"""步骤默认值：新建步骤时预填的参数（后台「任务 → 动作配置」页可改）。

存在 `app_meta.step_defaults` 一个键里（**不建表** → 不碰备份覆盖红线），
与 `notify_webhooks` 同一套做法：**出厂默认 + 用户覆盖**，读的时候合并。

为什么是"出厂 + 覆盖"而不是只存用户值：以后调整某个步骤的出厂默认时，
**没配过的字段**会跟着变好，**配过的字段**不动——这符合直觉。

字段白名单 + 范围校验都在这里（`SPEC`）：写进库的东西必须能校验，否则手改
JSON 塞个奇怪值进去，之后新建步骤就把它带进任务里了。

⚠️ 这里只管**编辑器预填**；`tasks/generic/task.py` 的 `STEP_TYPES` 仍是执行侧
的默认值来源（AI/MCP 造步骤也用它）。两处都改了要一起同步。
"""
import json

# 出厂默认（前端「动作配置」页的初始内容，也是没配过时的回退）
FACTORY = {
    "swipe": {"direction": "up", "duration_min": 0.25, "duration_max": 0.5,
              "distance_ratio": 0.6, "jitter": 0.15, "humanize": True},
    "click": {"wait_timeout": 2},
    "long_click": {"duration": 1.0, "wait_timeout": 2},
    "wait": {"min": 1.0, "max": 3.0},
    "key_event": {"key": "back"},
    "input_text": {"mode": "random", "texts": "你好\n有趣\n支持",
                   "fixed_text": "", "clear_first": True},
}

# 字段规格：("num", 最小, 最大) / ("bool",) / ("choice", 可选值) / ("text", 最大长度)
SPEC = {
    "swipe": {
        "direction": ("choice", ("up", "down", "left", "right")),
        "duration_min": ("num", 0.05, 5.0),
        "duration_max": ("num", 0.05, 5.0),
        "distance_ratio": ("num", 0.1, 0.9),
        "jitter": ("num", 0.0, 0.4),
        "humanize": ("bool",),
    },
    "click": {"wait_timeout": ("num", 0.0, 30.0)},
    "long_click": {"duration": ("num", 0.2, 10.0),
                   "wait_timeout": ("num", 0.0, 30.0)},
    "wait": {"min": ("num", 0.1, 600.0), "max": ("num", 0.1, 600.0)},
    "key_event": {"key": ("text", 30)},
    "input_text": {"mode": ("choice", ("random", "fixed")),
                   "texts": ("text", 2000), "fixed_text": ("text", 200),
                   "clear_first": ("bool",)},
}

# 与 notifier 的键同住 app_meta（`key` 是 MySQL 保留字，读写只走 db_config.meta_get/set）
META_KEY = "step_defaults"


def factory():
    """出厂默认的深拷贝（别让调用方改到常量）。"""
    return json.loads(json.dumps(FACTORY, ensure_ascii=False))


def _clean_one(stype, raw):
    """校验并清洗单个步骤类型的默认值；非法字段**丢弃**（不让脏值进库）。"""
    spec = SPEC.get(stype)
    if not spec or not isinstance(raw, dict):
        return None
    out = {}
    for k, v in raw.items():
        rule = spec.get(k)
        if not rule:
            continue
        kind = rule[0]
        try:
            if kind == "bool":
                out[k] = bool(v)
            elif kind == "num":
                n = float(v)
                lo, hi = rule[1], rule[2]
                out[k] = max(lo, min(hi, n))
            elif kind == "choice":
                s = str(v)
                if s in rule[1]:
                    out[k] = s
            elif kind == "text":
                out[k] = str(v)[:rule[1]]
        except (TypeError, ValueError):
            continue
    return out or None


def clean(raw):
    """清洗整份配置（只保留白名单里的步骤类型与字段）。"""
    if not isinstance(raw, dict):
        return {}
    out = {}
    for stype in SPEC:
        got = _clean_one(stype, raw.get(stype))
        if got:
            out[stype] = got
    return out


def merged(user):
    """出厂默认 + 用户覆盖（按字段合并）。"""
    out = factory()
    for stype, vals in (clean(user) or {}).items():
        out.setdefault(stype, {}).update(vals)
    return out


def get():
    """当前生效的默认值（读库，必须在 app context 内调）。"""
    from core.db_config import meta_get
    raw = meta_get(META_KEY) or ""
    if not raw:
        return factory()
    try:
        return merged(json.loads(raw))
    except (ValueError, TypeError):
        return factory()


def save(raw):
    """保存（只落用户显式给的字段）。返回 (ok, msg)。

    与出厂默认**相同的字段不入库**：这样以后调出厂值，这些字段能跟着更新
    ——库里只留"用户真的改过"的部分。
    """
    from core.db_config import meta_set
    cleaned = clean(raw)
    fac = FACTORY
    diff = {}
    for stype, vals in cleaned.items():
        keep = {k: v for k, v in vals.items()
                if not (stype in fac and k in fac[stype] and fac[stype][k] == v)}
        if keep:
            diff[stype] = keep
    try:
        meta_set(META_KEY, json.dumps(diff, ensure_ascii=False))
    except Exception as e:
        return False, f"保存失败: {e}"
    return True, "已保存"


def as_payload():
    """给前端的完整载荷：生效值 + 出厂值 + 字段规格（前端据此画表单与范围）。"""
    spec = {st: {k: (list(r[1]) if r[0] == "choice" else
                      (list(r[1:]) if r[0] == "num" else None))
                 for k, r in fields.items()}
            for st, fields in SPEC.items()}
    kinds = {st: {k: r[0] for k, r in fields.items()} for st, fields in SPEC.items()}
    return {"defaults": get(), "factory": factory(), "spec": spec, "kinds": kinds}