# -*- coding: utf-8 -*-
"""统一配置加载器。

加载优先级（高 -> 低）：
    1. 进程环境变量
    2. config/.env （若存在，仅本地开发用）
    3. config/*.yaml 默认值

YAML 中可使用 ${VAR:default} 占位符引用环境变量，未设置时取 default。

Phase 1 目标：消除硬编码 IP/密码/端口，运行时业务路径全部经此模块读取配置。
"""
from __future__ import absolute_import

import os
import re
import logging

try:
    import yaml
except ImportError:  # pragma: no cover - 依赖缺失时给出明确错误
    raise ImportError("PyYAML is required: pip install pyyaml")

__all__ = ["get_config", "get_settings", "get_redis_config", "get_db_config", "get_models_config"]

_CONFIG_DIR = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "config")
_CACHE = {}

_PLACEHOLDER_RE = re.compile(r"\$\{([A-Z0-9_]+)(?::([^}]*))?\}")


def _load_env_file():
    """读取 config/.env，把键值写入 os.environ（已存在的环境变量优先）。"""
    env_path = os.path.join(_CONFIG_DIR, ".env")
    if not os.path.exists(env_path):
        return
    with open(env_path, "r", encoding="utf-8") as f:
        for raw in f:
            line = raw.strip()
            if not line or line.startswith("#") or "=" not in line:
                continue
            key, _, value = line.partition("=")
            key = key.strip()
            value = value.strip().strip('"').strip("'")
            if key and key not in os.environ:
                os.environ[key] = value


def _expand_placeholders(value):
    """递归展开 ${VAR:default} 占位符。"""
    if isinstance(value, dict):
        return {k: _expand_placeholders(v) for k, v in value.items()}
    if isinstance(value, list):
        return [_expand_placeholders(v) for v in value]
    if isinstance(value, str):
        def _sub(m):
            var, default = m.group(1), m.group(2) or ""
            return os.environ.get(var, default)
        # 同一字符串内可能有多个占位符，循环到稳定
        prev = None
        cur = value
        while prev != cur:
            prev = cur
            cur = _PLACEHOLDER_RE.sub(_sub, cur)
        return cur
    return value


def _read_yaml(name):
    path = os.path.join(_CONFIG_DIR, name)
    if not os.path.exists(path):
        return {}
    with open(path, "r", encoding="utf-8") as f:
        data = yaml.safe_load(f) or {}
    return _expand_placeholders(data)


def get_config(name):
    """读取 config/<name>.yaml，带缓存。"""
    if name not in _CACHE:
        _load_env_file()
        _CACHE[name] = _read_yaml("%s.yaml" % name)
    return _CACHE[name]


def get_settings():
    return get_config("settings")


def get_redis_config():
    return get_config("redis")


def get_db_config():
    return get_config("db")


def get_models_config():
    return get_config("models")


def reload():
    """清空缓存，用于测试或热加载。"""
    _CACHE.clear()


# ===== 常用便捷读取 =====

def server_port(name="web"):
    """获取服务端口。优先环境变量 BIDDINGKG_WEB_PORT / BIDDINGKG_SINGLE_PORT。"""
    env_key = "BIDDINGKG_%s_PORT" % name.upper()
    if env_key in os.environ:
        return int(os.environ[env_key])
    settings = get_settings()
    port_field = "web_port" if name == "web" else "single_port"
    return int(settings.get("server", {}).get(port_field, 15014))


def model_input_shape(name):
    """获取模型输入 shape，name ∈ role/money/person。"""
    settings = get_settings()
    shapes = settings.get("model_input_shape", {})
    if name not in shapes:
        raise KeyError("model_input_shape.%s not configured" % name)
    return tuple(shapes[name])


def pai_eas_settings():
    """返回 (use_pai_eas, api_url, use_api)。"""
    env_flag = os.environ.get("BIDDINGKG_USE_PAI_EAS", "").lower()
    if env_flag in ("1", "true", "yes", "on"):
        use_pai = True
    elif env_flag in ("0", "false", "no", "off"):
        use_pai = False
    else:
        use_pai = bool(get_settings().get("pai_eas", {}).get("enabled", False))
    pai_cfg = get_settings().get("pai_eas", {})
    return use_pai, pai_cfg.get("api_url", ""), bool(pai_cfg.get("use_api", False))


def internal_api_url(key="article_extract_url"):
    """获取内部 API URL。优先环境变量。"""
    settings = get_settings()
    return settings.get("internal_api", {}).get(key, "")


def logging_settings():
    """返回日志配置 dict：level/format/date_format/file。"""
    return get_settings().get("logging", {})


def redis_main_config():
    """主 Redis 连接参数（host/port/db/password）。"""
    cfg = get_redis_config()
    main = dict(cfg.get("main", {}))
    env_host = os.environ.get("BIDDINGKG_REDIS_HOST")
    env_pass = os.environ.get("BIDDINGKG_REDIS_PASS")
    if env_host:
        main["host"] = env_host
    if env_pass is not None:
        main["password"] = env_pass
    return main


def redis_queue_names():
    """队列名 dict：content/preprocess/preprocess_legacy_alias/error/timeout。"""
    return dict(get_redis_config().get("queues", {}))


def redis_consumer_params():
    """消费者参数：batch_size/server_sleep/client_sleep/timeout。"""
    return dict(get_redis_config().get("consumer", {}))


def pg_db_config(dbname="BiddingKG"):
    """返回指定库的 PG 连接参数 dict。"""
    cfg = get_db_config()
    default = dict(cfg.get("default", {}))
    dbs = cfg.get("databases", {})
    if dbname not in dbs:
        raise KeyError("db.databases.%s not configured" % dbname)
    merged = dict(default)
    merged.update(dbs[dbname])
    env_host = os.environ.get("BIDDINGKG_PG_HOST")
    env_user = os.environ.get("BIDDINGKG_PG_USER")
    env_pass = os.environ.get("BIDDINGKG_PG_PASS")
    if env_host:
        merged["host"] = env_host
    if env_user:
        merged["user"] = env_user
    if env_pass is not None:
        merged["password"] = env_pass
    return merged


def mongo_uri():
    """返回 MongoDB URI，优先环境变量 BIDDINGKG_MONGO_URI。"""
    return os.environ.get("BIDDINGKG_MONGO_URI", "")