poster_compositor.py

#!/usr/bin/env python3
"""
Campus-AI — Poster Compositor v5
CounciL Strategic Systems
Smart quiet-zone detection + PIL typography
"""

import os, textwrap, requests
import numpy as np
from PIL import Image, ImageDraw, ImageFont, ImageFilter

FONTS_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "assets", "fonts")
FONT_URLS = {
    "Montserrat-ExtraBold": "https://github.com/JulietaUla/Montserrat/raw/master/fonts/ttf/Montserrat-ExtraBold.ttf",
    "Montserrat-Bold":      "https://github.com/JulietaUla/Montserrat/raw/master/fonts/ttf/Montserrat-Bold.ttf",
    "Montserrat-Medium":    "https://github.com/JulietaUla/Montserrat/raw/master/fonts/ttf/Montserrat-Medium.ttf",
    "Montserrat-Regular":   "https://github.com/JulietaUla/Montserrat/raw/master/fonts/ttf/Montserrat-Regular.ttf",
    "Playfair-Bold":        "https://github.com/google/fonts/raw/main/ofl/playfairdisplay/PlayfairDisplay%5Bwght%5D.ttf",
    "Playfair-Regular":     "https://github.com/google/fonts/raw/main/ofl/playfairdisplay/PlayfairDisplay-Italic%5Bwght%5D.ttf",
}


def ensure_fonts():
    os.makedirs(FONTS_DIR, exist_ok=True)
    for name, url in FONT_URLS.items():
        path = os.path.join(FONTS_DIR, f"{name}.ttf")
        if not os.path.exists(path):
            print(f"  Downloading font: {name}…")
            try:
                r = requests.get(url, timeout=30)
                r.raise_for_status()
                with open(path, "wb") as f:
                    f.write(r.content)
            except Exception as e:
                print(f"  Warning: could not download {name}: {e}")


def _font(name: str, size: int) -> ImageFont.FreeTypeFont:
    path = os.path.join(FONTS_DIR, f"{name}.ttf")
    if os.path.exists(path):
        return ImageFont.truetype(path, size)
    try:
        return ImageFont.truetype("arial.ttf", size)
    except OSError:
        return ImageFont.load_default()


def _measure(text: str, font) -> tuple:
    bb = font.getbbox(text)
    return bb[2] - bb[0], bb[3] - bb[1]


def _hex_to_rgb(hex_color: str) -> tuple:
    h = hex_color.lstrip("#")
    return tuple(int(h[i:i + 2], 16) for i in (0, 2, 4))


# ── Zone detection ────────────────────────────────────────────────────────────
def _quiet_zone(img: Image.Image, n: int = 6):
    edges  = np.array(img.convert("L").filter(ImageFilter.FIND_EDGES), dtype=np.float32)
    h      = img.size[1]
    zone_h = h // n
    scores = []
    for i in range(n):
        ys, ye = i * zone_h, min((i + 1) * zone_h, h)
        scores.append((i, ys, ye, float(np.mean(edges[ys:ye, :]))))
    scores.sort(key=lambda x: x[3])
    _, ys, ye, _ = scores[0]
    yc  = (ys + ye) // 2
    pos = "top" if yc / h < 0.35 else ("bottom" if yc / h > 0.65 else "middle")
    return yc, ys, ye, pos


# ── Gradient overlay ──────────────────────────────────────────────────────────
def _local_gradient(img: Image.Image, ys: int, ye: int,
                    intensity: float = 0.88) -> Image.Image:
    overlay = Image.new("RGBA", img.size, (0, 0, 0, 0))
    draw    = ImageDraw.Draw(overlay)
    w, h    = img.size
    feather = 80
    top     = max(0, ys - feather)
    bottom  = min(h, ye + feather)
    for y in range(top, bottom):
        if y < ys:
            a = int(210 * intensity * (y - top) / max(1, ys - top))
        elif y > ye:
            a = int(210 * intensity * (1 - (y - ye) / max(1, bottom - ye)))
        else:
            a = int(210 * intensity)
        draw.line([(0, y), (w, y)], fill=(0, 0, 0, min(a, 215)))
    result = Image.alpha_composite(img.convert("RGBA"), overlay)
    return result.convert("RGB")


