import axios from "axios";
import qs from "qs";
import { HttpsProxyAgent } from "https-proxy-agent";
import { AssetType, Chain, ClobClient, OrderType, Side, SignatureTypeV2 } from "@polymarket/clob-client-v2";
import { BuilderConfig } from "@polymarket/builder-signing-sdk";
import { deriveProxyWallet, RelayerTxType, RelayClient } from "@polymarket/builder-relayer-client";
import {
  createPublicClient,
  createWalletClient,
  encodeFunctionData,
  erc20Abi,
  formatUnits,
  http,
  parseUnits,
} from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { polygon } from "viem/chains";

export { OrderType, Side, SignatureTypeV2 };

const CHAIN_ID = 137;
const GAMMA_HOST = "https://gamma-api.polymarket.com";
const CLOB_HOST = "https://clob.polymarket.com";
const PUSD_ADDRESS = "0xC011a7E12a19f7B1f670d46F03B03f3342E82DFB";
const PUSD_DECIMALS = 6;
const PROXY_FACTORY_ADDRESS = "0xaB45c5A4B0c941a2F231C04C3f49182e1A254052";

const axiosDefaultOptions = {
  baseURL: "",
  url: "",
  method: "GET",
  headers: {},
  params: {},
  data: {},
  timeout: 10000,
};

const clientRequest = async (options, baseURL, proxyAgent) => {
  const { url } = options;
  if (!url || !baseURL) {
    throw new Error("url and baseURL are required");
  }

  return axios({
    ...axiosDefaultOptions,
    ...options,
    baseURL,
    proxy: false,
    ...(proxyAgent ? { httpAgent: proxyAgent, httpsAgent: proxyAgent } : {}),
    paramsSerializer: params => qs.stringify(params, { arrayFormat: "repeat" }),
  }).then(res => res.data);
}

const getRequiredConfig = (config, key) => {
  const value = config[key];
  if (!value) {
    throw new Error(`${key} is required`);
  }
  return value;
}

const normalizePrivateKey = (privateKey) => {
  return privateKey.startsWith("0x") ? privateKey : `0x${privateKey}`;
}

const getOptionalConfig = (config, key) => {
  const value = config[key];
  return value && String(value).trim() ? String(value).trim() : undefined;
}

const getPolymarketFunderAddress = (config, accountAddress) => {
  return getOptionalConfig(config, "depositWalletAddress")
    || getOptionalConfig(config, "funderAddress")
    || accountAddress;
}

const getPolymarketSignatureType = (config, funderAddress, accountAddress) => {
  const configuredType = getOptionalConfig(config, "signatureType");
  if (configuredType) {
    const signatureType = SignatureTypeV2[configuredType] ?? Number(configuredType);
    if (!Number.isInteger(signatureType) || !SignatureTypeV2[signatureType]) {
      throw new Error(`signatureType is invalid: ${configuredType}`);
    }
    return signatureType;
  }

  return funderAddress.toLowerCase() === accountAddress.toLowerCase()
    ? SignatureTypeV2.POLY_PROXY
    : SignatureTypeV2.POLY_1271;
}

const createViemHttpTransport = (rpcUrl, proxyAgent) => {
  if (!proxyAgent) {
    return rpcUrl ? http(rpcUrl) : http();
  }

  const fetchFn = async (url, init = {}) => {
    const headers = Object.fromEntries(new Headers(init.headers ?? {}).entries());
    const response = await axios({
      url,
      method: init.method || "POST",
      headers,
      data: init.body,
      transformResponse: [data => data],
      responseType: "text",
      validateStatus: () => true,
      proxy: false,
      httpAgent: proxyAgent,
      httpsAgent: proxyAgent,
    });

    return new Response(response.data, {
      status: response.status,
      statusText: response.statusText,
      headers: response.headers,
    });
  };

  return http(rpcUrl, { fetchFn });
}

export const createPolymarketSdk = (config = {}) => {
  const proxyAgent = config.httpProxy ? new HttpsProxyAgent(config.httpProxy) : undefined;

  const requestMarketData = (options) => clientRequest(options, GAMMA_HOST, proxyAgent);
  const requestClobData = (options) => clientRequest(options, CLOB_HOST, proxyAgent);

