#!/usr/bin/env python3
"""校验运输计划模块 Pydantic Schema 是否具备 camelCase alias（防 422）。

用法（在 backend 目录）:
    ./venv/bin/python scripts/check_pl_json_aliases.py
"""
from __future__ import annotations

import ast
import re
import sys
from pathlib import Path

SCHEMA_FILES = [
    "app/schemas/pl/base_data.py",
    "app/schemas/pl/plan.py",
    "app/schemas/pl/transport.py",
    "app/schemas/pl/freight.py",
    "app/schemas/pl/inventory.py",
]

# 单段 snake_case 公共字段可不加 alias（JSON 与 Python 同名）
SINGLE_WORD_OK = {
    "id",
    "q",
    "page",
    "status",
    "remark",
    "model",
    "unit",
    "action",
    "comment",
    "total",
    "list",
    "products",
    "transports",
    "period",
    "qty",
    "amount",
}


def snake_to_camel(name: str) -> str:
    parts = name.split("_")
    return parts[0] + "".join(p.capitalize() for p in parts[1:])


def iter_field_assignments(tree: ast.AST):
    for node in ast.walk(tree):
        if not isinstance(node, ast.ClassDef):
            continue
        for stmt in node.body:
            if isinstance(stmt, ast.AnnAssign) and isinstance(stmt.target, ast.Name):
                yield node.name, stmt.target.id, stmt.value
            elif isinstance(stmt, ast.Assign):
                for target in stmt.targets:
                    if isinstance(target, ast.Name):
                        yield node.name, target.id, stmt.value


def field_has_alias(value: ast.expr | None) -> bool:
    if value is None:
        return False
    if isinstance(value, ast.Call):
        for kw in value.keywords:
            if kw.arg == "alias":
                return True
    return False


def main() -> int:
    root = Path(__file__).resolve().parents[1]
    errors: list[str] = []

    for rel in SCHEMA_FILES:
        path = root / rel
        if not path.exists():
            errors.append(f"缺少文件: {rel}")
            continue
        source = path.read_text(encoding="utf-8")
        tree = ast.parse(source, filename=str(path))
        for class_name, field_name, value in iter_field_assignments(tree):
            if "_" not in field_name:
                continue
            if field_name in SINGLE_WORD_OK or field_name == "model_config":
                continue
            if not field_has_alias(value):
                expected = snake_to_camel(field_name)
                errors.append(
                    f"{rel}: {class_name}.{field_name} 缺少 Field(alias=\"{expected}\")"
                )

    if errors:
        print("PL JSON alias 校验失败（可能导致前端 camelCase 请求 422）:\n")
        for e in errors:
            print(f"  - {e}")
        print("\n规范: openspec/changes/transport-plan-management/specs/pl-api-json/spec.md")
        return 1

    print("PL JSON alias 校验通过。")
    return 0


if __name__ == "__main__":
    sys.exit(main())