"""P1-1: 单测 — capability_discovery 核心函数(双 Claw 共享层)。

为什么这个文件存在:
    历史上 #866 部署因为端侧重写了发现逻辑,把 #764/#765 的注入改动覆盖回退。
    这次把 discovery 层的关键纯函数 + 三级降级路径锁死为单测,
    防止「第二个实现」再悄悄出现。

验证范围:
    1. rank_by_query: 池子 ≤ top_k 原样返回, 池子 > top_k 按词元重叠排序
    2. rank_by_query: 中文友好(整词 + 2-gram)
    3. _env_int / _env_flag: 缺失 / 异常 / 正常 路径
    4. _safe_name: 命名安全(消除 mcp__tool__ 里被注入特殊字符)
    5. discover_skills: 三级降级(installed / published / empty) + 异常降级
    6. discover_agents: explicit 优先 + 三级降级
    7. discover_mcp_servers: explicit 走 resolve_active, auto 走 list_enabled
    8. 双 Claw 标签注入(log 里有 claw=web/im)
"""
from __future__ import annotations

import os
import sys
import asyncio
import logging
import importlib

import pytest

_HERE = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, os.path.join(_HERE, ".."))

from app.core import capability_discovery as cd  # noqa: E402
from app.core.capability_discovery import (  # noqa: E402
    rank_by_query,
    _env_int,
    _env_flag,
    _safe_name,
    _tokens,
    discover_skills,
    discover_agents,
    discover_mcp_servers,
    build_mcp_tool_defs,
)


# =====================================================================
# 1. rank_by_query: 纯函数
# =====================================================================

def test_rank_by_query_empty():
    assert rank_by_query([], "query", 5) == []


def test_rank_by_query_below_limit_returns_intact():
    items = [
        {"name": "search", "description": "网页搜索"},
        {"name": "calc", "description": "数学计算"},
    ]
    out = rank_by_query(items, "anything", 5)
    assert out == items  # top_k 大于池子,原样返回


def test_rank_by_query_above_limit_sorts_by_overlap():
    items = [
        {"name": "weather", "description": "查天气"},
        {"name": "translate", "description": "翻译文档"},
        {"name": "weather_alert", "description": "天气预警"},
        {"name": "ocr", "description": "图片文字识别"},
    ]
    out = rank_by_query(items, "天气", top_k=2)
    # "天气" 在 weather/weather_alert 描述里都出现,应排前
    assert len(out) == 2
    assert all("weather" in (x.get("name") or "") or "天气" in (x.get("description") or "") for x in out)


def test_rank_by_query_zh_2gram_friendly():
    items = [
        {"name": "code_review", "description": "代码审查"},
        {"name": "music", "description": "音乐生成"},
    ]
    out = rank_by_query(items, "代码审查", top_k=1)
    assert out[0]["name"] == "code_review"


def test_rank_by_query_top_k_zero_returns_empty():
    assert rank_by_query([{"a": 1}], "x", 0) == []


def test_tokens_chinese_split():
    toks = _tokens("代码审查 Code Review")
    assert "code" in toks
    assert "review" in toks
    assert "代码" in toks
    assert "码审" in toks  # 2-gram


# =====================================================================
# 2. 环境旋钮
# =====================================================================

def test_env_int_default_when_missing(monkeypatch):
    monkeypatch.delenv("CAP_SKILL_LIMIT", raising=False)
    assert _env_int("CAP_SKILL_LIMIT", 12) == 12


def test_env_int_uses_value(monkeypatch):
    monkeypatch.setenv("CAP_SKILL_LIMIT", "20")
    assert _env_int("CAP_SKILL_LIMIT", 12) == 20


def test_env_int_handles_garbage(monkeypatch):
    monkeypatch.setenv("CAP_SKILL_LIMIT", "not-a-number")
    assert _env_int("CAP_SKILL_LIMIT", 12) == 12


def test_env_flag_default_true():
    assert _env_flag("__NONEXIST__") is True


def test_env_flag_default_false():
    assert _env_flag("__NONEXIST__", default=False) is False


def test_env_flag_truthy(monkeypatch):
    for v in ("1", "true", "yes", "on", "TRUE"):
        monkeypatch.setenv("__TEST_FLAG__", v)
        assert _env_flag("__TEST_FLAG__") is True


def test_env_flag_falsy(monkeypatch):
    for v in ("0", "false", "no", "off", "garbage"):
        monkeypatch.setenv("__TEST_FLAG__", v)
        assert _env_flag("__TEST_FLAG__") is False


