'use strict';

// ---------------------------------------------------------------------------
// Two tools in the library's head (docs/library.md):
//   ⇩  the whole library as an XML file: every book's diora metadata (decrypted here),
//      folders, series, the reading position, the magazines' articles — made on this
//      device from the list already decrypted, nothing new goes to the server;
//   ✦  "Ordnen" with Claude (docs/ai.md): folders, series, cleaned titles and authors,
//      magazine marks suggested for the books shown; the user ticks what to take.
// They are added to the head 53-library.js draws (after each drawing).
// ---------------------------------------------------------------------------

function _libToolsAdd() {
  const head = document.querySelector('#book-list .lib-head');
  if (!head || head.querySelector('.lib-tools-x')) return;
  const add = head.querySelector('.lib-add');
  const mk = (label, title, act) => {
    const b = document.createElement('button');
    b.type = 'button';
    b.className = 'lib-icon lib-tools-x';
    b.textContent = label;
    b.title = title;
    b.setAttribute('aria-label', title);
    b.addEventListener('click', e => { e.stopPropagation(); act(); });
    head.insertBefore(b, add || null);
  };
  if (window.DioraAI && DioraAI.available()) mk('✦', 'Mit KI ordnen', libraryOrganize);
  mk('⇩', 'Bibliothek als XML exportieren', libraryExportXml);
}

(function () {
  const watch = () => {
    const list = document.getElementById('book-list');
    if (!list) return;
    new MutationObserver(_libToolsAdd).observe(list, {childList: true});
    _libToolsAdd();
  };
  if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', watch);
  else watch();
  // ai.js is a module and comes after: add ✦ then.
  window.addEventListener('diora-ai', () => {
    const old = document.querySelector('#book-list .lib-head');
    if (old) old.querySelectorAll('.lib-tools-x').forEach(b => b.remove());
    _libToolsAdd();
  });
})();

// ---- XML export -------------------------------------------------------------

function _xmlEsc(s) {
  return String(s == null ? '' : s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;').replace(/[\u0000-\u0008\u000B\u000C\u000E-\u001F]/g, '');
}

function _xmlEl(name, value, attrs) {
  const a = Object.entries(attrs || {}).filter(([, v]) => v !== undefined && v !== null && v !== '')
    .map(([k, v]) => ` ${k}="${_xmlEsc(v)}"`).join('');
  if (value === undefined || value === null || value === '') return `<${name}${a}/>`;
  return `<${name}${a}>${_xmlEsc(value)}</${name}>`;
}

const _xmlTime = v => (v ? (typeof v === 'number' ? new Date(v).toISOString() : String(v)) : '');

