const express = require("express");
const bodyParser = require("body-parser");
const { sha } = require("sha256quanvn");
const { PrismaClient } = require("@prisma/client");
const multer = require("multer");
const fs = require("fs");
const statusMonitor = require("express-status-monitor")({
    path: "/bee3hivestatuspagethatnoonewillrememberthisurl",
    title: "Bee3Hive API Status",
});
const cors = require("cors");
const { withAccelerate } = require("@prisma/extension-accelerate");
const { error } = require("console");
const prisma = new PrismaClient().$extends(withAccelerate())
const app = express();

const SALT = process.env.PRIVATE_KEY;

const services = ["https://quanvndzai-ipfs-server-1.hf.space"];
const queueFileUpload = {};

const info = (message) => {
    console.log(`<${new Date()}> [INFO] - ${message}`);
};
const warn = (message) => {
    console.log(`<${new Date()}> [INFO] - ${message}`);
};

//* Sussy bigint thing
BigInt.prototype["toJSON"] = function () {
    return this.toString();
};

//* Safe Base64 Encode
const safeb64 = (str) => {
    return btoa(str).replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
};


/**
 * Returns a new array with all duplicates removed.
 *
 * @param {Array} a - The array to remove duplicates from.
 * @return {Array} - A new array with all duplicates removed.
 */
function uniq(a) {
    var seen = {};
    return a.filter(function(item) {
        return seen.hasOwnProperty(item) ? false : (seen[item] = true);
    });
}


/**
 * Generates a new JSON Web Token for the given user ID, and returns it as a string.
 *
 * The token is valid for 1 day, and is signed with the server's private key.
 *
 * @param {number} id - The user's ID.
 * @return {string} A new JSON Web Token, as a string.
 */
const generateJWT = async (id) => {
    const header = {
        alg: "SHA256QUANVN",
        typ: "JWT",
    };

    const payload = {
        id: id,
        exp: Date.now() + 3600000 * 24 * 7, // 7 days
    };

    await prisma.users.update({
        where: {
            id: payload.id,
        },
        data: {
            last_login: new Date(),
        },
    });

    const token =
        safeb64(JSON.stringify(header)) + "." + safeb64(JSON.stringify(payload));

    const sig = sha(token + "." + SALT);

    info("Generated new token for user: " + id);
    // console.log("New Token generated: " + token + "." + sig)

    return token + "." + safeb64(sig);
};

const generateFileID = () => {
    const characters =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    let fileID = "";
    for (let i = 0; i < 6; i++) {
        fileID += characters.charAt(Math.floor(Math.random() * characters.length));
    }
    return fileID;
};

async function checkServer() {
    // info("Checking servers...");
    for(var i = services.length - 1; i >= 0; i--) {
        try {
            const resp = await fetch(services[i] + "/availible");

            if(!resp.ok) {
                // This server is ded but can try again later lol
                info(await resp.text());
                warn("Server " + services[i] + " fail to ping");
                continue;
            }

            const data = await resp.text();
            // info(data)
            if(data != "\"Ok!\"") {
                //This server is full
                warn("Server " + services[i] + " is full");
                services.splice(i, 1);
            }
        } catch(e) {
            // This server is ded but can try again later lol
            warn("Server " + services[i] + " fail to fetch");
            // services.splice(i, 1);
        }
    }
}

setInterval(checkServer, 60 * 1000)
checkServer()

// Configure Multer storage
const storage = multer.diskStorage({
    destination: (req, file, cb) => {
        cb(null, "uploads/");
    },
    filename: (req, file, cb) => {
        // cb(null, generateFileID() + '-' + Date.now());
        cb(null, generateFileID() + "-" + file.originalname);
    },
});

// Set file size limit to 10GB
const upload = multer({
    storage: storage,
    limits: { fileSize: 10 * 1024 * 1024 * 1024 }, // 10GB
});

// console.log(file)

const current_connections = [];

app.use(
    cors({
        origin: "*",
    })
);

app.use(bodyParser.json()); //utilizes the body-parser package
app.use(bodyParser.urlencoded({extended: true}));

app.use(statusMonitor);

app.use("/upload_queue", express.static("uploads"));

app.get(
    "/bee3hivestatuspagethatnoonewillrememberthisurl",
    statusMonitor.pageRoute
);

app.get("/bee3hive/internal/files/:node_id", async (req, res) => {
    // TODO: Make database query for services
    const node_id = req.params.node_id;
    const record = await prisma.storage.findMany({
        where: {
            handle: node_id,
        },
        cacheStrategy: {
            ttl: 60, //* 1 min
        },
    })

    if(!record) {
        res.sendStatus(404);
        return;
    }

    res.send(record);
})

