#!/usr/bin/env python3
"""Builds the graphic LifeWave backgrounds as SVG and renders them to JPEG.

Square 2048 px, so `background-size: cover` crops them evenly in portrait and
landscape. Palette: ink #292a2b / #1a1b1c, gold #f5c26b / #d59040, paper
#f7f3ea. Deterministic: same seed, same file.

Usage: python3 build_graphic.py [out_dir]   (default dev/backgrounds/graphic)
"""
import os, random, subprocess, sys

ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
OUT = sys.argv[1] if len(sys.argv) > 1 else os.path.join(ROOT, 'dev', 'backgrounds', 'graphic')
S = 2048

GRAIN = '''
  <filter id="grain" x="0" y="0" width="100%" height="100%">
    <feTurbulence type="fractalNoise" baseFrequency="0.9" numOctaves="2" seed="7" stitchTiles="stitch"/>
    <feColorMatrix type="saturate" values="0"/>
    <feComponentTransfer><feFuncA type="linear" slope="{alpha}"/></feComponentTransfer>
  </filter>'''

def svg(defs, body):
    return f'<svg xmlns="http://www.w3.org/2000/svg" width="{S}" height="{S}" viewBox="0 0 {S} {S}">\n<defs>{defs}</defs>\n{body}\n</svg>\n'

def ink():
    defs = '''
  <radialGradient id="g" cx="50%" cy="46%" r="72%">
    <stop offset="0" stop-color="#2f3032"/><stop offset="0.65" stop-color="#232425"/><stop offset="1" stop-color="#161718"/>
  </radialGradient>''' + GRAIN.format(alpha=0.06)
    body = f'<rect width="{S}" height="{S}" fill="url(#g)"/><rect width="{S}" height="{S}" filter="url(#grain)" opacity="0.5"/>'
    return svg(defs, body)

def gold_dust():
    rnd = random.Random(2026)
    specks = []
    for _ in range(5200):
        # Denser and brighter towards the bottom; the middle band stays calm.
        y = S * (1 - rnd.random() ** 0.45)
        x = rnd.random() * S
        r = rnd.choice([1.0, 1.3, 1.6, 2.0, 2.6, 3.4, 4.2])
        depth = y / S
        o = min(0.95, (0.08 + 1.1 * depth ** 1.6) * rnd.uniform(0.35, 1.0))
        c = '#f5c26b' if rnd.random() < 0.7 else '#d59040'
        specks.append(f'<circle cx="{x:.0f}" cy="{y:.0f}" r="{r}" fill="{c}" opacity="{o:.2f}"/>')
    defs = '''
  <radialGradient id="g" cx="50%" cy="40%" r="75%">
    <stop offset="0" stop-color="#2c2d2f"/><stop offset="1" stop-color="#151617"/>
  </radialGradient>
  <linearGradient id="warm" x1="0" y1="0" x2="0" y2="1">
    <stop offset="0.5" stop-color="#d59040" stop-opacity="0"/><stop offset="1" stop-color="#d59040" stop-opacity="0.22"/>
  </linearGradient>
  <filter id="soft" x="-20%" y="-20%" width="140%" height="140%"><feGaussianBlur stdDeviation="2"/></filter>''' + GRAIN.format(alpha=0.05)
    body = (f'<rect width="{S}" height="{S}" fill="url(#g)"/>'
            f'<rect width="{S}" height="{S}" fill="url(#warm)"/>'
            f'<g filter="url(#soft)">{"".join(specks[:2200])}</g><g>{"".join(specks[2200:])}</g>'
            f'<rect width="{S}" height="{S}" filter="url(#grain)" opacity="0.4"/>')
    return svg(defs, body)

def horizon():
    defs = '''
  <linearGradient id="sky" x1="0" y1="0" x2="0" y2="1">
    <stop offset="0" stop-color="#0f1013"/><stop offset="0.52" stop-color="#1b1c1f"/>
    <stop offset="0.66" stop-color="#2e2415"/><stop offset="0.74" stop-color="#241c12"/><stop offset="1" stop-color="#12100b"/>
  </linearGradient>
  <filter id="blur" x="-50%" y="-400%" width="200%" height="900%"><feGaussianBlur stdDeviation="120"/></filter>''' + GRAIN.format(alpha=0.05)
    body = (f'<rect width="{S}" height="{S}" fill="url(#sky)"/>'
            f'<ellipse cx="{S/2}" cy="{S*0.665:.0f}" rx="{S*1.1:.0f}" ry="60" fill="#d59040" opacity="0.32" filter="url(#blur)"/>'
            f'<ellipse cx="{S/2}" cy="{S*0.665:.0f}" rx="{S*0.7:.0f}" ry="14" fill="#f5c26b" opacity="0.22" filter="url(#blur)"/>'
            f'<rect width="{S}" height="{S}" filter="url(#grain)" opacity="0.5"/>')
    return svg(defs, body)