  const createClobClient = () => {
    const account = privateKeyToAccount(normalizePrivateKey(getRequiredConfig(config, "privateKey")));
    const signer = createWalletClient({
      account,
      chain: polygon,
      transport: createViemHttpTransport(getOptionalConfig(config, "polygonRpcUrl"), proxyAgent),
    });
    const funderAddress = getPolymarketFunderAddress(config, account.address);
    const userApiCreds = {
      key: getRequiredConfig(config, "apiKey"),
      secret: getRequiredConfig(config, "apiSecret"),
      passphrase: getRequiredConfig(config, "apiPassphrase"),
    };

    return new ClobClient({
      host: CLOB_HOST,
      chain: Chain.POLYGON,
      signer,
      creds: userApiCreds,
      signatureType: getPolymarketSignatureType(config, funderAddress, account.address),
      funderAddress,
      throwOnError: true,
    });
  }

  const createPolymarketContext = () => {
    const transport = createViemHttpTransport(getOptionalConfig(config, "polygonRpcUrl"), proxyAgent);
    const account = privateKeyToAccount(normalizePrivateKey(getRequiredConfig(config, "privateKey")));
    const signer = createWalletClient({ account, chain: polygon, transport });
    const publicClient = createPublicClient({ chain: polygon, transport });
    const creds = {
      key: getRequiredConfig(config, "apiKey"),
      secret: getRequiredConfig(config, "apiSecret"),
      passphrase: getRequiredConfig(config, "apiPassphrase"),
    };

    return { account, signer, publicClient, creds };
  }

  const createBuilderConfig = () => {
    return new BuilderConfig({
      localBuilderCreds: {
        key: getRequiredConfig(config, "builderApiKey"),
        secret: getRequiredConfig(config, "builderSecret"),
        passphrase: getRequiredConfig(config, "builderPassPhrase"),
      },
    });
  }

  const createRelayer = ({ signer, relayTxType = RelayerTxType.PROXY } = {}) => {
    const relayerUrl = getOptionalConfig(config, "relayerUrl") || "https://relayer-v2.polymarket.com";
    const relayer = new RelayClient(relayerUrl, CHAIN_ID, signer, createBuilderConfig(), relayTxType);
    if (proxyAgent) {
      relayer.httpClient.instance.defaults.proxy = false;
      relayer.httpClient.instance.defaults.httpAgent = proxyAgent;
      relayer.httpClient.instance.defaults.httpsAgent = proxyAgent;
    }
    return relayer;
  }

  const getProxyWalletAddress = ({ ownerAddress }) => {
    return getOptionalConfig(config, "proxyWalletAddress")
      || deriveProxyWallet(ownerAddress, PROXY_FACTORY_ADDRESS);
  }

  const getDepositWalletAddress = async ({ signer }) => {
    const configuredAddress = getOptionalConfig(config, "depositWalletAddress");
    if (configuredAddress) {
      return configuredAddress;
    }

    const relayer = createRelayer({ signer });
    return relayer.deriveDepositWalletAddress();
  }

  const normalizeWalletMode = (wallet = "both") => {
    const value = wallet.toLowerCase();
    if (!["deposit", "proxy", "both"].includes(value)) {
      throw new Error("wallet must be deposit, proxy, or both", { cause: 400 });
    }
    return value;
  }

  const createBalanceClobClient = ({ signer, creds, funderAddress, signatureType }) => {
    return new ClobClient({
      host: CLOB_HOST,
      chain: Chain.POLYGON,
      signer,
      creds,
      signatureType,
      funderAddress,
      throwOnError: true,
    });
  }

  const getChainPusdBalance = async ({ publicClient, address }) => {
    const balance = await publicClient.readContract({
      address: PUSD_ADDRESS,
      abi: erc20Abi,
      functionName: "balanceOf",
      args: [address],
    });
    return formatUnits(balance, PUSD_DECIMALS);
  }

  const getClobBalanceAllowance = async ({ signer, creds, funderAddress, signatureType }) => {
    const client = createBalanceClobClient({ signer, creds, funderAddress, signatureType });
    return client.getBalanceAllowance({ asset_type: AssetType.COLLATERAL });
  }

  const getRawPusdBalance = ({ publicClient, address }) => {
    return publicClient.readContract({
      address: PUSD_ADDRESS,
      abi: erc20Abi,
      functionName: "balanceOf",
      args: [address],
    });
  }

