"""Lay the model's renders beside the picture, view by view (system Python with PIL):

    python nv_compare.py <tag> [--overlay] [--src fit|cycles]

previews/compare/<tag>.png: for each view the picture's panel on the left, the render (same camera, same framing) on
the right; --overlay adds a third column, the picture with the render's outline drawn over it.
"""
import os, sys
from PIL import Image, ImageFilter, ImageChops, ImageDraw

HERE = os.path.dirname(os.path.abspath(__file__))
FOLDER = os.path.dirname(HERE)
args = [a for a in sys.argv[1:] if not a.startswith("--")]
TAG = args[0] if args else "v01"
OVER = "--overlay" in sys.argv
SRC = sys.argv[sys.argv.index("--src") + 1] if "--src" in sys.argv else "fit"
PANELS = {"left": (20, 20, 330, 570), "mid": (350, 10, 690, 570), "right": (670, 20, 990, 570)}
K = 2                                   # renders are twice the picture's size

ref = Image.open(os.path.join(FOLDER, "reference", "ref_user.jpg")).convert("RGB")
ref2 = ref.resize((ref.width * K, ref.height * K), Image.LANCZOS)
cols = []
for v, (u0, v0, u1, v1) in PANELS.items():
    path = os.path.join(FOLDER, "previews", SRC, "%s_%s.png" % (TAG, v))
    if not os.path.exists(path):
        continue
    box = (u0 * K, v0 * K, u1 * K, v1 * K)
    a = ref2.crop(box)
    rnd = Image.open(path).convert("RGBA").crop(box)
    bg = Image.new("RGBA", rnd.size, (24, 24, 26, 255))
    bg.alpha_composite(rnd)
    row = [a, bg.convert("RGB")]
    if OVER:
        al = rnd.split()[3].point(lambda x: 255 if x > 40 else 0)
        edge = al.filter(ImageFilter.FIND_EDGES).filter(ImageFilter.MaxFilter(3))
        ov = a.copy()
        red = Image.new("RGB", a.size, (255, 40, 40))
        ov.paste(red, (0, 0), edge)
        row.append(ov)
    w = sum(r.width for r in row) + 10 * (len(row) - 1)
    im = Image.new("RGB", (w, a.height), (0, 0, 0))
    x = 0
    for r in row:
        im.paste(r, (x, 0))
        x += r.width + 10
    cols.append(im)
    os.makedirs(os.path.join(FOLDER, "previews", "compare"), exist_ok=True)
    im.save(os.path.join(FOLDER, "previews", "compare", "%s_%s%s.png" % (TAG, v, "_overlay" if OVER else "")))
H = sum(c.height for c in cols) + 10 * (len(cols) - 1)
Wd = max(c.width for c in cols)
sheet = Image.new("RGB", (Wd, H), (0, 0, 0))
y = 0
for c in cols:
    sheet.paste(c, (0, y))
    y += c.height + 10
os.makedirs(os.path.join(FOLDER, "previews", "compare"), exist_ok=True)
out = os.path.join(FOLDER, "previews", "compare", "%s%s.png" % (TAG, "_overlay" if OVER else ""))
sheet.save(out)
print("COMPARE OK", out, sheet.size)