"
 COPYRIGHT (c) 2012-2013 by Jan Vrany
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
"{ Package: 'stx:libscm/mercurial' }"

ByteArray variableByteSubclass:#HGChangesetId
	instanceVariableNames:'revno'
	classVariableNames:'NullId'
	poolDictionaries:''
	category:'SCM-Mercurial-Core'
!

!HGChangesetId class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 2012-2013 by Jan Vrany
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
!

documentation
"
    Represent a changeset id in Mercurial repository.

    !!!!!! WARNING !!!!!!

    Due to a stupid design here, DO NOT USE put it into hashed collections!!
    I have to change it later...

    [author:]
        Jan Vrany <jan.vrany@fit.cvut.cz>

    [instance variables:]

    [class variables:]

    [see also:]

"
! !

!HGChangesetId class methodsFor:'instance creation'!

fromBytes: aByteArrayOrString

    | sz |

    sz := aByteArrayOrString size.
    (sz ~~ 20 and:[sz ~~ 6]) ifTrue:[
        self error:'Node ID has either 20 or 6 bytes (short form)'.
        ^nil.
    ].
    ^(self new: sz) replaceBytesFrom: 1 to: sz with: aByteArrayOrString startingAt: 1

    "Created: / 25-09-2012 / 21:00:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 13-11-2012 / 16:47:40 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

fromString: aString
    ^self readFrom: aString readStream

    "Created: / 10-09-2012 / 10:49:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 13-11-2012 / 16:49:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

new
    ^self new: 20

    "Created: / 10-09-2012 / 10:42:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 19-10-2012 / 15:51:45 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

new: size
    (size ~~ 0 and:[size ~~ 20 and:[size ~~ 6]]) ifTrue:[
        self error: 'Size of HGNodeId must be either 20 bytes or 6 bytes (short form) or 0 (revno only)'.
        ^nil.
    ].
    ^super new: size

    "Created: / 10-09-2012 / 10:44:00 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 16-11-2012 / 21:24:52 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

readFrom: aStringOrStream 
    ^self readFrom: aStringOrStream onError:[:msg|self error:msg].

    "Created: / 13-11-2012 / 16:56:58 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

readFrom: aStringOrStream onError: aBlock
    "Parses node id from stream and returns it. Support both,
     short and full node ids"

    | stream c c1 c2 sign revno hash hashPos short |

    hash := ByteArray new: 20.
    hashPos := 1.
    short := true.
    revno := 0.

    stream := aStringOrStream readStream.
    stream peek == $- ifTrue:[        
        stream next.
        sign := -1.
    ] ifFalse:[
        sign := 1.
    ].

    "/ Read revno...

    [ stream atEnd not and:[(c := stream peek) isDigit] ] whileTrue:[
        "/ Update revno
        revno := (revno * 10) + c digitValue.
        "/ Update hash for case we're reading hash instead..."
        c1 isNil ifTrue:[
            c1 := c.
        ] ifFalse:[
            c2 := c.
            hash at:hashPos put: (c1 digitValue << 4) | c2 digitValue.
            hashPos := hashPos + 1.
            c1 := c2 := nil.
        ].
        stream next.
    ].
    revno := revno * sign.
    (stream atEnd or:[stream peek isSeparator]) ifTrue:[
        ^(HGChangesetId new: 0)
            revno: revno;
            yourself
    ].
    stream peek == $: ifTrue:[
        "/OK. we have read revno"
        hashPos := 1.
        c1 := c2 := nil.
        stream next. "/eat :
    ] ifFalse:[
        revno := nil.
    ].
    "/ Read hash
    hashPos <= 6 ifTrue:[
        hashPos to: 6 do:[:i|
            stream atEnd ifTrue:[
                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.
            ].
            c1 isNil ifTrue:[
                c1 := stream peek.
                c1 isHexDigit ifFalse:[
                    aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c1 , ' found'.
                ].
                stream next.
            ].
            stream atEnd ifTrue:[
                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.
            ].
            c2 := stream peek.
            c2 isHexDigit ifFalse:[
                aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c1 , ' found'.
            ].
            hash at:i put: (c1 digitValue << 4) | c2 digitValue.
            hashPos := i + 1.
            c1 := c2 := nil.
            stream next.
        ].
    ].
    (stream atEnd not and:[stream peek isHexDigit]) ifTrue:[
        "/OK, full 40-char node id
        short := false.
        hashPos to: 20 do:[:i|
            stream atEnd ifTrue:[
                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.
            ].
                        c1 := stream peek.
            c1 isHexDigit ifFalse:[
                aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c1 , ' found'.
            ].
            stream next.
            stream atEnd ifTrue:[
                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.
            ].
            c2 := stream peek.
            c2 isHexDigit ifFalse:[
                aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c1 , ' found'.
            ].
            hash at:i put: (c1 digitValue << 4) + c2 digitValue.
            stream next.
        ].
    ].
    (revno == -1) ifTrue:[
        (hash = #[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 
            or:[hash = #[0 0 0 0 0 0]]) ifTrue:[
            ^self null
        ].
    ].
    short ifTrue:[
        ^(HGChangesetId new: 6)
            revno: revno;
            replaceBytesFrom: 1 to: 6 with: hash startingAt: 1;
            yourself
    ] ifFalse:[
        ^(HGChangesetId fromBytes: hash) revno: revno.
    ]

