"""Moteur Reperes de coupe autonomes."""

from pypdf import PdfReader, PdfWriter, PageObject, Transformation
from reportlab.pdfgen import canvas
from .pdf_utils import get_page_size
import io


def add_crop_marks(input_path, output_path, mark_length=14.17, mark_offset=7.09,
                   line_width=0.25, color=(0, 0, 0), center_marks=False,
                   apply_to="all", current_page=0, **_kwargs):
    """Ajouter des reperes de coupe sur les pages.

    Les marques sont placees a l'exterieur de la zone d'impression.
    Chaque coin a 2 traits (1 horizontal + 1 vertical) formant un L.
    La page est agrandie pour contenir les marques.
    """
    reader = PdfReader(input_path)
    writer = PdfWriter()

    margin = mark_offset + mark_length

    for i, page in enumerate(reader.pages):
        page_num = i + 1
        should_apply = False
        if apply_to == "all":
            should_apply = True
        elif apply_to == "even":
            should_apply = page_num % 2 == 0
        elif apply_to == "odd":
            should_apply = page_num % 2 != 0
        elif apply_to == "current":
            should_apply = i == current_page

        if should_apply:
            w, h = get_page_size(page)
            # Canvas agrandi pour inclure les marques
            cw = w + 2 * margin
            ch = h + 2 * margin

            packet = io.BytesIO()
            c = canvas.Canvas(packet, pagesize=(cw, ch))
            c.setLineWidth(line_width)
            c.setStrokeColorRGB(*color)

            # Les coordonnees de la zone d'impression dans le canvas agrandi
            ox, oy = margin, margin  # origine de la page originale

            # 4 coins — 2 traits par coin (L exterieur)
            # Bas-gauche
            c.line(ox - mark_offset - mark_length, oy, ox - mark_offset, oy)
            c.line(ox, oy - mark_offset - mark_length, ox, oy - mark_offset)
            # Bas-droite
            c.line(ox + w + mark_offset, oy, ox + w + mark_offset + mark_length, oy)
            c.line(ox + w, oy - mark_offset - mark_length, ox + w, oy - mark_offset)
            # Haut-gauche
            c.line(ox - mark_offset - mark_length, oy + h, ox - mark_offset, oy + h)
            c.line(ox, oy + h + mark_offset, ox, oy + h + mark_offset + mark_length)
            # Haut-droite
            c.line(ox + w + mark_offset, oy + h, ox + w + mark_offset + mark_length, oy + h)
            c.line(ox + w, oy + h + mark_offset, ox + w, oy + h + mark_offset + mark_length)

            # Reperes de centrage
            if center_marks:
                mid_x = ox + w / 2
                mid_y = oy + h / 2
                ml = mark_length * 0.7
                # Haut
                c.line(mid_x, oy + h + mark_offset, mid_x, oy + h + mark_offset + ml)
                # Bas
                c.line(mid_x, oy - mark_offset, mid_x, oy - mark_offset - ml)
                # Gauche
                c.line(ox - mark_offset, mid_y, ox - mark_offset - ml, mid_y)
                # Droite
                c.line(ox + w + mark_offset, mid_y, ox + w + mark_offset + ml, mid_y)

            c.showPage()
            c.save()
            packet.seek(0)
            overlay_reader = PdfReader(packet)
            overlay_page = overlay_reader.pages[0]

            # Creer une nouvelle page agrandie
            new_page = PageObject.create_blank_page(width=cw, height=ch)
            # Placer la page originale au centre (decalee de margin)
            page.add_transformation(Transformation().translate(margin, margin))
            new_page.merge_page(page)
            # Ajouter les marques de coupe par-dessus
            new_page.merge_page(overlay_page)
            writer.add_page(new_page)
        else:
            writer.add_page(page)

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


def remove_crop_marks(input_path, output_path):
    """Enlever les reperes de coupe (remet mediabox = cropbox)."""
    reader = PdfReader(input_path)
    writer = PdfWriter()
    for page in reader.pages:
        page.cropbox = page.mediabox
        writer.add_page(page)
    with open(output_path, "wb") as f:
        writer.write(f)
    return output_path