package Torello.Languages;

import java.util.*;
import java.util.regex.*;
import java.io.*;

import Torello.HTML.*;
import Torello.HTML.NodeSearch.*;

import Torello.Java.*;

import Torello.Java.Additional.URLs;

import Torello.JavaDoc.StaticFunctional;
import Torello.JavaDoc.Excuse;

/**
 * Google Cloud Services, Translation API Wrapper.
 * 
 * <BR /><BR /><EMBED CLASS='external-html' DATA-FILE-ID=GCSTAPI>
 */
@StaticFunctional(Excused="key", Excuses=Excuse.CONFIGURATION)
public class GCSTAPI
{
    private GCSTAPI() { }

    private static final String baseQ =
        "https://www.googleapis.com/language/translate/v2?key=";

    private static final Pattern P1 =
        Pattern.compile(
            "\\{\\s+\"translatedText\":\\s+\"(.*?)\"\\s+\\}",
             Pattern.DOTALL | Pattern.CASE_INSENSITIVE
        );

    /**
     * This is a key that may be obtained from Google Corporation.  Complete the form for "Cloud
     * Server Login" and then try adding the Translation package.  Google expects you to pay for
     * translation services, but single articles are usually a penny or so.  Long articles with
     * many translations can become expensive.  Set this key to a specific value to register it. 
     * 
     * <BR /><BR /><B>NOTE:</B> This class only has static methods for brevity and simplicity.  If
     * you wish to use multiple keys for different projects, well, copy the code from these two
     * methods and add them to one of your own classes - for "multi-threaded" applications.
     * <I><B>Otherwise you might also just change/update the {@code public static String key}
     * field</I></B> whenver you wish to bill your translations to a different billing project,
     * card or account. 
     * 
     * <BR /><BR /><B>ALSO NOTE:</B> Use of this Java Package will not transmit your key to me
     * (Ralph P. Torello), I'm not trying to steal your google key or account.  Obviously, I cannot
     * prove this Java Package does not make outgoing connections to any server I own, but,
     * <B>Guess What? It DOESN'T!</B> 
     * 
     * <BR /><BR /><I>If you do not set the key field here, Google Cloud Server Translate API will
     * not respond to your query.</I>  Google bills each query on a word by word basis.  See their
     * metrics on the GCS Translate API documentation website.
     */
    public static String key;

    /**
     * This method takes what is expected to be a sentence in (any) foreign language.  The
     * foreign-language used is passed as a two-character String from Google Translate' list of
     * two-character language codes.  The Target language may be any.  Usually it is
     * English/Spanish.<BR /><BR />
     * 
     * @param text Any string in a foreign language.  This is expected to be a single sentence.
     * 
     * @param srcLang Two-Character String Language Code identifying the foreign language used.
     * See the enum "LC" (Language Code)
     * 
     * @param targetLang Two-Character String Language Code of the "target" or "destination"
     * language.  See the enum "LC" (Language Code)
     * 
     * @return Translated Sentence - generated by a call to Google Cloud Server Translate API.
     * 
     * @see Torello.Languages.LC
     */
    public static String sentence(String text, LC srcLang, LC targetLang) throws IOException
    {
        StringBuffer    sb      = new StringBuffer();
        String          json    = null;

        // REST API Query String
        String q = baseQ + key + "&source=" + srcLang.gcsLanguageCode +
            "&target=" + targetLang.gcsLanguageCode +
            "&q=" + URLs.toProperURLV2(text);

        try
        {
            json        = Scrape.scrapePage(Scrape.openConn_UTF8(q)).toString();
            Matcher m   = P1.matcher(json);

            // Since only a Single text-string was queried, it is better to return the result
            // as a single string.

            while (m.find()) sb.append(m.group(1) + "\n");

            return sb.toString();
        }
        catch (Exception e)
        {
            System.out.println(
                '\n' +
                "TextTranslate.sentence(q=\n" + q + '\n' +
                "TextTranslate.sentence(text=\n" + text + '\n' +
                "TextTranslate.sentence(json=\n" + json
            );

            throw e;
        }
    }

    /**
     * This is similar to sentence, but the input is expected to be a series of individual
     * vocabulary words.  The source and target/destination language codes are necessary.  A Vector
     * of equal length to the original input Vector is returned.  It contains each vocabulary word
     * from the original Vector in the destination/target language.
     * 
     * @param words Any string in a foreign language.  This is expected to be a single sentence.
     * 
     * @param srcLang Two-Character String Language Code identifying the foreign language used.
     * See the enum "LC" (Language Code)
     * 
     * @param targetLang Two-Character String Language Code of the "target" or "destination"
     * language.  See the enum "LC" (Language Code)
     * 
     * @return Translated Sentence - generated by a call to Google Cloud Server Translate API.
     * 
     * @see Torello.HTML.Scrape
     * @see Torello.Languages.LC
     */
    public static Vector<String> wordByWord(Vector<String> words, LC srcLang, LC targetLang)
        throws IOException
    {
        int             i       = 0;
        int             len     = words.size();
        Vector<String>  ret     = new Vector<String>();
        String          q       = null;
        String          json    = null;

        while (i < len)
        {
            try
            {
                q = baseQ + key + "&source=" + srcLang.gcsLanguageCode +
                        "&target=" + targetLang.gcsLanguageCode;

                for (int j=0; (j < 50) && ((j + i) < len); j++)
                    q += "&q=" + URLs.toProperURLV2(words.elementAt(j + i));

                i += 50;

                json = Scrape.scrapePage(Scrape.openConn_UTF8(q)).toString();
                Matcher m = P1.matcher(json);

                while (m.find()) ret.addElement(m.group(1).trim());
            }
            catch (Exception e)
            {
                System.out.println(
                    '\n' +
                    "TextTranslate.wordByWord, q=\n" + q + '\n' +
                    "TextTranslate.wordByWord, json=\n" + json
                );

                throw e;
            }
        }

        return ret;
    }
}