from fastapi import APIRouter, Depends, HTTPException, Request
from sqlalchemy.orm import Session
from typing import List
import bcrypt

from typing import Optional
from pydantic import BaseModel
from ..database import get_db
from ..models import User, Topic, SystemConfig
from ..schemas import UserCreate, UserUpdate, UserResponse
from ..core.audit_logger import audit_log
from .auth import get_current_admin, org_filter
import json

router = APIRouter(prefix="/api/admin", tags=["admin"])

@router.get("/users", response_model=List[UserResponse])
def list_users(
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    """获取用户列表（管理员）"""
    q = db.query(User)
    of = org_filter(admin_user, User)
    if of is not True:
        q = q.filter(of)
    users = q.all()
    return [UserResponse.from_orm(u) for u in users]

@router.post("/users", response_model=UserResponse)
def create_user(
    user_data: UserCreate,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    """创建新用户（管理员）"""
    # 检查用户名是否已存在
    existing = db.query(User).filter(User.username == user_data.username).first()
    if existing:
        raise HTTPException(status_code=400, detail="用户名已存在")

    # bcrypt 密码哈希
    hashed_password = bcrypt.hashpw(user_data.password.encode('utf-8'), bcrypt.gensalt()).decode('utf-8')

    user = User(
        username=user_data.username,
        password_hash=hashed_password,
        role=user_data.role or "user",
        org_id=user_data.org_id or admin_user.org_id or "default"
    )
    db.add(user)
    db.commit()
    db.refresh(user)

    audit_log(
        action="create_user",
        user=admin_user,
        resource_type="user",
        resource_id=str(user.id),
        details={"username": user.username, "role": user.role},
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return UserResponse.from_orm(user)

@router.put("/users/{user_id}", response_model=UserResponse)
def update_user(
    user_id: int,
    user_update: UserUpdate,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    """更新用户（管理员）"""
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")
    if admin_user.role != "admin" and user.org_id != admin_user.org_id:
        raise HTTPException(status_code=404, detail="用户不存在")

    changes = {}
    if user_update.username is not None:
        if user_update.username != user.username:
            existing = db.query(User).filter(User.username == user_update.username).first()
            if existing:
                raise HTTPException(status_code=400, detail="用户名已存在")
        changes["username"] = {"old": user.username, "new": user_update.username}
        user.username = user_update.username

    if user_update.password is not None:
        changes["password"] = {"changed": True}
        user.password_hash = bcrypt.hashpw(user_update.password.encode('utf-8'), bcrypt.gensalt()).decode('utf-8')

    if user_update.role is not None and user_update.role != user.role:
        changes["role"] = {"old": user.role, "new": user_update.role}
        user.role = user_update.role

    db.commit()
    db.refresh(user)

    audit_log(
        action="update_user",
        user=admin_user,
        resource_type="user",
        resource_id=str(user.id),
        details=changes,
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return UserResponse.from_orm(user)

@router.delete("/users/{user_id}")
def delete_user(
    user_id: int,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    """删除用户（管理员）"""
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")
    if admin_user.role != "admin" and user.org_id != admin_user.org_id:
        raise HTTPException(status_code=404, detail="用户不存在")

    if user.role == "admin":
        raise HTTPException(status_code=400, detail="不能删除管理员用户")

    username = user.username  # 保存用于日志
    db.delete(user)
    db.commit()

    audit_log(
        action="delete_user",
        user=admin_user,
        resource_type="user",
        resource_id=str(user_id),
        details={"username": username},
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return {"message": "删除成功"}

# ---------- Org Management ----------

class OrgCreate(BaseModel):
    org_id: str
    name: str
    description: Optional[str] = None

class OrgUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None

@router.get("/orgs")
def list_orgs(
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    distinct_orgs = db.query(User.org_id).distinct().all()
    result = []
    for (org_id,) in distinct_orgs:
        if not org_id:
            continue
        cfg = db.query(SystemConfig).filter(SystemConfig.key == f"org:{org_id}").first()
        meta = json.loads(cfg.value) if cfg and cfg.value else {}
        user_count = db.query(User).filter(User.org_id == org_id).count()
        topic_count = db.query(Topic).filter(Topic.org_id == org_id).count()
        result.append({
            "org_id": org_id,
            "name": meta.get("name", org_id),
            "description": meta.get("description", ""),
            "user_count": user_count,
            "topic_count": topic_count,
            "is_default": org_id == "default"
        })
    return result

@router.post("/orgs")
def create_org(
    data: OrgCreate,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    existing = db.query(SystemConfig).filter(SystemConfig.key == f"org:{data.org_id}").first()
    if existing:
        raise HTTPException(status_code=400, detail="组织已存在")
    cfg = SystemConfig(
        key=f"org:{data.org_id}",
        value=json.dumps({"name": data.name, "description": data.description or ""}, ensure_ascii=False),
        description=f"Organization: {data.org_id}"
    )
    db.add(cfg)
    db.commit()
    audit_log(
        action="create_org", user=admin_user,
        resource_type="org", resource_id=data.org_id,
        details=data.model_dump(),
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return {"org_id": data.org_id, "name": data.name, "description": data.description or ""}

@router.put("/orgs/{org_id}")
def update_org(
    org_id: str,
    data: OrgUpdate,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    cfg = db.query(SystemConfig).filter(SystemConfig.key == f"org:{org_id}").first()
    if not cfg:
        raise HTTPException(status_code=404, detail="组织不存在")
    meta = json.loads(cfg.value) if cfg.value else {}
    if data.name is not None:
        meta["name"] = data.name
    if data.description is not None:
        meta["description"] = data.description
    cfg.value = json.dumps(meta, ensure_ascii=False)
    db.commit()
    audit_log(
        action="update_org", user=admin_user,
        resource_type="org", resource_id=org_id,
        details=data.model_dump(exclude_unset=True),
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return {"org_id": org_id, **meta}

@router.delete("/orgs/{org_id}")
def delete_org(
    org_id: str,
    request: Request,
    db: Session = Depends(get_db),
    admin_user: User = Depends(get_current_admin)
):
    if org_id == "default":
        raise HTTPException(status_code=400, detail="不能删除默认组织")
    cfg = db.query(SystemConfig).filter(SystemConfig.key == f"org:{org_id}").first()
    if cfg:
        db.delete(cfg)
    db.commit()
    audit_log(
        action="delete_org", user=admin_user,
        resource_type="org", resource_id=org_id,
        ip_address=request.client.host if request.client else None,
        user_agent=request.headers.get("user-agent", ""),
        db=db
    )
    return {"message": "删除成功"}