property NSSet : a reference to current application’s NSSet
property |NSURL| : a reference to current application’s |NSURL|
property NSArray : a reference to current application’s NSArray
property NSString : a reference to current application’s NSString
property NSImage : a reference to current application’s NSImage
property PDFDocument : a reference to current application’s PDFDocument
property NSSortDescriptor : a reference to current application’s NSSortDescriptor

tell application "Skim"
　　set docCount to count every document
　　if docCount = 0 then return
　　
　　tell front document
　　　　set curInd to index of current page
　　　　set docFile to file of it
　　　　close without saving
　　end tell
end tell

set aPOSIX to POSIX path of docFile
set aURL to (|NSURL|’s fileURLWithPath:aPOSIX)

set aPDFdoc to PDFDocument’s alloc()’s initWithURL:aURL
set pCount to aPDFdoc’s pageCount()

set pRes to removePDFPageAfter(docFile, curInd) of me

tell application "Skim"
　　open docFile
　　tell front document
　　　　go to last page
　　end tell
end tell

–指定パスのPDFの指定ページ以降（指定ページも含む）をすべて削除
on removePDFPageAfter(inFile, sPage)
　　set pCount to pdfPageCount(inFile) of me
　　set eCount to pCount – sPage + 1
　　
　　set targPageList to makeSuccessfulNumArray(sPage, pCount) of me
　　set rList to reverse of targPageList
　　return removeSpecificPagesFromPDF(inFile, rList) of me
end removePDFPageAfter

–指定PDF書類の複数ページの一括削除
on removeSpecificPagesFromPDF(inFileAlias, targPageNumList as list)
　　set inNSURL to |NSURL|’s fileURLWithPath:(POSIX path of inFileAlias)
　　set theDoc to PDFDocument’s alloc()’s initWithURL:inNSURL
　　
　　–削除対象ページリストをユニーク化して降順ソート（後方から削除）
　　set pRes to theDoc’s pageCount()
　　set t3List to relativeToAbsNumList(targPageNumList, pRes) of me
　　
　　repeat with i in t3List
　　　　copy i to targPageNum
　　　　(theDoc’s removePageAtIndex:(targPageNum – 1))
　　end repeat
　　
　　–Overwrite Exsiting PDF
　　set aRes to (theDoc’s writeToURL:inNSURL) as boolean
　　
　　return aRes
end removeSpecificPagesFromPDF

–絶対ページと相対ページが混在した削除対象ページリストを絶対ページに変換して重複削除して降順ソート
on relativeToAbsNumList(aList, aMax)
　　set newList to {}
　　
　　repeat with i in aList
　　　　set j to contents of i
　　　　if i < 0 then
　　　　　　set j to aMax + j
　　　　end if
　　　　
　　　　if (j ≤ aMax) and (j is not equal to 0) then
　　　　　　set the end of newList to j
　　　　end if
　　end repeat
　　
　　set t1List to uniquify1DList(newList, true) of me
　　set t2List to sort1DNumListWithOrder(t1List, false) of me
　　
　　return t2List
end relativeToAbsNumList

–1D/2D Listをユニーク化
on uniquify1DList(theList as list, aBool as boolean)
　　set aArray to NSArray’s arrayWithArray:theList
　　set bArray to aArray’s valueForKeyPath:"@distinctUnionOfObjects.self"
　　return bArray as list
end uniquify1DList

–Sort 1-Dimension List（String Number List）
on sort1DNumListWithOrder(theList as list, aBool as boolean)
　　tell NSSet to set theSet to setWithArray_(theList)
　　tell NSSortDescriptor to set theDescriptor to sortDescriptorWithKey_ascending_("floatValue", aBool)
　　set sortedList to theSet’s sortedArrayUsingDescriptors:{theDescriptor}
　　return (sortedList) as list
end sort1DNumListWithOrder

–指定PDFのページ数をかぞえる
on pdfPageCount(aFile)
　　set aFile to POSIX path of aFile
　　set theURL to |NSURL|’s fileURLWithPath:aFile
　　set aPDFdoc to PDFDocument’s alloc()’s initWithURL:theURL
　　set aRes to aPDFdoc’s pageCount()
　　return aRes as integer
end pdfPageCount

–連番1D Listを作成
on makeSuccessfulNumArray(sNum, eNum)
　　script spd
　　　　property aList : {}
　　end script
　　
　　if sNum ≥ eNum then return {}
　　
　　set (aList of spd) to {}
　　
　　repeat with i from sNum to eNum
　　　　set the end of (aList of spd) to i
　　end repeat
　　
　　return (aList of spd)
end makeSuccessfulNumArray