#!/usr/bin/env python3
"""Regenerate Android launcher icons from piti-icon.png.

Usage:  python3 tools/gen_launcher_icons.py
Requires: Pillow  (pip install Pillow)

Produces, under app/src/main/res/:
  - mipmap-<dpi>/ic_launcher.png          legacy square (rounded), all densities
  - mipmap-<dpi>/ic_launcher_round.png    legacy round, all densities
  - mipmap-<dpi>/ic_launcher_foreground.png  adaptive-icon foreground (padded)
The adaptive XMLs (mipmap-anydpi-v26/) and the black background drawable are
checked in and don't need regenerating.
"""
import os
from PIL import Image, ImageDraw

ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
SRC = os.path.join(ROOT, "piti-icon.png")
RES = os.path.join(ROOT, "app", "src", "main", "res")
BG = (0, 0, 0, 255)  # matches the app's black theme / ic_launcher_background.xml

brain = Image.open(SRC).convert("RGBA")

LEGACY = {"mdpi": 48, "hdpi": 72, "xhdpi": 96, "xxhdpi": 144, "xxxhdpi": 192}
ADAPTIVE = {"mdpi": 108, "hdpi": 162, "xhdpi": 216, "xxhdpi": 324, "xxxhdpi": 432}


def fit(img, box):
    w, h = img.size
    s = box / max(w, h)
    return img.resize((max(1, int(w * s)), max(1, int(h * s))), Image.LANCZOS)


def rounded_mask(size, radius):
    m = Image.new("L", (size, size), 0)
    ImageDraw.Draw(m).rounded_rectangle([0, 0, size - 1, size - 1], radius=radius, fill=255)
    return m


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


def compose(size, mask, content_scale):
    canvas = Image.new("RGBA", (size, size), BG)
    fg = fit(brain, int(size * content_scale))
    canvas.paste(fg, ((size - fg.width) // 2, (size - fg.height) // 2), fg)
    out = Image.new("RGBA", (size, size), (0, 0, 0, 0))
    out.paste(canvas, (0, 0), mask)
    return out


def save(img, folder, name):
    d = os.path.join(RES, folder)
    os.makedirs(d, exist_ok=True)
    img.save(os.path.join(d, name))


for bucket, size in LEGACY.items():
    save(compose(size, rounded_mask(size, int(size * 0.18)), 0.86), f"mipmap-{bucket}", "ic_launcher.png")
    save(compose(size, circle_mask(size), 0.86), f"mipmap-{bucket}", "ic_launcher_round.png")

for bucket, size in ADAPTIVE.items():
    fg_canvas = Image.new("RGBA", (size, size), (0, 0, 0, 0))
    fg = fit(brain, int(size * 0.64))  # keep within the adaptive-icon safe zone
    fg_canvas.paste(fg, ((size - fg.width) // 2, (size - fg.height) // 2), fg)
    save(fg_canvas, f"mipmap-{bucket}", "ic_launcher_foreground.png")

print("launcher icons regenerated under app/src/main/res/")