####################################################################################################################################
# CONFIG HELP MODULE
####################################################################################################################################
package pgBackRest::Config::ConfigHelp;

use strict;
use warnings FATAL => qw(all);
use Carp qw(confess);

use Exporter qw(import);
    our @EXPORT = qw();
use File::Basename qw(dirname);

use lib dirname($0) . '/../lib';
use pgBackRest::Common::Exception;
use pgBackRest::Common::Ini;
use pgBackRest::Common::Log;
use pgBackRest::Common::String;
use pgBackRest::Config::Config;
use pgBackRest::Version;

####################################################################################################################################
# Help types
####################################################################################################################################
use constant CONFIG_HELP_COMMAND                                    => 'command';
     push @EXPORT, qw(CONFIG_HELP_COMMAND);
use constant CONFIG_HELP_CURRENT                                    => 'current';
     push @EXPORT, qw(CONFIG_HELP_CURRENT);
use constant CONFIG_HELP_DEFAULT                                    => 'default';
     push @EXPORT, qw(CONFIG_HELP_DEFAULT);
use constant CONFIG_HELP_DESCRIPTION                                => 'description';
     push @EXPORT, qw(CONFIG_HELP_DESCRIPTION);
use constant CONFIG_HELP_OPTION                                     => 'option';
     push @EXPORT, qw(CONFIG_HELP_OPTION);
use constant CONFIG_HELP_SECTION                                    => 'section';
     push @EXPORT, qw(CONFIG_HELP_SECTION);
use constant CONFIG_HELP_SUMMARY                                    => 'summary';
     push @EXPORT, qw(CONFIG_HELP_SUMMARY);

use constant CONFIG_HELP_SOURCE                                     => 'source';
     push @EXPORT, qw(CONFIG_HELP_SOURCE);
use constant CONFIG_HELP_SOURCE_DEFAULT                             => 'default';
     push @EXPORT, qw(CONFIG_HELP_SOURCE_DEFAULT);
use constant CONFIG_HELP_SOURCE_SECTION                             => CONFIG_HELP_SECTION;
     push @EXPORT, qw(CONFIG_HELP_SOURCE_SECTION);
use constant CONFIG_HELP_SOURCE_COMMAND                             => CONFIG_HELP_COMMAND;
     push @EXPORT, qw(CONFIG_HELP_SOURCE_COMMAND);

####################################################################################################################################
# Config Section Types
####################################################################################################################################
use constant CONFIG_SECTION_COMMAND                                 => 'command';
    push @EXPORT, qw(CONFIG_SECTION_COMMAND);
use constant CONFIG_SECTION_GENERAL                                 => 'general';
    push @EXPORT, qw(CONFIG_SECTION_GENERAL);
use constant CONFIG_SECTION_LOG                                     => 'log';
    push @EXPORT, qw(CONFIG_SECTION_LOG);
use constant CONFIG_SECTION_EXPIRE                                  => 'expire';
    push @EXPORT, qw(CONFIG_SECTION_EXPIRE);

####################################################################################################################################
# configHelp
#
# Display command-line help.
####################################################################################################################################
sub configHelp
{
    my $strCommand = shift;
    my $strOption = shift;
    my $bVersion = shift;
    my $bConfigResult = shift;

    # Load module dynamically
    require pgBackRest::Config::ConfigHelpData;
    pgBackRest::Config::ConfigHelpData->import();

    # Get config data
    my $oCommandHash = commandHashGet();
    my $oOptionRule = optionRuleGet();
    my $oConfigHelpData = configHelpDataGet();

    # Build version
    my $strVersion = (!$bConfigResult ? "\n" : '') . BACKREST_NAME . ' ' . BACKREST_VERSION;

    # Display version
    if ($bVersion)
    {
        syswrite(*STDOUT, "${strVersion}\n");
        return;
    }

    # Build the title
    my $strTitle;
    my $strHelp;

    # Since there's no command this will be general help
    if (!defined($strCommand))
    {
        $strTitle = "General"
    }
    # Else check the command
    else
    {
        $strCommand = lc($strCommand);

        if (defined($$oCommandHash{$strCommand}))
        {
            $strTitle = "'${strCommand}' command";

            # And check the option
            if (defined($strOption))
            {
                $strOption = lc($strOption);

                if (defined($$oConfigHelpData{&CONFIG_HELP_COMMAND}{$strCommand}{&CONFIG_HELP_OPTION}{$strOption}))
                {
                    $strTitle .= " - '${strOption}' option";
                }
                else
                {
                    $strHelp = "Invalid option '${strOption}' for command '${strCommand}'";
                }
            }
        }
        else
        {
            $strHelp = "Invalid command '${strCommand}'";
        }
    }