# =====================================================================
# 3. _safe_name — MCP 工具命名安全
# =====================================================================

def test_safe_name_basic():
    assert _safe_name("hello world", 30) == "hello_world"


def test_safe_name_maxlen():
    assert _safe_name("abcdefghij" * 5, 10) == "abcdefghij"


def test_safe_name_special_chars():
    # 工具名只允许 [A-Za-z0-9_-]
    assert _safe_name("tool/name:v1", 30) == "tool_name_v1"


def test_safe_name_empty():
    assert _safe_name("", 30) == ""


# =====================================================================
# 4. discover_skills: 三级降级(用 mock db 模拟 SQLAlchemy session)
# =====================================================================

class FakeQuery:
    def __init__(self, rows):
        self._rows = rows
    def filter(self, *a, **kw):
        return self
    def all(self):
        return self._rows
    def order_by(self, *a, **kw):
        return self


class FakeDb:
    """极简 db mock: 支持 .query(Class).filter(...).all() 链式调用。"""
    def __init__(self, app_install_rows=None, market_app_rows=None):
        self._app_install = app_install_rows or []
        self._market_app = market_app_rows or []
    def query(self, cls):
        name = getattr(cls, "__name__", str(cls))
        if name == "AppInstallation":
            return FakeQuery(self._app_install)
        if name == "MarketApp":
            return FakeQuery(self._market_app)
        return FakeQuery([])


class FakeAppInstall:
    def __init__(self, app_id):
        self.app_id = app_id


class FakeMarketApp:
    def __init__(self, id, type, status):
        self.id = id
        self.type = type
        self.status = status


def test_discover_skills_installed_path(monkeypatch):
    """user_id 提供 + app_installations 非空 → 走 installed 路径"""
    db = FakeDb(
        app_install_rows=[FakeAppInstall("skill-1")],
        market_app_rows=[FakeMarketApp("skill-1", "skill", "published")],
    )
    # stub _resolve_market_skills 返回一个标定 list
    monkeypatch.setattr(
        "app.api.chat_skill._resolve_market_skills",
        lambda d, ids, uid: [{"id": "skill-1", "name": "Search"}],
        raising=False,
    )
    out = discover_skills(db, user_id="u-1", query="", limit=5, claw="web")
    assert out and out[0]["id"] == "skill-1"


def test_discover_skills_fallback_published(monkeypatch):
    """app_installations 为空 → 降级 published 全集"""
    db = FakeDb(
        app_install_rows=[],
        market_app_rows=[
            FakeMarketApp("skill-1", "skill", "published"),
            FakeMarketApp("skill-2", "skill", "published"),
        ],
    )
    monkeypatch.setattr(
        "app.api.chat_skill._resolve_market_skills",
        lambda d, ids, uid: [{"id": i} for i in ids],
        raising=False,
    )
    out = discover_skills(db, user_id="u-1", query="", limit=5, claw="web")
    assert len(out) == 2
    ids = {x["id"] for x in out}
    assert ids == {"skill-1", "skill-2"}


def test_discover_skills_fallback_disabled(monkeypatch):
    """CAP_SKILL_FALLBACK_PUBLISHED=0 → 不降级,空池"""
    monkeypatch.setenv("CAP_SKILL_FALLBACK_PUBLISHED", "0")
    db = FakeDb(
        app_install_rows=[],
        market_app_rows=[FakeMarketApp("skill-1", "skill", "published")],
    )
    out = discover_skills(db, user_id="u-1", query="", limit=5, claw="web")
    assert out == []


def test_discover_skills_handles_exception(monkeypatch, caplog):
    """db.query 抛异常 → 降级继续,不冒泡"""
    class BoomDb:
        def query(self, *a, **kw):
            raise RuntimeError("DB down")

    with caplog.at_level(logging.WARNING):
        out = discover_skills(BoomDb(), user_id="u-1", query="", limit=5, claw="web")
    assert out == []
    assert any("安装技能发现失败" in r.message for r in caplog.records)


def test_discover_skills_limit_zero():
    db = FakeDb()
    out = discover_skills(db, user_id=None, query="", limit=0, claw="im")
    assert out == []


