#!/usr/bin/env python3
"""
gen_skin_template.py — Generate a skin template PNG for sdlamp2.

Creates a 642x420 PNG showing the sprite grid layout with labeled gutters.
Each 200x200 cell is blank white (ready to draw on). The 20px gutters between
cells are gray with small text labels identifying adjacent cells.

Grid layout:
  Col 0 (0-199)    Col 1 (220-419)   Col 2 (440-639)
  Row 0: REWIND     PLAY              FF
         ----gutter y=200-219 with labels----
  Row 1: STOP       PREV              NEXT

Two extra pixels on the right (640-641) are gutter fill to reach 642px width,
matching the spritesheet dimensions.

Usage: python3 tools/gen_skin_template.py [output.png]

Requires Pillow.
"""
import sys

from PIL import Image, ImageDraw, ImageFont

CELL = 200
GAP = 20
COLS = 3
ROWS = 2
WIDTH = COLS * CELL + (COLS - 1) * GAP + 2   # 642
HEIGHT = ROWS * CELL + (ROWS - 1) * GAP       # 420

CELL_COLOR = (255, 255, 255)
GUTTER_COLOR = (180, 180, 180)
TEXT_COLOR = (80, 80, 80)

LABELS = [
    ["REWIND", "PLAY", "FF"],
    ["STOP", "PREV", "NEXT"],
]


def cell_x(col):
    return col * (CELL + GAP)


def cell_y(row):
    return row * (CELL + GAP)


def main():
    output_path = sys.argv[1] if len(sys.argv) > 1 else "skin_template.png"

    img = Image.new("RGB", (WIDTH, HEIGHT), GUTTER_COLOR)
    draw = ImageDraw.Draw(img)

    # Try to load a small font for labels
    try:
        font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 11)
    except OSError:
        try:
            font = ImageFont.truetype("/System/Library/Fonts/Helvetica.ttc", 11)
        except OSError:
            font = ImageFont.load_default()

    # Draw white cells
    for row in range(ROWS):
        for col in range(COLS):
            x = cell_x(col)
            y = cell_y(row)
            draw.rectangle([x, y, x + CELL - 1, y + CELL - 1], fill=CELL_COLOR)

    # Label the horizontal gutter (y = 200..219)
    gutter_y = CELL  # 200
    for col in range(COLS):
        cx = cell_x(col) + CELL // 2

        # Row 0 label above center of gutter
        label_0 = LABELS[0][col]
        bbox = draw.textbbox((0, 0), label_0, font=font)
        tw = bbox[2] - bbox[0]
        draw.text((cx - tw // 2, gutter_y + 1), label_0, fill=TEXT_COLOR, font=font)

        # Row 1 label below center of gutter
        label_1 = LABELS[1][col]
        bbox = draw.textbbox((0, 0), label_1, font=font)
        tw = bbox[2] - bbox[0]
        th = bbox[3] - bbox[1]
        draw.text((cx - tw // 2, gutter_y + GAP - th - 2), label_1, fill=TEXT_COLOR, font=font)

    img.save(output_path)
    print(f"Skin template saved to {output_path} ({WIDTH}x{HEIGHT})")


if __name__ == "__main__":
    main()