"""Moteur Imposition manuelle."""

from pypdf import PdfReader, PdfWriter, PageObject, Transformation
from .pdf_utils import get_page_size, create_crop_marks_page


def manual_impose(input_path, output_path, sheet_size, placements, crop_marks=False):
    """Imposition manuelle : placer des pages a des positions precises.

    sheet_size: (largeur, hauteur) en points
    placements: liste de dicts:
        {"page": int (1-based), "x": float, "y": float, "scale": float, "rotation": int}
    """
    reader = PdfReader(input_path)
    pages = reader.pages
    sheet_w, sheet_h = sheet_size

    writer = PdfWriter()
    sheet = PageObject.create_blank_page(width=sheet_w, height=sheet_h)

    mark_positions = []

    for p in placements:
        page_idx = p["page"] - 1
        if page_idx < 0 or page_idx >= len(pages):
            continue

        page = pages[page_idx]
        page_w, page_h = get_page_size(page)
        x = p.get("x", 0)
        y = p.get("y", 0)
        scale = p.get("scale", 1.0)
        rotation = p.get("rotation", 0)

        overlay = PageObject.create_blank_page(width=sheet_w, height=sheet_h)
        overlay.merge_page(page)

        transform = Transformation()
        if rotation:
            # Rotation autour du centre de la page
            cx = page_w / 2
            cy = page_h / 2
            transform = transform.translate(-cx, -cy)
            transform = transform.rotate(rotation)
            transform = transform.translate(cx, cy)
        transform = transform.scale(scale, scale).translate(x, y)
        overlay.add_transformation(transform)
        sheet.merge_page(overlay)

        if crop_marks:
            scaled_w = page_w * scale
            scaled_h = page_h * scale
            mark_positions.extend([
                (x, y),
                (x + scaled_w, y),
                (x, y + scaled_h),
                (x + scaled_w, y + scaled_h),
            ])

    if crop_marks and mark_positions:
        marks = create_crop_marks_page(sheet_w, sheet_h, mark_positions)
        sheet.merge_page(marks)

    writer.add_page(sheet)

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