package com.megatim.manuel.core.convert;

import org.apache.poi.hwpf.HWPFDocument;
import org.apache.poi.hwpf.model.StyleSheet;
import org.apache.poi.hwpf.usermodel.*;

import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;

/**
 * Word .doc hérité (HWPF) -> HTML : gras/italique/souligné/barré, couleur, police, taille,
 * alignement, titres (Heading/Titre 1..6), listes et tableaux.
 */
public class DocConverter extends AbstractHtmlConverter {

    public DocConverter(Path outputDir) {
        super(outputDir);
    }

    @Override
    public ConversionResult convert(Path source, int order) throws IOException {
        String safe = safeBase(source, order);
        String htmlName = safe + ".html";
        List<Heading> headings = new ArrayList<>();
        StringBuilder body = new StringBuilder();
        int[] hc = {0};

        try (FileInputStream fis = new FileInputStream(source.toFile());
             HWPFDocument doc = new HWPFDocument(fis)) {

            Range range = doc.getRange();
            StyleSheet styles = doc.getStyleSheet();

            HeaderStories hs = new HeaderStories(doc);
            body.append(headerFooterDiv(
                    firstNonBlank(hs.getOddHeader(), hs.getFirstHeader(), hs.getEvenHeader()), true));

            boolean inList = false;

            int i = 0;
            while (i < range.numParagraphs()) {
                Paragraph p = range.getParagraph(i);

                if (p.isInTable()) {
                    if (inList) { body.append("</ul>\n"); inList = false; }
                    Table table = range.getTable(p);
                    renderTable(table, body);
                    int end = table.getEndOffset();
                    i++;
                    while (i < range.numParagraphs() && range.getParagraph(i).getStartOffset() < end) i++;
                    continue;
                }

                boolean isList = p.getIlfo() != 0;
                if (isList && !inList) { body.append("<ul>\n"); inList = true; }
                if (!isList && inList) { body.append("</ul>\n"); inList = false; }

                renderParagraph(styles, p, body, headings, hc, safe, isList);
                i++;
            }
            if (inList) body.append("</ul>\n");

            body.append(headerFooterDiv(
                    firstNonBlank(hs.getOddFooter(), hs.getFirstFooter(), hs.getEvenFooter()), false));
        }

        String title = stripExt(source.getFileName().toString());
        for (Heading h : headings) {
            if (h.level <= 1 && !h.text.isBlank()) { title = h.text.trim(); break; }
        }

        writeHtml(htmlName, title, body.toString());
        return new ConversionResult(htmlName, title, headings, new ArrayList<>());
    }

    private void renderParagraph(StyleSheet styles, Paragraph p, StringBuilder out,
                                 List<Heading> headings, int[] hc, String safe, boolean isList) {
        int level = headingLevel(styles, p);
        String inner = renderRuns(p);
        String align = alignOf(p);

        if (level > 0) {
            String anchor = safe + "_h" + (++hc[0]);
            headings.add(new Heading(cleanText(p.text()), level, anchor));
            out.append("<h").append(level).append(" id=\"").append(anchor).append("\"").append(align)
               .append(">").append(inner).append("</h").append(level).append(">\n");
        } else if (isList) {
            out.append("<li").append(align).append(">").append(inner.isEmpty() ? "&nbsp;" : inner).append("</li>\n");
        } else if (inner.trim().isEmpty()) {
            out.append("<p class=\"sp\">&nbsp;</p>\n");
        } else {
            out.append("<p").append(align).append(">").append(inner).append("</p>\n");
        }
    }

    private void renderTable(Table table, StringBuilder out) {
        out.append("<table class=\"wt\">\n");
        for (int r = 0; r < table.numRows(); r++) {
            TableRow row = table.getRow(r);
            out.append("<tr>");
            for (int c = 0; c < row.numCells(); c++) {
                TableCell cell = row.getCell(c);
                out.append("<td>");
                for (int pi = 0; pi < cell.numParagraphs(); pi++) {
                    String inner = renderRuns(cell.getParagraph(pi));
                    out.append("<div>").append(inner.isEmpty() ? "&nbsp;" : inner).append("</div>");
                }
                out.append("</td>");
            }
            out.append("</tr>\n");
        }
        out.append("</table>\n");
    }

    private String renderRuns(Paragraph p) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < p.numCharacterRuns(); i++) {
            CharacterRun r = p.getCharacterRun(i);
            String text = cleanText(r.text());
            if (text.isEmpty()) continue;

