"""主动扫描 data/input/{contracts,materials}/：CSV → contracts 表，PDF/Word → materials_content 表。

对 sandbox 用户尤其重要：HR API 拿不到时，把材料直接丢进 input/materials/ 即可被自动识别。

约定：
  - input/contracts/*.csv
      列名与 contracts 表一致（contract_id / teacher_name / unit_name / contract_end / ...）
      也兼容中文别名（合同ID / 教职工姓名 / 单位 / 合同到期日 / 工号 / 岗位 / 合同类型）
  - input/materials/{contract_id}__{filename}.{pdf|docx|doc}
      文件名 __ 之前是 contract_id；无 __ 时回退 parent dir 名
      拷贝到 data/materials/ + insert materials_content(parse_method='pending')
"""

from __future__ import annotations

import csv
import shutil
import sqlite3
from pathlib import Path

from db import repository as repo
from db.migrations import ensure_materials_content_schema
from util.logging_setup import get_skill_logger
from util.runtime_paths import (
    get_data_dir,
    get_input_contracts_dir,
    get_input_materials_dir,
)

logger = get_skill_logger()

MATERIAL_EXTS = {".pdf", ".docx", ".doc"}


def _derive_contract_id_from_filename(mat_path: Path) -> str:
    """从文件名推导 contract_id。约定：{contract_id}__{filename}.{ext}。"""
    parts = mat_path.stem.split("__", 1)
    if len(parts) == 2 and parts[0]:
        return parts[0]
    # 兜底：parent dir 名
    return mat_path.parent.name or "UNKNOWN"


def import_input_dir(conn: sqlite3.Connection) -> dict:
    """扫描 input 目录 → 入库。返回统计 dict。

    Returns:
        {
            "contracts_added": int,
            "materials_added": int,
            "files_scanned": int,
            "errors": [str, ...],
        }
    """
    ensure_materials_content_schema(conn)

    contracts_dir = get_input_contracts_dir()
    materials_dir = get_input_materials_dir()

    contracts_added = 0
    materials_added = 0
    files_scanned = 0
    errors: list[str] = []

    # 1. CSV → contracts（contract_id 重复 → upsert 覆盖）
    for csv_path in sorted(contracts_dir.glob("*.csv")):
        files_scanned += 1
        try:
            with open(csv_path, "r", encoding="utf-8", newline="") as f:
                reader = csv.DictReader(f)
                for row in reader:
                    if not row.get("contract_id") and not row.get("合同ID"):
                        errors.append(f"{csv_path.name}: row 缺 contract_id 跳过")
                        continue
                    repo.upsert_contract_from_csv_row(conn, row)
                    contracts_added += 1
        except Exception as e:
            errors.append(f"{csv_path.name}: {e}")
            logger.warning("importer: CSV 解析失败 %s: %s", csv_path, e)

    # 2. PDF/Word → materials_content（parse_method='pending'），文件拷贝到 data/materials/
    materials_target_dir = get_data_dir() / "materials"
    materials_target_dir.mkdir(parents=True, exist_ok=True)
    for mat_path in sorted(materials_dir.iterdir()):
        if not mat_path.is_file() or mat_path.suffix.lower() not in MATERIAL_EXTS:
            continue
        files_scanned += 1
        try:
            contract_id = _derive_contract_id_from_filename(mat_path)
            target = materials_target_dir / mat_path.name
            if not target.exists():
                shutil.copy2(mat_path, target)
            repo.insert_material(
                conn, contract_id, mat_path.name, str(target),
                None, "pending",
            )
            materials_added += 1
            logger.info(
                "importer: 入库 %s → contract_id=%s", mat_path.name, contract_id,
            )
        except Exception as e:
            errors.append(f"{mat_path.name}: {e}")
            logger.warning("importer: 材料导入失败 %s: %s", mat_path, e)

    conn.commit()
    return {
        "contracts_added": contracts_added,
        "materials_added": materials_added,
        "files_scanned": files_scanned,
        "errors": errors,
    }