# ── Text helpers ──────────────────────────────────────────────────────────────
def _shadow_text(draw, xy, text, font, fill="#FFFFFF",
                 shadow="#000000", offset=4, anchor="lt"):
    x, y = xy
    draw.text((x + offset,     y + offset),     text, font=font, fill=(0, 0, 0, 200), anchor=anchor)
    draw.text((x + offset // 2, y + offset // 2), text, font=font, fill=(0, 0, 0, 120), anchor=anchor)
    draw.text((x, y), text, font=font, fill=fill,
              stroke_width=2, stroke_fill=shadow, anchor=anchor)


def _pill_text(draw, xy, text, font, text_fill="#FFFFFF",
               bg=(0, 0, 0, 170), pad=14, anchor="lt"):
    bb   = font.getbbox(text, anchor=anchor)
    x, y = xy
    draw.rounded_rectangle(
        [x + bb[0] - pad,     y + bb[1] - pad // 2,
         x + bb[2] + pad,     y + bb[3] + pad // 2],
        radius=10, fill=bg,
    )
    draw.text((x, y), text, font=font, fill=text_fill, anchor=anchor)


# ── Layout renderers ──────────────────────────────────────────────────────────
def _layout_modern(draw, w, h, title, subtitle, date, venue, organizer,
                   accent_rgb, start_y):
    GAP = 18
    cy  = start_y
    ac  = f"#{accent_rgb[0]:02x}{accent_rgb[1]:02x}{accent_rgb[2]:02x}"
    if organizer:
        fo = _font("Montserrat-Medium", 20)
        _pill_text(draw, (w // 2, 28), organizer.upper(), fo,
                   text_fill="#FFFFFF", bg=(0, 0, 0, 180), anchor="mt")
    draw.rectangle([w // 2 - 80, cy - 14, w // 2 + 80, cy - 11], fill=accent_rgb)
    ts = 66 if len(title) < 18 else 50 if len(title) < 28 else 40
    ft = _font("Montserrat-ExtraBold", ts)
    ww = 18 if ts >= 56 else 22
    for line in textwrap.wrap(title.upper(), width=ww):
        _shadow_text(draw, (w // 2, cy), line, ft, anchor="mt")
        _, lh = _measure(line, ft)
        cy += lh + 10
    cy += GAP
    if subtitle:
        fs = _font("Playfair-Regular", 26)
        _shadow_text(draw, (w // 2, cy), subtitle, fs, fill=ac, anchor="mt")
        _, sh = _measure(subtitle, fs)
        cy += sh + GAP
    if date or venue:
        fi   = _font("Montserrat-Medium", 18)
        info = "  ·  ".join(filter(None, [date, venue]))
        _pill_text(draw, (w // 2, cy), info, fi, anchor="mt")
    draw.rectangle([0, h - 6, w, h], fill=accent_rgb)


def _layout_bold(draw, w, h, title, subtitle, date, venue, organizer,
                 accent_rgb, start_y):
    GAP, LEFT = 20, 48
    cy = start_y
    ac = f"#{accent_rgb[0]:02x}{accent_rgb[1]:02x}{accent_rgb[2]:02x}"
    draw.rectangle([0, 0, 8, h], fill=accent_rgb)
    if organizer:
        fo = _font("Montserrat-Bold", 17)
        _pill_text(draw, (LEFT, 28), organizer.upper(), fo,
                   text_fill=ac, bg=(0, 0, 0, 210))
    ts = 72 if len(title) < 15 else 56 if len(title) < 24 else 42
    ft = _font("Montserrat-ExtraBold", ts)
    for line in textwrap.wrap(title.upper(), width=14 if ts >= 56 else 18):
        _shadow_text(draw, (LEFT, cy), line, ft, offset=5, anchor="lt")
        _, lh = _measure(line, ft)
        cy += lh + 8
    draw.rectangle([LEFT, cy + 6, LEFT + 60, cy + 9], fill=accent_rgb)
    cy += GAP + 14
    if subtitle:
        fs = _font("Playfair-Regular", 24)
        draw.text((LEFT, cy), subtitle, font=fs, fill=ac)
        _, sh = _measure(subtitle, fs)
        cy += sh + GAP
    if date or venue:
        fi = _font("Montserrat-Regular", 18)
        for part in filter(None, [date, venue]):
            draw.text((LEFT, cy), part, font=fi, fill="#DDDDDD")
            cy += 28