  const normalizeTransferAmount = (amount) => {
    if (!amount || !Number.isFinite(Number(amount)) || Number(amount) <= 0) {
      throw new Error("amount must be greater than 0", { cause: 400 });
    }
    return parseUnits(String(amount), PUSD_DECIMALS);
  }

  const normalizeTransferDirection = ({ from, to } = {}) => {
    const normalizedFrom = String(from || "").toLowerCase();
    const normalizedTo = String(to || "").toLowerCase();
    if (
      !["proxy", "deposit"].includes(normalizedFrom)
      || !["proxy", "deposit"].includes(normalizedTo)
      || normalizedFrom === normalizedTo
    ) {
      throw new Error("Transfer direction must be proxy -> deposit or deposit -> proxy", { cause: 400 });
    }
    return { from: normalizedFrom, to: normalizedTo };
  }

  const createPusdTransferData = ({ to, amount }) => {
    return encodeFunctionData({
      abi: erc20Abi,
      functionName: "transfer",
      args: [to, amount],
    });
  }

  const buildTransferResult = ({
    owner,
    from,
    to,
    sourceAddress,
    destinationAddress,
    amount,
    sourceBalance,
    transactionID,
    transactionHash,
    confirmed,
  }) => {
    return {
      owner,
      pUSD: PUSD_ADDRESS,
      from,
      to,
      sourceAddress,
      destinationAddress,
      amount: String(amount),
      sourceBalance: formatUnits(sourceBalance, PUSD_DECIMALS),
      transactionID,
      transactionHash,
      confirmed,
    };
  }

  const ensureSufficientPusdBalance = ({ wallet, balance, amount }) => {
    if (balance < amount) {
      throw new Error(`Insufficient ${wallet} wallet pUSD balance: ${formatUnits(balance, PUSD_DECIMALS)}`, { cause: 400 });
    }
  }

  const getTransferWalletContext = async () => {
    const { account, signer, publicClient } = createPolymarketContext();
    const proxyRelayer = createRelayer({ signer, relayTxType: RelayerTxType.PROXY });
    const proxyWalletAddress = getProxyWalletAddress({ ownerAddress: account.address });
    const depositWalletAddress = await getDepositWalletAddress({ signer });

    return {
      account,
      signer,
      publicClient,
      proxyRelayer,
      proxyWalletAddress,
      depositWalletAddress,
    };
  }

  const executePusdTransfer = ({
    from,
    to,
    context,
    data,
    amount,
  }) => {
    if (from === "proxy" && to === "deposit") {
      return context.proxyRelayer.execute(
        [{
          to: PUSD_ADDRESS,
          data,
          value: "0",
        }],
        `transfer ${amount} pUSD from proxy to deposit wallet`,
      );
    }

    const depositRelayer = createRelayer({ signer: context.signer });
    return depositRelayer.executeDepositWalletBatch(
      [{
        target: PUSD_ADDRESS,
        data,
        value: "0",
      }],
      context.depositWalletAddress,
      String(Math.floor(Date.now() / 1000) + 600),
    );
  }

  const transferPusdBetweenWallets = async ({ amount, from, to } = {}) => {
    const transferAmount = normalizeTransferAmount(amount);
    const context = await getTransferWalletContext();
    const sourceAddress = from === "proxy"
      ? context.proxyWalletAddress
      : context.depositWalletAddress;
    const destinationAddress = to === "proxy"
      ? context.proxyWalletAddress
      : context.depositWalletAddress;
    const sourceBalance = await getRawPusdBalance({
      publicClient: context.publicClient,
      address: sourceAddress,
    });
    ensureSufficientPusdBalance({
      wallet: from,
      balance: sourceBalance,
      amount: transferAmount,
    });

    const data = createPusdTransferData({
      to: destinationAddress,
      amount: transferAmount,
    });
    const response = await executePusdTransfer({
      from,
      to,
      context,
      data,
      amount,
    });
    const confirmed = await response.wait();

    return buildTransferResult({
      owner: context.account.address,
      from,
      to,
      sourceAddress,
      destinationAddress,
      amount,
      sourceBalance,
      transactionID: response.transactionID,
      transactionHash: response.transactionHash || response.hash,
      confirmed,
    });
  }

  const getSoccerSports = async () => {
    return requestMarketData({ url: "/sports" })
    .then(sportsData => {
      return sportsData.filter(item => {
        const { tags } = item;
        const tagIds = tags.split(",").map(item => +item);
        return tagIds.includes(100350);
      });
    });
  }