function libraryExportXml() {
  const books = (typeof _lastBookListData !== 'undefined' && _lastBookListData) || [];
  if (!books.length) { if (typeof customAlert === 'function') customAlert('Noch keine Bücher geladen.'); return; }
  const user = document.querySelector('meta[name="username"]')?.content || '';
  const order = (typeof _lib !== 'undefined' && _lib && Array.isArray(_lib.order)) ? _lib.order : [];
  const out = ['<?xml version="1.0" encoding="UTF-8"?>',
    `<diora-library version="1" exported="${new Date().toISOString()}" account="${_xmlEsc(user)}" books="${books.length}">`];
  if (order.length) {
    out.push('  <folder-order>');
    order.forEach(f => out.push('    ' + _xmlEl('folder', f)));
    out.push('  </folder-order>');
  }
  for (const b of books) {
    const m = (typeof bookMetaCache !== 'undefined' && bookMetaCache[b.id]) || {};
    const kind = (typeof _isMagazine === 'function' && _isMagazine(b)) ? 'magazine' : 'book';
    out.push(`  <book id="${b.id}" kind="${kind}" type="${_xmlEsc(b.type || m.type || 'epub')}"${b.keyOk === false ? ' decrypted="false"' : ''}>`);
    out.push('    ' + _xmlEl('title', b.title));
    out.push('    ' + _xmlEl('author', b.author));
    if (m.filename) out.push('    ' + _xmlEl('filename', m.filename));
    if (b.isbn || m.isbn) out.push('    ' + _xmlEl('isbn', b.isbn || m.isbn));
    if (b.pages || m.pages) out.push('    ' + _xmlEl('pages', b.pages || m.pages));
    if (b.shelfTag || m.shelfTag) out.push('    ' + _xmlEl('shelf-category', b.shelfTag || m.shelfTag));
    if (b.series) out.push('    ' + _xmlEl('series', b.series, {number: b.seriesIndex}));
    if (b.work) out.push('    ' + _xmlEl('work', b.work));
    if (b.magazine === true || b.magazine === false) out.push('    ' + _xmlEl('magazine-mark', String(b.magazine)));
    if (b.cover) out.push('    ' + _xmlEl('cover', b.cover));
    const folders = typeof _foldersOfMeta === 'function' ? _foldersOfMeta(b) : (b.folders || []);
    if (folders.length) {
      out.push('    <folders>');
      folders.forEach(f => out.push('      ' + _xmlEl('folder', f)));
      out.push('    </folders>');
    }
    out.push('    ' + _xmlEl('progress', '', {
      percent: b.scroll_fraction != null ? (Math.round(b.scroll_fraction * 1000) / 10).toFixed(1) : '',
      anchor: b.position_anchor,
      read: String(!!b.is_read),
      'read-at': _xmlTime(b.read_at),
      'last-read': _xmlTime(b.last_read),
      device: b.device,
      'furthest-percent': b.furthest_fraction ? (Math.round(b.furthest_fraction * 1000) / 10).toFixed(1) : '',
      'furthest-anchor': b.furthest_anchor,
    }));
    out.push('    ' + _xmlEl('uploaded', _xmlTime(b.uploaded_at)));
    if (b.has_highlights) out.push('    ' + _xmlEl('highlights', 'true'));
    const issue = b.issue || m.issue;
    if (issue && Array.isArray(issue.a) && issue.a.length) {
      const readState = b.issueRead || m.issueRead || {};
      out.push(`    <articles${(b.issueAt || m.issueAt) ? ` current="${_xmlEsc(b.issueAt || m.issueAt)}"` : ''}>`);
      issue.a.forEach(x => out.push('      ' + _xmlEl('article', x.t, {
        section: x.r, author: x.a, minutes: x.m, 'first-page': x.p, 'last-page': x.e,
        state: readState[x.h] === 'r' ? 'read' : readState[x.h] === 's' ? 'skipped' : '', href: x.h,
      })));
      out.push('    </articles>');
    }
    out.push('  </book>');
  }
  out.push('</diora-library>', '');
  const blob = new Blob([out.join('\n')], {type: 'application/xml;charset=utf-8'});
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = `diora-bibliothek-${new Date().toISOString().slice(0, 10)}.xml`;
  document.body.appendChild(a);
  a.click();
  a.remove();
  setTimeout(() => URL.revokeObjectURL(url), 1000);
}

// ---- ✦ Ordnen with Claude ------------------------------------------------------

const _LIB_AI_SYSTEM = `Du hilfst, eine private E-Book-Bibliothek zu ordnen. Du bekommst die Bücher als JSON
(id, Titel, Autor, Ordner, Serie, Zeitschrift) und die vorhandenen Ordner. Schlage nur Änderungen vor, die
wirklich helfen; ein Buch ohne sinnvolle Änderung lässt du weg.

- Ordner wirken wie Schlagwörter, ein Buch kann in mehreren sein. Nutze vorhandene Ordner bevorzugt.
  Einen neuen Ordner nur, wenn mindestens drei Bücher hineinpassen; kurze deutsche Namen nach Thema oder
  Gattung (z. B. „Philosophie“, „Geschichte“, „Romane“). Du schlägst nur Ordner zum Hinzufügen vor,
  entfernst keine.
- Serie nur bei klar mehrbändigen Werken (Band, Teil, Volume …), mit Bandnummer, wenn erkennbar.
- Titel und Autor nur korrigieren, wenn sie offensichtlich kaputt sind: Dateinamen, Unterstriche,
  „Unknown“, Autor im Titel, durchgehend Großbuchstaben, vertauschte Felder. Sonst null.
- zeitschrift: true nur für Hefte oder Ausgaben von Zeitschriften, false nur wenn etwas fälschlich als
  Zeitschrift markiert ist, sonst null.
- warum: ein kurzer deutscher Satz.`;