    # Build the help
    my $strMore;

    if (!defined($strHelp))
    {
        my $iScreenWidth = 80;

        # General help
        if (!defined($strCommand))
        {
            $strHelp =
                "Usage:\n" .
                "    " . BACKREST_EXE . " [options] [command]\n\n" .
                "Commands:\n";

            # Find longest command length
            my $iCommandLength = 0;

            foreach my $strCommand (sort(keys(%{$$oConfigHelpData{&CONFIG_HELP_COMMAND}})))
            {
                if (length($strCommand) > $iCommandLength)
                {
                    $iCommandLength = length($strCommand);
                }
            }

            # Output commands
            foreach my $strCommand (sort(keys(%{$$oConfigHelpData{&CONFIG_HELP_COMMAND}})))
            {
                my $oCommand = $$oConfigHelpData{&CONFIG_HELP_COMMAND}{$strCommand};

                $strHelp .= "    ${strCommand}" . (' ' x ($iCommandLength - length($strCommand)));
                $strHelp .=
                    '  ' .
                    configHelpFormatText($$oCommand{&CONFIG_HELP_SUMMARY}, 4 + $iCommandLength + 2, false, $iScreenWidth + 1) .
                    "\n";
            }

            $strMore = '[command]';
        }
        # Else command help
        elsif (!defined($strOption))
        {
            my $oCommand = $$oConfigHelpData{&CONFIG_HELP_COMMAND}{$strCommand};

            $strHelp =
                configHelpFormatText($$oCommand{&CONFIG_HELP_SUMMARY} . "\n\n" .
                           $$oCommand{&CONFIG_HELP_DESCRIPTION}, 0, true, $iScreenWidth + 1);

            # Find longest option length and unique list of sections
            my $iOptionLength = 0;
            my $oSection = {};

            if (defined($$oCommand{&CONFIG_HELP_OPTION}))
            {
                foreach my $strOption (sort(keys(%{$$oCommand{&CONFIG_HELP_OPTION}})))
                {
                    if (length($strOption) > $iOptionLength)
                    {
                        $iOptionLength = length($strOption);
                    }

                    my ($oOption, $strSection) = configHelpOptionFind($oConfigHelpData, $oOptionRule, $strCommand, $strOption);

                    $$oSection{$strSection}{$strOption} = $oOption;
                }

                # Iterate sections
                foreach my $strSection (sort(keys(%{$oSection})))
                {
                    $strHelp .=
                        "\n\n" . ucfirst($strSection) . " Options:\n";

                    # Iterate options
                    foreach my $strOption (sort(keys(%{$$oSection{$strSection}})))
                    {
                        $strHelp .= "\n";

                        my $iIndent = 4 + $iOptionLength + 2;
                        my $oOption = $$oSection{$strSection}{$strOption};

                        # Set current and default values
                        my $strDefault = '';

                        if ($$oOption{&CONFIG_HELP_CURRENT} || $$oOption{&CONFIG_HELP_DEFAULT})
                        {
                            $strDefault = undef;

                            if ($$oOption{&CONFIG_HELP_CURRENT})
                            {
                                $strDefault .= 'current=' . $$oOption{&CONFIG_HELP_CURRENT};
                            }

                            if ($$oOption{&CONFIG_HELP_DEFAULT})
                            {
                                if (defined($strDefault))
                                {
                                    $strDefault .= ', ';
                                }

                                $strDefault .= 'default=' . $$oOption{&CONFIG_HELP_DEFAULT};
                            }

                            $strDefault = " [${strDefault}]";
                        }

                        # Output help
                        $strHelp .= "  --${strOption}" . (' ' x ($iOptionLength - length($strOption)));
                        $strHelp .= '  ' . configHelpFormatText(lcfirst(substr($$oOption{&CONFIG_HELP_SUMMARY}, 0,
                                                                        length($$oOption{&CONFIG_HELP_SUMMARY}) - 1)) .
                                                                $strDefault, $iIndent, false, $iScreenWidth + 1);
                    }
                }

                $strMore = "${strCommand} [option]";
                $strHelp .= "\n";
            }
        }
        # Else option help
        else
        {
            my ($oOption) = configHelpOptionFind($oConfigHelpData, $oOptionRule, $strCommand, $strOption);

