import csv
from typing import List, Optional
from pathlib import Path
from datetime import date
from src.dal.abstract_dal import IStudentDAL
from src.models.student import Student


class CSVStudentDAL(IStudentDAL):
    def __init__(self, file_path: str = "data/students.csv"):
        self.file_path = Path(file_path)
        self.file_path.parent.mkdir(parents=True, exist_ok=True)
        if not self.file_path.exists():
            with open(self.file_path, "w", newline="", encoding="utf-8") as f:
                writer = csv.writer(f)
                writer.writerow([
                    "name", "id_card", "stu_id", "gender",
                    "height", "weight", "enrollment_date",
                    "class_name", "major"
                ])

    def _read_all(self) -> List[Student]:
        students = []
        with open(self.file_path, "r", newline="", encoding="utf-8") as f:
            reader = csv.DictReader(f)
            for row in reader:
                try:
                    student = Student(
                        name=row["name"],
                        id_card=row["id_card"],
                        stu_id=row["stu_id"],
                        gender=bool(int(row["gender"])) if row["gender"] else None,
                        height=int(row["height"]) if row["height"] else None,
                        weight=float(row["weight"]) if row["weight"] else None,
                        enrollment_date=row["enrollment_date"],
                        class_name=row["class_name"],
                        major=row["major"]
                    )
                    students.append(student)
                except (ValueError, KeyError) as e:
                    continue
        return students

    def _write_all(self, students: List[Student]) -> bool:
        try:
            with open(self.file_path, "w", newline="", encoding="utf-8") as f:
                writer = csv.DictWriter(f, fieldnames=[
                    "name", "id_card", "stu_id", "gender",
                    "height", "weight", "enrollment_date",
                    "class_name", "major"
                ])
                writer.writeheader()
                for student in students:
                    writer.writerow(student.to_dict())
            return True
        except Exception:
            return False

    # 实现所有抽象方法...
    # 完整实现会根据上述_reader_all和_write_all方法完成各个接口