package com.trafficaudit.holiday.service;

import com.trafficaudit.holiday.HolidayNumberUtils;
import com.trafficaudit.holiday.service.HolidayStatService.DailyMetrics;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.math.BigDecimal;
import java.nio.file.Files;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

@Slf4j
@Service
public class HolidayBulletinService {

    private static final String WORD_NS = "http://schemas.openxmlformats.org/wordprocessingml/2006/main";
    private static final BigDecimal EPSILON = new BigDecimal("0.0000001");

    @Value("${holiday.bulletin-template:docs/专项统计/重要节假日/湖北省国庆假期综合运输客流快报模板.docx}")
    private String bulletinTemplatePath;

    private final HolidayStatService statService;
    private static final ThreadLocal<Document> CURRENT_DOCUMENT = new ThreadLocal<>();

    public HolidayBulletinService(HolidayStatService statService) {
        this.statService = statService;
    }

    public byte[] generate(LocalDate date) {
        DailyMetrics current = statService.findMetricsByDate(date);
        if (current == null) {
            throw new IllegalArgumentException("所选日期不在已配置的节假日范围内");
        }
        DailyMetrics previousDay = current.getDayIndex() > 1
                ? statService.dailyMetrics(current.getYear(), current.getHolidayType(), current.getDayIndex() - 1) : null;
        DailyMetrics previousYear = statService.dailyMetrics(current.getYear() - 1, current.getHolidayType(), current.getDayIndex());
        DailyMetrics currentCumulative = statService.cumulativeMetrics(current.getYear(), current.getHolidayType(), current.getDayIndex());
        DailyMetrics previousYearCumulative = statService.cumulativeMetrics(current.getYear() - 1, current.getHolidayType(), current.getDayIndex());

        if (current.getTotalPersonFlow() == null) {
            throw new IllegalArgumentException("所选日期的全社会跨区域人员流动量没有足够数据，无法生成快报");
        }

        String currentTotal = formatNumber(current.getTotalPersonFlow());
        String cumulativeTotalYi = formatNumber(currentCumulative.getTotalPersonFlow() == null
                ? null : HolidayNumberUtils.divide(currentCumulative.getTotalPersonFlow(), BigDecimal.valueOf(10000)));
        String ringRatioClause = previousDay == null ? "" : "，环比" + ratioPhrase(
                current.getTotalPersonFlow(), previousDay.getTotalPersonFlow());
        String paragraph1 = String.format("%d月%d日（假期第%d天），全省全社会跨区域人员流动量%s万人次%s，比2025年同期%s。",
                date.getMonthValue(), date.getDayOfMonth(), current.getDayIndex(), currentTotal,
                ringRatioClause,
                ratioPhrase(current.getTotalPersonFlow(), previousYear == null ? null : previousYear.getTotalPersonFlow()));
        String paragraph2 = String.format("假期以来，全省全社会跨区域人员流动量累计%s亿人次，比2025年同期%s。",
                cumulativeTotalYi,
                ratioPhrase(currentCumulative.getTotalPersonFlow(),
                        previousYearCumulative == null ? null : previousYearCumulative.getTotalPersonFlow()));

        File template = resolveTemplateFile();
        if (!template.exists() || !template.isFile()) {
            throw new IllegalArgumentException("快报模板文件不存在: " + template.getAbsolutePath());
        }

        try {
            byte[] templateBytes;
            try (InputStream in = new FileInputStream(template)) {
                templateBytes = readAll(in);
            }
            byte[] documentXml = readZipEntry(templateBytes, "word/document.xml");
            Document document = parseDocument(documentXml);
            CURRENT_DOCUMENT.set(document);
            try {
                replaceParagraph(document, text -> text.startsWith("10月") && text.contains("假期第"), paragraph1);
                replaceParagraph(document, text -> text.startsWith("假期以来"), paragraph2);
                fillTable(document, current, previousDay, previousYear, currentCumulative, previousYearCumulative);
                byte[] replacedXml = serializeDocument(document);
                return replaceZipEntry(templateBytes, "word/document.xml", replacedXml);
            } finally {
                CURRENT_DOCUMENT.remove();
            }
        } catch (Exception e) {
            throw new IllegalArgumentException("快报生成失败: " + e.getMessage(), e);
        }
    }

