const https = require("https");
const http = require("http");
const {
  allAssetNames,
  allReleaseAssetNames,
  checksumManifestUrl,
  releaseAssetUrl,
} = require("./artifacts");

const pkg = require("../package.json");

function resolveBinaryVersion() {
  const configuredVersion =
    process.env.DEEPSEEK_TUI_VERSION ||
    process.env.DEEPSEEK_VERSION ||
    pkg.codewhaleBinaryVersion || pkg.deepseekBinaryVersion ||
    pkg.version;
  return String(configuredVersion).trim();
}

function resolveRepo() {
  return process.env.DEEPSEEK_TUI_GITHUB_REPO || process.env.DEEPSEEK_GITHUB_REPO || "Hmbown/CodeWhale";
}

function hasReleaseBaseOverride() {
  return Boolean(
    process.env.CODEWHALE_RELEASE_BASE_URL ||
      process.env.DEEPSEEK_TUI_RELEASE_BASE_URL ||
      process.env.DEEPSEEK_RELEASE_BASE_URL ||
      process.env.CODEWHALE_USE_CNB_MIRROR,
  );
}

function packageVersionMatchesBinaryVersion(version) {
  return String(pkg.version).trim() === version;
}

function assertPackageVersionMatchesBinaryVersion(version) {
  if (packageVersionMatchesBinaryVersion(version)) {
    return;
  }
  if (process.env.CODEWHALE_ALLOW_NPM_BINARY_MISMATCH === "1") {
    console.log(
      `npm package version ${pkg.version} points at binary release ${version} (allowed packaging-only mismatch).`,
    );
    return;
  }
  throw new Error(
    `npm package version ${pkg.version} does not match codewhaleBinaryVersion ${version}. ` +
      "Set CODEWHALE_ALLOW_NPM_BINARY_MISMATCH=1 only for an intentional packaging-only npm release.",
  );
}

function requestStatus(url, method = "HEAD", redirects = 0) {
  if (redirects > 10) {
    throw new Error(`Too many redirects while checking ${url}`);
  }
  const client = url.startsWith("https:") ? https : http;
  return new Promise((resolve, reject) => {
    const req = client.request(
      url,
      {
        method,
        headers: {
          "User-Agent": "codewhale-npm-release-check",
        },
      },
      (res) => {
        const status = res.statusCode || 0;
        const location = res.headers.location;
        res.resume();
        if (status >= 300 && status < 400 && location) {
          const next = new URL(location, url).toString();
          resolve(requestStatus(next, method, redirects + 1));
          return;
        }
        resolve(status);
      },
    );
    req.on("error", reject);
    req.end();
  });
}

async function verifyAsset(url, label) {
  let status = await requestStatus(url, "HEAD");
  if (status === 403 || status === 405) {
    status = await requestStatus(url, "GET");
  }
  if (status < 200 || status >= 400) {
    throw new Error(`${label} returned HTTP ${status} (${url})`);
  }
}

async function downloadText(url, redirects = 0) {
  if (redirects > 10) {
    throw new Error(`Too many redirects while downloading ${url}`);
  }
  const client = url.startsWith("https:") ? https : http;
  return new Promise((resolve, reject) => {
    client
      .get(
        url,
        {
          headers: {
            "User-Agent": "codewhale-npm-release-check",
          },
        },
        (res) => {
          const status = res.statusCode || 0;
          if (status >= 300 && status < 400 && res.headers.location) {
            const next = new URL(res.headers.location, url).toString();
            res.resume();
            resolve(downloadText(next, redirects + 1));
            return;
          }
          if (status !== 200) {
            reject(new Error(`Request failed with status ${status}: ${url}`));
            res.resume();
            return;
          }
          const chunks = [];
          res.setEncoding("utf8");
          res.on("data", (chunk) => chunks.push(chunk));
          res.on("end", () => resolve(chunks.join("")));
        },
      )
      .on("error", reject);
  });
}

async function downloadJson(url, redirects = 0) {
  if (redirects > 10) {
    throw new Error(`Too many redirects while downloading ${url}`);
  }
  const client = url.startsWith("https:") ? https : http;
  return new Promise((resolve, reject) => {
    const headers = {
      Accept: "application/vnd.github+json",
      "User-Agent": "codewhale-npm-release-check",
      "X-GitHub-Api-Version": "2022-11-28",
    };
    const token = process.env.GITHUB_TOKEN || process.env.GH_TOKEN;
    if (token) {
      headers.Authorization = `Bearer ${token}`;
    }
    client
      .get(url, { headers }, (res) => {
        const status = res.statusCode || 0;
        if (status >= 300 && status < 400 && res.headers.location) {
          const next = new URL(res.headers.location, url).toString();
          res.resume();
          resolve(downloadJson(next, redirects + 1));
          return;
        }
        const chunks = [];
        res.setEncoding("utf8");
        res.on("data", (chunk) => chunks.push(chunk));
        res.on("end", () => {
          const body = chunks.join("");
          let parsed;
          try {
            parsed = body ? JSON.parse(body) : {};
          } catch (error) {
            reject(new Error(`Invalid JSON from ${url}: ${error.message}`));
            return;
          }
          if (status < 200 || status >= 300) {
            const message = parsed.message ? `: ${parsed.message}` : "";
            reject(new Error(`GitHub API request failed with status ${status}${message} (${url})`));
            return;
          }
          resolve(parsed);
        });
      })
      .on("error", reject);
  });
}

function githubApiUrl(repo, path) {
  return `https://api.github.com/repos/${repo}${path}`;
}

async function githubApi(repo, path) {
  return downloadJson(githubApiUrl(repo, path));
}

