"""Offline orb tracking metadata and antialiased numeral sprites; no runtime Python."""
from pathlib import Path
import json
import struct

import numpy as np
from PIL import Image, ImageDraw, ImageFilter, ImageFont

ROOT = Path(__file__).resolve().parents[2]
OUT = ROOT / "assets/animations/fortune"
ART = ROOT / "assets/sprites/fortune"
PREVIEW = ROOT / "build/hall-expansion"


def load_orbs():
    raw = (OUT / "orb-mist-v1.bin").read_bytes()
    magic, width, height, count, length = struct.unpack_from("<4s4I", raw)
    assert magic == b"ANM1" and count == 16
    assert length == width * height * count * 4 == len(raw) - 20
    stride = width * height * 4
    return [Image.frombytes("RGBA", (width, height), raw[20+i*stride:20+(i+1)*stride],
                            "raw", "BGRA") for i in range(count)]


def sphere_geometry(frame):
    # Fit the upper glass silhouette, explicitly excluding the metal pedestal.
    alpha = np.asarray(frame.getchannel("A"))
    rows, midpoints, half_widths = [], [], []
    for y in range(12, round(frame.height * .70)):
        xs = np.flatnonzero(alpha[y] >= 170)
        if len(xs) < frame.width * .35:
            continue
        left, right = int(xs[0]), int(xs[-1])
        rows.append(y)
        midpoints.append((left + right) / 2)
        half_widths.append((right - left) / 2)
    a, b, c = np.polyfit(rows, np.square(half_widths), 2)
    assert a < 0
    cy = -b / (2*a)
    cx = float(np.median(midpoints))
    rx = float(np.sqrt(c - b*b/(4*a)))
    ry = float(rx / np.sqrt(-a))
    assert 70 < cx < 125 and 60 < cy < 115
    assert 55 < rx < 95 and 55 < ry < 95
    return {"cx": cx, "cy": cy, "rx": rx, "ry": ry}


def numeral(digit, font):
    factor = 4
    mask = Image.new("L", (32*factor, 48*factor))
    draw = ImageDraw.Draw(mask)
    box = draw.textbbox((0, 0), str(digit), font=font)
    x = (mask.width-(box[2]-box[0]))/2-box[0]
    y = (mask.height-(box[3]-box[1]))/2-box[1]
    draw.text((round(x), round(y)), str(digit), font=font, fill=255)
    mask = mask.resize((32, 48), Image.Resampling.LANCZOS)
    shadow = Image.new("RGBA", mask.size, (8, 30, 66, 0))
    shadow.putalpha(mask.filter(ImageFilter.MaxFilter(3)).point(lambda a: round(a*.65)))
    halo = Image.new("RGBA", mask.size, (65, 168, 243, 0))
    halo.putalpha(mask.filter(ImageFilter.GaussianBlur(2.0)).point(lambda a: round(a*.65)))
    ink = Image.new("RGBA", mask.size, (200, 235, 255, 0))
    ink.putalpha(mask.point(lambda a: round(a*.90)))
    return Image.alpha_composite(Image.alpha_composite(halo, shadow), ink)


def main():
    PREVIEW.mkdir(parents=True, exist_ok=True)
    orbs = load_orbs()
    geometry = [sphere_geometry(frame) for frame in orbs]
    # Q8 offsets in the exact 128px runtime drawing rectangle, not its centre.
    lines = ["; Generated by tools/generators/pack_fortune_orb.py; glass only, pedestal excluded."]
    for name, key in (("fortuneOrbAnchorX3D", "cx"), ("fortuneOrbAnchorY3D", "cy")):
        values = [round(item[key] * 128 / 192 * 256) for item in geometry]
        lines.append(name + " dd " + ",".join(map(str, values)))
    (ROOT / "src_graphics/fortune_orb_art.inc").write_text("\n".join(lines)+"\n", encoding="ascii")
    font = ImageFont.truetype("C:/Windows/Fonts/cambria.ttc", 34*4)
    digits = [numeral(i, font) for i in range(10)]
    payload = b"".join(frame.tobytes("raw", "BGRA") for frame in digits)
    (OUT / "orb-numerals-v1.bin").write_bytes(struct.pack("<4s4I", b"ANM1", 32, 48, 10,
                                                          len(payload)) + payload)
    sheet = Image.new("RGBA", (320, 48))
    for i, digit in enumerate(digits):
        sheet.alpha_composite(digit, (32*i, 0))
    sheet.save(ART / "orb-numerals-v1.png")
    (ART / "orb-tracking-v1.json").write_text(json.dumps({"canvas": [192, 192],
        "font": "Cambria Regular, rasterized at 4x; no font needed at runtime",
        "frames": geometry}, indent=2)+"\n", encoding="ascii")
    sheet = Image.new("RGB", (192*4, 192*4), (5, 15, 28))
    for i, (frame, item) in enumerate(zip(orbs, geometry)):
        debug = frame.copy()
        draw = ImageDraw.Draw(debug)
        x, y = item["cx"], item["cy"]
        draw.ellipse((x-item["rx"], y-item["ry"], x+item["rx"], y+item["ry"]), outline="yellow")
        draw.line((x-5, y, x+5, y), fill="yellow")
        draw.line((x, y-5, x, y+5), fill="yellow")
        sheet.paste(debug, ((i%4)*192, (i//4)*192), debug)
    sheet.save(PREVIEW / "fortune-orb-tracking.png")
    print("Packed 10 antialiased Cambria numerals and 16 measured glass-centre anchors.")


if __name__ == "__main__":
    main()