"""
设计相关路由
提供设计生成、查询、删除、下载接口
"""
import os
from fastapi import APIRouter, Depends, HTTPException, status, Query
from fastapi.responses import FileResponse, RedirectResponse
from sqlalchemy.orm import Session

from ..database import get_db
from ..models import User, Design
from ..schemas import DesignCreate, DesignResponse, DesignListResponse, DesignImageResponse
from ..utils.deps import get_current_user
from ..services import design_service

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


def design_to_response(design: Design) -> DesignResponse:
    """将 Design 模型转换为响应格式"""
    # 构建多视角图片列表
    images = []
    if hasattr(design, 'images') and design.images:
        images = [
            DesignImageResponse(
                id=img.id,
                view_name=img.view_name,
                image_url=img.image_url,
                model_used=img.model_used,
                prompt_used=img.prompt_used,
                sort_order=img.sort_order,
            )
            for img in design.images
        ]

    return DesignResponse(
        id=design.id,
        user_id=design.user_id,
        category={
            "id": design.category.id,
            "name": design.category.name,
            "icon": design.category.icon,
            "sort_order": design.category.sort_order,
            "flow_type": design.category.flow_type
        },
        sub_type={
            "id": design.sub_type.id,
            "category_id": design.sub_type.category_id,
            "name": design.sub_type.name,
            "description": design.sub_type.description,
            "preview_image": design.sub_type.preview_image,
            "sort_order": design.sub_type.sort_order
        } if design.sub_type else None,
        color={
            "id": design.color.id,
            "category_id": design.color.category_id,
            "name": design.color.name,
            "hex_code": design.color.hex_code,
            "sort_order": design.color.sort_order
        } if design.color else None,
        prompt=design.prompt,
        carving_technique=design.carving_technique,
        design_style=design.design_style,
        motif=design.motif,
        size_spec=design.size_spec,
        surface_finish=design.surface_finish,
        usage_scene=design.usage_scene,
        image_url=design.image_url,
        images=images,
        status=design.status,
        created_at=design.created_at,
        updated_at=design.updated_at
    )


@router.post("/generate", response_model=DesignResponse)
async def generate_design(
    design_data: DesignCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """
    提交设计生成请求（异步，支持 AI 多视角生图）
    需要认证
    """
    try:
        design = await design_service.create_design_async(
            db=db,
            user_id=current_user.id,
            design_data=design_data
        )
        return design_to_response(design)
    except ValueError as e:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(e)
        )


@router.get("", response_model=DesignListResponse)
def get_designs(
    page: int = Query(1, ge=1, description="页码"),
    page_size: int = Query(20, ge=1, le=100, description="每页数量"),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """
    获取当前用户的设计历史列表（分页）
    需要认证
    """
    designs, total = design_service.get_user_designs(
        db=db,
        user_id=current_user.id,
        page=page,
        page_size=page_size
    )
    
    return DesignListResponse(
        items=[design_to_response(d) for d in designs],
        total=total,
        page=page,
        page_size=page_size
    )


@router.get("/{design_id}", response_model=DesignResponse)
def get_design(
    design_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """
    获取设计详情
    只能查看自己的设计，非本人设计返回 404
    """
    design = design_service.get_design_by_id(
        db=db,
        design_id=design_id,
        user_id=current_user.id
    )
    
    if not design:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="设计不存在"
        )
    
    return design_to_response(design)


@router.delete("/{design_id}")
def delete_design(
    design_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """
    删除设计
    只能删除自己的设计，非本人设计返回 404
    """
    success = design_service.delete_design(
        db=db,
        design_id=design_id,
        user_id=current_user.id
    )
    
    if not success:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="设计不存在"
        )
    
    return {"message": "删除成功"}


@router.get("/{design_id}/download")
def download_design(
    design_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """
    下载设计图
    只能下载自己的设计，非本人设计返回 404
    支持远程 URL（重定向）和本地文件（兼容历史数据）
    """
    design = design_service.get_design_by_id(
        db=db,
        design_id=design_id,
        user_id=current_user.id
    )
    
    if not design:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="设计不存在"
        )
    
    if not design.image_url:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="设计图片不存在"
        )
    
    # 远程 URL 直接重定向
    if design.image_url.startswith("http"):
        return RedirectResponse(url=design.image_url)
    
    # 本地文件（兼容历史数据）
    file_path = design.image_url.lstrip("/")
    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="设计图片文件不存在"
        )
    
    return FileResponse(
        path=file_path,
        filename=f"design_{design_id}.png",
        media_type="image/png"
    )