Author's book list:

def _norm(s: str) -> str:
    """Normaliza texto: minúsculas, sin acentos, espacios compactados."""
    if not s:
        return ""
    s = unicodedata.normalize("NFKD", s)
    s = "".join(c for c in s if not unicodedata.combining(c))
    return " ".join(s.lower().strip().split())


def _fetch_books_catalog(file_id):
    """Descarga books.xml desde Drive y devuelve el catálogo completo normalizado.

    Es la parte cara (~12 MB de descarga + parseo de ~10.000 items), así que su
    resultado se cachea; los campos *_norm precomputados dejan el filtro por
    request en una pasada barata sobre la lista.
    """
    xml_bytes = download_gdrive_public_file(file_id)
    root = parse_xml_bytes(xml_bytes)
    catalog = []
    # Recorremos items; las etiquetas son <item>, <auth>, <book>, etc.
    for node in root.findall(".//item"):
        def tx(tag):
            el = node.find(tag)
            return (el.text if el is not None and el.text is not None else "").strip()

        author_raw = tx("auth")
        title_raw  = tx("book")

        img_raw = tx("img_url")
        if img_raw and not img_raw.startswith(("http://", "https://")):
            img_raw = "https://" + img_raw.lstrip("/")

        catalog.append({
            "id":           tx("isbn"),
            "title":        title_raw,
            "title_norm":   _norm(title_raw),
            "author_norm":  _norm(author_raw),
            "language":     tx("lang").capitalize(),
            "price":        tx("euro"),
            "publish_date": tx("year"),
            "description":  tx("about"),
            "publisher":    tx("publ").capitalize(),
            "tags":         tx("tags"),
            "img":          img_raw,
            "page":         tx("page"),
        })
    return catalog


def xml_books(request):
    # Desde el disco, nunca por HTTP a este mismo host: una vista que se pide a sí
    # misma puede quedarse esperándose y acabar en error.
    content_json_url = "/static/json/data-science/content.json"
    project_key   = "books-store-xml"
    template_path = "portfolio/templates/data-science/books-store-xml/index.html"

    # --- Cargar snippets/metadata/plantilla ---------------------------------
    try:
        views_code        = get_source_lines(_norm, _fetch_books_catalog, xml_books)
        content_json_data = get_content_json_data(content_json_url, project_key)
        template_code     = get_template_code(template_path)
    except FileNotFoundError:
        ctx = {
            "description": "File not found. Please check the file path or create the file if it does not",
            "reference": "Read & Process Excel files with Data Frame",
        }
        print("❌ Error cargando content_json/plantilla/snippets (FileNotFoundError)")
        return render(request, "data-science/retrieve_error.html", ctx)
    except TemplateDoesNotExist:
        ctx = {
            "description": "Template not found. Please check the file path or create the file if it does not",
            "reference": "Books Store connection from XML File",
        }
        print("❌ Error: TemplateDoesNotExist")
        return render(request, "data-science/retrieve_error.html", ctx)

    # --- Descargar y parsear el XML desde Drive ------------------------------
    file_id = BOOKS_FILE_ID
    if not file_id:
        ctx = {
            "description": "Falta la variable de entorno GDRIVE_BOOKS_FILE_ID con el ID del archivo XML.",
            "reference": "Books Store connection from XML File",
        }
        print("❌ Falta GDRIVE_BOOKS_FILE_ID")
        return render(request, "data-science/retrieve_error.html", ctx)

    try:
        # Caché de 15 minutos: se ahorra la descarga y el parseo del XML en
        # cada visita.
        catalog = cache.get_or_set(
            "xml_books_catalog", lambda: _fetch_books_catalog(file_id), 60 * 15
        )
    except Exception as e:
        # El detalle de la excepción va solo al log: renderizarlo exponía la
        # URL de la Drive API (con la key incluida) en la página pública.
        ctx = {"description": "No se pudo descargar books.xml desde Google Drive. Inténtalo más tarde.",
               "reference": "Books Store connection from XML File"}
        print("❌ Error descargando o parseando XML:", repr(e))
        return render(request, "data-science/retrieve_error.html", ctx)

