import express from "express";
import path from "path";
import open from "open";
import fs from "fs";

const app = express();

app.use("/public", express.static(path.join(__dirname, "public")));
app.use(express.urlencoded({ extends: true }));
app.use(express.json());

app.listen(4000, () => {
    console.log("✅Pass: Server running at http://127.0.0.1:4000");
});

app.get("/", (req, res) => {
    res.sendFile(__dirname + "/public/index.html");
});

app.get("/api/meal", async (req, res) => {
    const item = req.query;
    const date = item.date;
    const type = item.type;

    const base_url = new URL("https://open.neis.go.kr/hub/mealServiceDietInfo");
    const params = new URLSearchParams({
        key: "504b37988adb4251b9fae916ae8c360a",
        Type: "json",
        ATPT_OFCDC_SC_CODE: "D10",
        SD_SCHUL_CODE: "7240450",
        MLSV_YMD: date,
        MMEAL_SC_CODE: type,
    });
    const url = `${base_url}?${params.toString()}`;

    try {
        let data = await fetch(url);

        if (!data.ok) {
            res.send("No Information");
        }

        data = await data.json();

        if (!data.mealServiceDietInfo[1].row[0]) {
            res.send("No Information");
        }

        let meal_list = data.mealServiceDietInfo[1].row[0].DDISH_NM;
        meal_list = meal_list.replace(/\([^)]+\)/g, "").split("<br/>");

        res.json({
            meal_list: meal_list,
            kcal: data.mealServiceDietInfo[1].row[0].CAL_INFO,
        });
    } catch (error) {
        res.send("No Information");
    }
});

// G-Cal api ------------------------------------------------------------

const checkClientSecret = () => {
    if (!fs.existsSync("client_secret.json")) {
        throw new Error("No client_secret.json");
    }
    console.log("✅Pass: client_secret.json exists");
};

const checkToken = () => {
    if (!fs.existsSync("token.json")) {
        console.error("❌Error: No token.json");
        console.warn("📣Notice: Trying to get token");
        getToken();
    } else {
        console.log("✅Pass: token.json exists");
    }
};

const getToken = () => {
    const base_url = new URL("https://accounts.google.com/o/oauth2/auth");
    const params = new URLSearchParams({
        client_id: client().client_id,
        redirect_uri: "http://localhost:4000/callback",
        response_type: "code",
        scope: "https://www.googleapis.com/auth/calendar",
        access_type: "offline",
        prompt: "consent",
    });
    const url = `${base_url}?${params.toString()}`;
    open(url);
};

const client = () => {
    const fileContent = fs.readFileSync("client_secret.json", "utf8");
    return JSON.parse(fileContent).web;
};

const token = (type) => {
    const fileContent = fs.readFileSync("token.json", "utf8");
    if (type) {
        return JSON.parse(fileContent)[type];
    }
    return JSON.parse(fileContent).access_token;
};

app.get("/callback", async (req, res) => {
    try {
        const response = await fetch("https://oauth2.googleapis.com/token", {
            method: "POST",
            headers: {},
            body: JSON.stringify({
                client_id: client().client_id,
                client_secret: client().client_secret,
                code: req.query.code,
                grant_type: "authorization_code",
                redirect_uri: "http://localhost:4000/callback",
            }),
        });

        const data = await response.json();

        if (data.error) {
            console.error(`❌Error: ${data.error}, ${data.error_description}`);
            res.send(
                "Error occured. Automatically reopen new Oauth page if token is not saved."
            );
            checkToken();
            return;
        }

        console.log("✅Pass: Successfully load token");
        saveToken(data);
        res.json(data);
    } catch (err) {
        console.error(`❌Error: ${err.message}`);
        res.status(500).json({ error: err.message });
    }
});

const saveToken = (data) => {
    fs.writeFileSync("token.json", JSON.stringify(data, null, 2));
    console.log("✅Pass: Successfully sace token.json");
};

const refreshToken = async () => {
    try {
        const response = await fetch("https://oauth2.googleapis.com/token", {
            method: "POST",
            headers: {},
            body: JSON.stringify({
                client_id: client().client_id,
                client_secret: client().client_secret,
                grant_type: "refresh_token",
                refresh_token: token("refresh_token"),
            }),
        });

        const data = await response.json();

        if (data.error) {
            return data;
        }

        data.refresh_token = token("refresh_token");
        saveToken(data);
        return "success";
    } catch (err) {
        return err;
    }
};

checkClientSecret();
checkToken();

app.get("/api/tasklist", async (req, res) => {
    const process = async () => {
        const task_calender_id =
            "729f5bea9ba83ff9b82dd797f15089a051fe850a4da66fcc3936835e89e3de89@group.calendar.google.com";
        const base_url = new URL(
            `https://www.googleapis.com/calendar/v3/calendars/${task_calender_id}/events`
        );
        const params = new URLSearchParams({
            singleEvents: true,
            orderBy: "startTime",
            timeMin: new Date().toISOString(),
        });
        const url = `${base_url}?${params.toString()}`;

