# -*- coding: utf-8 -*-
"""环境变量解析"""
import os
import json
from copy import deepcopy

ENV_MAP = {
    "TIMEZONE":               ("app.timezone",),
    "STORE_ID":               ("app.store_id",),
    "SCHEMA_OLTP":            ("app.schema_oltp",),
    "SCHEMA_ETL":             ("app.schema_etl",),
    "PG_DSN":                 ("db.dsn",),
    "PG_HOST":                ("db.host",),
    "PG_PORT":                ("db.port",),
    "PG_NAME":                ("db.name",),
    "PG_USER":                ("db.user",),
    "PG_PASSWORD":            ("db.password",),
    "API_BASE":               ("api.base_url",),
    "API_TOKEN":              ("api.token",),
    "API_TIMEOUT":            ("api.timeout_sec",),
    "API_PAGE_SIZE":          ("api.page_size",),
    "EXPORT_ROOT":            ("io.export_root",),
    "LOG_ROOT":               ("io.log_root",),
    "OVERLAP_SECONDS":        ("run.overlap_seconds",),
    "WINDOW_BUSY_MIN":        ("run.window_minutes.default_busy",),
    "WINDOW_IDLE_MIN":        ("run.window_minutes.default_idle",),
}

def _deep_set(d, dotted_keys, value):
    cur = d
    for k in dotted_keys[:-1]:
        cur = cur.setdefault(k, {})
    cur[dotted_keys[-1]] = value

def _coerce_env(v: str):
    if v is None:
        return None
    s = v.strip()
    if s.lower() in ("true", "false"):
        return s.lower() == "true"
    try:
        if s.isdigit() or (s.startswith("-") and s[1:].isdigit()):
            return int(s)
    except Exception:
        pass
    if (s.startswith("{") and s.endswith("}")) or (s.startswith("[") and s.endswith("]")):
        try:
            return json.loads(s)
        except Exception:
            return s
    return s

def load_env_overrides(defaults: dict) -> dict:
    cfg = deepcopy(defaults)
    for env_key, dotted in ENV_MAP.items():
        val = os.environ.get(env_key)
        if val is None:
            continue
        v2 = _coerce_env(val)
        for path in dotted:
            _deep_set(cfg, path.split("."), v2)
    return cfg