    # --- Filtrado sobre el catálogo cacheado ---------------------------------
    books = []

    q_author = _norm(request.GET.get("author_name") or "")
    q_title  = _norm(request.GET.get("title") or "")

    for book in catalog:
        ok = True
        if q_author:
            ok = ok and (q_author in book["author_norm"])
        if q_title:
            ok = ok and (q_title in book["title_norm"])
        if ok:
            books.append(book)

    # Log de depuración
    print(f"xml_books: encontrados {len(books)} libros para author='{q_author}' title='{q_title}'")

    # (Opcional) ver 3 ejemplos sin filtrar
    # for i, sample in enumerate(root.findall('.//item')[:3], 1):
    #     print("SAMPLE", i, "AUTH=", (sample.findtext('auth') or '').strip(),
    #           "TITLE=", (sample.findtext('book') or '').strip())

    # --- Paginación ----------------------------------------------------------
    # Sin ella, los ~10.000 libros del XML generaban un HTML de ~31 MB.
    paginator = Paginator(books, 12)
    page = request.GET.get("page")
    try:
        books_page = paginator.page(page)
    except PageNotAnInteger:
        books_page = paginator.page(1)
    except EmptyPage:
        books_page = paginator.page(paginator.num_pages)

    # Query string extra para que PREV/NEXT conserven los filtros activos.
    filter_params = {k: request.GET[k] for k in ("author_name", "title") if request.GET.get(k)}
    extra_qs = "&" + urlencode(filter_params) if filter_params else ""

    context = {
        "books": books_page,
        "extra_qs": extra_qs,
        "author": q_author,
        "views": views_code,
        "content": content_json_data,
        "template": template_code,
    }
    return render(request, "data-science/books-store-xml/index.html", context)

{% extends 'base.html' %}

{% load i18n %}
{% load static %}
{% load cached_pygments %}
{% block title %}{% trans "XML Books Store (ElementTree)" %} | Marco A. Parra F.{% endblock %}
{% block meta_description %}{% trans "Parse an XML catalogue with ElementTree and filter it from a Django form." %}{% endblock %}
{% block content %}
<br>
<br>
<!-- ================= XML BOOKS: DOCUMENTACIÓN ================= -->
<!-- ===== XML BOOKS: Compact Doc Section with Show More ===== -->
<section id="xml-books-docs" class="container my-5">
  <!-- Header -->
  <div class="row align-items-center">
    <div class="col">
      <h2 class="mb-1">XML Books — Project Overview</h2>
      <div class="small text-muted">Django + XML + Google Drive API</div>
    </div>
  </div>

  <!-- Always-visible essentials -->
  <div class="card shadow-sm mt-3">
    <div class="card-body">
      <p class="mb-3">
        <strong>Summary:</strong> XML Books loads a book catalog from an XML file stored in Google Drive, validates and parses it
        at request time, and exposes simple filters by <em>author</em> and <em>title</em>. The goal is to keep the app lightweight
        (no large datasets in the repo) while demonstrating external storage integration and clean UI rendering in Django.
      </p>

      <div class="mb-3">
        <span class="badge bg-dark me-1">Django 4.1</span>
        <span class="badge bg-secondary me-1">Python 3.11</span>
        <span class="badge bg-info text-dark me-1">Requests</span>
        <span class="badge bg-warning text-dark me-1">Google Drive API</span>
        <span class="badge bg-primary">XML</span>
      </div>

      <div class="d-flex flex-wrap gap-2">
        <a class="btn btn-success btn-sm" target="_blank"
           href="https://portfolio-mparraf.herokuapp.com/data-science/books-filter/">
          Open Endpoint
        </a>

        <!-- Show more toggle -->
        <button class="btn btn-outline-primary btn-sm"
                type="button"
                data-bs-toggle="collapse"
                data-bs-target="#xmlBooksMore"
                aria-expanded="false"
                aria-controls="xmlBooksMore">
          Show more
        </button>
      </div>
    </div>

    <!-- Collapsible: more details -->
    <div id="xmlBooksMore" class="collapse">
      <hr class="my-0">
      <div class="card-body pt-4">
        <!-- Goals -->
        <h5 class="mb-2">Goals</h5>
        <ul class="mb-4">
          <li>Load and validate an XML dataset from Google Drive (folder-scoped query + file download).</li>
          <li>Defend against HTML previews/warnings from Drive before parsing.</li>
          <li>Filter results via query params (<code>?author=...</code>, <code>?title=...</code>).</li>
          <li>Keep the Heroku slug small (no heavy datasets in the repo).</li>
        </ul>

