#!/usr/bin/env python3
"""config_loader.py - Customization loader for the markdown-html design-system skill.

Stdlib-only. Importable from every converter sub-skill (md-document, md-review,
md-slides) via `sys.path.insert(0, .../design-system/scripts)` so each renderer
picks up the user's onboarded brand tokens automatically.

Precedence (highest wins):
  1. Project config:  <cwd>/.markdown-html/design-system.json
  2. Global config:   ~/.config/markdown-html/design-system.json
  3. Built-in DEFAULTS

Set MARKDOWN_HTML_NO_CONFIG=1 to ignore saved config (always returns DEFAULTS).

The onboarding answers (written by onboard.py) live in these files and are read
here so every converter renders with the user's tokens. Pattern lifted from
research-ops/skills/clinical-research/scripts/config_loader.py and adapted for
the markdown-html domain (brand palette + typography + layout + save location).
"""

from __future__ import annotations

import argparse
import json
import os
import sys
from pathlib import Path
from typing import Any

SKILL = "design-system"
DOMAIN = "markdown-html"

GLOBAL_CONFIG_DIR = Path.home() / ".config" / DOMAIN
GLOBAL_CONFIG_PATH = GLOBAL_CONFIG_DIR / f"{SKILL}.json"
PROJECT_CONFIG_DIRNAME = f".{DOMAIN}"

DEFAULTS: dict[str, Any] = {
    "version": 1,
    "skill": SKILL,
    "default_output_dir": "./markdown-html-out/",
    "brand": {
        "primary": "#0A1628",
        "accent": "#00D4AA",
        "bg": None,
        "text": None,
    },
    "typography": {
        "heading_font": "Inter",
        "body_font": "Inter",
        "scale_ratio": 1.25,
    },
    "design_style": "technical",
    "code_theme": "auto",
    "toc": {
        "behavior": "sticky-sidebar",
        "max_depth": 3,
    },
    "company_name": "",
    "logo_url": "",
    "derived_palette": {},
    "setup_completed_at": None,
}


def project_config_path(cwd: Path | None = None) -> Path:
    cwd = cwd or Path.cwd()
    return cwd / PROJECT_CONFIG_DIRNAME / f"{SKILL}.json"


def _read_json(path: Path) -> dict[str, Any] | None:
    try:
        with path.open(encoding="utf-8") as f:
            data = json.load(f)
        return data if isinstance(data, dict) else None
    except (FileNotFoundError, json.JSONDecodeError, OSError):
        return None


def _deep_merge(base: dict[str, Any], override: dict[str, Any]) -> dict[str, Any]:
    out = dict(base)
    for k, v in override.items():
        if isinstance(v, dict) and isinstance(out.get(k), dict):
            out[k] = _deep_merge(out[k], v)
        else:
            out[k] = v
    return out


def load_config(cwd: Path | None = None) -> dict[str, Any]:
    """Effective config = DEFAULTS <- global <- project. Honors MARKDOWN_HTML_NO_CONFIG."""
    config = dict(DEFAULTS)
    if os.environ.get("MARKDOWN_HTML_NO_CONFIG") == "1":
        return config
    global_cfg = _read_json(GLOBAL_CONFIG_PATH)
    if global_cfg:
        config = _deep_merge(config, global_cfg)
    project_cfg = _read_json(project_config_path(cwd))
    if project_cfg:
        config = _deep_merge(config, project_cfg)
    return config


def setup_completed() -> bool:
    cfg = _read_json(GLOBAL_CONFIG_PATH) or _read_json(project_config_path())
    return bool(cfg and cfg.get("setup_completed_at"))


def write_config(config: dict[str, Any], scope: str = "global", cwd: Path | None = None) -> Path:
    if scope == "project":
        path = project_config_path(cwd)
    else:
        path = GLOBAL_CONFIG_PATH
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("w", encoding="utf-8") as f:
        json.dump(config, f, indent=2, sort_keys=True)
    return path


def main(argv: list[str] | None = None) -> int:
    p = argparse.ArgumentParser(description=f"Inspect {DOMAIN}/{SKILL} customization config.")
    p.add_argument("--show", action="store_true", help="Print the effective config")
    p.add_argument("--status", action="store_true", help="Print setup status + paths")
    p.add_argument("--sample", action="store_true", help="Print the built-in defaults")
    args = p.parse_args(argv)

    if args.sample:
        print(json.dumps(DEFAULTS, indent=2, sort_keys=True))
    elif args.status:
        print(json.dumps({
            "domain": DOMAIN,
            "skill": SKILL,
            "global_config_path": str(GLOBAL_CONFIG_PATH),
            "global_config_exists": GLOBAL_CONFIG_PATH.exists(),
            "project_config_path": str(project_config_path()),
            "project_config_exists": project_config_path().exists(),
            "setup_completed": setup_completed(),
            "bypass_env_set": os.environ.get("MARKDOWN_HTML_NO_CONFIG") == "1",
        }, indent=2))
    else:
        print(json.dumps(load_config(), indent=2, sort_keys=True))
    return 0


if __name__ == "__main__":
    sys.exit(main())