USING: alien alien.c-types arrays assocs combinators
continuations destructors io io.backend io.ports io.timeouts
io.backend.windows io.files.windows io.files.windows.nt io.files
io.pathnames io.buffers io.streams.c libc kernel math namespaces
sequences threads windows windows.errors windows.kernel32
strings splitting ascii system accessors locals ;
QUALIFIED: windows.winsock
IN: io.backend.windows.nt

! Global variable with assoc mapping overlapped to threads
SYMBOL: pending-overlapped

TUPLE: io-callback port thread ;

C: <io-callback> io-callback

: (make-overlapped) ( -- overlapped-ext )
    "OVERLAPPED" malloc-object &free ;

: make-overlapped ( port -- overlapped-ext )
    [ (make-overlapped) ] dip
    handle>> ptr>> [ over set-OVERLAPPED-offset ] when* ;

M: winnt FileArgs-overlapped ( port -- overlapped )
    make-overlapped ;

: <completion-port> ( handle existing -- handle )
     f 1 CreateIoCompletionPort dup win32-error=0/f ;

SYMBOL: master-completion-port

: <master-completion-port> ( -- handle )
    INVALID_HANDLE_VALUE f <completion-port> ;

M: winnt add-completion ( win32-handle -- )
    handle>> master-completion-port get-global <completion-port> drop ;

: eof? ( error -- ? )
    [ ERROR_HANDLE_EOF = ] [ ERROR_BROKEN_PIPE = ] bi or ;

: twiddle-thumbs ( overlapped port -- bytes-transferred )
    [
        drop
        [ pending-overlapped get-global set-at ] curry "I/O" suspend
        {
            { [ dup integer? ] [ ] }
            { [ dup array? ] [
                first dup eof?
                [ drop 0 ] [ (win32-error-string) throw ] if
            ] }
        } cond
    ] with-timeout ;

:: wait-for-overlapped ( us -- bytes-transferred overlapped error? )
    master-completion-port get-global
    0 <int> [ ! bytes
        f <void*> ! key
        f <void*> [ ! overlapped
            us [ 1000 /i ] [ INFINITE ] if* ! timeout
            GetQueuedCompletionStatus zero?
        ] keep *void*
    ] keep *int spin ;

: resume-callback ( result overlapped -- )
    pending-overlapped get-global delete-at* drop resume-with ;

: handle-overlapped ( us -- ? )
    wait-for-overlapped [
        dup [
            [ drop GetLastError 1array ] dip resume-callback t
        ] [ 2drop f ] if
    ] [ resume-callback t ] if ;

M: win32-handle cancel-operation
    [ check-disposed ] [ handle>> CancelIo drop ] bi ;

M: winnt io-multiplex ( us -- )
    handle-overlapped [ 0 io-multiplex ] when ;

M: winnt init-io ( -- )
    <master-completion-port> master-completion-port set-global
    H{ } clone pending-overlapped set-global
    windows.winsock:init-winsock ;

ERROR: invalid-file-size n ;

: handle>file-size ( handle -- n )
    0 <ulonglong> [ GetFileSizeEx win32-error=0/f ] keep *ulonglong ;

ERROR: seek-before-start n ;

: set-seek-ptr ( n handle -- )
    [ dup 0 < [ seek-before-start ] when ] dip (>>ptr) ;

M: winnt seek-handle ( n seek-type handle -- )
    swap {
        { seek-absolute [ set-seek-ptr ] }
        { seek-relative [ [ ptr>> + ] keep set-seek-ptr ] }
        { seek-end [ [ handle>> handle>file-size + ] keep set-seek-ptr ] }
        [ bad-seek-type ]
    } case ;

: file-error? ( n -- eof? )
    zero? [
        GetLastError {
            { [ dup expected-io-error? ] [ drop f ] }
            { [ dup eof? ] [ drop t ] }
            [ (win32-error-string) throw ]
        } cond
    ] [ f ] if ;

: wait-for-file ( FileArgs n port -- n )
    swap file-error?
    [ 2drop 0 ] [ [ lpOverlapped>> ] dip twiddle-thumbs ] if ;

: update-file-ptr ( n port -- )
    handle>> dup ptr>> [ rot + >>ptr drop ] [ 2drop ] if* ;

: finish-write ( n port -- )
    [ update-file-ptr ] [ buffer>> buffer-consume ] 2bi ;

M: winnt (wait-to-write)
    [
        [ make-FileArgs dup setup-write WriteFile ]
        [ wait-for-file ]
        [ finish-write ]
        tri
    ] with-destructors ;

: finish-read ( n port -- )
    [ update-file-ptr ] [ buffer>> n>buffer ] 2bi ;

M: winnt (wait-to-read) ( port -- )
    [
        [ make-FileArgs dup setup-read ReadFile ]
        [ wait-for-file ]
        [ finish-read ]
        tri
    ] with-destructors ;

: console-app? ( -- ? ) GetConsoleWindow >boolean ;

M: winnt (init-stdio)
    console-app? [ init-c-stdio t ] [ f f f f ] if ;

winnt set-io-backend