  const getEvents = async ({
    limit = 500, tag_id = 100350, active = true,
    closed = false, endDateMin = "", endDateMax = "",
  } = {}) => {
    return requestMarketData({
      url: "/events",
      params: {
        limit, tag_id, active, closed,
        end_date_min: endDateMin,
        end_date_max: endDateMax,
      }
    }).then(events => events.filter(item => !!item.series));
  }

  const getOrderBook = async (tokenId) => {
    return requestClobData({
      url: "/book",
      params: {
        token_id: tokenId,
      }
    });
  }

  const getMultipleOrderBooks = async (tokenIds) => {
    return requestClobData({
      url: "/books",
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      data: tokenIds.map(tokenId => ({ token_id: tokenId })),
    });
  }

  const getBalanceAllowance = async ({ wallet = "both" } = {}) => {
    const walletMode = normalizeWalletMode(wallet);
    const { account, signer, publicClient, creds } = createPolymarketContext();
    const wallets = [];

    if (walletMode === "proxy" || walletMode === "both") {
      wallets.push({
        type: "proxy",
        address: getProxyWalletAddress({ ownerAddress: account.address }),
        signatureType: SignatureTypeV2.POLY_PROXY,
      });
    }

    if (walletMode === "deposit" || walletMode === "both") {
      wallets.push({
        type: "deposit",
        address: await getDepositWalletAddress({ signer }),
        signatureType: SignatureTypeV2.POLY_1271,
      });
    }

    const results = [];
    for (const item of wallets) {
      const [chainPusdBalance, clobBalanceAllowance] = await Promise.all([
        getChainPusdBalance({ publicClient, address: item.address }),
        getClobBalanceAllowance({
          signer,
          creds,
          funderAddress: item.address,
          signatureType: item.signatureType,
        }),
      ]);
      results.push({
        type: item.type,
        owner: account.address,
        address: item.address,
        signatureType: SignatureTypeV2[item.signatureType],
        chainPusdBalance,
        clobBalanceAllowance,
      });
    }

    return results;
  }

  const transferWallet = async ({ amount, from, to } = {}) => {
    const direction = normalizeTransferDirection({ from, to });
    return transferPusdBetweenWallets({
      amount,
      from: direction.from,
      to: direction.to,
    });
  }

  const createLimitOrder = async ({
    tokenID,
    price,
    size,
    side = Side.BUY,
    tickSize = "0.01",
    negRisk = false,
    orderType = OrderType.GTC,
    postOnly = true,
    expiration,
    deferExec = false,
  } = {}) => {
    return Promise.reject(new Error("not implemented", { cause: 501 }));
    if (!tokenID) {
      throw new Error("tokenID is required", { cause: 400 });
    }
    if (!Number.isFinite(Number(price))) {
      throw new Error("price is required", { cause: 400 });
    }
    if (!Number.isFinite(Number(size))) {
      throw new Error("size is required", { cause: 400 });
    }
    if (orderType !== OrderType.GTC && orderType !== OrderType.GTD) {
      throw new Error(`orderType must be ${OrderType.GTC} or ${OrderType.GTD}`, { cause: 400 });
    }

    const client = createClobClient();
    return client.createAndPostOrder({
      tokenID,
      price: Number(price),
      size: Number(size),
      side,
      ...(expiration ? { expiration: Number(expiration) } : {}),
    }, { tickSize, negRisk }, orderType, postOnly, deferExec);
  }

  const getOrder = async (orderID) => {
    if (!orderID) {
      throw new Error("orderID is required", { cause: 400 });
    }

    const client = createClobClient();
    return client.getOrder(orderID);
  }

  const getOpenOrders = async ({
    id,
    market,
    asset_id,
    only_first_page = false,
    next_cursor,
  } = {}) => {
    const client = createClobClient();
    return client.getOpenOrders({
      ...(id ? { id } : {}),
      ...(market ? { market } : {}),
      ...(asset_id ? { asset_id } : {}),
    }, Boolean(only_first_page), next_cursor);
  }

  return {
    createClobClient,
    getSoccerSports,
    getEvents,
    getOrderBook,
    getMultipleOrderBooks,
    getBalanceAllowance,
    transferWallet,
    createLimitOrder,
    getOrder,
    getOpenOrders,
  };
}

export default createPolymarketSdk;