from datetime import datetime

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.models import JobTitle, Permission, Role, User


DEFAULT_ROLES = {
    "employee": "普通员工",
    "admin": "业务管理员",
    "system_admin": "系统管理员",
}

# 业务职级预设。用户在个人资料里选的头衔。跟制度里的分组名不一定字面一致，
# 字面不一致时必须在 JOB_TITLE_GROUP_ALIASES 里加映射，否则 chat.py 拿 job_title
# 做子串匹配会全部落空，LLM 反问澄清。
DEFAULT_JOB_TITLES: list[str] = [
    "董事长",
    "总经理",
    "领导班子副职",
    "总助级",
    "中层干部正职及相当职级人员",
    "中层干部副职及相当职级人员",
    "教授级高工及相当职称人员",
    "普通员工",
]

# 业务职级 -> 制度里"按职级分组"分组名的关键词列表。
# 制度里分组常写作"总院领导班子正职"这种复合词，用户选的却是"董事长"这种具体头衔，
# chat.py 会拿这里的关键词代替原 job_title 做子串规则（"包含任一关键词"）。
# 未在此表的 job_title 回退成拿它本身做子串匹配（老行为）。
# 加/改字典项时，同步维护此表；关键词要够特异，避免误命中相邻分组
# （例如"正职"太泛，会同时命中"领导班子正职"和"中层正职"）。
JOB_TITLE_GROUP_ALIASES: dict[str, list[str]] = {
    "董事长": ["领导班子正职"],
    "总经理": ["领导班子正职"],
    "领导班子副职": ["领导班子副职"],
    "总助级": ["总助级"],
    "中层干部正职及相当职级人员": ["中层正职", "中层干部正职"],
    "中层干部副职及相当职级人员": ["中层副职", "中层干部副职"],
    "教授级高工及相当职称人员": ["教授级高工"],
    "普通员工": ["普通员工"],
}

# 页面级权限：code -> (显示名, 模块)
DEFAULT_PAGE_PERMISSIONS: dict[str, tuple[str, str]] = {
    "page.chat": ("智能问答", "page"),
    "page.documents": ("知识文档", "page"),
    "page.audit": ("问答审计", "page"),
    "page.analytics": ("数据分析", "page"),
    "page.settings": ("系统设置", "page"),
}

# 角色 -> 页面权限 code 列表
DEFAULT_ROLE_PAGE_PERMISSIONS: dict[str, list[str]] = {
    "employee": ["page.chat"],
    "admin": ["page.chat", "page.documents", "page.audit", "page.analytics"],
    "system_admin": list(DEFAULT_PAGE_PERMISSIONS.keys()),
}


def _ensure_page_permissions(db: Session) -> dict[str, Permission]:
    existing = {p.code: p for p in db.scalars(select(Permission)).all()}
    for code, (name, module) in DEFAULT_PAGE_PERMISSIONS.items():
        if code not in existing:
            p = Permission(code=code, name=name, module=module)
            db.add(p)
            existing[code] = p
    db.flush()
    return existing


def ensure_roles(db: Session) -> None:
    perms = _ensure_page_permissions(db)
    existing_roles = {role.code: role for role in db.scalars(select(Role)).all()}
    for code, name in DEFAULT_ROLES.items():
        role = existing_roles.get(code)
        if role is None:
            role = Role(code=code, name=name)
            db.add(role)
            existing_roles[code] = role
    db.flush()
    # 只补齐默认页面权限，不覆盖管理员后续在后台自定义的权限
    for code, page_codes in DEFAULT_ROLE_PAGE_PERMISSIONS.items():
        role = existing_roles.get(code)
        if role is None:
            continue
        current = {p.code for p in role.permissions}
        for page_code in page_codes:
            if page_code not in current and page_code in perms:
                role.permissions.append(perms[page_code])
    db.flush()


def ensure_job_titles(db: Session) -> None:
    """把 DEFAULT_JOB_TITLES 里没入库的补进去；已存在的保留，不覆盖启用状态/顺序。"""
    existing = {jt.name for jt in db.scalars(select(JobTitle)).all()}
    for idx, name in enumerate(DEFAULT_JOB_TITLES):
        if name in existing:
            continue
        db.add(JobTitle(name=name, sort_order=idx, is_active=True))
    db.flush()


def ensure_default_admin(db: Session) -> User:
    ensure_roles(db)
    ensure_job_titles(db)
    user = db.scalar(select(User).where(User.phone == "13800000000"))
    if user:
        return user
    role = db.scalar(select(Role).where(Role.code == "system_admin"))
    user = User(phone="13800000000", name="系统管理员", is_superuser=True)
    if role:
        user.roles.append(role)
    db.add(user)
    db.flush()
    return user


def get_or_create_login_user(db: Session, phone: str) -> User:
    ensure_roles(db)
    user = db.scalar(select(User).where(User.phone == phone))
    if user:
        user.last_login_at = datetime.utcnow()
        return user
    role = db.scalar(select(Role).where(Role.code == "employee"))
    user = User(phone=phone, name=f"用户{phone[-4:]}", status="active", last_login_at=datetime.utcnow())
    if role:
        user.roles.append(role)
    db.add(user)
    db.flush()
    return user


def apply_roles(db: Session, user: User, role_codes: list[str]) -> None:
    ensure_roles(db)
    roles = db.scalars(select(Role).where(Role.code.in_(role_codes))).all() if role_codes else []
    user.roles = list(roles)