const axios = require("axios");
const crypto = require("crypto");
const level = require("level");
const fs = require("fs");
const { spawn } = require("child_process");
const leveldb = level("leveldb");
const getAccount = require("../lib/account");
const { Op, col } = require("sequelize");
const shallow = a => {
  let b = {};
  for (x in a) {
    if (a[x] instanceof Date || typeof a[x] !== "object") b[x] = a[x];
  }
  return b;
};

const assets = {
  b2e15d0d7a0c94e4e2ce0fe6e8691b9e451377f6e46e8045a86f7c4b5d4f0f23: "bitcoin",
  "4eebe36eb0819e6daa5dd3c97733251ff4eb728c810d949365d6dacaad5ef6e8": "tether"
};

const swapsdir = "swaps/";
if (!fs.existsSync(swapsdir)) {
  fs.mkdirSync(swapsdir);
}

const timeout = 20000;

const cli = (...args) => {
  const params = ["--regtest", "-c", config.liquid.conf, ...args];
  if (config.liquid.network !== "regtest") params.shift();
  l.info("spawning liquidswap-cli with params:", params);
  return spawn("liquidswap-cli", params);
};

const getInfo = filename =>
  new Promise((resolve, reject) => {
    const proc = cli("info", swapsdir + filename);

    proc.stdout.on("data", data => {
      resolve(data.toString());
    });

    proc.stderr.on("data", err => {
      l.error("info error", err.toString());
      reject(err.toString());
    });

    proc.on("close", (code, signal) => {
      let msg = (code && code.toString()) || (signal && signal.toString());
      reject(new Error(`Liquid swap tool process closed unexpectedly: ${msg}`));
    });

    proc.on("exit", (code, signal) => {
      let msg = (code && code.toString()) || (signal && signal.toString());
      reject(new Error(`Liquid swap tool process exited unexpectedly: ${msg}`));
    });

    setTimeout(
      () => reject(new Error("Liquid swap tool timed out"), proc),
      timeout
    );
  });

const swap = async (user, { a1, a2, v1, v2 }) => {
  let rate = v2 / v1;

  const b = await lq.getBalance();

  Object.keys(b).map(asset => {
    assets[asset] = asset;
  });

  assets[config.liquid.btcasset] = "bitcoin";
  assets["ce091c998b83c78bb71a632313ba3760f1763d9cfcffae02258ffa9865a37bd2"] =
    "tether";
  assets["a0c358a0f6947864af3a06f3f6a2aeb304df7fd95c922f2f22d7412399ce7691"] =
    "adamcoin";

  if (!assets[a1]) throw new Error("unsupported asset");
  if (v1 > Math.round(b[assets[a1]] * SATS))
    throw new Error(`insufficient server funds, ${v1} ${b[assets[a1]]}`);

  await db.transaction(async transaction => {
    let a1acc = await getAccount(a1, user, transaction);
    let a2acc = await getAccount(a2, user, transaction);

    if (v1 > a1acc.balance)
      throw new Error(`insufficient funds, ${v1} ${a1acc.balance}`);

    l.info(
      `trade ${v1} ${a1.substr(0, 6)} for ${v2} ${a2.substr(0, 6)}`,
      user.username
    );

    await a1acc.decrement({ balance: v1 }, { transaction });
    await a1acc.reload({ transaction });

    let payment = await db.Payment.create(
      {
        hash: "Trade Funding",
        amount: -v1,
        account_id: a1acc.id,
        user_id: user.id,
        currency: user.currency,
        rate: app.get("rates")[user.currency],
        confirmed: true,
        received: false,
        network: "COINOS"
      },
      { transaction }
    );

    emit(user.username, "payment", payment.get({ plain: true }));
    emit(user.username, "account", a1acc.get({ plain: true }));

    const orders = await db.Order.findAll(
      {
        where: {
          "$acc1.asset$": a2,
          "$acc2.asset$": a1,
          rate: { [Op.lte]: 1/rate },
          accepted: false
        },
        order: [
          ["rate", "ASC"],
          ["id", "ASC"]
        ],
        include: [
          {
            model: db.User,
            as: "user"
          },
          {
            model: db.Account,
            as: "acc1"
          },
          {
            model: db.Account,
            as: "acc2"
          }
        ]
      },
      { transaction }
    );

    for (let i = 0; i < orders.length; i++) {
      if (!v1) break;
      p = orders[i];
      if (p.v2 > v1) {
        p.v2 -= v1;
        await p.save({ transaction });

