import java.awt.print.PrinterAbortException;
import java.io.*;
import java.util.Scanner;

public class BibCreator {

    public static void processFilesForValidation(Scanner[] scanners) {
        String field = null;
        String line = null;
        int invalidFileCounter = 0;
        File file = null;
        File file2 = null;
        File file3 = null;



        for(int scanner = 0; scanner < scanners.length; scanner++) {

            int articleCount = 0;

            try {

                // file is valid, start reading articles

                String author = null;
                String journal = null;
                String title = null;
                String year = null;
                String volume = null;
                String number = null;
                String pages = null;
                String keywords = null;
                String doi = null;
                String ISSN = null;
                String month = null;

                while (scanners[scanner].hasNextLine()) {

                    line = scanners[scanner].nextLine();

                    if (line.contains("@ARTICLE{")) { // if this is true, i am at the beginning of an article, and reset all the information to null on next article

                        articleCount++;

                        author = null;
                        journal = null;
                        title = null;
                        year = null;
                        volume = null;
                        number = null;
                        pages = null;
                        keywords = null;
                        doi = null;
                        ISSN = null;
                        month = null;

                        //consume another line
                        line = scanners[scanner].nextLine();
                    }

                    // if the line contains the specific word, split the next line into two segments
                    // everything after the regex is saved as the information pertaining to the contained word

                    if (line.contains("author=")) {
                        field = "author";
                        author = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("journal=")) {
                        field = "journal";
                        journal = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("title=")) {
                        field = "title";
                        title = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("year=")) {
                        field = "year";
                        year = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("volume=")) {
                        field = "volume";
                        volume = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("number=")) {
                        field = "number";
                        number = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("pages=")) {
                        field = "pages";
                        pages = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("keywords=")) {
                        field = "keywords";
                        keywords = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("doi=")) {
                        field = "doi";
                        doi = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("ISSN=")) {
                        field = "ISSN";
                        ISSN = line.substring(line.indexOf("{") + 1, line.indexOf("}"));
                    }

                    if (line.contains("month=")) {
                        field = "month";
                        month = line.split("month=")[1];
                    }

                    if (line.equals("}")) {

                        // recording to an IEEE file
                        file = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\IEEE" + (scanner + 1) + ".json");
                        try {
                            PrintWriter pw;

                            if (articleCount == 1) {
                                pw = new PrintWriter(new FileOutputStream(file, false), true);
                            } else {
                                pw = new PrintWriter(new FileOutputStream(file, true), true);
                            }

                            pw.println(author.replace("and", ".") + "," + journal + "," + title + "," + year + "," + volume + "," + number + "," + pages + "," + keywords + "," + doi + "," + ISSN + "," + month);
                            pw.flush();
                            pw.close();
                        } catch (FileNotFoundException e) {
                            System.out.print("There was an error processing IEEE" + (scanner + 1) + ".json, the program will terminate.");
                            System.exit(0);
                        }

                        // recording to an ACM file
                        file2 = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\ACM" + (scanner + 1) + ".json");
                        try {
                            PrintWriter pw;

                            if (articleCount == 1) {
                                pw = new PrintWriter(new FileOutputStream(file2, false), true);
                            } else {
                                pw = new PrintWriter(new FileOutputStream(file2, true), true);
                            }

                            pw.println(author.replace("and", "et al") + "," + journal + "," + title + "," + year + "," + volume + "," + number + "," + pages + "," + keywords + "," + doi + "," + ISSN + "," + month);
                            pw.flush();
                            pw.close();
                        } catch (FileNotFoundException e) {
                            System.out.print("There was an error processing ACM" + (scanner + 1) + ".json, the program will terminate.");
                            System.exit(0);
                        }

                        // recording to an NJ file
                        file3 = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\NJ" + (scanner + 1) + ".json");
                        try {
                            PrintWriter pw;

                            if (articleCount == 1) {
                                pw = new PrintWriter(new FileOutputStream(file3, false), true);
                            } else {
                                pw = new PrintWriter(new FileOutputStream(file3, true), true);
                            }