    "
    HGNodeId fromString:'4:6f88e1f44d9eb86e0b56ca15e30e5d786acd83c7'

    Bad ones:

    HGNodeId fromString:'4:6f88e1f44d9eb86e0b56ca15e30e5d786acd' 
    HGNodeId fromString:'4:6f88Z1f44d9eb86e0b56ca15e30e5d786acd83c7' 
    "

    "Created: / 13-11-2012 / 16:49:19 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 22-01-2013 / 12:00:18 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId class methodsFor:'accessing'!

null
    NullId isNil ifTrue:[
        NullId := self new.
        NullId revno: -1
    ].
    ^NullId

    "
        HGChangesetId null
    "

    "Created: / 19-10-2012 / 15:51:25 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified (comment): / 30-11-2012 / 22:00:52 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId methodsFor:'accessing'!

revno
    ^ revno

    "Created: / 13-11-2012 / 09:52:02 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 30-11-2012 / 22:05:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

revno:anInteger
    revno := anInteger.
! !

!HGChangesetId methodsFor:'comparing'!

= anotherId

    self class == anotherId class ifFalse:[ ^ false].
    (self size == 0 or:[anotherId size == 0]) ifTrue:[
        ^(self revno == anotherId revno and:[ self revno ~~ -2 ])
    ].
    self size == anotherId size ifTrue:[
        ^super = anotherId
    ].
    "One of them must be short, another long"
    1 to: 6 do:[:i|
        (self at:i) ~~ (anotherId at:i) ifTrue:[ ^ false ].
    ].
    ^true

    "Created: / 13-11-2012 / 17:37:48 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 16-11-2012 / 21:39:17 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

hash
    ^self size > 0 
        ifTrue:[self computeXorHashFrom:1 to:6]
        ifFalse:[revno hash].

    "Created: / 16-11-2012 / 21:45:16 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId methodsFor:'converting'!

asHGChangesetId
    ^ self

    "Created: / 16-11-2012 / 21:22:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

asString
    ^self printString

    "Created: / 17-11-2012 / 01:08:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId methodsFor:'printing & storing'!

displayOn:aStream

    ^self printOn: aStream

    "Created: / 13-11-2012 / 09:55:00 / Jan Vrany <jan.vrany@fit.cvut.cz>"
    "Modified: / 30-11-2012 / 22:01:12 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

printOn:aStream
    "append a printed representation if the receiver to the argument, aStream"

    | rn |

    rn := self revno.
    rn notNil ifTrue:[
        rn printOn: aStream.
        self isEmpty ifTrue:[ ^ self ].
        aStream nextPut: $:.
    ].

    aStream nextPutAll: (self copyTo: 6) hexPrintString asLowercase

    "Modified: / 01-12-2012 / 00:55:49 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId methodsFor:'queries'!

hasHashOnly
    ^revno isNil

    "Created: / 16-11-2012 / 21:54:38 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

hasRevno
    ^revno notNil

    "Created: / 22-01-2013 / 22:30:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

hasRevnoOnly
    ^self size == 0

    "Created: / 16-11-2012 / 21:54:18 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId methodsFor:'testing'!

isFull
    "Return true, if given changeset id is shortened"

    ^self size = 20

    "Created: / 22-01-2013 / 22:28:59 / Jan Vrany <jan.vrany@fit.cvut.cz>"
!

isShort
    "Return true, if given changeset id is shortened"

    ^self size < 20

    "Created: / 16-12-2012 / 00:54:19 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !

!HGChangesetId class methodsFor:'documentation'!

version_HG

    ^ '$Changeset: <not expanded> $'
!

version_SVN
    ^ '§Id::                                                                                                                        §'
! !