"""Hand-drawn weather icons using the panel's actual 6-color palette (from
epd4in0e's getbuffer() quantization palette: black, white, yellow, red, blue,
green) instead of relying on font glyph coverage for weather emoji, which
turned out to be incomplete (DejaVu Sans has no partly-cloudy glyph) and is
monochrome anyway.
"""

import math

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
YELLOW = (255, 255, 0)
BLUE = (0, 0, 255)

# WMO weather code -> (description, icon kind). Not exhaustive, covers the
# common cases; unmapped codes fall back to "clear".
WMO_CODES = {
    0: ("Klarer Himmel", "clear"),
    1: ("Überwiegend klar", "clear"),
    2: ("Teilweise bewölkt", "partly_cloudy"),
    3: ("Bedeckt", "cloudy"),
    45: ("Nebel", "fog"),
    48: ("Nebel", "fog"),
    51: ("Leichter Nieselregen", "rain"),
    53: ("Nieselregen", "rain"),
    55: ("Starker Nieselregen", "rain"),
    61: ("Leichter Regen", "rain"),
    63: ("Regen", "rain"),
    65: ("Starker Regen", "rain"),
    71: ("Leichter Schneefall", "snow"),
    73: ("Schneefall", "snow"),
    75: ("Starker Schneefall", "snow"),
    80: ("Regenschauer", "rain"),
    81: ("Regenschauer", "rain"),
    82: ("Heftige Regenschauer", "rain"),
    85: ("Schneeschauer", "snow"),
    86: ("Schneeschauer", "snow"),
    95: ("Gewitter", "thunder"),
    96: ("Gewitter mit Hagel", "thunder"),
    99: ("Gewitter mit Hagel", "thunder"),
}


def _cloud_shape(draw, cx, cy, w, h, color):
    draw.rounded_rectangle((cx - w / 2, cy - h * 0.1, cx + w / 2, cy + h * 0.55), radius=h * 0.28, fill=color)
    draw.ellipse((cx - w * 0.42, cy - h * 0.48, cx - w * 0.02, cy + h * 0.12), fill=color)
    draw.ellipse((cx - w * 0.18, cy - h * 0.62, cx + w * 0.22, cy + h * 0.02), fill=color)
    draw.ellipse((cx + w * 0.05, cy - h * 0.42, cx + w * 0.45, cy + h * 0.18), fill=color)


def draw_cloud(draw, cx, cy, size, outline=BLACK, fill=WHITE):
    """Simple line-art cloud: draw the silhouette in `outline`, then a
    shrunk-down copy in `fill` on top -- fakes an outlined shape without
    needing real path-offsetting."""
    w, h = size, size * 0.7
    border = max(2, size * 0.07)
    _cloud_shape(draw, cx, cy, w, h, outline)
    _cloud_shape(draw, cx, cy, w - border * 2.4, h - border * 2.4, fill)


def draw_sun(draw, cx, cy, r, color=YELLOW, outline=BLACK):
    ray_w = max(2, int(r * 0.16))
    for angle_deg in range(0, 360, 45):
        rad = math.radians(angle_deg)
        # Kept within roughly r*1.4 so the whole icon (rays included) stays
        # inside the nominal size x size box callers lay out around it.
        inner, outer = r * 1.15, r * 1.4
        draw.line(
            (cx + math.cos(rad) * inner, cy + math.sin(rad) * inner,
             cx + math.cos(rad) * outer, cy + math.sin(rad) * outer),
            fill=color, width=ray_w,
        )
    draw.ellipse((cx - r, cy - r, cx + r, cy + r), fill=color, outline=outline, width=max(2, int(r * 0.1)))


def _draw_snowflake(draw, cx, cy, r, color):
    for angle_deg in range(0, 180, 60):
        rad = math.radians(angle_deg)
        draw.line(
            (cx - math.cos(rad) * r, cy - math.sin(rad) * r,
             cx + math.cos(rad) * r, cy + math.sin(rad) * r),
            fill=color, width=max(2, int(r * 0.35)),
        )


def draw_weather_icon(draw, kind: str, cx: float, cy: float, size: float):
    """Draws into a roughly `size` x `size` box centered on (cx, cy)."""
    if kind == "clear":
        draw_sun(draw, cx, cy, size * 0.34)
    elif kind == "partly_cloudy":
        draw_sun(draw, cx - size * 0.16, cy - size * 0.18, size * 0.22)
        draw_cloud(draw, cx + size * 0.08, cy + size * 0.14, size * 0.75)
    elif kind == "cloudy":
        draw_cloud(draw, cx, cy, size * 0.9)
    elif kind == "fog":
        for i, dy in enumerate((-0.25, -0.05, 0.15, 0.35)):
            band_w = size * (0.9 - i * 0.12)
            yy = cy + size * dy
            draw.line((cx - band_w / 2, yy, cx + band_w / 2, yy), fill=BLACK, width=max(2, int(size * 0.05)))
    elif kind == "rain":
        draw_cloud(draw, cx, cy - size * 0.12, size * 0.85)
        for dx in (-0.28, -0.02, 0.24):
            x0, y0 = cx + size * dx, cy + size * 0.3
            draw.line((x0, y0, x0 - size * 0.08, y0 + size * 0.24), fill=BLUE, width=max(2, int(size * 0.05)))
    elif kind == "snow":
        draw_cloud(draw, cx, cy - size * 0.12, size * 0.85)
        for dx in (-0.28, -0.02, 0.24):
            _draw_snowflake(draw, cx + size * dx, cy + size * 0.38, size * 0.08, BLUE)
    elif kind == "thunder":
        draw_cloud(draw, cx, cy - size * 0.16, size * 0.85)
        bolt = [
            (cx + size * 0.05, cy + size * 0.16),
            (cx - size * 0.08, cy + size * 0.42),
            (cx + size * 0.02, cy + size * 0.42),
            (cx - size * 0.1, cy + size * 0.7),
            (cx + size * 0.18, cy + size * 0.36),
            (cx + size * 0.06, cy + size * 0.36),
        ]
        draw.polygon(bolt, fill=YELLOW, outline=BLACK)
    else:
        draw_sun(draw, cx, cy, size * 0.34)