#
# File:: %RS_TOOLSLIB%/util/perforce/p4_revert_files.rb
# Description:: Mass-revert files for a particular user.
#
# Author:: David Muir <david.muir@rockstarnorth.com>
# Date:: 5 March 2012
#

#-----------------------------------------------------------------------------
# Uses
#-----------------------------------------------------------------------------
require 'pipeline/config/projects'
require 'pipeline/os/getopt'
require 'pipeline/os/path'
require 'pipeline/scm/perforce'
include Pipeline

#-----------------------------------------------------------------------------
# Constants
#-----------------------------------------------------------------------------
OPTIONS = [
    [ '--user', '-u', OS::Getopt::REQUIRED, 'user changelists to revert.' ],
	[ '--help', '-h', OS::Getopt::BOOLEAN, 'display usage information.' ]
]
TRAILING = {
	'paths' => 'paths to revert changelists for.'
}

#-----------------------------------------------------------------------------
# Functions
#-----------------------------------------------------------------------------

# The meat function that handles the revert.
def revert_changelists_for_user( p4, log, username, path )

    files_with_rev = []
    files = []

    count = 0
    flog_records = p4.run_filelog( path )
    flog_records.each do |flog_file|    
        log.info( "Processing: #{flog_file.depot_file}..." )
                
        # Most recent version is first.
        next unless ( 0 == username.casecmp( flog_file.revisions.first.user ) )
        
        # User touched #head revision; we need to revert it.
        log.info( "\tUser #{username} has touched \#head revision!" )
        
        # Find revision to revert to; i.e. latest one that user didn't commit.
        rev_revert = nil
        flog_file.revisions.each do |revision|
            next unless ( 0 != username.casecmp( revision.user ) )
            
            rev_revert = revision.rev
            break
        end
        
        if ( rev_revert.nil? ) then
            log.warn( "\tNo known file revision to revert to." )
        else
            count += 1
            log.info( "\tRevert #{flog_file.depot_file} to revision #{rev_revert}/#{flog_file.revisions.size}." )
        
            files_with_rev << "#{flog_file.depot_file}\##{rev_revert}"
            files << flog_file.depot_file
        end
    end
    
    # Handle batching of sync, edit and resolve for more efficient Perforce
    # usage.
    changelist = p4.create_changelist( "p4_revert_files: #{count} files for user #{username}." )
    p4.run_sync( *files_with_rev )
    p4.run_edit( '-c', changelist, *files )
    p4.run_sync( *files )
    p4.run_resolve( '-ay', *files )
    
    count
end

#-----------------------------------------------------------------------------
# Implementation
#-----------------------------------------------------------------------------

if ( __FILE__ == $0 ) then
	g_AppName = OS::Path::get_filename( __FILE__ )
	g_Config = Pipeline::Config::instance( )
	g_Opts, g_Trailing = OS::Getopt::getopts( OPTIONS )	
	g_Log = Log.new( g_AppName )
	if ( g_Opts['help'] ) then
		puts OS::Getopt::usage( OPTIONS, TRAILING )
		exit( 1 )
	end
    if ( not g_Opts.has_key?( 'user' ) ) then
        g_Log.error( "--user option required." )
		puts OS::Getopt::usage( OPTIONS, TRAILING )
		exit( 1 )
    end
    
    begin
        user = g_Opts['user']
    
        project = Pipeline::Config::instance().project
        project.load_config( )
        p4 = project.scm( )
        p4.connect( )
        
        count = 0
        g_Trailing.each do |path|
            count += revert_changelists_for_user( p4, g_Log, user, path )
        end
        g_Log.info( "User #{user} touched #{count} files that are reverted." )
        
        p4.disconnect( )
    
    rescue SystemExit => ex
        exit( ex.exitstatus )    
    rescue Exception => ex
        g_Log.exception( ex, 'Unhandled exception' )
        puts "Press any key to continue..."
        $stdin.gets
    end
end

# %RS_TOOLSLIB%/util/perforce/p4_revert_files.rb