import com.itextpdf.awt.geom.Rectangle2D.Float;

import com.itextpdf.text.pdf.PdfDictionary;

import com.itextpdf.text.pdf.PdfName;

import com.itextpdf.text.pdf.PdfReader;

import com.itextpdf.text.pdf.parser.*;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

/**

 * 消失的太阳

 */

public class MyTest {

    public static void main(String[] args) throws IOException {

        //1.给定文件

        File pdfFile = new File("D://test.pdf");

        //2.定义一个byte数组，长度为文件的长度

        byte[] pdfData = new byte[(int) pdfFile.length()];

        //3.IO流读取文件内容到byte数组

        FileInputStream inputStream = null;

        try {

            inputStream = new FileInputStream(pdfFile);

            inputStream.read(pdfData);

        } catch (IOException e) {

            throw e;

        } finally {

            if (inputStream != null) {

                try {

                    inputStream.close();

                } catch (IOException e) {

                }

            }

        }

        //4.指定关键字

        String keyword = "消失的太阳：";

        //5.调用方法，给定关键字和文件

        List<float[]> positions = findKeywordPostions(pdfData, keyword);

        //6.返回值类型是  List<float[]> 每个list元素代表一个匹配的位置，分别为 float[0]所在页码  float[1]所在x轴 float[2]所在y轴

        System.out.println("total:" + positions.size());

        if (positions != null && positions.size() > 0) {

            for (float[] position : positions) {

                System.out.print("pageNum: " + (int) position[0]);

                System.out.print("\tx: " + position[1]);

                System.out.println("\ty: " + position[2]);

            }

        }

    }

    /**

     * findKeywordPostions

     * @param pdfData     通过IO流 PDF文件转化的byte数组

     * @param keyword     关键字

     * @return List<float [ ]> : float[0]:pageNum float[1]:x float[2]:y

     * @throws IOException

     */

    public static List<float[]> findKeywordPostions(byte[] pdfData, String keyword) throws IOException {

        List<float[]> result = new ArrayList<>();

        List<PdfPageContentPositions> pdfPageContentPositions = getPdfContentPostionsList(pdfData);

        for (PdfPageContentPositions pdfPageContentPosition : pdfPageContentPositions) {

            List<float[]> charPositions = findPositions(keyword, pdfPageContentPosition);

            if (charPositions == null || charPositions.size() < 1) {

                continue;

            }

            result.addAll(charPositions);

        }

        return result;

    }

    private static List<PdfPageContentPositions> getPdfContentPostionsList(byte[] pdfData) throws IOException {

        PdfReader reader = new PdfReader(pdfData);

        List<PdfPageContentPositions> result = new ArrayList<>();

        int pages = reader.getNumberOfPages();

        for (int pageNum = 1; pageNum <= pages; pageNum++) {

            float width = reader.getPageSize(pageNum).getWidth();

            float height = reader.getPageSize(pageNum).getHeight();

            PdfRenderListener pdfRenderListener = new PdfRenderListener(pageNum, width, height);

            //解析pdf，定位位置

            PdfContentStreamProcessor processor = new PdfContentStreamProcessor(pdfRenderListener);

            PdfDictionary pageDic = reader.getPageN(pageNum);

            PdfDictionary resourcesDic = pageDic.getAsDict(PdfName.RESOURCES);

            try {

                processor.processContent(ContentByteUtils.getContentBytesForPage(reader, pageNum), resourcesDic);

            } catch (IOException e) {

                reader.close();

                throw e;

            }

            String content = pdfRenderListener.getContent();

            List<CharPosition> charPositions = pdfRenderListener.getcharPositions();

            List<float[]> positionsList = new ArrayList<>();

            for (CharPosition charPosition : charPositions) {

                float[] positions = new float[]{charPosition.getPageNum(), charPosition.getX(), charPosition.getY()};

                positionsList.add(positions);

            }

            PdfPageContentPositions pdfPageContentPositions = new PdfPageContentPositions();

            pdfPageContentPositions.setContent(content);

            pdfPageContentPositions.setPostions(positionsList);

            result.add(pdfPageContentPositions);

        }

        reader.close();

        return result;

    }

    private static List<float[]> findPositions(String keyword, PdfPageContentPositions pdfPageContentPositions) {

        List<float[]> result = new ArrayList<>();

        String content = pdfPageContentPositions.getContent();

        List<float[]> charPositions = pdfPageContentPositions.getPositions();

        for (int pos = 0; pos < content.length(); ) {

            int positionIndex = content.indexOf(keyword, pos);

            if (positionIndex == -1) {

                break;

            }

            float[] postions = charPositions.get(positionIndex);

            result.add(postions);

            pos = positionIndex + 1;

        }

        return result;

    }

    private static class PdfPageContentPositions {

        private String content;

        private List<float[]> positions;

        public String getContent() {

            return content;

        }

        public void setContent(String content) {

            this.content = content;

        }

        public List<float[]> getPositions() {

            return positions;

        }

        public void setPostions(List<float[]> positions) {

            this.positions = positions;

        }

    }

    private static class PdfRenderListener implements RenderListener {

        private int pageNum;

        private float pageWidth;

        private float pageHeight;

        private StringBuilder contentBuilder = new StringBuilder();

        private List<CharPosition> charPositions = new ArrayList<>();

        public PdfRenderListener(int pageNum, float pageWidth, float pageHeight) {

            this.pageNum = pageNum;

            this.pageWidth = pageWidth;

            this.pageHeight = pageHeight;

        }

        public void beginTextBlock() {

        }

        public void renderText(TextRenderInfo renderInfo) {

            List<TextRenderInfo> characterRenderInfos = renderInfo.getCharacterRenderInfos();

            for (TextRenderInfo textRenderInfo : characterRenderInfos) {

                String word = textRenderInfo.getText();

                if (word.length() > 1) {

                    word = word.substring(word.length() - 1, word.length());

                }

                Float rectangle = textRenderInfo.getAscentLine().getBoundingRectange();

                float x = (float)rectangle.getX();

                float y = (float)rectangle.getY();

//                float x = (float)rectangle.getCenterX();

//                float y = (float)rectangle.getCenterY();

//                double x = rectangle.getMinX();

//                double y = rectangle.getMaxY();

                //这两个是关键字在所在页面的XY轴的百分比

                float xPercent = Math.round(x / pageWidth * 10000) / 10000f;

                float yPercent = Math.round((1 - y / pageHeight) * 10000) / 10000f;

//                CharPosition charPosition = new CharPosition(pageNum, xPercent, yPercent);

                CharPosition charPosition = new CharPosition(pageNum, (float)x, (float)y);

                charPositions.add(charPosition);

                contentBuilder.append(word);

            }

        }

        public void endTextBlock() {

        }

        public void renderImage(ImageRenderInfo renderInfo) {

        }

        public String getContent() {

            return contentBuilder.toString();

        }

        public List<CharPosition> getcharPositions() {

            return charPositions;

        }

    }

    private static class CharPosition {

        private int pageNum = 0;

        private float x = 0;

        private float y = 0;

        public CharPosition(int pageNum, float x, float y) {

            this.pageNum = pageNum;

            this.x = x;

            this.y = y;

        }

        public int getPageNum() {

            return pageNum;

        }

        public float getX() {

            return x;

        }

        public float getY() {

            return y;

        }

        @Override

        public String toString() {

            return "[pageNum=" + this.pageNum + ",x=" + this.x + ",y=" + this.y + "]";

        }

    }

}