"""Compose the rendered mosswart head into an app-icon badge."""
import math, os
import numpy as np
from PIL import Image, ImageDraw, ImageFilter, ImageChops

HERE = os.path.dirname(os.path.abspath(__file__))


def rounded_mask(size, radius_frac=0.225, ss=4):
    W = size * ss
    m = Image.new("L", (W, W), 0)
    d = ImageDraw.Draw(m)
    d.rounded_rectangle([0, 0, W - 1, W - 1], radius=int(W * radius_frac), fill=255)
    return m.resize((size, size), Image.LANCZOS)


def circle_mask(size, ss=4):
    W = size * ss
    m = Image.new("L", (W, W), 0)
    ImageDraw.Draw(m).ellipse([0, 0, W - 1, W - 1], fill=255)
    return m.resize((size, size), Image.LANCZOS)


def field(size, inner="#2C3A1A", outer="#0B1006", cx=0.5, cy=0.36):
    """Radial swamp-light gradient behind the head."""
    y, x = np.mgrid[0:size, 0:size].astype(np.float32) / max(size - 1, 1)
    r = np.sqrt(((x - cx) * 1.05) ** 2 + ((y - cy) * 1.05) ** 2) / 0.78
    r = np.clip(r, 0, 1) ** 1.15
    ci = np.array([int(inner[i:i + 2], 16) for i in (1, 3, 5)], dtype=np.float32)
    co = np.array([int(outer[i:i + 2], 16) for i in (1, 3, 5)], dtype=np.float32)
    img = ci[None, None, :] * (1 - r[..., None]) + co[None, None, :] * r[..., None]
    return Image.fromarray(img.astype(np.uint8), "RGB").convert("RGBA")


def drop_shadow(subject, blur=26, dy=18, opacity=0.55, spread=1.03):
    a = subject.split()[3]
    w, h = a.size
    s = a.resize((int(w * spread), int(h * spread)), Image.LANCZOS)
    canvas = Image.new("L", (w, h), 0)
    canvas.paste(s, ((w - s.width) // 2, (h - s.height) // 2 + dy))
    canvas = canvas.filter(ImageFilter.GaussianBlur(blur))
    canvas = canvas.point(lambda v: int(v * opacity))
    sh = Image.new("RGBA", (w, h), (0, 0, 0, 0))
    sh.putalpha(canvas)
    return sh


def fit_subject(sub, size, occupancy=0.86, offset_y=0.0):
    """Trim to content, scale so the longest side hits `occupancy`, centre it."""
    bbox = sub.split()[3].getbbox()
    sub = sub.crop(bbox)
    scale = (size * occupancy) / max(sub.width, sub.height)
    sub = sub.resize((max(1, int(sub.width * scale)), max(1, int(sub.height * scale))),
                     Image.LANCZOS)
    out = Image.new("RGBA", (size, size), (0, 0, 0, 0))
    out.paste(sub, ((size - sub.width) // 2,
                    int((size - sub.height) / 2 + size * offset_y)), sub)
    return out


def badge(subject, size=1024, shape="rounded", occupancy=0.84, offset_y=0.02,
          inner="#2C3A1A", outer="#0B1006", shadow=True, rim=True):
    bg = field(size, inner, outer)
    if rim:
        # faint inner rim so the badge has an edge in dark UI
        ring = Image.new("RGBA", (size, size), (0, 0, 0, 0))
        d = ImageDraw.Draw(ring)
        d.rounded_rectangle([2, 2, size - 3, size - 3],
                            radius=int(size * 0.225) if shape == "rounded" else size // 2,
                            outline=(150, 172, 92, 46), width=max(2, size // 220))
        bg = Image.alpha_composite(bg, ring)

    sub = fit_subject(subject, size, occupancy, offset_y)
    if shadow:
        bg = Image.alpha_composite(bg, drop_shadow(sub, blur=int(size * 0.028),
                                                   dy=int(size * 0.018)))
    out = Image.alpha_composite(bg, sub)

    mask = rounded_mask(size) if shape == "rounded" else circle_mask(size)
    out.putalpha(ImageChops.multiply(out.split()[3], mask))
    return out


def free(subject, size=1024, occupancy=0.94):
    """No field -- the head alone on transparency."""
    return fit_subject(subject, size, occupancy)


def contact(images, labels, cell=280, pad=14, bg=(22, 24, 20)):
    sheet = Image.new("RGB", (len(images) * cell, cell + 24), bg)
    d = ImageDraw.Draw(sheet)
    for i, (im, lb) in enumerate(zip(images, labels)):
        t = im.copy().resize((cell - 2 * pad, cell - 2 * pad), Image.LANCZOS)
        base = Image.new("RGBA", t.size, bg + (255,))
        sheet.paste(Image.alpha_composite(base, t).convert("RGB"), (i * cell + pad, pad))
        d.text((i * cell + pad, cell + 4), lb, fill=(200, 210, 170))
    return sheet


def size_strip(icon, sizes=(128, 64, 48, 32, 24, 16), bg=(22, 24, 20)):
    W = sum(s + 18 for s in sizes) + 20
    H = max(sizes) + 34
    sheet = Image.new("RGB", (W, H), bg)
    d = ImageDraw.Draw(sheet)
    x = 12
    for s in sizes:
        t = icon.resize((s, s), Image.LANCZOS)
        base = Image.new("RGBA", t.size, bg + (255,))
        sheet.paste(Image.alpha_composite(base, t).convert("RGB"), (x, 10 + (max(sizes) - s)))
        d.text((x, H - 18), "%d" % s, fill=(200, 210, 170))
        x += s + 18
    return sheet