// pool: DB connection pool configured using mysql2

const viewAllTables = FunctionTool.from(
      async ({ dummy }: { dummy: string }): Promise<JSONValue> => {
        const query = "SHOW TABLES";
        return pool
          .promise()
          .query(query)
          .then(([rows]) => {
            if (Array.isArray(rows)) {
              const listString: string = rows
                .map((row: any): string => row[`Tables_in_${db_name}`] || "")
                .join(", ");
              return listString;
            } else {
              throw new Error("rows not in correct format");
            }
          })
          .catch((error: unknown) => {
            if (error instanceof Error) {
              return error.message;
            }
            return "Unknown Error Occurred";
          });
      },
      {
        name: "viewAllTables",
        description: "Use this function to get table names from database.",
        parameters: {
          type: "object",
          properties: {
            dummy: {
              type: "string",
              description:
                "This is a placeholder parameter and will be ignored",
            },
          },
          required: ["dummy"],
        },
      }
    );

const applyQuery = FunctionTool.from(
      async ({ query }: { query: string }): Promise<JSONValue> => {
        console.log({ query });
        return pool
          .promise()
          .query(query)
          .then(([rows, fields]) => {
            console.log({ rows });
            console.log({ fields });
            console.log({ stringified: JSON.stringify({ rows, fields }) });

            return `1500`;
          })
          .catch((error: unknown) => {
            console.log(error);
            if (error instanceof Error) {
              return error.message;
            }
            return "Unknown Error Occurred";
          });
      },
      {
        name: "applyQuery",
        description:
          "Use this function to apply any SQL query on the pre-defined database.",
        parameters: {
          type: "object",
          properties: {
            query: {
              type: "string",
              description: "Enter Syntax-Correct SQL Query.",
            },
          },
          required: ["query"],
        },
      }
    );

const gemini = new Gemini({
        model: GEMINI_MODEL.GEMINI_PRO_1_5_FLASH_LATEST,
        session: new GeminiSession({ apiKey: process.env.GOOGLE_API_KEY }),
      });
      const agent = new LLMAgent({
        llm: gemini,
        tools: [viewAllTables, applyQuery],
      });

// chat with agent:
const response = await agent.chat({
        message:
          "Which tables are in the database? Then count the rows of online_charity table",
      });

// error handling below ...