import fs from "node:fs/promises";
import path from "node:path";
import { gzipSync } from "node:zlib";
import { spawn } from "node:child_process";
import Arweave from "arweave";
import mime from "mime-types";
import arbundles from "warp-arbundles";

const { createData, ArweaveSigner } = arbundles;

const root = process.cwd();
const distDir = path.join(root, "dist");
const sourceConfigPath = path.join(root, "src", "config.ts");
const DEFAULT_GATEWAY = "https://arweave.net";
const DEFAULT_UPLOAD_MODE = "arweave";
const UP_UPLOAD_MODE = "up";
const SUPPORTED_UPLOAD_MODES = new Set([DEFAULT_UPLOAD_MODE, UP_UPLOAD_MODE]);
const DEFAULT_UP_UPLOAD_SERVICE = "https://up.arweave.net";

function parseArg(name) {
  const raw = process.argv.find((arg) => arg.startsWith(`--${name}=`));
  if (!raw) return "";
  return raw.slice(name.length + 3).trim();
}

function buildGatewayConfig(gateway) {
  const parsed = new URL(gateway);
  return {
    host: parsed.hostname,
    port: parsed.port ? Number.parseInt(parsed.port, 10) : parsed.protocol === "https:" ? 443 : 80,
    protocol: parsed.protocol.replace(":", "")
  };
}

async function pathExists(targetPath) {
  try {
    await fs.access(targetPath);
    return true;
  } catch {
    return false;
  }
}

async function listFiles(dir) {
  const entries = await fs.readdir(dir, { withFileTypes: true });
  const nested = await Promise.all(
    entries.map(async (entry) => {
      const absolutePath = path.join(dir, entry.name);
      if (entry.isDirectory()) return listFiles(absolutePath);
      return [absolutePath];
    })
  );
  return nested.flat();
}

function runBinary(command, args, cwd) {
  return new Promise((resolve, reject) => {
    const child = spawn(command, args, {
      cwd,
      stdio: ["ignore", "pipe", "pipe"]
    });

    const stdoutChunks = [];
    let stderr = "";

    child.stdout.on("data", (chunk) => stdoutChunks.push(chunk));
    child.stderr.on("data", (chunk) => {
      stderr += chunk.toString();
    });

    child.on("error", reject);
    child.on("close", (code) => {
      if (code !== 0) {
        reject(new Error(`${command} exited with code ${code}${stderr ? `: ${stderr.trim()}` : ""}`));
        return;
      }
      resolve({ stdout: Buffer.concat(stdoutChunks), stderr });
    });
  });
}

async function createCodeArchiveBuffer() {
  const { stdout } = await runBinary(
    "tar",
    ["--exclude=./node_modules", "--exclude=./wallet.json", "-cf", "-", "."],
    root
  );
  return gzipSync(stdout);
}

async function loadWallet(arweave, walletArg) {
  const envWallet = process.env.ARWEAVE_WALLET?.trim();

  if (walletArg) {
    const absoluteWalletPath = path.resolve(root, walletArg);
    if (!(await pathExists(absoluteWalletPath))) {
      throw new Error(`Wallet file not found: ${absoluteWalletPath}`);
    }
    const jwkRaw = await fs.readFile(absoluteWalletPath, "utf8");
    return { walletPath: absoluteWalletPath, generated: false, jwk: JSON.parse(jwkRaw) };
  }

  if (envWallet) {
    const absoluteWalletPath = path.resolve(root, envWallet);
    if (!(await pathExists(absoluteWalletPath))) {
      throw new Error(`ARWEAVE_WALLET points to a missing file: ${absoluteWalletPath}`);
    }
    const jwkRaw = await fs.readFile(absoluteWalletPath, "utf8");
    return { walletPath: absoluteWalletPath, generated: false, jwk: JSON.parse(jwkRaw) };
  }

  const defaultWalletPath = path.join(root, "wallet.json");
  if (!(await pathExists(defaultWalletPath))) {
    const jwk = await arweave.wallets.generate();
    await fs.writeFile(defaultWalletPath, `${JSON.stringify(jwk, null, 2)}\n`, "utf8");
    return { walletPath: defaultWalletPath, generated: true, jwk };
  }

  const jwkRaw = await fs.readFile(defaultWalletPath, "utf8");
  return { walletPath: defaultWalletPath, generated: false, jwk: JSON.parse(jwkRaw) };
}

async function uploadTransaction(arweave, jwk, data, tags) {
  const tx = await arweave.createTransaction({ data }, jwk);
  for (const [key, value] of tags) tx.addTag(key, value);

  await arweave.transactions.sign(tx, jwk);
  const uploader = await arweave.transactions.getUploader(tx);
  while (!uploader.isComplete) await uploader.uploadChunk();
  return tx.id;
}