        try {
            let data = await fetch(url, {
                method: "GET",
                headers: {
                    Authorization: `Bearer ${token()}`,
                },
            });

            data = await data.json();

            if (data.error) {
                if (data.error.code === 401) {
                    console.warn("📣Notice: Token expired, refreshing...");

                    const refreshStatus = await refreshToken();
                    if (refreshStatus === "success") {
                        console.warn("📣Notice: Token refresh success");
                        return await process();
                    } else {
                        console.error("❌Error: Can't refresh token");
                        return refreshStatus;
                    }
                }

                console.error(
                    `❌Error: ${data.error.code}, ${data.error.message}`
                );

                return data;
            }

            const li = data.items;

            res.json(li);
        } catch (err) {
            console.error(`❌Error: ${err}`);
            return err;
        }
    };

    return await process();
});

app.get("/api/gettask", async (req, res) => {
    const process = async () => {
        const task_calender_id =
            "729f5bea9ba83ff9b82dd797f15089a051fe850a4da66fcc3936835e89e3de89@group.calendar.google.com";
        const base_url = new URL(
            `https://www.googleapis.com/calendar/v3/calendars/${task_calender_id}/events/${req.query.event_id}`
        );
        const params = new URLSearchParams({
            singleEvents: true,
            orderBy: "startTime",
            timeMin: new Date().toISOString(),
        });
        const url = `${base_url}?${params.toString()}`;

        try {
            let data = await fetch(url, {
                method: "GET",
                headers: {
                    Authorization: `Bearer ${token()}`,
                },
            });

            data = await data.json();

            if (data.error) {
                if (data.error.code === 401) {
                    console.warn("📣Notice: Token expired, refreshing...");

                    const refreshStatus = await refreshToken();
                    if (refreshStatus === "success") {
                        console.warn("📣Notice: Token refresh success");
                        return await process();
                    } else {
                        console.error("❌Error: Can't refresh token");
                        return refreshStatus;
                    }
                }

                console.error(
                    `❌Error: ${data.error.code}, ${data.error.message}`
                );

                return data;
            }

            res.json(data);
        } catch (err) {
            console.error(`❌Error: ${err}`);
            return err;
        }
    };

    return await process();
});

app.post("/api/edittask", async (req, res) => {
    const process = async () => {
        const task_calender_id =
            "729f5bea9ba83ff9b82dd797f15089a051fe850a4da66fcc3936835e89e3de89@group.calendar.google.com";
        const url = new URL(
            `https://www.googleapis.com/calendar/v3/calendars/${task_calender_id}/events/${req.body.event_id}`
        );

        try {
            let data = await fetch(url, {
                method: "PUT",
                headers: {
                    Authorization: `Bearer ${token()}`,
                },
                body: JSON.stringify(req.body.data),
            });

            data = await data.json();

            if (data.error) {
                if (data.error.code === 401) {
                    console.warn("📣Notice: Token expired, refreshing...");

                    const refreshStatus = await refreshToken();
                    if (refreshStatus === "success") {
                        console.warn("📣Notice: Token refresh success");
                        return await process();
                    } else {
                        console.error("❌Error: Can't refresh token");
                        return refreshStatus;
                    }
                }

                console.error(
                    `❌Error: ${data.error.code}, ${data.error.message}`
                );

                return data;
            }

            res.json(data);
        } catch (err) {
            console.error(`❌Error: ${err}`);
            return err;
        }
    };

    return await process();
});

app.post("/api/createtask", async (req, res) => {
    const process = async () => {
        const task_calender_id =
            "729f5bea9ba83ff9b82dd797f15089a051fe850a4da66fcc3936835e89e3de89@group.calendar.google.com";
        const url = new URL(
            `https://www.googleapis.com/calendar/v3/calendars/${task_calender_id}/events`
        );

        try {
            let data = await fetch(url, {
                method: "POST",
                headers: {
                    Authorization: `Bearer ${token()}`,
                },
                body: JSON.stringify(req.body.data),
            });

            data = await data.json();

            if (data.error) {
                if (data.error.code === 401) {
                    console.warn("📣Notice: Token expired, refreshing...");

                    const refreshStatus = await refreshToken();
                    if (refreshStatus === "success") {
                        console.warn("📣Notice: Token refresh success");
                        return await process();
                    } else {
                        console.error("❌Error: Can't refresh token");
                        return refreshStatus;
                    }
                }

                console.error(
                    `❌Error: ${data.error.code}, ${data.error.message}`
                );

                return data;
            }

            res.json(data);
        } catch (err) {
            console.error(`❌Error: ${err}`);
            return err;
        }
    };

    return await process();
});