import fitz  # PyMuPDF
from pathlib import Path
from utils.text_metrics import get_text_width

def add_date(input_path, output_path, month_year, font_path, position=("right", 30), font_size=22):
    doc = fitz.open(input_path)
    font_path = str(Path(font_path).resolve())

    for page in doc:
        page_width = page.rect.width

        # Register font and get its name
        page.insert_font(fontname="custom", fontfile=font_path)
        font_name = "custom"

        # Measure exact pixel width
        text_width = get_text_width(month_year, font_path, font_size)

        # Calculate X position
        x = page_width - text_width - 40 if position[0] == "right" else position[0]
        y = position[1]

        # Insert the text
        page.insert_text(
            (x, y),
            month_year,
            fontname=font_name,
            fontsize=font_size,
            color=(0, 0, 0),
        )

    doc.save(output_path)
    doc.close()