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

function isRetriableUploadError(message) {
  return (
    message.includes("timeout") ||
    message.includes("504") ||
    message.includes("502") ||
    message.includes("503") ||
    message.includes("429") ||
    message.includes("EAI_AGAIN") ||
    message.includes("ECONNRESET") ||
    message.includes("failed to fetch")
  );
}

async function uploadWithUpService(serviceUrl, signer, data, tags) {
  const payload = Buffer.isBuffer(data) ? data : Buffer.from(data);
  const dataItem = createData(payload, signer, {
    tags: tags.map(([name, value]) => ({ name, value }))
  });
  await dataItem.sign(signer);
  const txId = await dataItem.id;

  for (let attempt = 1; attempt <= 3; attempt += 1) {
    try {
      const response = await fetch(`${serviceUrl.replace(/\/+$/, "")}/tx`, {
        method: "POST",
        headers: { "content-type": "application/octet-stream" },
        body: dataItem.getRaw()
      });

      const bodyText = await response.text();
      if (!response.ok) {
        throw new Error(
          `up upload failed (${response.status}${bodyText ? `): ${bodyText.slice(0, 220)}` : ")"}`
        );
      }

      let responseTxId = "";
      try {
        const bodyJson = JSON.parse(bodyText);
        if (typeof bodyJson?.id === "string") responseTxId = bodyJson.id.trim();
      } catch {
        responseTxId = bodyText.trim();
      }

      return responseTxId || txId;
    } catch (error) {
      const message = error?.message || String(error);
      if (!isRetriableUploadError(message) || attempt === 3) throw error;
      await sleep(1500 * attempt);
    }
  }

  throw new Error("up upload failed unexpectedly.");
}

function resolveUploadMode(uploadModeArg) {
  const mode = (uploadModeArg || process.env.ARWEAVE_UPLOAD_MODE || DEFAULT_UPLOAD_MODE).trim();
  if (!SUPPORTED_UPLOAD_MODES.has(mode)) {
    throw new Error(
      `Unsupported upload mode "${mode}". Supported values: ${[...SUPPORTED_UPLOAD_MODES].join(", ")}`
    );
  }
  return mode;
}

async function createUploader(uploadMode, arweave, jwk) {
  if (uploadMode === DEFAULT_UPLOAD_MODE) {
    return {
      mode: DEFAULT_UPLOAD_MODE,
      serviceUrl: null,
      async beforeUpload() {},
      upload(data, tags) {
        return uploadTransaction(arweave, jwk, data, tags);
      }
    };
  }

  const signer = new ArweaveSigner(jwk);
  return {
    mode: UP_UPLOAD_MODE,
    serviceUrl: DEFAULT_UP_UPLOAD_SERVICE,
    async beforeUpload() {},
    upload(data, tags) {
      return uploadWithUpService(DEFAULT_UP_UPLOAD_SERVICE, signer, data, tags);
    }
  };
}

async function resolveBlogManifestTxId() {
  const source = await fs.readFile(sourceConfigPath, "utf8");
  const match = source.match(/MANIFEST_TX_ID\s*=\s*"([^"]+)"/);
  return match?.[1] || "";
}

async function resolvePostSlugs(gateway) {
  const blogManifestTxId = await resolveBlogManifestTxId();
  if (!blogManifestTxId) return [];

  try {
    const response = await fetch(`${gateway.replace(/\/+$/, "")}/${blogManifestTxId}`);
    if (!response.ok) return [];
    const payload = await response.json();
    if (!Array.isArray(payload?.posts)) return [];
    return payload.posts
      .map((post) => (typeof post?.slug === "string" ? post.slug.trim() : ""))
      .filter((slug) => slug.length > 0);
  } catch {
    return [];
  }
}