                            pw.println(author.replace("and", "&") + "," + journal + "," + title + "," + year + "," + volume + "," + number + "," + pages + "," + keywords + "," + doi + "," + ISSN + "," + month);
                            pw.flush();
                            pw.close();
                        } catch (FileNotFoundException e) {
                            System.out.print("There was an error processing NJ" + (scanner + 1) + ".json, the program will terminate.");
                            System.exit(0);
                        }
                    }

                    // if the content is empty, throw the exception
                    if (line.contains("{}")) {
                        throw new FileInvalidException();
                    }


                } //done reading file


            } // end of try
            catch (FileInvalidException e) {

                file.delete();
                file2.delete();
                file3.delete();

                invalidFileCounter++;

                System.out.println("Error: Detected empty field!");
                System.out.println("****************************");
                System.out.println("Problem detected with input file:" + " Latex" + (scanner + 1) + ".bib");
                System.out.println("File is invalid: Field " + field + " is empty. Processing stopped at this point. Other empty fields may be present as well.");
                System.out.println("\n");


            } // end of catch
        }
        System.out.print("A total of " + invalidFileCounter + " files were invalid, and could not be processed. All other " + (10-invalidFileCounter) + " 'valid' files have been created.");
    }


    public static void main(String[] args) {

        System.out.println("Welcome to the BibCreator program!\n");

        int i=0; // save the index of the file if one does not exist

        Scanner[] fileScanners = new Scanner[10];

        for (; i < 10; i++) {
            try {
                fileScanners[i] = new Scanner(new FileInputStream("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\Latex" + (i + 1) + ".bib"));
            } // end of try

            catch (FileNotFoundException e) {
                System.out.print("Could not open input file Latex" + (i + 1) + ".bib for reading. Please check if file exists! Program will terminate after closing any opened files.");
                fileScanners[i].close();
                System.exit(0); // if the file does not exist, close any open files and exit the program
            } // end of catch
        }

        //fileScanners[i].close(); // close the scanner



        processFilesForValidation(fileScanners);

        PrintWriter[] fileWriters = new PrintWriter[10];

        int j = 0;

        // create the IEEE files
        try {
            for (; j < fileWriters.length; j++) {
                fileWriters[j] = new PrintWriter(new FileOutputStream("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\IEEE" + (j + 1) + ".json", true));
            }
        }
        catch (FileNotFoundException e) {
            System.out.print("Error: Could not open/create IEEE" + j + ".json.");
            File file = null;
            for (; j < 10; j++) {
                file = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\IEEE" + j + ".json");
            }
            if(file.delete()) {
                System.out.print("All files in the directory will now be deleted");
                System.exit(0);
            }
        }

        // create the ACM files
        j = 0;

        try {
            for (; j < fileWriters.length; j++) {
                fileWriters[j] = new PrintWriter(new FileOutputStream("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\ACM" + (j + 1) + ".json", true));
            }
        }
        catch (FileNotFoundException e) {
            System.out.print("Error: Could not open/create ACM" + j + ".json.");
            File file = null;
            File file2 = null;
            for (; j < 10; j++) {
                file = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\IEEE" + j + ".json");
                file2 = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\ACM" + j + ".json");
            }
            if(file.delete() && file2.delete()) {
                System.out.print("All files in the directory will now be deleted");
                System.exit(0);
            }
        }


        // create the NJ files
        j = 0;

        try {
            for (; j < fileWriters.length; j++) {
                fileWriters[j] = new PrintWriter(new FileOutputStream("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\NJ" + (j + 1) + ".json", true));
            }
        }
        catch (FileNotFoundException e) {
            System.out.print("Error: Could not open/create NJ" + j + ".json.");
            File file = null;
            File file2 = null;
            File file3 = null;
            for (; j < 10; j++) {
                file = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\IEEE" + j + ".json");
                file2 = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\ACM" + j + ".json");
                file3 = new File("C:\\Users\\kimbe\\Desktop\\COMP249\\Assignment3\\src\\Files\\CreatedFiles\\NJ" + j + ".json");
            }
            if(file.delete() && file2.delete() && file3.delete()) {
                System.out.print("All files in the directory will now be deleted");
                System.exit(0);
            }
        }

      // fileWriters[j].close(); // close the printWriter

    } // end of main

} // end of class