        let payment = await db.Payment.create(
          {
            hash: "Trade Fill",
            amount: v2,
            account_id: p.a1_id,
            user_id: p.user_id,
            currency: p.user.currency,
            rate: app.get("rates")[p.user.currency],
            confirmed: true,
            received: true,
            network: "COINOS"
          },
          { transaction }
        );

        await p.acc1.increment({ balance: v2 }, { transaction });
        await p.acc1.reload({ transaction });

        emit(p.user.username, "payment", payment.get({ plain: true }));
        emit(p.user.username, "account", p.acc1.get({ plain: true }));

        payment = await db.Payment.create(
          {
            hash: "Trade Fill",
            amount: v1,
            account_id: a1acc.id,
            user_id: user.id,
            currency: user.currency,
            rate: app.get("rates")[user.currency],
            confirmed: true,
            received: true,
            network: "COINOS"
          },
          { transaction }
        );

        a1acc.increment({ balance: v1 }, { transaction });
        await a1acc.reload({ transaction });

        emit(user.username, "payment", payment.get({ plain: true }));
        emit(user.username, "account", a1acc.get({ plain: true }));

        if (p.fee) {
          const btc = await getAccount(
            config.liquid.btcasset,
            p.user,
            transaction
          );

          payment = await db.Payment.create(
            {
              hash: "Swap Fee Refund",
              amount: p.fee,
              account_id: btc.id,
              user_id: p.user_id,
              currency: p.user.currency,
              rate: app.get("rates")[p.user.currency],
              confirmed: true,
              received: true,
              network: "COINOS"
            },
            { transaction }
          );

          await btc.increment({ balance: p.fee }, { transaction });
          await btc.reload({ transaction });

          emit(p.user.username, "account", btc.get({ plain: true }));
        }

        emit(p.user.username, "payment", payment.get({ plain: true }));

        p = p.get({ plain: true });
        p.a1 = p.acc1.asset;
        p.a2 = p.acc2.asset;
        broadcast("order", shallow(p));
        v1 = 0;
      } else {
        v1 -= p.v2;
        v2 = Math.round(v1 * rate);

        p.accepted = true;
        p.completedAt = new Date();

        await p.save({ transaction });

        let payment = await db.Payment.create(
          {
            hash: "Trade Fill",
            amount: p.v1,
            account_id: a2acc.id,
            user_id: user.id,
            currency: user.currency,
            rate: app.get("rates")[user.currency],
            confirmed: true,
            received: true,
            network: "COINOS"
          },
          { transaction }
        );

        await a2acc.increment({ balance: p.v1 }, { transaction });
        await a2acc.reload({ transaction });

        emit(user.username, "payment", payment.get({ plain: true }));
        emit(user.username, "account", a2acc.get({ plain: true }));

        payment = await db.Payment.create(
          {
            hash: "Trade Fill",
            amount: p.v2,
            account_id: p.a2_id,
            user_id: p.user_id,
            currency: p.user.currency,
            rate: app.get("rates")[p.user.currency],
            confirmed: true,
            received: true,
            network: "COINOS"
          },
          { transaction }
        );

        emit(p.user.username, "payment", payment.get({ plain: true }));
        await p.acc2.increment({ balance: p.v2 }, { transaction });
        await p.acc2.reload({ transaction });

        p = p.get({ plain: true });
        p.a1 = p.acc1.asset;
        p.a2 = p.acc2.asset;
        broadcast("order", shallow(p));
      }
    }

    let order;
    if (v1) {
      order = await db.Order.create(
        {
          v1,
          v2,
          user_id: user.id,
          a1_id: a1acc.id,
          a2_id: a2acc.id
        },
        { transaction }
      );

      const text = await new Promise((resolve, reject) => {
        l.info(
          "running liquid-cli tool %s %s %s %s %s",
          config.liquid.conf,
          a1,
          v1,
          a2,
          v2
        );
        const proc = cli(
          "propose",
          a1,
          (v1 / SATS).toFixed(8),
          a2,
          (v2 / SATS).toFixed(8)
        );

        proc.stdout.on("data", data => {
          resolve(data.toString());
        });

        proc.stderr.on("error", err => {
          l.error("order error", err.toString());
          reject(err.toString());
        });