async function main() {
  const walletArg = parseArg("wallet");
  const gatewayArg = parseArg("gateway");
  const uploadModeArg = parseArg("upload-mode");
  const appName = parseArg("app-name") || "hyperzine";
  const appVersion = parseArg("app-version") || "1.0.0";
  const uploadMode = resolveUploadMode(uploadModeArg);
  const gateway = gatewayArg || process.env.ARWEAVE_GATEWAY || DEFAULT_GATEWAY;

  if (!(await pathExists(distDir))) {
    throw new Error("dist/ is missing. Run npm run build first.");
  }

  const arweave = Arweave.init({
    ...buildGatewayConfig(gateway),
    timeout: 30_000,
    logging: false
  });

  const { walletPath, generated, jwk } = await loadWallet(arweave, walletArg);
  console.log(`${generated ? "Generated" : "Using"} wallet: ${walletPath}`);
  console.log(`Gateway: ${gateway}`);
  console.log(`Upload mode: ${uploadMode}`);

  const uploader = await createUploader(uploadMode, arweave, jwk);
  if (uploader.serviceUrl) console.log(`Upload service: ${uploader.serviceUrl}`);
  await uploader.beforeUpload();

  const filePaths = await listFiles(distDir);
  if (!filePaths.length) {
    throw new Error("dist/ is empty. Run npm run build first.");
  }

  const codeArchiveData = await createCodeArchiveBuffer();
  const codeArchiveId = await uploader.upload(codeArchiveData, [
    ["Content-Type", "application/gzip"],
    ["Content-Encoding", "gzip"],
    ["App-Name", appName],
    ["App-Version", appVersion],
    ["Type", "code-archive"]
  ]);
  console.log(`Uploaded code archive: ${codeArchiveId}`);

  const pathMap = {};
  let indexTxId = "";

  for (const absolutePath of filePaths) {
    const relativePath = path.relative(distDir, absolutePath).replace(/\\/g, "/");
    const contentType = mime.lookup(relativePath) || "application/octet-stream";
    const data = await fs.readFile(absolutePath);

    const txId = await uploader.upload(data, [
      ["Content-Type", String(contentType)],
      ["App-Name", appName],
      ["App-Version", appVersion],
      ["Type", "app-asset"],
      ["File-Path", relativePath],
      ["code", codeArchiveId]
    ]);

    pathMap[relativePath] = { id: txId };
    if (relativePath === "index.html") indexTxId = txId;
    console.log(`Uploaded ${relativePath}: ${txId}`);
  }

  if (!indexTxId) {
    throw new Error("Could not find uploaded index.html. Dist output is invalid for SPA deploy.");
  }

  const slugs = await resolvePostSlugs(gateway);
  for (const slug of slugs) {
    pathMap[slug] = { id: indexTxId };
    pathMap[`${slug}/`] = { id: indexTxId };
  }

  const manifest = {
    manifest: "arweave/paths",
    version: "0.2.0",
    index: { path: "index.html" },
    paths: pathMap
  };

  const manifestId = await uploader.upload(JSON.stringify(manifest), [
    ["Content-Type", "application/x.arweave-manifest+json"],
    ["App-Name", appName],
    ["App-Version", appVersion],
    ["Type", "manifest"],
    ["code", codeArchiveId]
  ]);

  const appUrl = `${gateway.replace(/\/+$/, "")}/${manifestId}/`;
  const codeArchiveUrl = `${gateway.replace(/\/+$/, "")}/${codeArchiveId}`;

  console.log("");
  console.log(`Code Archive ID: ${codeArchiveId}`);
  console.log(`Code Archive URL: ${codeArchiveUrl}`);
  console.log(`Manifest ID (AppArweaveID): ${manifestId}`);
  console.log(`App URL: ${appUrl}`);
  if (slugs.length) {
    console.log(`Slug route aliases: ${slugs.join(", ")}`);
  } else {
    console.log("Slug route aliases: none generated.");
  }
}

main().catch((error) => {
  console.error(error?.message || String(error));
  process.exit(1);
});