// TODO: Make database query for services

app.post("/auth/email/register", async (req, res) => {
    let { username, email, password } = req.body;

    if (!username || !email || !password) {
        info("Missing required fields registration");
        res.sendStatus(400);
        return;
    }

    if (username.length < 6) {
        info("Username: " + username + " is too short!");
        res.sendStatus(400);
        return;
    }

    username = username.trim();
    password = password.trim();
    email = email.trim();

    // console.log(username, email, password)

    if (
        ["admin", "administrator", "root", "user", "anonymous", "guest"].includes(
            username
        )
    ) {
        warn("Username not allowed: " + username);
        res.sendStatus(401);
        return;
    }

    const record = await prisma.users.findUnique({
        where: {
            email: email,
        },
    });

    if (record) {
        info("User already exists: " + username);
        res.status(400).send({ error: "Username already exists" });
        return;
    }

    try {
        info(
            "Creating user: " +
            email +
            " username: " +
            username +
            " password: " +
            sha(password) +
            " " +
            new Date()
        );

        const created = await prisma.users.create({
            data: {
                username: username,
                email: email,
                password_hash: sha(password),
                last_login: new Date(),
            },
        });

        info("User created: " + email + " username: " + username);
        res.send({ token: await generateJWT(created.id) });
        return;
    } catch (e) {
        warn("Error on creating users");
        console.log(e);
        res.sendStatus(500);
        return;
    }
});

app.post("/auth/email/login", async (req, res) => {
    const { email, password } = req.body;

    if (!email || !password) {
        info("Missing required fields login");
        res.sendStatus(400);
        return;
    }

    const record = await prisma.users.findUnique({
        where: {
            email: email,
        },
    });

    if (!record) {
        info("User not found: " + email);
        res.sendStatus(401);
        return;
    }

    if (record.password_hash != sha(password)) {
        warn("Wrong password attempt: " + email);
        res.sendStatus(401);
        return;
    }

    info("User logged in: " + email);
    res.send({ token: await generateJWT(record.id) });
});

app.use(async (req, res, next) => {
    if (!req.headers.authorization) {
        info("Authorization header not found");
        res.sendStatus(401);
        return;
    }

    let token;
    try {
        token = req.headers.authorization.slice(7); // Bearer token
    } catch (e) {
        warn("Parsing token fail");
        console.log(e);
        return;
    }

    if (!token) {
        info("Token not found");
        res.sendStatus(401);
        return;
    }

    const [tokenHeader, tokenPayload, tokenSig] = token.split(".");

    if (!tokenHeader || !tokenPayload || !tokenSig) {
        info("Invalid token");
        res.sendStatus(401);
        return;
    }

    // console.log(tokenHeader, tokenPayload, tokenSig)

    try {
        // console.lo
        const header = JSON.parse(Buffer.from(tokenHeader, "base64").toString());
        const payload = JSON.parse(Buffer.from(tokenPayload, "base64").toString());
        const token_sig = Buffer.from(tokenSig, "base64").toString();
        const sig = sha(tokenHeader + "." + tokenPayload + "." + SALT);

        // console.log(header, payload, token_sig, sig)

        if (sig !== token_sig) {
            warn("Invalid signature");
            res.sendStatus(401);
            return;
        }

        if (Date.now() > payload.exp) {
            warn("Token expired");
            res.sendStatus(401);
            return;
        }

        const record = await prisma.users.findUnique({
            where: {
                id: payload.id,
            },
        });

        if (!record) {
            warn("Record not found");
            res.sendStatus(500); // How?
            return;
        }

        info("Authorized: " + record.id);

        req.user = record;
        next();
        return;
    } catch (e) {
        console.log(e);
        res.sendStatus(401);
        return;
    }
});

app.post("/auth/me", async (req, res) => {
    if (!Array.isArray(queueFileUpload[req.user.username])) {
        queueFileUpload[req.user.username] = [];
    }
    // User already authorize
    res.send(req.user);
});

app.post("/auth/delete", async (req, res) => {
    // User already authorize
    const { password } = req.body;

    if (!password) {
        info("Missing password when deleting user");
        res.sendStatus(400);
        return;
    }

    // Check password
    if (sha(password) != req.user.password_hash) {
        res.sendStatus(401);
        return;
    }

    // Delete User
    try {
        await prisma.users.delete({
            where: {
                id: req.user.id,
            },
        });
        res.sendStatus(200);
        return;
    } catch (e) {
        warn("Error on deleting user");
        console.log(e);
        res.sendStatus(500);
        return;
    }
});

app.post("/file/upload", upload.single("file"), async (req, res) => {

    try {
        const tests = fs.readdirSync("uploads");
        console.log(tests)
        console.log(req.file)
        const upload_path = req.file.path;
        const file_path = req.body.filePath;
        const full_file_path = req.user.username + (file_path ? "/" + file_path : "");