        <!-- Architecture -->
        <h5 class="mb-2">High-level Architecture</h5>
        <ol class="mb-4">
          <li>View <code>xml_books</code> reads query params and builds the Drive request.</li>
          <li>File listing by folder + exact filename; then direct file download.</li>
          <li>Guard: if payload looks like HTML, abort parsing (Drive preview pages).</li>
          <li>Parse with <code>xml.etree.ElementTree</code> and normalize CDATA/text.</li>
          <li>Filter and render results with Bootstrap.</li>
        </ol>

        <!-- Env Vars -->
        <h5 class="mb-2">Environment Variables</h5>
        <div class="table-responsive mb-3">
          <table class="table table-sm align-middle">
            <thead class="table-light">
              <tr><th scope="col">Variable</th><th scope="col">Description</th><th scope="col">Example</th></tr>
            </thead>
            <tbody>
              <tr>
                <td><code>GOOGLE_DRIVE_API_KEY</code></td>
                <td>API Key for Google Drive (Files: list/get).</td>
                <td><code>AIzaSy...xyz</code></td>
              </tr>
              <tr>
                <td><code>GOOGLE_DRIVE_FOLDER_ID</code></td>
                <td>Folder ID containing the XML file.</td>
                <td><code>1AbCdEfGhIJ...</code></td>
              </tr>
              <tr>
                <td><code>BOOKS_XML_FILENAME</code></td>
                <td>Exact XML filename to fetch.</td>
                <td><code>books.xml</code></td>
              </tr>
            </tbody>
          </table>
        </div>

        <!-- Endpoint usage -->
        <h5 class="mb-2">Endpoint & Usage</h5>
        <div class="table-responsive mb-3">
          <table class="table table-hover align-middle">
            <thead class="table-light">
              <tr><th scope="col">Endpoint</th><th scope="col">Description</th><th scope="col">Params</th><th scope="col">Examples</th></tr>
            </thead>
            <tbody>
              <tr>
                <td><code>/data-science/books-filter/</code></td>
                <td>Returns the book list from remote XML with optional filters.</td>
                <td><code>author</code> (optional), <code>title</code> (optional)</td>
                <td>
                  <code>?author=arturo</code><br>
                  <code>?title=sidi</code><br>
                  <code>?author=arturo&amp;title=sidi</code>
                </td>
              </tr>
            </tbody>
          </table>
        </div>

        <!-- Error handling -->
        <h5 class="mb-2">Error Handling</h5>
        <ul class="mb-0">
          <li><strong>404/403</strong> listing Drive: check <code>GOOGLE_DRIVE_FOLDER_ID</code> permissions.</li>
          <li><strong>HTML payload</strong> (preview/warning): abort parsing to avoid XML errors.</li>
          <li><strong>XML ParseError</strong>: malformed or truncated XML; verify the source file.</li>
          <li><strong>Timeouts</strong>: add caching and increase request timeout if needed.</li>
        </ul>
      </div>
    </div>
  </div>
</section>
<!-- ===== /XML BOOKS: Compact Doc Section with Show More ===== -->



<!-- ================= /XML BOOKS: DOCUMENTACIÓN ================= -->


<section class="container-section mb-4">
    <div class="container-fluid">
        <div class="row g-0">
            <div class="portfolio-box-caption">
                Books Store
            </div>
        </div>
        <hr>
        <div>

        </div>
        <div class="container">
            <div class="row border mt-3">
                <h2>{% trans "Search Form" %}</h2>
                <form method="get" action="{% url 'xml_books' %}">
                    {% csrf_token %}
                    <div class="row">
                        <div class="col-12 col-sm-6">
                            <div class="form-group mb-3">
                                <label for="author_name">Author Name:</label>
                                <input type="text" class="form-control" id="author_name" name="author_name" placeholder="Enter a value">
                            </div>
                        </div>
                        <div class="col-12 col-sm-6">
                            <div class="form-group mb-3">
                                <label for="title">Book Title:</label>
                                <input type="text" class="form-control" id="title" name="title" placeholder="Enter a value">
                            </div>
                        </div>
                    </div>
                    <button type="submit" class="btn btn-primary">{% trans "Search" %}</button>
                </form>
            </div>
            <hr>
            <div class="row mb-5 border">
                <h1>Author's book list: {{ author }}</h1>
            </div>