            StringBuilder style = new StringBuilder();
            String hex = colorHex(r);
            if (hex != null) style.append("color:#").append(hex).append(';');
            String font = r.getFontName();
            if (font != null && !font.isEmpty()) style.append("font-family:'").append(font.replace("'", "")).append("';");
            int halfPts = r.getFontSize();
            if (halfPts > 0) style.append("font-size:").append(halfPts / 2).append("pt;");

            StringBuilder open = new StringBuilder();
            StringBuilder close = new StringBuilder();
            if (r.isBold())          { open.append("<b>"); close.insert(0, "</b>"); }
            if (r.isItalic())        { open.append("<i>"); close.insert(0, "</i>"); }
            if (r.getUnderlineCode() != 0) { open.append("<u>"); close.insert(0, "</u>"); }
            if (r.isStrikeThrough()) { open.append("<s>"); close.insert(0, "</s>"); }

            String content = esc(text);
            String span = style.length() > 0 ? "<span style=\"" + style + "\">" + content + "</span>" : content;
            sb.append(open).append(span).append(close);
        }
        return sb.toString();
    }

    private int headingLevel(StyleSheet styles, Paragraph p) {
        try {
            int idx = p.getStyleIndex();
            if (styles != null && idx >= 0 && idx < styles.numStyles()) {
                return matchHeading(styles.getStyleDescription(idx).getName());
            }
        } catch (Exception ignore) { /* style introuvable */ }
        return 0;
    }

    /** getIco24() renvoie une COLORREF (0x00BBGGRR). On la convertit en RRGGBB, ou null si absente/noir. */
    private String colorHex(CharacterRun r) {
        try {
            int c = r.getIco24();
            if (c < 0) return null;
            int red = c & 0xFF;
            int green = (c >> 8) & 0xFF;
            int blue = (c >> 16) & 0xFF;
            if (red == 0 && green == 0 && blue == 0) return null; // noir par défaut : on n'impose rien
            return String.format("%02X%02X%02X", red, green, blue);
        } catch (Exception ignore) {
            return null;
        }
    }

    private String alignOf(Paragraph p) {
        switch (p.getJustification()) {
            case 1:  return " style=\"text-align:center\"";
            case 2:  return " style=\"text-align:right\"";
            case 3:  return " style=\"text-align:justify\"";
            default: return "";
        }
    }

    /** Bloc HTML d'en-tête/pied de page (texte brut, une ligne = un paragraphe). */
    private String headerFooterDiv(String text, boolean isHeader) {
        if (text == null) return "";
        StringBuilder sb = new StringBuilder();
        for (String line : text.split("[\\r\\n\\u000B\\u000C]+")) {
            String c = cleanText(line);
            if (!c.isEmpty()) sb.append("<p>").append(esc(c)).append("</p>\n");
        }
        if (sb.length() == 0) return "";
        return "<div class=\"" + (isHeader ? "page-header" : "page-footer") + "\">\n" + sb + "</div>\n";
    }

    private static String firstNonBlank(String... values) {
        for (String v : values) {
            if (v != null && !cleanText(v).isEmpty()) return v;
        }
        return null;
    }

    /** Retire les marqueurs de contrôle Word (fin de cellule, champs, sauts...). */
    private static String cleanText(String s) {
        if (s == null) return "";
        return s.replace('\r', ' ')
                .replaceAll("[\\u0000-\\u0008\\u000B\\u000C\\u000E-\\u001F]", " ")
                .trim();
    }
}