        // Upload the file to another backend

        if(services.length == 0) {
            res.status(500).send("Service unavailable");
            return;
        }

        const server = services[Math.floor(Math.random() * services.length)];

        const body = {
            filename: file_path,
            directory: full_file_path,
            username: req.user.username,
            fileURI: req.file.filename,
        }

        // console.log(body)

        // Upload the file
        try {
            info("Uploading file to " + server);
            const resp = await fetch(server + "/fetch", {
                method: "POST",
                headers: {
                    "Content-Type": "application/json",
                },
                body: JSON.stringify(body),
            });

            if(!resp.ok) {
                warn(await resp.text());
                res.sendStatus(500);
                return;
            }

            const json = await resp.json();
            console.log(json)

            if(await prisma.storage.findUnique({ where: { dir: full_file_path } })) {
                // File already exists and same content
                warn("File already exists. No override: " + full_file_path);
                res.sendStatus(200);
                return;
            }

            if(await prisma.storage.findUnique({ where: { dir: full_file_path } })) {
                warn("File already exists. Override: " + full_file_path);
                await prisma.storage.update({
                    where:{
                        dir: full_file_path
                    },

                    data: {
                        handle: server,
                        username: req.user.username,
                        CID: json[0].Hash,
                        size: +json[0].Size,
                        dir: full_file_path,
                    }
                })
            } else {
                info("Adding record: " + full_file_path);
                //* Add record
                await prisma.storage.create({
                    data: {
                        handle: server,
                        username: req.user.username,
                        CID: json[0].Hash,
                        size: +json[0].Size,
                        dir: full_file_path,
                    }
                })
            }
        } catch (e) {
            warn("Error on uploading file");
            console.log(e);
            res.sendStatus(500);
            fs.unlinkSync(upload_path);
            return;
        }

        fs.unlinkSync(upload_path);

        info("File uploaded successfully: " + full_file_path);
        res.send("File uploaded successfully.");
    } catch (error) {
        // Fail to upload
        warn("File upload failed");
        console.log(error);
        res.status(500).send("File upload failed.");
    }
});

app.get("/file/list", async (req, res) => {
    const filePath = req.query.filePath;
    const recursive = req.query.recursive == "true";
    const files = []

    const setsDirectory = []

    try{
        const record = await prisma.storage.findMany({
            where: {
                username: req.user.username,
            }
        })

        for (const r of record) {
            const path = r.dir ? r.dir.split("/") : [];
            // remove first element too
            if(path.length > 1) {
                path.shift();
                path.pop();
            } else {
                path = [];
            }
            // console.log(path)
            let dir = "";
            for (const p of path) {
                dir += p;
                setsDirectory.push({
                    type:"directory",
                    dir
                });
            }

            r.type = "file";

            files.push(r)
        }
    } catch (e) {
        info("No file found")
        console.log(e)
    }
    res.send(files.concat(uniq(setsDirectory)));
})

app.post("/file/delete", async (req, res) => {
    const filePath = req.body.filePath;
    const full_file_path = req.user.username + (filePath ? "/" + filePath : "");


    const record = await prisma.storage.findUnique({
        where: {
            dir: full_file_path,
        }
    })

    if(!record) {
        warn("File not found: " + (full_file_path ? (full_file_path + "/") : ""))
        res.status(404).send("File not found.");
        return;
    }

    try {
        // Tell the server to unpin the file
        const resp = await fetch(record.handle + "/delete", {
            method: "POST",
            headers: {
                "Content-Type": "application/json",
            },
            body: JSON.stringify({
                CID: record.CID
            }),
        })

        if(!resp.ok) {
            throw "Respone not ok";
        }

        console.log(await resp.json())

        await prisma.storage.delete({
            where: {
                CID: record.CID
            }
        })
    } catch (e) {
        console.log(e);
        res.sendStatus(500);
        return;
    }

    info("File deleted: " + (filePath ? (filePath + "/") : ""))
    res.send("File deleted successfully.");
})

app.post("/file/getdownloadurl", async (req, res) => {
    const filePath = req.body.filePath;
    const full_file_path = req.user.username + (filePath ? "/" + filePath : "");


    info("Get download url: " + full_file_path)

    const record = await prisma.storage.findUnique({
        where: {
            dir: full_file_path
        }
    })

    if(!record) {
        res.status(404).send("File not found")
        return;
    }

    try {
        const IPFS_GATEWAY = "https://ipfs.io/ipfs/";
        res.send(IPFS_GATEWAY + record.CID);
    } catch(e) {
        console.log(e);
        res.sendStatus(500)
    }
})

app.listen(7860, () => info("Server started on port 7860"));