#!/usr/bin/env python3
"""Build NexusOS xfwm4 theme from Mint-Y-Dark-Aqua base.

- Copies all xfwm4 PNGs + themerc
- Aqua pixels (close-active/pressed glyph) → NexusOS green via HSV hue swap
- Dark Mint-Y greys repainted to NexusOS surface_bg_alt / border_strong
- themerc title text colors updated to NexusOS palette
"""
from __future__ import annotations

import colorsys
import shutil
import sys
from pathlib import Path

THEMES_ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(THEMES_ROOT))
import _palette as P  # noqa: E402

from PIL import Image  # noqa: E402

SRC = Path("/usr/share/themes/Mint-Y-Dark-Aqua/xfwm4")
OUT = THEMES_ROOT / "NexusOS" / "xfwm4"

# Aqua → green HSV swap (identical to gtk2 build)
AQUA_RGB = (0x1F, 0x9E, 0xDE)
AQUA_HSV = colorsys.rgb_to_hsv(*(c / 255 for c in AQUA_RGB))
GREEN_HSV = P.hex_to_hsv(P.BRAND_GREEN)
S_SCALE = GREEN_HSV[1] / AQUA_HSV[1]
V_SCALE = GREEN_HSV[2] / AQUA_HSV[2]
HUE_TOLERANCE = 30 / 360
SAT_FLOOR = 0.18

# Gray repaints — direct RGB substitutions
GRAY_REMAP = {
    (34, 34, 38): P.hex_to_rgb(P.SURFACE_BG_ALT),
    (46, 46, 46): P.hex_to_rgb(P.BORDER_STRONG),
    (36, 36, 39): P.hex_to_rgb(P.SURFACE_BG_ALT),
    (76, 76, 80): P.hex_to_rgb(P.BORDER_STRONG),
    (85, 85, 89): (130, 130, 134),
    (106, 106, 109): (150, 150, 154),
}


def hue_distance(a: float, b: float) -> float:
    d = abs(a - b)
    return min(d, 1 - d)


def recolor_pixel(r: int, g: int, b: int, a: int) -> tuple[int, int, int, int]:
    if a < 8:
        return (r, g, b, a)
    # Direct gray remap
    if (r, g, b) in GRAY_REMAP:
        nr, ng, nb = GRAY_REMAP[(r, g, b)]
        return (nr, ng, nb, a)
    # Aqua → green
    h, s, v = colorsys.rgb_to_hsv(r / 255, g / 255, b / 255)
    if s >= SAT_FLOOR and hue_distance(h, AQUA_HSV[0]) <= HUE_TOLERANCE:
        new_s = min(1.0, s * S_SCALE)
        new_v = min(1.0, v * V_SCALE)
        nr, ng, nb = colorsys.hsv_to_rgb(GREEN_HSV[0], new_s, new_v)
        return (round(nr * 255), round(ng * 255), round(nb * 255), a)
    return (r, g, b, a)


def recolor_png(path: Path) -> int:
    im = Image.open(path).convert("RGBA")
    px = im.load()
    w, h = im.size
    changed = 0
    for y in range(h):
        for x in range(w):
            r, g, b, a = px[x, y]
            new = recolor_pixel(r, g, b, a)
            if new != (r, g, b, a):
                px[x, y] = new
                changed += 1
    if changed:
        im.save(path, optimize=True)
    return changed


THEMERC_REPLACEMENTS = {
    "active_text_color=#e3e3e3":   f"active_text_color=#{P.TEXT_PRIMARY}",
    "active_text_shadow_color=#e3e3e3": f"active_text_shadow_color=#{P.TEXT_PRIMARY}",
    "inactive_text_color=#acacac": f"inactive_text_color=#{P.TEXT_SECONDARY}",
    "inactive_text_shadow_color=#acacac": f"inactive_text_shadow_color=#{P.TEXT_SECONDARY}",
}


def patch_themerc(path: Path) -> None:
    text = path.read_text()
    for src, dst in THEMERC_REPLACEMENTS.items():
        text = text.replace(src, dst)
    path.write_text(text)


def main() -> None:
    if OUT.exists():
        shutil.rmtree(OUT)
    shutil.copytree(SRC, OUT)
    print(f"Copied {SRC} → {OUT}")

    recolored = 0
    for png in sorted(OUT.glob("*.png")):
        changed = recolor_png(png)
        if changed:
            recolored += 1
    print(f"Recolored {recolored} PNGs")

    patch_themerc(OUT / "themerc")
    print("Patched themerc")


if __name__ == "__main__":
    main()