"""目录扫描模块。

扫描项目根目录下按约定的子目录结构，识别 ABAP 开发对象。
"""
from __future__ import annotations

import logging
import os
from dataclasses import dataclass

logger = logging.getLogger("sapcli.scanner")

DIRECTORY_TYPE_MAP: dict[str, str] = {
    "reports": "report",
    "classes": "class",
    "interfaces": "interface",
    "functions": "function",
    "domains": "domain",
    "dataelements": "dataelement",
    "tables": "table",
    "structures": "structure",
    "tabletypes": "tabletype",
    "includes": "include",
    "cdsviews": "cdsview",
    "messageclasses": "messageclass",
    "views": "view",
    "searchhelps": "searchhelp",
    "lockobjects": "lockobject",
}

FUNCTIONS_DIR = "functions"


@dataclass
class ScannedObject:
    """扫描到的对象。"""

    name: str   # 大写对象名，function 类型含 / (GROUP/FUNC)
    type: str   # 对象类型
    file: str   # 相对于项目根目录的路径


def scan_project(project_path: str) -> list[ScannedObject]:
    """扫描项目目录，返回识别到的所有对象列表。

    遍历已知目录名，每个目录下找 .abap 文件。
    functions/ 特殊处理：子目录 = 函数组名。
    """
    results: list[ScannedObject] = []

    for dir_name, obj_type in DIRECTORY_TYPE_MAP.items():
        dir_path = os.path.join(project_path, dir_name)
        if not os.path.isdir(dir_path):
            logger.debug("目录不存在，跳过: %s", dir_path)
            continue

        if dir_name == FUNCTIONS_DIR:
            _scan_functions(dir_path, results)
        else:
            _scan_flat_directory(dir_path, dir_name, obj_type, results)

    logger.info("扫描完成: %d 个对象", len(results))
    return results


def _scan_flat_directory(
    dir_path: str,
    dir_name: str,
    obj_type: str,
    results: list[ScannedObject],
) -> None:
    """扫描普通目录（一对一：文件名 = 对象名）。"""
    for filename in sorted(os.listdir(dir_path)):
        if not filename.endswith(".abap"):
            continue
        # 隐藏文件跳过
        if filename.startswith("."):
            continue

        obj_name = filename[:-5].upper()  # 去掉 .abap，转大写
        rel_path = f"{dir_name}/{filename}"

        results.append(ScannedObject(
            name=obj_name,
            type=obj_type,
            file=rel_path,
        ))
        logger.debug("扫描到: %s (%s) → %s", obj_name, obj_type, rel_path)


def _scan_functions(dir_path: str, results: list[ScannedObject]) -> None:
    """扫描 functions/ 目录（特殊处理：子目录 = 函数组名）。

    目录结构: functions/{组名小写}/{模块名小写}.abap
    对象名: {组名大写}/{模块名大写}
    """
    for group_dir_name in sorted(os.listdir(dir_path)):
        group_dir = os.path.join(dir_path, group_dir_name)
        if not os.path.isdir(group_dir):
            continue
        if group_dir_name.startswith("."):
            continue

        group_name = group_dir_name.upper()

        for filename in sorted(os.listdir(group_dir)):
            if not filename.endswith(".abap"):
                continue
            if filename.startswith("."):
                continue

            func_name = filename[:-5].upper()
            obj_name = f"{group_name}/{func_name}"
            rel_path = f"{FUNCTIONS_DIR}/{group_dir_name}/{filename}"

            results.append(ScannedObject(
                name=obj_name,
                type="function",
                file=rel_path,
            ))
            logger.debug("扫描到: %s (function) → %s", obj_name, rel_path)