"""Import the user's Arkham City artwork and build the app icon from it.

    python tools/make_assets.py ["C:/Users/<you>/Downloads/Arkham City"]

tools/build_app.py runs this by itself when app/assets is missing or older than this script (from the default
folder or --art FOLDER).

Input folder: bac_logo_full.png (logo with transparent background) and wallpaper.jpg.
Output (app/assets/, git-ignored because it is Warner Bros. artwork):
  wallpaper.jpg   background of the filter panel
  app_icon.png    256 px icon: the logo bat in black over a red audio waveform, on a white rounded tile
  app_icon.ico    Windows icon (16-256 px)
"""
import math
import os
import shutil
import struct
import sys

from PySide6.QtCore import QBuffer, QByteArray, QIODevice, QPointF, QRect, QRectF, Qt
from PySide6.QtGui import QColor, QGuiApplication, QImage, QLinearGradient, QPainter

ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
OUT = os.path.join(ROOT, "app", "assets")
DEFAULT_SRC = os.path.join(os.path.expanduser("~"), "Downloads", "Arkham City")
RED, RED_HI = "#b0242c", "#d8434b"          # the app accent


def crop_bat(logo):
    """The bat is the opaque block above the first fully transparent band (the text sits below it)."""
    logo = logo.convertToFormat(QImage.Format.Format_ARGB32)
    w, h = logo.width(), logo.height()
    opaque = [any(logo.pixelColor(x, y).alpha() > 40 for x in range(0, w, 2)) for y in range(h)]
    top = opaque.index(True)
    bottom = top
    while bottom < h and (opaque[bottom] or any(opaque[bottom:bottom + 12])):
        bottom += 1
    cols = [x for x in range(w) if any(logo.pixelColor(x, y).alpha() > 40 for y in range(top, bottom, 2))]
    return logo.copy(QRect(cols[0], top, cols[-1] - cols[0] + 1, bottom - top))


def silhouette(bat, w, color):
    """The bat's outline filled with one flat colour (drops the stone texture and the lettering)."""
    h = round(w * bat.height() / bat.width())
    img = bat.scaled(w, h, Qt.AspectRatioMode.IgnoreAspectRatio, Qt.TransformationMode.SmoothTransformation)
    p = QPainter(img)
    p.setCompositionMode(QPainter.CompositionMode.CompositionMode_SourceIn)
    p.fillRect(img.rect(), QColor(color))
    p.end()
    return img


def draw_icon(bat, s):
    """White rounded tile, a red audio waveform (rounded bars) across it, the logo bat in black on top."""
    img = QImage(s, s, QImage.Format.Format_ARGB32)
    img.fill(Qt.GlobalColor.transparent)
    p = QPainter(img)
    p.setRenderHint(QPainter.RenderHint.Antialiasing)
    p.setRenderHint(QPainter.RenderHint.SmoothPixmapTransform)
    small = s <= 24
    m = s * 0.04
    bg = QLinearGradient(0, 0, 0, s)
    bg.setColorAt(0, QColor("#ffffff"))
    bg.setColorAt(1, QColor("#ececec"))
    p.setPen(Qt.PenStyle.NoPen)
    p.setBrush(bg)
    p.drawRoundedRect(QRectF(m, m, s - 2 * m, s - 2 * m), s * 0.22, s * 0.22)
    # waveform: symmetric bars, tallest in the middle so they rise above and below the bat
    cy = s / 2
    n = 5 if small else 9
    x0, x1 = s * 0.12, s * 0.88
    step = (x1 - x0) / n
    bar = step * 0.68
    for i in range(n):
        j = min(i, n - 1 - i)                               # mirror
        t = (i + 0.5) / n
        env = math.exp(-((t - 0.5) / 0.34) ** 2)
        h = s * (0.10 + 0.32 * env * (0.65 + 0.35 * abs(math.sin(j * 2.3 + 0.7))))
        g = QLinearGradient(0, cy - h, 0, cy + h)
        g.setColorAt(0, QColor(RED_HI))
        g.setColorAt(0.5, QColor(RED))
        g.setColorAt(1, QColor(RED_HI))
        p.setBrush(g)
        p.drawRoundedRect(QRectF(x0 + i * step + (step - bar) / 2, cy - h, bar, 2 * h), bar / 2, bar / 2)
    # the logo bat, flat black
    sil = silhouette(bat, max(1, round(s * (0.84 if small else 0.78))), "#0d0d0d")
    p.drawImage(QPointF((s - sil.width()) / 2, cy - sil.height() / 2), sil)
    p.end()
    return img


def write_ico(images, path):
    """Multi-size .ico with PNG-compressed entries (Windows Vista+)."""
    blobs = []
    for im in images:
        ba = QByteArray()
        buf = QBuffer(ba)
        buf.open(QIODevice.OpenModeFlag.WriteOnly)
        im.save(buf, "PNG")
        blobs.append((im.width(), bytes(ba)))
    out = struct.pack("<HHH", 0, 1, len(blobs))
    off = 6 + 16 * len(blobs)
    for w, b in blobs:
        out += struct.pack("<BBBBHHII", w % 256, w % 256, 0, 0, 1, 32, len(b), off)
        off += len(b)
    out += b"".join(b for _, b in blobs)
    open(path, "wb").write(out)


def main(src=None):
    src = src or (sys.argv[1] if len(sys.argv) > 1 else DEFAULT_SRC)
    global _APP
    _APP = QGuiApplication.instance() or QGuiApplication(sys.argv[:1])  # needed for QPainter
    os.makedirs(OUT, exist_ok=True)
    logo = QImage(os.path.join(src, "bac_logo_full.png"))
    if logo.isNull():
        raise SystemExit("bac_logo_full.png not found in %s" % src)
    bat = crop_bat(logo)
    shutil.copy(os.path.join(src, "wallpaper.jpg"), os.path.join(OUT, "wallpaper.jpg"))
    icon = draw_icon(bat, 256)
    icon.save(os.path.join(OUT, "app_icon.png"))
    write_ico([draw_icon(bat, n) for n in (16, 24, 32, 48, 64, 128, 256)], os.path.join(OUT, "app_icon.ico"))
    print("assets written to", OUT)


if __name__ == "__main__":
    main()