    private void fillTable(Document document, DailyMetrics current, DailyMetrics previousDay,
                           DailyMetrics previousYear, DailyMetrics currentCumulative,
                           DailyMetrics previousYearCumulative) {
        Element table = firstElement(document, "tbl");
        if (table == null) {
            throw new IllegalArgumentException("快报模板中找不到数据表");
        }
        writeTableRow(table, 2, new String[]{
                number(current.getNonBusinessPersonFlow()),
                ratio(current.getNonBusinessPersonFlow(), previousDay == null ? null : previousDay.getNonBusinessPersonFlow()),
                ratio(current.getNonBusinessPersonFlow(), previousYear == null ? null : previousYear.getNonBusinessPersonFlow()),
                "—",
                number(currentCumulative.getNonBusinessPersonFlow()),
                ratio(currentCumulative.getNonBusinessPersonFlow(),
                        previousYearCumulative == null ? null : previousYearCumulative.getNonBusinessPersonFlow()),
                "—"
        });
        writeTableRow(table, 3, new String[]{
                number(current.getRoad()),
                ratio(current.getRoad(), previousDay == null ? null : previousDay.getRoad()),
                ratio(current.getRoad(), previousYear == null ? null : previousYear.getRoad()),
                "—",
                number(currentCumulative.getRoad()),
                ratio(currentCumulative.getRoad(), previousYearCumulative == null ? null : previousYearCumulative.getRoad()),
                "—"
        });
        writeTableRow(table, 4, new String[]{
                number(current.getRoadPersonFlow()),
                ratio(current.getRoadPersonFlow(), previousDay == null ? null : previousDay.getRoadPersonFlow()),
                ratio(current.getRoadPersonFlow(), previousYear == null ? null : previousYear.getRoadPersonFlow()),
                "—",
                number(currentCumulative.getRoadPersonFlow()),
                ratio(currentCumulative.getRoadPersonFlow(), previousYearCumulative == null ? null : previousYearCumulative.getRoadPersonFlow()),
                "—"
        });
        writeTableRow(table, 5, transportRow(current.getRail(), previousDay == null ? null : previousDay.getRail(),
                previousYear == null ? null : previousYear.getRail(), currentCumulative.getRail(),
                previousYearCumulative == null ? null : previousYearCumulative.getRail()));
        writeTableRow(table, 6, transportRow(current.getCivilAviation(), previousDay == null ? null : previousDay.getCivilAviation(),
                previousYear == null ? null : previousYear.getCivilAviation(), currentCumulative.getCivilAviation(),
                previousYearCumulative == null ? null : previousYearCumulative.getCivilAviation()));
        writeTableRow(table, 7, transportRow(current.getWater(), previousDay == null ? null : previousDay.getWater(),
                previousYear == null ? null : previousYear.getWater(), currentCumulative.getWater(),
                previousYearCumulative == null ? null : previousYearCumulative.getWater()));
        writeTableRow(table, 8, transportRow(current.getTotalPersonFlow(), previousDay == null ? null : previousDay.getTotalPersonFlow(),
                previousYear == null ? null : previousYear.getTotalPersonFlow(), currentCumulative.getTotalPersonFlow(),
                previousYearCumulative == null ? null : previousYearCumulative.getTotalPersonFlow()));
    }

    private String[] transportRow(BigDecimal current, BigDecimal previousDay, BigDecimal previousYear,
                                  BigDecimal currentCumulative, BigDecimal previousYearCumulative) {
        return new String[]{
                number(current),
                ratio(current, previousDay),
                ratio(current, previousYear),
                "—",
                number(currentCumulative),
                ratio(currentCumulative, previousYearCumulative),
                "—"
        };
    }

    private void writeTableRow(Element table, int rowIndex, String[] values) {
        List<Element> rows = childElements(table, "tr");
        if (rowIndex >= rows.size()) return;
        Element row = rows.get(rowIndex);
        List<Element> cells = cellRefs(row);
        int logicalColumn = 0;
        for (Element cell : cells) {
            int span = gridSpan(cell);
            if (logicalColumn >= 2 && logicalColumn < 9) {
                int valueIndex = logicalColumn - 2;
                if (valueIndex < values.length) {
                    setCellText(cell, values[valueIndex]);
                }
            }
            logicalColumn += span;
        }
    }

