gen_certificates.py

gen_certificates.py

#!/usr/bin/env python3
"""Generate Vidaya completion certificates, one per name in names.csv.

Template = page 0 of certs.pdf. For each name we:
  - remove the old name text and insert the new name in Flatlion (centered, fit to width)
  - change the year's final digit 5 -> 6 (OpenSans-Italic, matching the others)
  - place the signature firma.png on the line above LAURA CASSADO
Background image and the printed rules are left untouched (text-only redaction).
"""
import sys, os, re
import fitz
from PIL import Image
import numpy as np

SRC = "certs.pdf"
FLATLION = "/Users/ramon/Library/Fonts/Flatlion Personal Use Only.ttf"
OPENSANS_IT = "/Applications/TouchDesigner.app/Contents/Resources/tfs/Samples/Fonts/OpenSans-Italic.ttf"
OUTDIR = "certificates"

INK = (61/255, 59/255, 58/255)          # 0x3d3b3a, the body text colour

# --- geometry captured from the template (page 0) ---
NAME_BBOX   = fitz.Rect(302.1, 297.7, 540.1, 388.7)
NAME_BASE_Y = 375.5
NAME_SIZE   = 91.0
NAME_CX     = 421.125                    # page centre
NAME_RULE   = (217.7, 624.5)            # underline extent
NAME_MAXW   = 400.0                      # max name width (inside the rule)

YEAR5_BBOX  = fitz.Rect(464.9, 422.6, 471.5, 438.9)
YEAR_X      = 464.9
YEAR_BASE_Y = 435.4
YEAR_SIZE   = 12.0

# signature: sit on the rule above LAURA CASSADO (rule y=495.2, centre x=421.1)
SIG_CX      = 421.1
SIG_BOTTOM  = 500.0                      # just over the rule, above LAURA text (503.7)
SIG_HEIGHT  = 58.0


def make_signature_png():
    """Trim firma.png to its ink (black strokes on transparent) and return
    (png_bytes, aspect w/h). Forces black ink + clean alpha from luminance."""
    im = Image.open("firma.png").convert("RGBA")
    a = np.array(im)
    lum = a[:, :, :3].mean(axis=2)
    alpha = a[:, :, 3]
    ink = (lum < 160) & (alpha > 20)            # dark, visible pixels
    ys, xs = np.where(ink)
    x0, x1, y0, y1 = xs.min(), xs.max(), ys.min(), ys.max()
    pad = 6
    x0 = max(0, x0 - pad); y0 = max(0, y0 - pad)
    x1 = min(im.width - 1, x1 + pad); y1 = min(im.height - 1, y1 + pad)
    crop = a[y0:y1 + 1, x0:x1 + 1].copy()
    cl = crop[:, :, :3].mean(axis=2)
    ca = crop[:, :, 3]
    out = np.zeros_like(crop)
    mask = (cl < 200) & (ca > 20)               # ink -> opaque black
    out[:, :, 0] = 0; out[:, :, 1] = 0; out[:, :, 2] = 0
    out[:, :, 3] = np.where(mask, 255, 0).astype("uint8")
    res = Image.fromarray(out, "RGBA")
    import io
    buf = io.BytesIO(); res.save(buf, format="PNG")
    res.save("firma_trim.png")                  # for inspection
    return buf.getvalue(), res.width / res.height


def build_one(name, sig_png, sig_aspect, out_path):
    doc = fitz.open(SRC)
    # keep only the template page
    doc.select([0])
    page = doc[0]

    # remove old name + old final year digit (text only, keep background & rules)
    page.add_redact_annot(NAME_BBOX, fill=None)
    page.add_redact_annot(YEAR5_BBOX, fill=None)
    page.apply_redactions(images=fitz.PDF_REDACT_IMAGE_NONE,
                          graphics=fitz.PDF_REDACT_LINE_ART_NONE)

    # new name: fit to width, centred on the rule, baseline on the line
    font = fitz.Font(fontfile=FLATLION)
    size = NAME_SIZE
    w = font.text_length(name, size)
    if w > NAME_MAXW:
        size *= NAME_MAXW / w
        w = font.text_length(name, size)
    x = NAME_CX - w / 2
    page.insert_text((x, NAME_BASE_Y), name, fontfile=FLATLION,
                     fontname="flatlion", fontsize=size, color=INK)

    # year final digit 5 -> 6
    page.insert_text((YEAR_X, YEAR_BASE_Y), "6", fontfile=OPENSANS_IT,
                     fontname="osit", fontsize=YEAR_SIZE, color=INK)

    # signature above LAURA CASSADO
    sh = SIG_HEIGHT
    sw = sh * sig_aspect
    rect = fitz.Rect(SIG_CX - sw / 2, SIG_BOTTOM - sh, SIG_CX + sw / 2, SIG_BOTTOM)
    page.insert_image(rect, stream=sig_png, keep_proportion=True, overlay=True)

    doc.save(out_path, garbage=4, deflate=True)
    doc.close()


def safe_filename(name):
    s = name.strip()
    s = re.sub(r"\s+", " ", s)
    s = s.replace("/", "-")
    return s


def main():
    names = [l.strip() for l in open("names.csv", encoding="utf-8") if l.strip()]
    os.makedirs(OUTDIR, exist_ok=True)
    sig_png, sig_aspect = make_signature_png()

    only = sys.argv[1] if len(sys.argv) > 1 else None
    if only is not None:
        names = [names[int(only)]]

    for i, name in enumerate(names):
        out = os.path.join(OUTDIR, f"{safe_filename(name)}.pdf")
        build_one(name, sig_png, sig_aspect, out)
        print("wrote", out)


if __name__ == "__main__":
    main()