from pathlib import Path

import uvicorn
from fastapi import FastAPI, UploadFile, File, HTTPException
from pymysql.cursors import DictCursor

from Dao.KbDao import KbDao
from Model.KbModel import KbModel, KbFileModel
from Util.MySQLUtil import init_mysql_pool
from contextlib import asynccontextmanager

@asynccontextmanager
async def lifespan(app: FastAPI):
    # 启动时初始化数据库连接池
    app.state.kb_dao = KbDao(await init_mysql_pool())
    yield
    # 关闭时清理资源
    await app.state.kb_dao.mysql_pool.close()

app = FastAPI(lifespan=lifespan)


@app.post("/kb")
async def create_kb(kb: KbModel):
    return await app.state.kb_dao.create_kb(kb)

@app.get("/kb/{kb_id}")
async def read_kb(kb_id: int):
    """获取知识库详情
    Args:
        kb_id: 知识库ID
    Returns:
        返回知识库详细信息
    """
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute("SELECT * FROM t_ai_kb WHERE id = %s", (kb_id,))
            result = await cur.fetchone()
            if not result:
                raise HTTPException(status_code=404, detail="知识库不存在")
            return result

@app.post("/kb/update/{kb_id}")
async def update_kb(kb_id: int, kb: KbModel):
    """更新知识库信息
    Args:
        kb_id: 知识库ID
        kb: 包含更新后知识库信息的对象
    Returns:
        返回更新结果
    """
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(
                """UPDATE t_ai_kb 
                SET kb_name=%s, short_name=%s, is_delete=%s 
                WHERE id=%s""",
                (kb.kb_name, kb.short_name, kb.is_delete, kb_id)
            )
            await conn.commit()
            return {"status": "success", "affected_rows": cur.rowcount}

@app.delete("/kb/{kb_id}")
async def delete_kb(kb_id: int):
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute("DELETE FROM t_ai_kb WHERE id = %s", (kb_id,))
            await conn.commit()
            return {"message": "Knowledge base deleted"}

# 知识库文件CRUD接口
@app.post("/kb_file")
async def create_kb_file(file: KbFileModel):
    """创建知识库文件
    Args:
        file: 包含文件名(file_name)、扩展名(ext_name)、关联知识库ID(kb_id)等信息的对象
    Returns:
        返回创建成功的文件ID
    """
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(
                """INSERT INTO t_ai_kb_files 
                (file_name, ext_name, kb_id, is_delete, state) 
                VALUES (%s, %s, %s, %s, %s)""",
                (file.file_name, file.ext_name, file.kb_id, file.is_delete, file.state)
            )
            await conn.commit()
            return {"id": cur.lastrowid}

@app.get("/kb_files/{file_id}")
async def read_kb_file(file_id: int):
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor(DictCursor) as cur:
            await cur.execute("SELECT * FROM t_ai_kb_files WHERE id = %s", (file_id,))
            result = await cur.fetchone()
            if not result:
                raise HTTPException(status_code=404, detail="File not found")
            return result

# 知识库文件更新接口修改
@app.post("/kb_files/update/{file_id}")
async def update_kb_file(file_id: int, file: KbFileModel):
    """更新知识库文件信息
    Args:
        file_id: 文件ID
        file: 包含更新后文件信息的对象
    Returns:
        返回更新结果
    """
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(
                """UPDATE t_ai_kb_files 
                SET file_name=%s, ext_name=%s, kb_id=%s, 
                    is_delete=%s, state=%s 
                WHERE id=%s""",
                (file.file_name, file.ext_name, file.kb_id, 
                 file.is_delete, file.state, file_id)
            )
            await conn.commit()
            return {"status": "success", "affected_rows": cur.rowcount}

@app.delete("/kb_files/{file_id}")
async def delete_kb_file(file_id: int):
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute("DELETE FROM t_ai_kb_files WHERE id = %s", (file_id,))
            await conn.commit()
            return {"message": "File deleted"}

# 允许的文件类型
ALLOWED_EXTENSIONS = {'txt', 'pdf', 'docx', 'ppt', 'pptx'}
MAX_FILE_SIZE = 100 * 1024 * 1024  # 100MB

@app.post("/upload")
async def upload_file(
    kb_id: int, 
    file: UploadFile = File(...)
):
    """
    上传文件接口
    Args:
        kb_id: 关联的知识库ID
        file: 上传的文件对象
    Returns:
        返回文件保存信息和数据库记录ID
    """
    # 检查文件类型
    file_ext = Path(file.filename).suffix.lower()[1:]
    if file_ext not in ALLOWED_EXTENSIONS:
        raise HTTPException(
            status_code=400, 
            detail=f"不支持的文件类型: {file_ext}, 仅支持: {', '.join(ALLOWED_EXTENSIONS)}"
        )

    # 检查文件大小
    file_size = 0
    for chunk in file.file:
        file_size += len(chunk)
        if file_size > MAX_FILE_SIZE:
            raise HTTPException(
                status_code=400,
                detail=f"文件大小超过限制: {MAX_FILE_SIZE/1024/1024}MB"
            )
    file.file.seek(0)

    # 创建Upload目录
    upload_dir = Path("Upload")
    upload_dir.mkdir(exist_ok=True)

    # 保存文件
    file_path = upload_dir / file.filename
    with open(file_path, "wb") as f:
        f.write(await file.read())

    # 记录到数据库
    async with app.state.mysql_pool.acquire() as conn:
        async with conn.cursor() as cur:
            await cur.execute(
                """INSERT INTO t_ai_kb_files 
                (file_name, ext_name, kb_id, file_path, file_size) 
                VALUES (%s, %s, %s, %s, %s)""",
                (file.filename, file_ext, kb_id, str(file_path), file_size)
            )
            await conn.commit()
            return {
                "id": cur.lastrowid,
                "filename": file.filename,
                "size": file_size,
                "path": str(file_path)
            }

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)