# =====================================================================
# 5. discover_agents: explicit > installed > published
# =====================================================================

def test_discover_agents_explicit_priority(monkeypatch):
    """explicit_ids 存在 → 跳过 installed/published"""
    db = FakeDb()  # 即便有 installed/published,也不该用
    monkeypatch.setattr(
        "app.api.chat_skill._resolve_market_agents",
        lambda d, ids, uid: [{"id": "a-explicit"}],
        raising=False,
    )
    out = discover_agents(db, user_id="u-1", query="", explicit_ids=["a-explicit"], limit=5, claw="im")
    assert out and out[0]["id"] == "a-explicit"


def test_discover_agents_installed_path(monkeypatch):
    db = FakeDb(
        app_install_rows=[FakeAppInstall("a-1")],
        market_app_rows=[FakeMarketApp("a-1", "agent", "published")],
    )
    monkeypatch.setattr(
        "app.api.chat_skill._resolve_market_agents",
        lambda d, ids, uid: [{"id": i} for i in ids],
        raising=False,
    )
    out = discover_agents(db, user_id="u-1", query="", explicit_ids=None, limit=5, claw="web")
    assert out and out[0]["id"] == "a-1"


# =====================================================================
# 6. discover_mcp_servers: explicit vs auto
# =====================================================================

def test_discover_mcp_explicit(monkeypatch):
    db = FakeDb()
    monkeypatch.setattr(
        "app.api.chat_mcp._resolve_active_mcp_servers",
        lambda d, ids: [{"id": i, "name": i} for i in ids],
        raising=False,
    )
    out = discover_mcp_servers(db, explicit_ids=["m1", "m2"], limit=5, claw="web")
    assert len(out) == 2
    assert {x["id"] for x in out} == {"m1", "m2"}


def test_discover_mcp_auto(monkeypatch):
    db = FakeDb()
    monkeypatch.setattr(
        "app.api.chat_mcp._list_enabled_mcp_servers",
        lambda d: [{"id": "m-auto", "name": "auto"}],
        raising=False,
    )
    out = discover_mcp_servers(db, explicit_ids=None, limit=5, claw="im")
    assert out and out[0]["id"] == "m-auto"


def test_discover_mcp_auto_disabled(monkeypatch):
    monkeypatch.setenv("CAP_MCP_AUTO", "0")
    db = FakeDb()
    out = discover_mcp_servers(db, explicit_ids=None, limit=5, claw="im")
    assert out == []


def test_discover_mcp_limit_clips(monkeypatch):
    db = FakeDb()
    monkeypatch.setattr(
        "app.api.chat_mcp._resolve_active_mcp_servers",
        lambda d, ids: [{"id": i, "name": i} for i in ids],
        raising=False,
    )
    out = discover_mcp_servers(db, explicit_ids=["a", "b", "c", "d"], limit=2, claw="web")
    assert len(out) == 2


# =====================================================================
# 7. build_mcp_tool_defs: 命名 + 异常降级
# =====================================================================

def test_build_mcp_tool_defs_naming():
    """验证命名规则 mcp__{server}__{tool}__{idx} 严格一致"""
    # 旁路 list_mcp_tools 直接构造 servers
    async def fake_list(srv):
        return [{"name": "list_things", "description": "List things", "inputSchema": {"type": "object"}}]
    import app.mcp_client
    orig = app.mcp_client.list_mcp_tools
    app.mcp_client.list_mcp_tools = fake_list
    try:
        defs, tool_map = asyncio.run(build_mcp_tool_defs(
            [{"id": "s1", "name": "github"}, {"id": "s2", "name": "fs"}],
            idx_start=0,
        ))
    finally:
        app.mcp_client.list_mcp_tools = orig
    assert len(defs) == 2
    assert defs[0]["name"] == "mcp__github__list_things__0"
    assert defs[1]["name"] == "mcp__fs__list_things__1"
    assert defs[0]["name"] in tool_map
    assert tool_map[defs[0]["name"]]["server_name"] == "github"


def test_build_mcp_tool_defs_continues_on_error(caplog):
    async def fake_list(srv):
        if srv["id"] == "bad":
            raise RuntimeError("mcp boom")
        return [{"name": "ok", "description": "ok", "inputSchema": {}}]
    import app.mcp_client
    orig = app.mcp_client.list_mcp_tools
    app.mcp_client.list_mcp_tools = fake_list
    try:
        with caplog.at_level(logging.WARNING):
            defs, tool_map = asyncio.run(build_mcp_tool_defs(
                [{"id": "bad", "name": "broken"}, {"id": "ok", "name": "good"}],
            ))
    finally:
        app.mcp_client.list_mcp_tools = orig
    assert len(defs) == 1
    assert defs[0]["name"] == "mcp__good__ok__1"
    assert any("MCP 拉取工具失败" in r.message for r in caplog.records)