            # Set current and default values
            my $strDefault = '';

            if ($$oOption{&CONFIG_HELP_CURRENT} || $$oOption{&CONFIG_HELP_DEFAULT})
            {
                $strDefault = undef;

                if ($$oOption{&CONFIG_HELP_CURRENT})
                {
                    $strDefault = 'current: ' . $$oOption{&CONFIG_HELP_CURRENT};
                }

                if ($$oOption{&CONFIG_HELP_DEFAULT})
                {
                    if (defined($strDefault))
                    {
                        $strDefault .= "\n";
                    }

                    $strDefault .= 'default: ' . $$oOption{&CONFIG_HELP_DEFAULT};
                }

                $strDefault = "\n\n${strDefault}";
            }

            # Output help
            $strHelp =
                configHelpFormatText($$oOption{&CONFIG_HELP_SUMMARY} . "\n\n" . $$oOption{&CONFIG_HELP_DESCRIPTION} .
                                     $strDefault, 0, true, $iScreenWidth + 1);
        }
    }

    # Output help
    syswrite(*STDOUT, "${strVersion} -" . (defined($strTitle) ? " ${strTitle}" : '') . " help\n\n${strHelp}\n" .
             (defined($strMore) ? 'Use \'' . BACKREST_EXE . " help ${strMore}' for more information.\n" : ''));
}

push @EXPORT, qw(configHelp);

# Helper function for configHelp() to make output look good on a console
sub configHelpFormatText
{
    my $strTextIn = shift;
    my $iIndent = shift;
    my $bIndentFirst = shift;
    my $iLength = shift;

    my @stryText = split("\n", trim($strTextIn));
    my $strText;
    my $iIndex = 0;

    foreach my $strLine (@stryText)
    {
        if (defined($strText))
        {
            $strText .= "\n";
        }

        my $strPart;
        my $bFirst = true;

        do
        {
            ($strPart, $strLine) = stringSplit($strLine, ' ', $iLength - $iIndent);

            if (!$bFirst || $bIndentFirst)
            {
                if (!$bFirst)
                {
                    $strText .= "\n";
                }

                $strText .= ' ' x $iIndent;
            }

            $strText .= trim($strPart);

            $bFirst = false;
        }
        while (defined($strLine));

        $iIndex++;
    }

    return $strText;
}

# Helper function for configHelp() to find options.  The option may be stored with the command or in the option list depending on
# whether it's generic or command-specific
sub configHelpOptionFind
{
    my $oConfigHelpData = shift;
    my $oOptionRule = shift;
    my $strCommand = shift;
    my $strOption = shift;

    my $strSection = CONFIG_HELP_COMMAND;
    my $oOption = $$oConfigHelpData{&CONFIG_HELP_COMMAND}{$strCommand}{&CONFIG_HELP_OPTION}{$strOption};

    if (ref(\$oOption) eq 'SCALAR')
    {
        $oOption = $$oConfigHelpData{&CONFIG_HELP_OPTION}{$strOption};

        if (defined($$oOption{&CONFIG_HELP_SECTION}))
        {
            $strSection = $$oOption{&CONFIG_HELP_SECTION};

            if ($strSection eq CONFIG_SECTION_COMMAND)
            {
                $strSection = CONFIG_SECTION_GENERAL;
            }
        }
        else
        {
            $strSection = CONFIG_SECTION_GENERAL;
        }

        if (($strSection ne CONFIG_SECTION_GENERAL && $strSection ne CONFIG_SECTION_LOG &&
             $strSection ne CONFIG_SECTION_STANZA && $strSection ne CONFIG_SECTION_EXPIRE) ||
             $strSection eq $strCommand)
        {
            $strSection = CONFIG_HELP_COMMAND;
        }
    }

    if (defined(optionDefault($strOption, $strCommand)))
    {
        if ($$oOptionRule{$strOption}{&OPTION_RULE_TYPE} eq &OPTION_TYPE_BOOLEAN)
        {
            $$oOption{&CONFIG_HELP_DEFAULT} = optionDefault($strOption, $strCommand) ? 'y' : 'n';
        }
        else
        {
            $$oOption{&CONFIG_HELP_DEFAULT} = optionDefault($strOption, $strCommand);
        }
    }

    if (optionTest($strOption) && optionSource($strOption) ne CONFIG_HELP_SOURCE_DEFAULT)
    {
        if ($$oOptionRule{$strOption}{&OPTION_RULE_TYPE} eq &OPTION_TYPE_BOOLEAN)
        {
            $$oOption{&CONFIG_HELP_CURRENT} = optionGet($strOption) ? 'y' : 'n';
        }
        else
        {
            $$oOption{&CONFIG_HELP_CURRENT} = optionGet($strOption);
        }
    }

    return $oOption, $strSection;
}

1;