Search PDF files for text 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

// This sample illustrates the basic text search capabilities of PDFNet.

func runTextSearchTest() -> Int {
    return autoreleasepool {
        var ret: Int = 0
        
        let input_path: String? = Bundle.main.path(forResource: "credit card numbers", ofType: "pdf")
        
        do {
            try PTPDFNet.catchException {
                let doc: PTPDFDoc! = PTPDFDoc(filepath: input_path)
                doc.initSecurityHandler()
                
                let txt_search: PTTextSearch! = PTTextSearch()
                var mode = e_ptwhole_word.rawValue | e_ptpage_stop.rawValue
                var pattern = "joHn sMiTh"
                
                //call Begin() method to initialize the text search.
                txt_search.begin(doc, pattern: pattern, mode: mode, start_page: -1, end_page: -1)
                
                var step: Int = 0
                
                //call run() method iteratively to find all matching instances.
                while true {
                    let result: PTSearchResult! = txt_search.run()
                    
                    if (result != nil) {
                        if step == 0 {
                            //step 0: found "John Smith"
                            //note that, here, 'ambient_string' and 'hlts' are not written to,
                            //as 'e_ambient_string' and 'e_highlight' are not set.
                            
                            print("\(result.getMatch()!)'s credit card number is: ")
                            //now switch to using regular expressions to find John's credit card number
                            mode = txt_search.getMode()
                            mode |= e_ptreg_expression.rawValue | e_pthighlight.rawValue
                            txt_search.setMode(mode)
                            pattern = "\\d{4}-\\d{4}-\\d{4}-\\d{4}"
                            //or "(\\d{4}-){3}\\d{4}"
                            txt_search.setPattern(pattern)
                            
                            step += 1
                        } else if step == 1 {
                            //step 1: found John's credit card number
                            print("  \(result.getMatch()!)")
                            
                            //note that, here, 'hlts' is written to, as 'e_highlight' has been set.
                            //output the highlight info of the credit card number.
                            let hlts: PTHighlights = result.getHighlights()
                            hlts.begin(doc)
                            while hlts.hasNext() {
                                print("The current highlight is from page: \(hlts.getCurrentPageNumber())")
                                hlts.next()
                            }
                            
                            //see if there is an AMEX card number
                            pattern = "\\d{4}-\\d{6}-\\d{5}"
                            txt_search.setPattern(pattern)
                            
                            step += 1
                        } else if step == 2 {
                            //found an AMEX card number
                            print("There is an AMEX card number: \(result.getMatch()!)")
                            
                            //change mode to find the owner of the credit card; supposedly, the owner's
                            //name proceeds the number
                            mode = txt_search.getMode()
                            mode |= e_ptsearch_up.rawValue
                            txt_search.setMode(mode)
                            pattern = "[A-z]++ [A-z]++"
                            txt_search.setPattern(pattern)
                            step += 1
                        } else if step == 3 {
                            //found the owner's name of the AMEX card
                            print("Is the owner's name: \(result.getMatch()!)?")
                            
                            //add a link annotation based on the location of the found instance
                            let hlts: PTHighlights = result.getHighlights()
                            hlts.begin(doc)
                            while hlts.hasNext() {
                                let cur_page: PTPage = doc.getPage(UInt32(hlts.getCurrentPageNumber()))
                                let quads: PTVectorQuadPoint = hlts.getCurrentQuads()
                                var i: Int = 0
                                
                                while i < quads.size() {
                                    //assume each quad is an axis-aligned rectangle
                                    let q: PTQuadPoint = quads.get(Int32(i))
                                    let x1: Double = min(min(min(q.getP1().getX(), q.getP2().getX()), q.getP3().getX()), q.getP4().getX())
                                    let x2: Double = max(max(max(q.getP1().getX(), q.getP2().getX()), q.getP3().getX()), q.getP4().getX())
                                    let y1: Double = min(min(min(q.getP1().getY(), q.getP2().getY()), q.getP3().getY()), q.getP4().getY())
                                    let y2: Double = max(max(max(q.getP1().getY(), q.getP2().getY()), q.getP3().getY()), q.getP4().getY())
                                    let rect = PTPDFRect(x1: x1, y1: y1, x2: x2, y2: y2)
                                    let action = PTAction.createURI(doc.getSDFDoc(), uri: "http://www.pdftron.com")
                                    let hyper_link = PTLink.create(withAction: doc.getSDFDoc(), pos: rect, action: action)
                                    cur_page.annotPushBack(hyper_link)
                                    i += 1
                                }
                                hlts.next()
                            }
                            doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("credit card numbers_linked.pdf").path, flags: e_ptlinearized.rawValue)
                            
                            break
                        }
                    } else if (result.isPageEnd()) {
                        //you can update your UI here if needed
                    } else {
                        break
                    }
                }
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        return ret
    }
}