        proc.on("close", (code, signal) => {
          let msg = (code && code.toString()) || (signal && signal.toString());
          reject(
            new Error(`Liquid swap tool process closed unexpectedly: ${msg}`)
          );
        });

        proc.on("exit", (code, signal) => {
          let msg = (code && code.toString()) || (signal && signal.toString());
          reject(
            new Error(`Liquid swap tool process exited unexpectedly: ${msg}`)
          );
        });

        setTimeout(
          () => reject(new Error("Liquid swap tool timed out"), proc),
          timeout
        );
      });

      const filename = `order-${order.id}.txt`;

      fs.writeFileSync(swapsdir + filename, text);
      let info = JSON.parse(await getInfo(filename));
      let [fee, rate, asset] = parse(info);

      const btc = await getAccount(config.liquid.btcasset, user, transaction);
      fee = Math.round(fee * SATS);
      await btc.decrement({ balance: fee }, { transaction });
      await btc.save({ transaction });
      emit(user.username, "account", btc.get({ plain: true }));

      let payment = await db.Payment.create(
        {
          hash: "Swap Fee Deposit",
          amount: -fee,
          account_id: btc.id,
          user_id: user.id,
          currency: user.currency,
          rate: app.get("rates")[user.currency],
          confirmed: true,
          received: false,
          network: "COINOS"
        },
        { transaction }
      );

      emit(user.username, "payment", payment.get({ plain: true }));

      order.fee = fee;
      order.text = text;
      await order.save({ transaction });

      order = order.get({ plain: true });
      order.rate = v2 / v1;
      order.a1 = a1;
      order.a2 = a2;

      broadcast("order", order);
    }
  });
};

const cancel = async (user, id) => {
  await db.transaction(async transaction => {
    let order = await db.Order.findOne(
      {
        where: {
          id,
          user_id: user.id
        },
        include: {
          model: db.Account,
          as: "acc1"
        }
      },

      { transaction }
    );

    let { acc1: account, v1, v2 } = order;
    await account.increment({ balance: v1 }, { transaction });
    await account.reload({ transaction });

    let rate = v2 / v1;
    let payment = await db.Payment.create(
      {
        hash: "Trade Cancelled",
        amount: v1,
        account_id: account.id,
        user_id: user.id,
        currency: user.currency,
        rate: app.get("rates")[user.currency],
        confirmed: true,
        received: true,
        network: "COINOS"
      },
      { transaction }
    );

    emit(user.username, "account", account.get({ plain: true }));
    emit(user.username, "payment", payment.get({ plain: true }));

    if (order.fee) {
      const btc = await getAccount(config.liquid.btcasset, user, transaction);

      payment = await db.Payment.create(
        {
          hash: "Swap Fee Refund",
          amount: order.fee,
          account_id: btc.id,
          user_id: user.id,
          currency: user.currency,
          rate: app.get("rates")[user.currency],
          confirmed: true,
          received: true,
          network: "COINOS"
        },
        { transaction }
      );

      await btc.increment({ balance: order.fee }, { transaction });
      await btc.reload({ transaction });

      emit(user.username, "account", btc.get({ plain: true }));
      emit(user.username, "payment", payment.get({ plain: true }));
    }

    broadcast("removeOrder", id);
    await order.destroy({ transaction });
  });
};

app.delete(
  "/order/:id",
  auth,
  ah(async (req, res) => {
    const { id } = req.params;
    const { user } = req;

    await cancel(user, id);
    res.end();
  })
);

app.post(
  "/orders",
  auth,
  ah(async (req, res) => {
    const { user } = req;
    try {
      await swap(user, req.body);
      res.end();
    } catch (e) {
      l.error(req.user.username, e.message, e.stack);
      res.status(500).send(e.message);
    }
  })
);

app.post(
  "/accept",
  optionalAuth,
  ah(async (req, res) => {
    try {
      const { id, text } = req.body;

      let order = await db.Order.findOne({
        where: {
          id
        },
        include: {
          model: db.User,
          as: "user"
        }
      });

      if (!order) throw new Error("Order not found");

      const { user } = req;

      if (text) {
        const filename = `acceptance-${id}.txt`;
        fs.writeFileSync(swapsdir + filename, text);

        let info = JSON.parse(await getInfo(filename));
        let [fee, rate, asset] = parse(info);
        let { tx, u_address_p, u_address_r } = JSON.parse(
          Buffer.from(text, "base64").toString()
        );
        const sha256 = crypto.createHash("sha256");
        sha256.update(tx);
        const hash = sha256.digest("hex");