def _layout_elegant(draw, w, h, title, subtitle, date, venue, organizer,
                    accent_rgb, start_y):
    GAP, LW = 18, 140
    cy = start_y
    ac = f"#{accent_rgb[0]:02x}{accent_rgb[1]:02x}{accent_rgb[2]:02x}"
    draw.rectangle([w // 2 - LW, 44, w // 2 + LW, 46], fill=accent_rgb)
    if organizer:
        fo = _font("Montserrat-Medium", 18)
        draw.text((w // 2, 58), organizer, font=fo, fill="#EEEEEE", anchor="mt")
    draw.rectangle([w // 2 - LW, 86, w // 2 + LW, 88], fill=accent_rgb)
    draw.rectangle([0, 0, 6, h], fill=accent_rgb)
    draw.rectangle([w - 6, 0, w, h], fill=accent_rgb)
    ts = 58 if len(title) < 20 else 44 if len(title) < 30 else 36
    ft = _font("Playfair-Bold", ts)
    for line in textwrap.wrap(title, width=22 if ts >= 44 else 28):
        _shadow_text(draw, (w // 2, cy), line, ft, offset=3, anchor="mt")
        _, lh = _measure(line, ft)
        cy += lh + 12
    draw.rectangle([w // 2 - 60, cy + 4, w // 2 + 60, cy + 6], fill=accent_rgb)
    cy += GAP + 10
    if subtitle:
        fs = _font("Playfair-Regular", 24)
        draw.text((w // 2, cy), f"— {subtitle} —", font=fs, fill=ac, anchor="mt")
        _, sh = _measure(subtitle, fs)
        cy += sh + GAP
    if date or venue:
        fi   = _font("Montserrat-Regular", 17)
        info = "  ·  ".join(filter(None, [date, venue]))
        draw.text((w // 2, cy), info, font=fi, fill="#CCCCCC", anchor="mt")
    draw.rectangle([w // 2 - LW, h - 46, w // 2 + LW, h - 44], fill=accent_rgb)
    draw.rectangle([w // 2 - LW + 24, h - 32, w // 2 + LW - 24, h - 30], fill=accent_rgb)


# ── Estimate text block height ────────────────────────────────────────────────
def _estimate_height(w, title, subtitle, date, venue, organizer, style):
    total = 0
    ts    = 66 if len(title) < 18 else 50 if len(title) < 28 else 40
    fname = "Montserrat-ExtraBold" if style != "elegant" else "Playfair-Bold"
    ft    = _font(fname, ts)
    ww    = 18 if ts >= 50 else 22
    for line in textwrap.wrap(title, width=ww):
        _, lh = _measure(line, ft)
        total += lh + 10
    total += 28
    if subtitle: total += 44
    if date:     total += 28
    if venue:    total += 28
    return total + 40


# ── Main entry point ──────────────────────────────────────────────────────────
def composite_poster(
    artwork:       Image.Image,
    title:         str,
    subtitle:      str = "",
    date:          str = "",
    venue:         str = "",
    organizer:     str = "",
    accent_color:  str = "#FFD700",
    style:         str = "modern",
) -> Image.Image:
    ensure_fonts()
    img        = artwork.copy().convert("RGB")
    w, h       = img.size
    accent_rgb = _hex_to_rgb(accent_color)

    est_h      = _estimate_height(w, title, subtitle, date, venue, organizer, style)
    yc, ys, ye, pos = _quiet_zone(img)

    if (ye - ys) < est_h:
        extra = est_h - (ye - ys)
        ys    = max(0, ys - extra // 2)
        ye    = min(h, ye + extra // 2)

    img     = _local_gradient(img, ys, ye)
    overlay = Image.new("RGBA", (w, h), (0, 0, 0, 0))
    draw    = ImageDraw.Draw(overlay)
    text_y  = max(ys + 20, yc - est_h // 2)

    if style == "bold":
        _layout_bold(draw, w, h, title, subtitle, date, venue,
                     organizer, accent_rgb, text_y)
    elif style == "elegant":
        _layout_elegant(draw, w, h, title, subtitle, date, venue,
                        organizer, accent_rgb, text_y)
    else:
        _layout_modern(draw, w, h, title, subtitle, date, venue,
                       organizer, accent_rgb, text_y)

    img = Image.alpha_composite(img.convert("RGBA"), overlay)
    return img.convert("RGB")