class-directory.py

import math
import os
import hashlib
import streamlit as st
import fitz  # PyMuPDF

st.set_page_config(page_title="PDF Tiler", layout="centered")
st.title("PDF Tiler")

uploaded = st.file_uploader("Upload a PDF", type=["pdf"])
debug_borders = st.checkbox("Show debug borders", value=False)

# ---- Fixed layout ----
inch = 72
page_w, page_h = 13.0 * inch, 8.5 * inch  # 8.5x13 landscape
cols, rows = 10, 5
tiles_per_sheet = cols * rows

margin_lr = 0.25 * inch
margin_top = 0.70 * inch
margin_bottom = 0.3 * inch  # your updated bottom margin

content_w = page_w - 2 * margin_lr
content_h = page_h - margin_top - margin_bottom
cell_w = content_w / cols
cell_h = content_h / rows

title_font = "cour"
title_fontsize = 10
title_baseline_from_bottom = 0.2 * inch


def tile_pdf(src_bytes: bytes, title_text: str, debug: bool) -> bytes:
    src = fitz.open(stream=src_bytes, filetype="pdf")
    out = fitz.open()

    total_pages = src.page_count
    out_pages = math.ceil(total_pages / tiles_per_sheet)

    for sheet_idx in range(out_pages):
        dst_page = out.new_page(width=page_w, height=page_h)

        start = sheet_idx * tiles_per_sheet
        end = min(start + tiles_per_sheet, total_pages)

        for j, pno in enumerate(range(start, end)):
            r = j // cols
            c = j % cols

            x0 = margin_lr + c * cell_w
            y0 = margin_top + r * cell_h
            rect = fitz.Rect(x0, y0, x0 + cell_w, y0 + cell_h)

            dst_page.show_pdf_page(rect, src, pno, keep_proportion=True, overlay=True)

            if debug:
                dst_page.draw_rect(rect, color=(0, 0, 0), width=0.3, overlay=True)

        # Title baseline 0.2 in above bottom
        y = page_h - title_baseline_from_bottom
        # text_w = fitz.get_text_length(title_text, fontname=title_font, fontsize=title_fontsize)
        # x = (page_w - text_w) / 2
        # x = max(margin_lr, min(x, page_w - margin_lr - text_w))
        x = margin_lr  # left-aligned at the left margin

        dst_page.insert_text(
            fitz.Point(x, y),
            title_text,
            fontsize=title_fontsize,
            fontname=title_font,
            color=(0, 0, 0),
            overlay=True,
        )

    out_bytes = out.tobytes()
    out.close()
    src.close()
    return out_bytes


# ---- Session state storage ----
if "job_key" not in st.session_state:
    st.session_state.job_key = None
    st.session_state.out_bytes = None
    st.session_state.out_name = None

if uploaded:
    src_bytes = uploaded.getvalue()
    filename = uploaded.name
    title_text = os.path.splitext(os.path.basename(filename))[0]
    out_name = f"{title_text}_tiled_5x10_8.5x13_landscape.pdf"

    # Key changes whenever file or debug_borders changes (add other params if you tweak them)
    h = hashlib.sha256()
    h.update(src_bytes)
    h.update(b"|debug=" + (b"1" if debug_borders else b"0"))
    job_key = h.hexdigest()

    # Generate only when something changed
    if st.session_state.job_key != job_key:
        with st.spinner("Preparing output..."):
            st.session_state.out_bytes = tile_pdf(src_bytes, title_text, debug_borders)
            st.session_state.out_name = out_name
            st.session_state.job_key = job_key

    # Only ONE button shown
    st.download_button(
        "Generate & Download",
        data=st.session_state.out_bytes,
        file_name=st.session_state.out_name,
        mime="application/pdf",
        type="primary",
    )
else:
    st.info("Upload a PDF to enable the Generate & Download button.")


## streamlit run 260215_class-directory/class-directory.py
## streamlit run class-directory.py