        const leg1 = info.legs.find(leg => !leg.incoming);
        const leg2 = info.legs.find(leg => leg.incoming);

        await db.transaction(async transaction => {
          const l2a2 = await getAccount(leg2.asset, order.user, transaction);

          let amount = Math.round(leg1.amount * SATS);
          fee = Math.round(fee * SATS);

          amount = Math.round(leg2.amount * SATS);

          await db.Invoice.create({
            user_id: order.user_id,
            text: u_address_p,
            address: u_address_p,
            unconfidential: u_address_p,
            currency: order.user.currency,
            memo: "Atomic Swap",
            rate: app.get("rates")[order.user.currency],
            amount,
            tip: 0,
            network: "liquid",
            account_id: l2a2.id
          });

          addresses[u_address_p] = order.user.username;

          await finalize(filename);

          order.accepted = true;
          order.completedAt = new Date();
          await order.save({ transaction });

          order = order.get({ plain: true });
          order.a1 = leg1.asset;
          order.a2 = leg2.asset;
          broadcast("order", shallow(order));
        });

        res.send(info);
      } else {
        throw new Error("No acceptance provided");
      }
    } catch (e) {
      l.error(e.message);
      res.status(500).send(e.message);
    }
  })
);

app.post(
  "/acceptance",
  ah(async (req, res) => {
    const { acceptance: text } = req.body;
    l.info("acceptance received");

    fs.writeFile(swapsdir + "accepted.txt", text, async err => {
      if (err) {
        return res.status(500).send(err);
      }

      try {
        let info = JSON.parse(
          await new Promise((resolve, reject) => {
            const proc = cli("info", swapsdir + "accepted.txt");

            proc.stdout.on("data", data => {
              resolve(data.toString());
            });

            proc.stderr.on("data", err => {
              reject(err.toString());
            });

            setTimeout(
              () => reject(new Error("Liquid swap tool timed out"), proc),
              timeout
            );
          })
        );

        const time = Math.floor(new Date()).toString();
        const [fee, rate, asset] = parse(info);
        if (!asset) throw new Error("Unsupported asset");
        l.info("accepted", info, rate, asset);

        leveldb.put(time, JSON.stringify({ text, info, rate, asset }));
        l.info({ text, info, rate, asset });

        res.send({ info, rate });
      } catch (e) {
        l.error(e);
        res.status(500).send(e.message);
      }
    });
  })
);

checkQueue = async () => {
  const ws = app.get("ws");
  const txs = [];

  leveldb
    .createReadStream()
    .on("data", async function(data) {
      txs.push({ ...JSON.parse(data.value), key: data.key });
    })
    .on("end", async function(data) {
      const rate = (a, b) => a.rate - b.rate;
      const time = (a, b) => b.time - a.time;

      const pending = txs.filter(tx => !tx.id);
      const completed = txs.filter(tx => tx.id).sort(time);

      const bitcoin = pending
        .filter(tx => tx.asset === "bitcoin")
        .sort(rate)
        .reverse();
      const tether = pending
        .filter(tx => tx.asset === "tether")
        .sort(rate)
        .reverse();

      const strip = a =>
        a.map(({ id, key, info, rate, time }) => ({
          id,
          key,
          info,
          rate,
          time
        }));

      ws &&
        ws.send(
          JSON.stringify({
            completed: strip(completed.slice(0, 3)),
            bitcoin: strip(bitcoin.slice(0, 3)),
            tether: strip(tether.slice(0, 3))
          })
        );

      let b, t, tx;
      if (bitcoin[0]) b = bitcoin[0].rate - app.get("ask");
      if (tether[0]) t = tether[0].rate - 1 / app.get("bid");

      if (b > 0 || t > 0) {
        if ((b && !t) || b > t) tx = bitcoin[0];
        if ((t && !b) || t > b) tx = tether[0];
      }

      if (tx) {
        try {
          tx.id = JSON.parse(await finalize(tx.text)).txid;
          tx.time = Date.now();
          delete tx.text;
          leveldb.put(tx.key, JSON.stringify(tx));
        } catch (e) {
          l.info(e);
          if (e.includes("Unexpected fees")) leveldb.del(tx.key);
          if (e.includes("unsigned inputs")) leveldb.del(tx.key);
          if (e.includes("insufficient fee")) leveldb.del(tx.key);
        }
      }
    });
};