def paper():
    defs = '''
  <radialGradient id="g" cx="50%" cy="45%" r="75%">
    <stop offset="0" stop-color="#f9f5ec"/><stop offset="0.7" stop-color="#f3ecdd"/><stop offset="1" stop-color="#e8dfcc"/>
  </radialGradient>
  <filter id="fibre" x="0" y="0" width="100%" height="100%">
    <feTurbulence type="fractalNoise" baseFrequency="0.02 0.35" numOctaves="3" seed="3" stitchTiles="stitch"/>
    <feColorMatrix type="saturate" values="0"/>
    <feComponentTransfer><feFuncA type="linear" slope="0.10"/></feComponentTransfer>
  </filter>''' + GRAIN.format(alpha=0.05)
    body = (f'<rect width="{S}" height="{S}" fill="url(#g)"/>'
            f'<rect width="{S}" height="{S}" filter="url(#fibre)" opacity="0.6"/>'
            f'<rect width="{S}" height="{S}" filter="url(#grain)" opacity="0.5"/>')
    return svg(defs, body)

def charcoal():
    rnd = random.Random(11)
    smudges = ''.join(
        f'<ellipse cx="{rnd.uniform(0.05, 0.95) * S:.0f}" cy="{rnd.choice([rnd.uniform(0.02, 0.22), rnd.uniform(0.78, 0.98)]) * S:.0f}" '
        f'rx="{rnd.uniform(220, 520):.0f}" ry="{rnd.uniform(40, 110):.0f}" fill="#f7f3ea" opacity="{rnd.uniform(0.025, 0.06):.3f}" '
        f'transform="rotate({rnd.uniform(-12, 12):.1f} {S/2} {S/2})" filter="url(#blur)"/>'
        for _ in range(9))
    defs = '''
  <radialGradient id="g" cx="50%" cy="50%" r="75%">
    <stop offset="0" stop-color="#2d2e30"/><stop offset="1" stop-color="#1d1e1f"/>
  </radialGradient>
  <filter id="chalk" x="0" y="0" width="100%" height="100%">
    <feTurbulence type="fractalNoise" baseFrequency="0.05" numOctaves="4" seed="5" stitchTiles="stitch"/>
    <feColorMatrix type="saturate" values="0"/>
    <feComponentTransfer><feFuncA type="table" tableValues="0 0 0.02 0.10 0.16"/></feComponentTransfer>
  </filter>
  <filter id="blur" x="-50%" y="-100%" width="200%" height="300%"><feGaussianBlur stdDeviation="40"/></filter>''' + GRAIN.format(alpha=0.08)
    body = (f'<rect width="{S}" height="{S}" fill="url(#g)"/>'
            f'<rect width="{S}" height="{S}" fill="#f7f3ea" filter="url(#chalk)" opacity="0.5"/>'
            f'{smudges}'
            f'<rect width="{S}" height="{S}" filter="url(#grain)" opacity="0.6"/>')
    return svg(defs, body)

BACKGROUNDS = [
    ('01-tinte', ink), ('02-goldstaub', gold_dust), ('03-horizont', horizon),
    ('04-papier', paper), ('07-kohle', charcoal),
]

if __name__ == '__main__':
    os.makedirs(OUT, exist_ok=True)
    for name, fn in BACKGROUNDS:
        svg_path = os.path.join(OUT, f'{name}.svg')
        png_path = os.path.join(OUT, f'{name}.png')
        jpg_path = os.path.join(OUT, f'{name}.jpg')
        open(svg_path, 'w').write(fn())
        subprocess.run(['rsvg-convert', '-w', str(S), '-h', str(S), svg_path, '-o', png_path], check=True)
        subprocess.run(['ffmpeg', '-v', 'error', '-y', '-i', png_path, '-q:v', '3', jpg_path], check=True)
        os.remove(png_path)
        print(jpg_path, os.path.getsize(jpg_path) // 1024, 'KB')