    private List<Element> cellRefs(Element row) {
        List<Element> cells = new ArrayList<>();
        for (Element child : childElements(row, "tc")) cells.add(child);
        return cells;
    }

    private int gridSpan(Element cell) {
        Element tcPr = firstChildElement(cell, "tcPr");
        if (tcPr == null) return 1;
        Element span = firstChildElement(tcPr, "gridSpan");
        if (span == null) return 1;
        String value = span.getAttributeNS(WORD_NS, "val");
        try {
            return Integer.parseInt(value);
        } catch (Exception e) {
            return 1;
        }
    }

    private void setCellText(Element cell, String text) {
        Element tcPr = firstChildElement(cell, "tcPr");
        Element templateParagraph = firstChildElement(cell, "p");
        Element paragraph = createElement("p");
        if (templateParagraph != null) {
            Element pPr = firstChildElement(templateParagraph, "pPr");
            if (pPr != null) paragraph.appendChild(pPr.cloneNode(true));
        }
        Element run = createElement("r");
        Element t = createElement("t");
        t.setAttributeNS("http://www.w3.org/XML/1998/namespace", "xml:space", "preserve");
        t.setTextContent(text == null ? "" : text);
        run.appendChild(t);
        paragraph.appendChild(run);

        List<Node> removals = new ArrayList<>();
        Node child = cell.getFirstChild();
        while (child != null) {
            Node next = child.getNextSibling();
            if (child instanceof Element && "p".equals(localName(child))) {
                removals.add(child);
            }
            child = next;
        }
        for (Node node : removals) cell.removeChild(node);
        if (tcPr != null && tcPr.getNextSibling() != null) {
            cell.insertBefore(paragraph, tcPr.getNextSibling());
        } else if (tcPr != null) {
            cell.appendChild(paragraph);
        } else {
            cell.insertBefore(paragraph, cell.getFirstChild());
        }
    }

    private void replaceParagraph(Document document, ParagraphMatcher matcher, String replacement) {
        NodeList paragraphs = document.getElementsByTagNameNS(WORD_NS, "p");
        for (int i = 0; i < paragraphs.getLength(); i++) {
            Element paragraph = (Element) paragraphs.item(i);
            String text = paragraphText(paragraph);
            if (matcher.matches(text)) {
                setParagraphText(paragraph, replacement);
                return;
            }
        }
        throw new IllegalArgumentException("快报模板缺少可替换段落: " + replacement);
    }

    private void setParagraphText(Element paragraph, String text) {
        Element pPr = firstChildElement(paragraph, "pPr");
        Element firstRun = firstChildElement(paragraph, "r");
        Element rPr = firstRun == null ? null : firstChildElement(firstRun, "rPr");
        List<Node> removals = new ArrayList<>();
        Node child = paragraph.getFirstChild();
        while (child != null) {
            Node next = child.getNextSibling();
            if (child != pPr) removals.add(child);
            child = next;
        }
        for (Node node : removals) paragraph.removeChild(node);

        Element run = createElement("r");
        if (rPr != null) run.appendChild(rPr.cloneNode(true));
        Element t = createElement("t");
        t.setAttributeNS("http://www.w3.org/XML/1998/namespace", "xml:space", "preserve");
        t.setTextContent(text);
        run.appendChild(t);
        paragraph.appendChild(run);
    }

    private String paragraphText(Element paragraph) {
        StringBuilder builder = new StringBuilder();
        NodeList texts = paragraph.getElementsByTagNameNS(WORD_NS, "t");
        for (int i = 0; i < texts.getLength(); i++) {
            builder.append(texts.item(i).getTextContent());
        }
        return builder.toString();
    }

    private String ratioPhrase(BigDecimal current, BigDecimal base) {
        if (current == null || base == null || base.abs().compareTo(EPSILON) < 0) return "无可比数据";
        BigDecimal ratio = HolidayNumberUtils.divide(current, base);
        BigDecimal percent = HolidayNumberUtils.multiply(ratio.subtract(BigDecimal.ONE), BigDecimal.valueOf(100));
        if (percent == null || percent.abs().compareTo(EPSILON) < 0) return "持平";
        return (percent.signum() > 0 ? "增长" : "下降") + HolidayNumberUtils.format1(percent.abs()) + "%";
    }

