"{ Encoding: utf8 }"

"
 COPYRIGHT (c) 2009 by eXept Software AG
              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:libtool' }"

"{ NameSpace: Smalltalk }"

Object subclass:#DiffListUtility
	instanceVariableNames:''
	classVariableNames:'DiffCommandTemplate'
	poolDictionaries:''
	category:'Views-Text'
!

!DiffListUtility class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 2009 by eXept Software AG
              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
"
    a utility to encapsulate access to the diff command
    (may also be a facade to a smalltalk-diff algorithm, eventually)

    [author:]
        cg (cg@CG-PC)

    [instance variables:]

    [class variables:]

    [see also:]

"
! !

!DiffListUtility class methodsFor:'defaults'!

diffCommand
    "return the diff-command (with argument placeHolders).
     By default, diff is used with windows, diff -b with Unix.
     You can change this via the diffCommandTemplate"

    DiffCommandTemplate notNil ifTrue:[ ^ DiffCommandTemplate ].
    ^ UserPreferences current externalDiffCommandTemplate
!

diffCommandTemplate:aCommandTemplateString
    "set the diff-command template"

    DiffCommandTemplate := aCommandTemplateString
! !

!DiffListUtility class methodsFor:'private'!

saveForDiff:text on:stream
    [
        text do:[:line |
            |lOut i|

            line notEmptyOrNil ifTrue:[
                lOut := line.
                (line includes:Character return) ifTrue: [
                    (line endsWith:Character return) ifTrue:[
                        lOut := line copyButLast:1.
                    ].
                ] ifFalse:[
                    (line endsWith:(String crlf)) ifTrue: [
                        lOut := line copyButLast:2.
                    ]
"/                        i := line indexOf:Character return.
"/                        (line at:i+1) == Character nl ifTrue:[
"/                            "/ crnl endings
"/                            lOut := line copyReplaceString:(String crlf) withString:(String lf).
"/                        ] ifFalse:[
"/                            "/ cr endings
"/                            lOut := line copyReplaceAll:(Character return) with:Character nl.
"/                        ].
"/                    ]
                ].
                lOut isWideString ifTrue:[
                    (lOut first = (Character value:16rFEFF)) ifTrue:[
                        lOut := (lOut copyFrom:2) asSingleByteStringReplaceInvalidWith:(Character value:16rFF).
                    ].
                ].
                lOut printOn:stream.
            ].
            stream cr
        ].
    ] ensure:[
        stream close.
    ].

    "Modified: / 22-10-2008 / 17:52:52 / cg"
! !

!DiffListUtility class methodsFor:'utilities'!

diffListFor:text1 and:text2
    "execute DiffCommand to get a list of diffs."

    "
     The returned list is in raw-diff output format, such as:
        1 : '1c1'
        2 : '< hello world'
        3 : '---'
        4 : '> Hello World'
        5 : '2a3'
        6 : '> line2'
        7 : '4d4'
        8 : '< line4'
    "

    |stream line 
     diffList diffTemplate diffCmd tmpStream1 tmpStream2|

    diffTemplate := self diffCommand.
    diffTemplate isEmptyOrNil ifTrue:[
        "/ self warn:'no diff command available'.
        ^ nil
    ].

    text1 = text2 ifTrue:[
        "no diff"
        ^ #()
    ].

    "
     save them texts in two temporary files ...
    "
    [
        self saveForDiff:text1 on:(tmpStream1 := FileStream newTemporary).
        self saveForDiff:text2 on:(tmpStream2 := FileStream newTemporary).
        tmpStream1 close.   
        tmpStream2 close.

        "
         start diff on it ...
        "
        diffCmd := diffTemplate
                    bindWith:tmpStream1 pathName
                    with:tmpStream2 pathName.

        stream := PipeStream readingFrom:diffCmd.
        stream isNil ifTrue:[
            "this code is not reached in win32.
             PipeStream starts a cmd.exe, which is always successful
             at the first place and fails later"
            stream := PipeStream readingFrom:('support' asFilename constructString:diffCmd).
            stream isNil ifTrue:[
                self error:'cannot execute diff' mayProceed:true.
                ^ nil.
            ]
        ].

        diffList := OrderedCollection new.
        (stream readWaitWithTimeout:10) ifTrue:[
            "/ timeout
            stream abortAndClose.
            self error:'cannot execute diff (timeout)' mayProceed:true.
            ^ nil.
        ].

        [stream atEnd] whileFalse:[
            line := stream nextLine.
            line notNil ifTrue:[diffList add:line]
        ].
        stream close.
    ] ensure:[
        tmpStream1 notNil ifTrue:[ tmpStream1 fileName remove ].
        tmpStream2 notNil ifTrue:[ tmpStream2 fileName remove ].
    ].
    ^ diffList

    "
     self 
        diffListFor:#(
                        'hello world'
                        'line1'
                        'line3'
                        'line4'
                    )
        and:        #(
                        'Hello World'
                        'line1'
                        'line2'
                        'line3'
                    )
    "

    "Modified: / 22-05-2018 / 18:18:34 / Stefan Vogel"
! !

!DiffListUtility class methodsFor:'documentation'!

version
    ^ '$Header$'
!

version_CVS
    ^ '$Header$'
! !