"""
Generator registry — every generator module imports @register and a Generator class.
The class is responsible for rendering a shell script given a params dict.
"""
from typing import Dict, List, Optional
import shlex

_REGISTRY: Dict[str, "Generator"] = {}


def register(gen: "Generator"):
    if gen.id in _REGISTRY:
        raise ValueError(f"Duplicate generator id: {gen.id}")
    _REGISTRY[gen.id] = gen
    return gen


def get_generator(gid: str) -> Optional["Generator"]:
    return _REGISTRY.get(gid)


def list_generators() -> Dict[str, "Generator"]:
    return dict(_REGISTRY)


def get_categories() -> List[str]:
    seen = []
    for g in _REGISTRY.values():
        if g.category not in seen:
            seen.append(g.category)
    return seen


# Human-readable labels and FontAwesome-style emoji icons
category_labels = {
    "middleware":  "中间件服务",
    "databases":   "数据库",
    "runtimes":    "开发语言运行时",
    "systemd":     "Systemd 服务",
    "system":      "系统工具",
    "network":     "网络工具",
    "monitoring":  "监控告警",
    "security":    "安全加固",
}

category_icons = {
    "middleware":  "🧩",
    "databases":   "🗄️",
    "runtimes":    "⚙️",
    "systemd":     "🛠️",
    "system":      "🖥️",
    "network":     "🌐",
    "monitoring":  "📊",
    "security":    "🔒",
}


# ----- Field / Param descriptors for the UI -----

class Field:
    """One form field rendered in the web UI."""

    def __init__(self, name, label, type="text", default="", placeholder="",
                 help="", options=None, required=False, min_=None, max_=None,
                 step=None, pattern=None, group=None):
        self.name = name
        self.label = label
        self.type = type            # text|number|select|checkbox|textarea|password|portlist
        self.default = default
        self.placeholder = placeholder
        self.help = help
        self.options = options or []
        self.required = required
        self.min = min_
        self.max = max_
        self.step = step
        self.pattern = pattern
        self.group = group          # for grouping in UI

    def to_dict(self):
        return {
            "name": self.name, "label": self.label, "type": self.type,
            "default": self.default, "placeholder": self.placeholder,
            "help": self.help, "options": self.options, "required": self.required,
            "min": self.min, "max": self.max, "step": self.step, "pattern": self.pattern,
            "group": self.group,
        }


# ----- Generator base class -----

class Generator:
    id: str = ""
    title: str = ""
    category: str = "middleware"
    description: str = ""
    icon: str = "📦"
    tags: List[str] = []
    fields: List[Field] = []
    warnings: List[str] = []
    post_steps: List[str] = []
    verify_steps: List[str] = []
    os_support: List[str] = ["ubuntu", "debian", "centos", "rhel"]
    dangerous: bool = False

    def render(self, params: dict) -> str:
        raise NotImplementedError

    def summary(self) -> dict:
        return {
            "id": self.id, "title": self.title, "category": self.category,
            "description": self.description, "icon": self.icon, "tags": self.tags,
            "os": self.os_support, "dangerous": self.dangerous,
            "fields": [f.to_dict() for f in self.fields],
        }


# ----------------------------- Helpers -----------------------------

BASH_HEADER = """#!/usr/bin/env bash
# Generated by shell-gen (https://github.com/yourname/shell-gen)
# Generator: {title}
# Generated at: {ts}
# OS: {os_hint}
set -euo pipefail
SCRIPT_DIR="$(cd -- "$(dirname -- "${{BASH_SOURCE[0]}}")" &>/dev/null && pwd)"
LOG_PREFIX="[{title}]"

log()  {{ echo "${{LOG_PREFIX}} $*" ; }}
warn() {{ echo "${{LOG_PREFIX}} WARN: $*" >&2 ; }}
die()  {{ echo "${{LOG_PREFIX}} ERROR: $*" >&2 ; exit 1 ; }}

[ "$(id -u)" -eq 0 ] || die "This script must be run as root. Re-run with sudo."

# ---- detect distro ----
. /etc/os-release 2>/dev/null || true
DISTRO_ID="${{ID:-unknown}}"
DISTRO_LIKE="${{ID_LIKE:-}}"
case "$DISTRO_ID" in
    ubuntu|debian) PKG="apt-get"; PKG_INSTALL="DEBIAN_FRONTEND=noninteractive apt-get install -y" ;;
    centos|rhel|rocky|almalinux|ol) PKG="yum"; PKG_INSTALL="yum install -y" ;;
    fedora) PKG="dnf"; PKG_INSTALL="dnf install -y" ;;
    *)
        if echo "$DISTRO_LIKE" | grep -qiE "rhel|centos|fedora"; then
            PKG="yum"; PKG_INSTALL="yum install -y"
        elif echo "$DISTRO_LIKE" | grep -qi "debian"; then
            PKG="apt-get"; PKG_INSTALL="DEBIAN_FRONTEND=noninteractive apt-get install -y"
        else
            die "Unsupported distribution: $DISTRO_ID"
        fi
        ;;
esac

log "Detected distro: $DISTRO_ID (package manager: $PKG)"
"""


def bash_header(title: str) -> str:
    return BASH_HEADER.format(
        title=title,
        ts=datetime_now_str(),
        os_hint="Ubuntu / Debian / CentOS / RHEL / Rocky / Alma",
    )


def datetime_now_str() -> str:
    import datetime as _dt
    return _dt.datetime.now().strftime("%Y-%m-%d %H:%M:%S")


def quote(value) -> str:
    """Bash-safe single-quote escape."""
    if value is None:
        return "''"
    s = str(value)
    if s == "":
        return "''"
    return "'" + s.replace("'", "'\\''") + "'"


def bool_str(value, default=False) -> bool:
    if isinstance(value, bool):
        return value
    if value is None:
        return default
    return str(value).lower() in ("1", "true", "yes", "on", "y", "t")


def yes(value) -> str:
    return "yes" if bool_str(value) else "no"


def port_list(value, default=None) -> str:
    """Normalize port list input: '80,443' or '80 443' -> '80 443'."""
    if value is None or value == "":
        value = default or ""
    s = str(value).replace(",", " ").replace(";", " ")
    parts = [p.strip() for p in s.split() if p.strip()]
    return " ".join(parts)