#!/usr/bin/env python3
"""Config storage for the ButtonTask web configurator.

Reads/writes the same JSON config file consumed by the Qt5 application.
Defaults here must stay in sync with ConfigManager::ensureDefaults() in C++.
"""
import copy
import json
import os
import tempfile
from pathlib import Path

ALLOWED_ICON_EXT = {".png", ".jpg", ".jpeg", ".bmp", ".svg", ".gif"}


def config_path():
    """Resolve the active config path.

    Priority:
      1. BUTTONTASK_CONFIG environment variable.
      2. <repo>/config/config.json next to this package (dev fallback).
    """
    env = os.environ.get("BUTTONTASK_CONFIG")
    if env:
        return Path(env)
    # webconfig/ -> repo root -> config/config.json
    return (Path(__file__).resolve().parent.parent / "config" / "config.json")


def _defaults():
    return {
        "version": 2,
        "layout": {"mode": "grid", "columns": 2, "spacing": 10, "showLabels": True, "labelColor": "#ffffff"},
        "background": {
            "type": "gradient",
            "color1": "#00007b",
            "color2": "#7b007b",
            "animated": True,
            "imagePath": "",
        },
        "feedback": {
            "okColor": "#00cc44",
            "errorColor": "#cc2200",
            "okWidth": 6,
            "errorWidth": 6,
            "glowRadius": 20,
            "holdColor": "#ffffff",
            "pendingColor": "#ffffff",
            "pendingWidth": 6,
        },
        "settings": {
            "darkMode": True,
            "password": "admin_26",
            "kioskMode": False,
            "iconsDir": "./icons",
            "webPort": 8080,
            "brightness": 60,
        },
        "buttons": [],
    }


def ensure_defaults(cfg):
    """Fill in any missing sections/keys without overwriting existing values."""
    base = _defaults()
    if not isinstance(cfg, dict):
        return base
    cfg.setdefault("version", base["version"])
    for section in ("layout", "background", "feedback", "settings"):
        sec = cfg.setdefault(section, {})
        if not isinstance(sec, dict):
            sec = {}
            cfg[section] = sec
        for k, v in base[section].items():
            sec.setdefault(k, v)
    if not isinstance(cfg.get("buttons"), list):
        cfg["buttons"] = []
    cfg.setdefault("settings", {})["darkMode"] = True
    return cfg


def load_config():
    p = config_path()
    if not p.exists():
        cfg = ensure_defaults(_defaults())
        # point iconsDir at a sensible absolute default for the web side
        cfg["settings"]["iconsDir"] = str((p.parent.parent / "icons"))
        return cfg
    with p.open("r", encoding="utf-8") as f:
        raw = json.load(f)
    migrated = ensure_defaults(raw if isinstance(raw, dict) else {})
    if migrated != raw:
        save_config(migrated)
    return migrated


def save_config(cfg):
    p = config_path()
    p.parent.mkdir(parents=True, exist_ok=True)
    fd, tmp = tempfile.mkstemp(prefix=".cfg.", suffix=".tmp", dir=str(p.parent))
    try:
        with os.fdopen(fd, "w", encoding="utf-8") as f:
            json.dump(cfg, f, indent=4, ensure_ascii=False)
        os.replace(tmp, p)
    except Exception:
        if os.path.exists(tmp):
            os.unlink(tmp)
        raise


def icons_dir():
    cfg = load_config()
    d = cfg.get("settings", {}).get("iconsDir") or "./icons"
    p = Path(d)
    if not p.is_absolute():
        p = (config_path().parent.parent / d).resolve()
    p.mkdir(parents=True, exist_ok=True)
    return p


def list_icons():
    return sorted(
        f.name for f in icons_dir().iterdir()
        if f.is_file() and f.suffix.lower() in ALLOWED_ICON_EXT
    )


def default_config():
    return copy.deepcopy(_defaults())