from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from sqlalchemy import or_, and_
from app.core.db import get_db
from app.core.deps import get_current_user
from app.models import User, PromptTemplate, UserPromptConfig
from app.schemas.prompt import (
    PromptTemplateOut, 
    PromptTemplateCreate, 
    PromptTemplateUpdate,
    UserPromptConfigUpdate
)
from typing import List, Optional

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

def is_admin(user: User):
    role_codes = [ur.role.role_code for ur in user.roles] if hasattr(user, 'roles') else []
    return "admin" in role_codes or "superuser" in role_codes

@router.get("", response_model=List[PromptTemplateOut])
def list_prompts(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
    keyword: Optional[str] = Query(None),
    category: Optional[str] = Query(None),
    scope: str = Query("personal", description="system or personal")
):
    """
    根据 scope 返回不同范围的模板
    """
    filters = []
    
    if scope == "system":
        # 系统管理入口：仅展示系统级模板
        if not is_admin(current_user):
            raise HTTPException(status_code=403, detail="无权访问系统模板库")
        filters.append(PromptTemplate.is_system == True)
    else:
        # 个人管理入口：展示已发布的系统模板 + 自己的个人模板
        accessibility_filter = or_(
            and_(PromptTemplate.is_system == True, PromptTemplate.status == 1),
            PromptTemplate.user_id == current_user.user_id
        )
        filters.append(accessibility_filter)
    
    if keyword:
        filters.append(or_(
            PromptTemplate.name.contains(keyword),
            PromptTemplate.description.contains(keyword),
            PromptTemplate.content.contains(keyword)
        ))
    if category:
        filters.append(PromptTemplate.category == category)

    query = db.query(
        PromptTemplate,
        UserPromptConfig.is_active,
        UserPromptConfig.user_sort_order
    ).outerjoin(
        UserPromptConfig,
        (UserPromptConfig.template_id == PromptTemplate.id) & (UserPromptConfig.user_id == current_user.user_id)
    ).filter(and_(*filters))

    results = query.all()
    
    out = []
    for template, is_active, user_sort_order in results:
        item = PromptTemplateOut.model_validate(template)
        item.is_active = is_active if is_active is not None else True
        item.user_sort_order = user_sort_order if user_sort_order is not None else template.sort_order
        out.append(item)
    
    # 排序：系统管理入口按全局排序，个人入口按个人排序
    if scope == "system":
        out.sort(key=lambda x: x.sort_order)
    else:
        out.sort(key=lambda x: (x.user_sort_order, x.sort_order))
    return out

@router.post("", response_model=PromptTemplateOut)
def create_prompt(
    payload: PromptTemplateCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    user_is_admin = is_admin(current_user)
    item_data = payload.model_dump()
    
    # 如果显式指定为系统模板，必须是管理员
    if item_data.get("is_system"):
        if not user_is_admin:
            raise HTTPException(status_code=403, detail="仅管理员可创建系统模板")
        item_data["user_id"] = None
    else:
        item_data["user_id"] = current_user.user_id
        item_data["is_system"] = False
    
    item = PromptTemplate(**item_data)
    db.add(item)
    db.commit()
    db.refresh(item)
    
    res = PromptTemplateOut.model_validate(item)
    res.is_active = True
    res.user_sort_order = item.sort_order
    return res

@router.put("/{prompt_id}", response_model=PromptTemplateOut)
def update_prompt(
    prompt_id: int,
    payload: PromptTemplateUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    item = db.query(PromptTemplate).filter(PromptTemplate.id == prompt_id).first()
    if not item:
        raise HTTPException(status_code=404, detail="模板不存在")
    
    user_is_admin = is_admin(current_user)
    
    # 系统模板仅管理员可改
    if item.is_system and not user_is_admin:
        raise HTTPException(status_code=403, detail="无权修改系统模板")
    # 个人模板仅主人可改
    if not item.is_system and item.user_id != current_user.user_id:
        raise HTTPException(status_code=403, detail="无权修改他人模板")

    update_data = payload.model_dump(exclude_unset=True)
    
    if "is_system" in update_data:
        if user_is_admin:
            new_val = update_data.pop("is_system")
            item.is_system = new_val
            item.user_id = None if new_val else current_user.user_id
        else:
            update_data.pop("is_system")

    for k, v in update_data.items():
        setattr(item, k, v)
    
    db.commit()
    db.refresh(item)
    return PromptTemplateOut.model_validate(item)

@router.delete("/{prompt_id}")
def delete_prompt(
    prompt_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    item = db.query(PromptTemplate).filter(PromptTemplate.id == prompt_id).first()
    if not item:
        raise HTTPException(status_code=404, detail="模板不存在")
    
    user_is_admin = is_admin(current_user)
    if item.is_system and not user_is_admin:
        raise HTTPException(status_code=403, detail="无权删除系统模板")
    if not item.is_system and item.user_id != current_user.user_id:
        raise HTTPException(status_code=403, detail="无权删除他人模板")

    db.delete(item)
    db.commit()
    return {"status": "ok"}

@router.patch("/{prompt_id}/config")
def update_user_config(
    prompt_id: int,
    payload: UserPromptConfigUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    config = db.query(UserPromptConfig).filter(
        UserPromptConfig.template_id == prompt_id,
        UserPromptConfig.user_id == current_user.user_id
    ).first()

    if not config:
        template = db.query(PromptTemplate).filter(PromptTemplate.id == prompt_id).first()
        config = UserPromptConfig(
            user_id=current_user.user_id,
            template_id=prompt_id,
            is_active=True,
            user_sort_order=template.sort_order if template else 0
        )
        db.add(config)

    for k, v in payload.model_dump(exclude_unset=True).items():
        setattr(config, k, v)
    
    db.commit()
    return {"status": "ok"}