"""Extraction de texte et images depuis un PDF."""

from pypdf import PdfReader
from .pdf_utils import get_page_size


def extract_text_from_page(input_path, page_index):
    """Extraire le texte d'une page avec positions approximatives."""
    reader = PdfReader(input_path)
    if page_index >= len(reader.pages):
        return []
    page = reader.pages[page_index]
    text = page.extract_text() or ""
    lines = text.split("\n")
    w, h = get_page_size(page)
    # Positions approximatives (pypdf ne donne pas les coords exactes)
    results = []
    line_height = h / max(len(lines), 1)
    for i, line in enumerate(lines):
        if line.strip():
            results.append({
                "text": line.strip(),
                "y_approx": h - (i + 1) * line_height,
                "line_index": i,
            })
    return results


def extract_images_from_page(input_path, page_index):
    """Extraire les images d'une page."""
    reader = PdfReader(input_path)
    if page_index >= len(reader.pages):
        return []
    page = reader.pages[page_index]
    images = []
    if "/XObject" in page["/Resources"]:
        xobjects = page["/Resources"]["/XObject"].get_object()
        for obj_name in xobjects:
            obj = xobjects[obj_name].get_object()
            if obj["/Subtype"] == "/Image":
                width = obj["/Width"]
                height = obj["/Height"]
                images.append({
                    "name": obj_name,
                    "width": width,
                    "height": height,
                })
    return images


def replace_image_in_page(input_path, output_path, page_index, image_name, new_image_path):
    """Remplacer une image dans une page (overlay avec masquage)."""
    from pypdf import PdfWriter
    from reportlab.pdfgen import canvas
    from reportlab.lib.utils import ImageReader
    import io

    reader = PdfReader(input_path)
    writer = PdfWriter()

    for i, page in enumerate(reader.pages):
        if i == page_index and new_image_path:
            w, h = get_page_size(page)
            # On ne peut pas vraiment remplacer l'image dans le flux PDF
            # On ajoute la nouvelle image par-dessus (avec un masque blanc si besoin)
            packet = io.BytesIO()
            c = canvas.Canvas(packet, pagesize=(w, h))
            try:
                img = ImageReader(new_image_path)
                img_w, img_h = img.getSize()
                # Centrer l'image
                scale = min(w / img_w, h / img_h) * 0.8
                draw_w = img_w * scale
                draw_h = img_h * scale
                x = (w - draw_w) / 2
                y = (h - draw_h) / 2
                c.drawImage(new_image_path, x, y, width=draw_w, height=draw_h,
                           preserveAspectRatio=True, mask='auto')
            except Exception:
                pass
            c.showPage()
            c.save()
            packet.seek(0)
            overlay = PdfReader(packet)
            page.merge_page(overlay.pages[0])
        writer.add_page(page)

    with open(output_path, "wb") as f:
        writer.write(f)
    return output_path