    private String ratio(BigDecimal current, BigDecimal base) {
        if (current == null || base == null || base.abs().compareTo(EPSILON) < 0) return "—";
        return ratioPhrase(current, base);
    }

    private String number(BigDecimal value) {
        return value == null ? "—" : formatNumber(value);
    }

    private String formatNumber(BigDecimal value) {
        if (value == null) return "";
        return HolidayNumberUtils.format2(value);
    }

    private File resolveTemplateFile() {
        List<File> candidates = new ArrayList<>();
        File configured = new File(bulletinTemplatePath);
        candidates.add(configured);
        if (!configured.isAbsolute()) {
            candidates.add(new File(System.getProperty("user.dir"), bulletinTemplatePath));
            candidates.add(new File(System.getProperty("user.dir"), "../" + bulletinTemplatePath));
        }
        for (File candidate : candidates) {
            try {
                if (candidate.exists() && candidate.isFile()) {
                    return candidate.getCanonicalFile();
                }
            } catch (Exception ignored) {
                // Keep checking.
            }
        }
        return configured;
    }

    private byte[] readZipEntry(byte[] zipBytes, String entryName) throws Exception {
        try (ZipInputStream zin = new ZipInputStream(new ByteArrayInputStream(zipBytes))) {
            ZipEntry entry;
            while ((entry = zin.getNextEntry()) != null) {
                if (entryName.equals(entry.getName())) {
                    return readAll(zin);
                }
            }
        }
        throw new IllegalArgumentException("模板中缺少 " + entryName);
    }

    private byte[] replaceZipEntry(byte[] zipBytes, String entryName, byte[] replacement) throws Exception {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try (ZipInputStream zin = new ZipInputStream(new ByteArrayInputStream(zipBytes));
             ZipOutputStream zout = new ZipOutputStream(out)) {
            ZipEntry entry;
            byte[] buffer = new byte[8192];
            while ((entry = zin.getNextEntry()) != null) {
                ZipEntry target = new ZipEntry(entry.getName());
                zout.putNextEntry(target);
                if (entryName.equals(entry.getName())) {
                    zout.write(replacement);
                } else {
                    int length;
                    while ((length = zin.read(buffer)) > 0) {
                        zout.write(buffer, 0, length);
                    }
                }
                zout.closeEntry();
            }
        }
        return out.toByteArray();
    }

    private Document parseDocument(byte[] xml) throws Exception {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        return factory.newDocumentBuilder().parse(new ByteArrayInputStream(xml));
    }

    private byte[] serializeDocument(Document document) throws Exception {
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        transformer.transform(new DOMSource(document), new StreamResult(out));
        return out.toByteArray();
    }

    private Element firstElement(Document document, String localName) {
        NodeList list = document.getElementsByTagNameNS(WORD_NS, localName);
        return list.getLength() == 0 ? null : (Element) list.item(0);
    }

    private Element createElement(String localName) {
        Document document = CURRENT_DOCUMENT.get();
        if (document == null) {
            throw new IllegalStateException("Word document is not initialized");
        }
        return document.createElementNS(WORD_NS, "w:" + localName);
    }

    private List<Element> childElements(Element parent, String localName) {
        List<Element> result = new ArrayList<>();
        Node child = parent.getFirstChild();
        while (child != null) {
            if (child instanceof Element && localName.equals(localName(child))) {
                result.add((Element) child);
            }
            child = child.getNextSibling();
        }
        return result;
    }

    private Element firstChildElement(Element parent, String localName) {
        Node child = parent.getFirstChild();
        while (child != null) {
            if (child instanceof Element && localName.equals(localName(child))) {
                return (Element) child;
            }
            child = child.getNextSibling();
        }
        return null;
    }

    private String localName(Node node) {
        return node.getLocalName() == null ? node.getNodeName().replaceFirst("^.*:", "") : node.getLocalName();
    }

    private byte[] readAll(InputStream in) throws Exception {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buffer = new byte[8192];
        int length;
        while ((length = in.read(buffer)) > 0) {
            out.write(buffer, 0, length);
        }
        return out.toByteArray();
    }

    private interface ParagraphMatcher {
        boolean matches(String text);
    }
}