! Copyright (C) 2008 Doug Coleman, Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: alien alien.c-types alien.data alien.strings libc destructors
locals kernel math assocs namespaces make continuations sequences
hashtables sorting arrays combinators math.bitwise strings
system accessors threads splitting io.backend
io.files.windows io.monitors io.ports
io.buffers io.files io.timeouts io.encodings.string literals
io.encodings.utf16n io windows.errors windows.kernel32 windows.types
io.pathnames classes.struct ;
IN: io.monitors.windows

: open-directory ( path -- handle )
    normalize-path
    FILE_LIST_DIRECTORY
    share-mode
    f
    OPEN_EXISTING
    flags{ FILE_FLAG_BACKUP_SEMANTICS FILE_FLAG_OVERLAPPED }
    f
    CreateFile opened-file ;

TUPLE: win32-monitor-port < input-port recursive ;

TUPLE: win32-monitor < monitor port ;

: begin-reading-changes ( port -- overlapped )
    {
        [ handle>> handle>> ]
        [ buffer>> ptr>> ]
        [ buffer>> size>> ]
        [ recursive>> 1 0 ? ]
    } cleave
    FILE_NOTIFY_CHANGE_ALL
    0 uint <ref>
    (make-overlapped)
    [ f ReadDirectoryChangesW win32-error=0/f ] keep ;

: read-changes ( port -- bytes-transferred )
    [
        [ begin-reading-changes ] [ twiddle-thumbs ] bi
    ] with-destructors ;

: parse-action ( action -- changed )
    {
        { FILE_ACTION_ADDED [ +add-file+ ] }
        { FILE_ACTION_REMOVED [ +remove-file+ ] }
        { FILE_ACTION_MODIFIED [ +modify-file+ ] }
        { FILE_ACTION_RENAMED_OLD_NAME [ +rename-file+ ] }
        { FILE_ACTION_RENAMED_NEW_NAME [ +rename-file+ ] }
        [ drop +modify-file+ ]
    } case 1array ;

: memory>u16-string ( alien len -- string )
    memory>byte-array utf16n decode ;

: parse-notify-record ( buffer -- path changed )
    [ [ FileName>> ] [ FileNameLength>> ] bi memory>u16-string ]
    [ Action>> parse-action ] bi ;

: (file-notify-records) ( buffer -- buffer )
    FILE_NOTIFY_INFORMATION memory>struct
    dup ,
    dup NextEntryOffset>> zero? [
        [ NextEntryOffset>> ] [ >c-ptr <displaced-alien> ] bi
        (file-notify-records)
    ] unless ;

: file-notify-records ( buffer -- seq )
    [ (file-notify-records) drop ] { } make ;

:: parse-notify-records ( monitor buffer -- )
    buffer file-notify-records [
        parse-notify-record
        [ monitor path>> prepend-path normalize-path ] dip
        monitor queue-change
    ] each ;

: fill-queue ( monitor -- )
    dup port>> dup check-disposed
    [ buffer>> ptr>> ] [ read-changes zero? ] bi
    [ 2dup parse-notify-records ] unless
    2drop ;

: (fill-queue-thread) ( monitor -- )
    dup fill-queue (fill-queue-thread) ;

: fill-queue-thread ( monitor -- )
    [ dup fill-queue (fill-queue-thread) ]
    [ dup already-disposed? [ 2drop ] [ rethrow ] if ] recover ;

M:: winnt (monitor) ( path recursive? mailbox -- monitor )
    [
        path normalize-path mailbox win32-monitor new-monitor
            path open-directory \ win32-monitor-port <buffered-port>
                recursive? >>recursive
            >>port
        dup [ fill-queue-thread ] curry
        "Windows monitor thread" spawn drop
    ] with-destructors ;

M: win32-monitor dispose
    [ port>> dispose ] [ call-next-method ] bi ;