            <div class="row mt-3" id="books-list">
                {% for item in books %}
                <div class="col-12 col-sm-6">
                    <div class="card text-dark bg-light mb-3 align-items-center">
                        <img src="{{ item.img }}" class="card-img-top img-fluid" style="height: 15rem;"alt="{{ item.title }}">
                        <div class="card-header">
                            <h2 class="card-title">{{ item.title }}</h2>
                            <div class="row">
                                <div class="col-lg-6 col-sm-12 ">
                                    <h6 class="card-subtitle mb-2 text-muted">ISBN: <strong>{{ item.id }}</strong></h6>
                                </div>
                                <div class="col-lg-6 col-sm-12 ">
                                    <h6 class="card-subtitle mb-2 text-muted">Page: <strong>{{ item.page }}</strong></h6>
                                </div>
                            </div>
                            <div class="row">
                                <div class="col-lg-5 col-sm-12 ">
                                    <h6 class="card-subtitle mb-2 text-muted">Lang: <strong>{{ item.language }}</strong></h6>
                                </div>
                                <div class="col-lg-3 col-sm-12 ">
                                    <h6 class="card-subtitle mb-2 text-muted">Year: <strong>{{ item.publish_date }}</strong></h6>
                                </div>
                                <div class="col-lg-4 col-sm-12 ">
                                    <h6 class="card-subtitle mb-2 text-muted">Price: <strong>{{ item.price }}</strong></h6>
                                </div>
                            </div>
                            <div class="row">
                                <h6 class="card-subtitle mb-2 text-muted">Publisher By: <strong>{{ item.publisher }}</strong></h6>
                            </div>
                            <div class="row">
                                <h6 class="card-subtitle mb-2 text-muted">Tags: <strong>{{ item.tags }}</strong></h6>
                            </div>
                        </div>
                        <div class="card-body" style="height: 15rem; overflow:auto;">
                            <p class="cart-text d-sm-block show-read-more p-3 mt-2">{{ item.description }}</p>
                        </div>
                    </div>
                </div>
                {% endfor %}
            </div>

            <div class="row d-flex align-items-center mb-4">
                <div class="col-auto">
                    {% if books.has_previous %}
                    <a class="btn btn-outline-secondary" href="?page={{ books.previous_page_number }}{{ extra_qs }}#books-list">« PREV</a>
                    {% endif %}
                </div>
                <div class="col-auto text-muted">
                    Page {{ books.number }} of {{ books.paginator.num_pages }} ({{ books.paginator.count }} books)
                </div>
                <div class="col-auto">
                    {% if books.has_next %}
                    <a class="btn btn-outline-secondary" href="?page={{ books.next_page_number }}{{ extra_qs }}#books-list">NEXT »</a>
                    {% endif %}
                </div>
            </div>
        </div>
    </div>
</section>

<section class="container-section mb-4">
    <div class="container-fluid">
        <div class="row g-0">
            <div class="portfolio-box-caption">
                <div class="row">
                    <div class="col-12 col-sm-10">
                        <h3 class="portfolio-box-headers" style="text-align:center">
                            {% trans "Show Code" %}</h3>
                    </div>
                    <div class="col">
                        <button type="button" class="btn btn-light" onclick="$('#section-w').toggle();">
                            Show/Hide
                        </button>
                    </div>
                </div>
            </div>
            <hr>
            <div class="container" style="display:none;" id="section-w">
                <div class="row mb-4">
                    <div class="col">
                        <h4>views.py Code</h4>
                        <div class="sourcecode">
                            {{ views|pygmentize:"python3" }}
                        </div>
                    </div>
                    <div class="col">
                        <h4>Template</h4>
                        <div class="sourcecode">
                            {{ template|pygmentize:"html" }}
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</section>

{% endblock %}