Merge, copy, delete and rearrange PDF pages in Swift

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2019 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

import PDFNet
import Foundation

func runPDFPageTest() -> Int {
    return autoreleasepool {
        var ret = 0
        
        
        // Sample 1 - Split a PDF document into multiple pages
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 1 - Split a PDF document into multiple pages...")
                print("Opening the input pdf...")
                let in_doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                in_doc.initSecurityHandler()
                
                let page_num = in_doc.getPageCount()
                for i in 1...page_num {
                    let new_doc: PTPDFDoc = PTPDFDoc()
                    let output_file: String = URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_split_page_\(i).pdf").path
                    new_doc.insertPages(0, src_doc: in_doc, start_page: i, end_page: i, flag: e_ptinsert_none)
                    new_doc.save(toFile: output_file, flags: e_ptremove_unused.rawValue)
                    print("Done. Result saved in newsletter_split_page_\(i).pdf")
                }
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // Sample 2 - Merge several PDF documents into one
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 2 - Merge several PDF documents into one...")
                let new_doc: PTPDFDoc = PTPDFDoc()
                new_doc.initSecurityHandler()
                
                let page_num: Int = 15
                for i in 1...page_num {
                    let input_file: String = URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_split_page_\(i).pdf").path
                    print("Opening newsletter_split_page_\(i).pdf")
                    let in_doc: PTPDFDoc = PTPDFDoc(filepath: input_file)
                    new_doc.insertPages(Int32(i), src_doc: in_doc, start_page: 1, end_page: in_doc.getPageCount(), flag: e_ptinsert_none)
                }
                new_doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_merge_pages.pdf").path, flags: e_ptremove_unused.rawValue)
                print("Done. Result saved in newsletter_merge_pages.pdf")
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // Sample 3 - Delete every second page
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 3 - Delete every second page...")
                print("Opening the input pdf...")
                let in_doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                in_doc.initSecurityHandler()
                
                var page_num = in_doc.getPageCount()
                while page_num >= 1 {
                    let itr: PTPageIterator = in_doc.getPageIterator(UInt32(page_num))
                    in_doc.pageRemove(itr)
                    page_num -= 2
                }
                
                in_doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_page_remove.pdf").path, flags: 0)
                print("Done. Result saved in newsletter_page_remove.pdf...")
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // Sample 4 - Inserts a page from one document at different
        // locations within another document
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 4 - Insert a page at different locations...")
                print("Opening the input pdf...")
                
                let in1_doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                in1_doc.initSecurityHandler()
                
                let in2_doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "fish", ofType: "pdf"))
                in2_doc.initSecurityHandler()
                
                let src_page: PTPageIterator = in2_doc.getPageIterator(1)
                let dst_page: PTPageIterator = in1_doc.getPageIterator(1)
                var page_num: Int = 1
                while dst_page.hasNext() {
                    if (page_num % 3) == 0 {
                        in1_doc.pageInsert(dst_page, page: src_page.current())
                    }
                    page_num += 1
                    dst_page.next()
                }
                
                in1_doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_page_insert.pdf").path, flags: 0)
                print("Done. Result saved in newsletter_page_insert.pdf...")
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // Sample 5 - Replicate pages within a single document
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 5 - Replicate pages within a single document...")
                print("Opening the input pdf...")
                let doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                doc.initSecurityHandler()
                
                // Replicate the cover page three times (copy page #1 and place it before the
                // seventh page in the document page sequence)
                let cover: PTPage = doc.getPage(1)
                let p7: PTPageIterator = doc.getPageIterator(7)
                doc.pageInsert(p7, page: cover)
                doc.pageInsert(p7, page: cover)
                doc.pageInsert(p7, page: cover)
                
                // Replicate the cover page two more times by placing it before and after
                // existing pages.
                doc.pagePushFront(cover)
                doc.pagePushBack(cover)
                
                doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_page_clone.pdf").path, flags: 0)
                print("Done. Result saved in newsletter_page_clone.pdf...")
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // Sample 6 - Use ImportPages() in order to copy multiple pages at once
        // in order to preserve shared resources between pages (e.g. images, fonts,
        // colorspaces, etc.)
        do {
            try PTPDFNet.catchException {
                print("_______________________________________________")
                print("Sample 6 - Preserving shared resources using ImportPages...")
                print("Opening the input pdf...")
                let in_doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                in_doc.initSecurityHandler()
                
                let new_doc: PTPDFDoc = PTPDFDoc()
                
                let copy_pages: PTVectorPage = PTVectorPage()
                let itr: PTPageIterator = in_doc.getPageIterator(1)
                while itr.hasNext() {
                    copy_pages.add(itr.current())
                    itr.next()
                }
                
                let imported_pages: PTVectorPage = new_doc.importPages(copy_pages, import_bookmarks: false)
                for i in 0..<imported_pages.size() {
                    new_doc.pagePushFront(imported_pages.get(Int32(i)))
                    // Order pages in reverse order.
                    // Use PagePushBack() if you would like to preserve the same order.
                }
                
                new_doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_import_pages.pdf").path, flags: 0)
                print("Done. Result saved in newsletter_import_pages.pdf...")
                
                print("Note that the output file size is less than half the size of the file produced using individual page copy operations between two documents")
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        return ret
    }
}