const _LIB_AI_SCHEMA = {
  type: 'object',
  properties: {
    vorschlaege: {
      type: 'array',
      items: {
        type: 'object',
        properties: {
          id: {type: 'integer'},
          ordner_hinzu: {type: ['array', 'null'], items: {type: 'string'}},
          serie: {type: ['string', 'null']},
          band: {type: ['number', 'null']},
          titel: {type: ['string', 'null']},
          autor: {type: ['string', 'null']},
          zeitschrift: {type: ['boolean', 'null']},
          warum: {type: 'string'},
        },
        required: ['id', 'ordner_hinzu', 'serie', 'band', 'titel', 'autor', 'zeitschrift', 'warum'],
        additionalProperties: false,
      },
    },
  },
  required: ['vorschlaege'],
  additionalProperties: false,
};

function libraryOrganize() {
  DioraAI.withKey(async () => {
    const all = (typeof _lastBookListData !== 'undefined' && _lastBookListData) || [];
    const section = typeof _bookSectionFilter === 'function' ? _bookSectionFilter(all) : all;
    const books = section.filter(b => b.keyOk !== false);
    if (!books.length) return;
    const folderOf = b => (typeof _foldersOfMeta === 'function' ? _foldersOfMeta(b) : (b.folders || []));
    const existing = [...new Set(all.flatMap(folderOf))].sort((a, b) => a.localeCompare(b, 'de'));
    const data = books.map(b => ({id: b.id, titel: b.title, autor: b.author, ordner: folderOf(b),
      serie: b.series || null, band: b.seriesIndex || null, zeitschrift: typeof _isMagazine === 'function' ? _isMagazine(b) : !!b.magazine}));
    DioraAI.progress('Mit KI ordnen', `Claude sieht sich ${books.length} ${books.length === 1 ? 'Buch' : 'Bücher'} an – das kann eine Minute dauern …`);
    let answer;
    try {
      answer = await DioraAI.ask({
        system: _LIB_AI_SYSTEM,
        prompt: `Vorhandene Ordner: ${JSON.stringify(existing)}\n\nBücher:\n${JSON.stringify(data)}`,
        schema: _LIB_AI_SCHEMA,
      });
    } catch (e) {
      DioraAI.showError('Mit KI ordnen', e);
      return;
    }
    const byId = new Map(books.map(b => [b.id, b]));
    const items = [];
    for (const s of answer.vorschlaege || []) {
      const b = byId.get(s.id);
      if (!b) continue;
      const have = folderOf(b);
      const addF = (s.ordner_hinzu || []).map(f => String(f).trim()).filter(f => f && !have.includes(f));
      const change = {};
      const lines = [];
      if (addF.length) { change.folders = have.concat(addF); lines.push('Ordner + ' + addF.join(', ')); }
      if (s.serie && s.serie !== b.series) {
        change.series = s.serie;
        if (s.band != null) change.seriesIndex = s.band;
        lines.push('Serie: ' + s.serie + (s.band != null ? ` (Band ${s.band})` : ''));
      }
      if (s.titel && s.titel !== b.title) { change.title = s.titel; lines.push('Titel: ' + s.titel); }
      if (s.autor && s.autor !== b.author) { change.author = s.autor; lines.push('Autor: ' + s.autor); }
      if (s.zeitschrift === true || s.zeitschrift === false) {
        const now = typeof _isMagazine === 'function' ? _isMagazine(b) : !!b.magazine;
        if (s.zeitschrift !== now) { change.magazine = s.zeitschrift; lines.push(s.zeitschrift ? 'als Zeitschrift führen' : 'als Buch führen'); }
      }
      if (!lines.length) continue;
      if (s.warum) lines.push('– ' + s.warum);
      items.push({id: s.id, title: b.title + (b.author ? ' · ' + b.author : ''), lines, change});
    }
    DioraAI.review({
      title: 'Mit KI ordnen',
      intro: 'Vorschläge von Claude. Was angehakt ist, wird übernommen; vorhandene Ordner bleiben.',
      items,
      onApply: async ids => {
        let n = 0;
        for (const id of ids) {
          const it = items.find(x => x.id === id);
          if (it && await _updateBookMeta(id, it.change)) n++;
        }
        if (typeof renderBookList === 'function') renderBookList(_lastBookListData);
        return `${n} ${n === 1 ? 'Buch' : 'Bücher'} geordnet`;
      },
    });
  });
}