_after_delete )
		{
			result.remove( element_to_delete );
		}
		return result;
	}
}