async function resolveTagCommitSha(repo, tag) {
  const ref = await githubApi(repo, `/git/ref/tags/${encodeURIComponent(tag)}`);
  if (!ref.object || !ref.object.sha || !ref.object.type) {
    throw new Error(`GitHub tag ref ${tag} did not include an object SHA`);
  }
  if (ref.object.type === "commit") {
    return ref.object.sha;
  }
  if (ref.object.type !== "tag") {
    throw new Error(`GitHub tag ref ${tag} points at ${ref.object.type}, not a commit or annotated tag`);
  }
  const tagObject = await githubApi(repo, `/git/tags/${ref.object.sha}`);
  if (!tagObject.object || tagObject.object.type !== "commit" || !tagObject.object.sha) {
    throw new Error(`Annotated tag ${tag} did not peel to a commit SHA`);
  }
  return tagObject.object.sha;
}

async function findReleaseWorkflowRun(repo, tag, tagSha) {
  const runs = await githubApi(repo, "/actions/workflows/release.yml/runs?per_page=100");
  const matches = (runs.workflow_runs || [])
    .filter((run) => run.head_sha === tagSha)
    .filter((run) => run.conclusion === "success")
    .filter((run) => run.event === "push" || run.event === "workflow_dispatch")
    .sort((a, b) => String(b.updated_at).localeCompare(String(a.updated_at)));
  const tagBranchMatch = matches.find((run) => run.head_branch === tag);
  const match = tagBranchMatch || matches[0];
  if (!match) {
    throw new Error(
      `No successful release.yml workflow run found for ${tag} at ${tagSha}. ` +
        "Rerun the Release workflow before publishing npm, or increase the verifier's last-100-runs search window.",
    );
  }
  return match;
}

function parseGitHubTime(value, label) {
  const timestamp = Date.parse(value);
  if (!Number.isFinite(timestamp)) {
    throw new Error(`GitHub ${label} timestamp is invalid: ${value}`);
  }
  return timestamp;
}

function assertReleaseAssetsFresh(release, expectedAssets, run) {
  const assetsByName = new Map((release.assets || []).map((asset) => [asset.name, asset]));
  const missing = expectedAssets.filter((asset) => !assetsByName.has(asset));
  if (missing.length > 0) {
    throw new Error(`GitHub Release is missing required npm-facing asset(s): ${missing.join(", ")}`);
  }

  const runStartedAt = parseGitHubTime(run.run_started_at || run.created_at, "workflow run start");
  const stale = [];
  for (const expected of expectedAssets) {
    const asset = assetsByName.get(expected);
    if (asset.state && asset.state !== "uploaded") {
      stale.push(`${expected} has state ${asset.state}`);
      continue;
    }
    const updatedAt = parseGitHubTime(asset.updated_at || asset.created_at, `${expected} update`);
    if (updatedAt < runStartedAt) {
      stale.push(`${expected} updated at ${asset.updated_at || asset.created_at}`);
    }
  }

  if (stale.length > 0) {
    throw new Error(
      `GitHub Release asset set is stale for workflow run ${run.database_id || run.id}: ${stale.join("; ")}`,
    );
  }
}

async function verifyGitHubReleaseFreshness(repo, version, expectedAssets) {
  const tag = `v${version}`;
  const tagSha = await resolveTagCommitSha(repo, tag);
  const release = await githubApi(repo, `/releases/tags/${encodeURIComponent(tag)}`);
  const run = await findReleaseWorkflowRun(repo, tag, tagSha);
  assertReleaseAssetsFresh(release, expectedAssets, run);
  console.log(
    `GitHub release asset freshness OK: ${expectedAssets.length} npm-facing assets for ${tag} were produced by run ${run.database_id || run.id} at ${tagSha.slice(0, 12)}.`,
  );
}

function parseChecksumManifest(text) {
  const checksums = new Map();
  for (const line of text.split(/\r?\n/)) {
    const trimmed = line.trim();
    if (!trimmed) {
      continue;
    }
    const match = trimmed.match(/^([a-fA-F0-9]{64})\s+\*?(.+)$/);
    if (!match) {
      throw new Error(`Invalid checksum manifest line: ${trimmed}`);
    }
    checksums.set(match[2], match[1].toLowerCase());
  }
  return checksums;
}

async function run() {
  const version = resolveBinaryVersion();
  const repo = resolveRepo();
  const assets = allReleaseAssetNames();

  assertPackageVersionMatchesBinaryVersion(version);

  console.log(`Verifying ${assets.length} release assets for ${repo}@v${version}...`);
  if (hasReleaseBaseOverride()) {
    console.log("Skipping GitHub workflow freshness check because a release asset mirror/base URL override is set.");
  } else {
    await verifyGitHubReleaseFreshness(repo, version, assets);
  }
  for (const asset of assets) {
    const url = releaseAssetUrl(asset, version, repo);
    await verifyAsset(url, asset);
    console.log(`  ok ${asset}`);
  }
  const checksums = parseChecksumManifest(
    await downloadText(checksumManifestUrl(version, repo)),
  );
  for (const asset of allAssetNames()) {
    if (!checksums.has(asset)) {
      throw new Error(`Checksum manifest is missing ${asset}`);
    }
  }
  console.log("Release assets verified.");
}

if (require.main === module) {
  run().catch((error) => {
    console.error("Release asset verification failed:", error.message);
    process.exit(1);
  });
}

module.exports = {
  assertPackageVersionMatchesBinaryVersion,
  assertReleaseAssetsFresh,
  hasReleaseBaseOverride,
  parseChecksumManifest,
};