const parse = info => {
  const fee = info.legs[0].fee;
  return [
    fee,
    (info.legs[1].amount / (info.legs[0].amount + fee)).toFixed(8),
    assets[info.legs[0].asset]
  ];
};

const finalize = (filename = "finalized.txt", text) => {
  if (text) fs.writeFileSync(swapsdir + filename, text);

  return new Promise((resolve, reject) => {
    const proc = cli("finalize", swapsdir + filename, "-s");

    proc.stdout.on("data", data => {
      resolve(data.toString());
    });

    proc.stderr.on("data", err => {
      reject(new Error(err.toString()));
    });

    proc.on("close", (code, signal) => {
      let msg = (code && code.toString()) || (signal && signal.toString());
      reject(new Error(`Liquid swap tool process closed unexpectedly: ${msg}`));
    });

    proc.on("exit", (code, signal) => {
      let msg = (code && code.toString()) || (signal && signal.toString());
      reject(new Error(`Liquid swap tool process exited unexpectedly: ${msg}`));
    });

    setTimeout(
      () => reject(new Error("Liquid swap tool timed out"), proc),
      timeout
    );
  });
};

app.get(
  "/orders",
  optionalAuth,
  ah(async (req, res) => {
    try {
      let orders = await db.Order.findAll({
        attributes: {
          include: [
            [col("acc1.asset"), "a1"],
            [col("acc2.asset"), "a2"]
          ]
        },
        include: [
          {
            model: db.Account,
            as: "acc1",
            attributes: []
          },
          {
            model: db.Account,
            as: "acc2",
            attributes: []
          }
        ]
      });

      res.send(
        orders.map(p => {
          if (p.user_id !== req.user.id) p.user_id = null;
          return p;
        })
      );
    } catch (e) {
      res.status(500).send(e.message);
    }
  })
);

app.post(
  "/publish",
  auth,
  ah(async (req, res) => {
    try {
      const { id } = req.body;
      await db.Order.update(
        { public: true },
        { where: { id, user_id: req.user.id } }
      );
      res.end();
    } catch (e) {
      res.status(500).send(e.message);
    }
  })
);

setInterval(async () => {
  if (!app.get("rates")) return;
  const amount = 0.01;
  const btc = "5ac9f65c0efcc4775e0baec4ec03abdde22473cd3cf33c0419ca290e0751b225";
  const lcad = "e749f7326d0ba155ec1d878e23458bc3f740a38bf91bbce955945ee10d6ab523";
  const { CAD, USD } = app.get("rates");
  const user = await db.User.findOne({
    where: {
      username: "maker"
    }
  });

  await db.transaction(async transaction => {
    let p = await db.Order.findOne(
      {
        where: {
          user_id: user.id,
          "$acc1.asset$": btc,
          accepted: false
        },
        include: [
          {
            model: db.Account,
            as: "acc1"
          }
        ]
      },
      { transaction }
    );

    let params = {
      a1: btc,
      a2: lcad,
      v1: amount * SATS,
      v2: Math.round(amount * SATS * (((app.get("ask") * CAD) / USD) * 1.01))
    };

    if (p && p.acc1.balance > p.v1) {
      p.v1 = params.v1;
      p.v2 = params.v2;
      await p.save();
      p = p.get({ plain: true });
      p.a1 = params.a1;
      p.a2 = params.a2;

      broadcast("order", shallow(p));
    } else { 
      try {
        await swap(user, params);
      } catch(e) {
        l.error("Failed to make ask", e.message);
      } 
    }

    p = await db.Order.findOne(
      {
        where: {
          user_id: user.id,
          "$acc1.asset$": lcad,
          accepted: false
        },
        include: [
          {
            model: db.Account,
            as: "acc1"
          }
        ]
      },
      { transaction }
    );

    params = {
      a1: lcad,
      a2: btc,
      v1: Math.round(amount * SATS * ((app.get("bid") * CAD) / USD) * 0.99),
      v2: amount * SATS
    }
    
    if (p && p.acc1.balance > p.v1) {
      p.v1 = params.v1;
      p.v2 = params.v2;
      await p.save();
      p = p.get({ plain: true });
      p.a1 = params.a1;
      p.a2 = params.a2;

      broadcast("order", shallow(p));
    } else { 
      try {
      await swap(user, params);
      } catch(e) {
        l.warn("Failed to make bid", e.message);
      } 
    }
  });
}, 6000);