import re

from sqlalchemy.orm import Session

from app.models import Learner, LearnerNameHistory


class LearnerIdentityConflict(ValueError):
    pass


def normalize_name(value: str) -> str:
    return " ".join(value.strip().split())


def normalize_phone(value: str) -> str:
    phone = re.sub(r"[\s-]", "", value.strip())
    if phone.startswith("+86"):
        phone = phone[3:]
    elif phone.startswith("0086"):
        phone = phone[4:]
    if not re.fullmatch(r"1\d{10}", phone):
        raise ValueError("手机号格式错误，请填写11位中国大陆手机号")
    return phone


def resolve_learner(
    db: Session,
    name: str,
    phone: str,
    *,
    source: str,
    create_if_missing: bool = True,
) -> tuple[Learner | None, bool]:
    normalized_name = normalize_name(name)
    normalized_phone = normalize_phone(phone)
    if not normalized_name:
        raise ValueError("姓名不能为空")

    learner = db.query(Learner).filter(Learner.phone == normalized_phone, Learner.status != "deleted").first()
    if learner:
        if normalize_name(learner.current_name) != normalized_name:
            raise LearnerIdentityConflict(
                f"手机号 {normalized_phone} 已属于学员“{learner.current_name}”，与本次姓名“{normalized_name}”不一致"
            )
        if learner.status != "active":
            raise LearnerIdentityConflict(f"学员“{normalized_name}”当前已停用，请先在学员管理中启用")
        return learner, False

    if not create_if_missing:
        return None, False

    learner = Learner(phone=normalized_phone, current_name=normalized_name)
    db.add(learner)
    db.flush()
    db.add(LearnerNameHistory(learner_id=learner.id, name=normalized_name, source=source))
    return learner, True