#!/usr/bin/env node
import { spawnSync } from "node:child_process";
import path from "node:path";
import process from "node:process";
import { fileURLToPath } from "node:url";

export class SourceProvenanceError extends Error {
  constructor(code) {
    super(code);
    this.name = "SourceProvenanceError";
    this.code = code;
  }
}

const ALLOWED_UNPUBLISHED_REASONS = new Set([
  "offline-disaster-recovery",
  "remote-outage-approved",
  "controlled-local-recovery",
]);

export function deriveCandidateBuildEnv(commit) {
  const normalized = String(commit ?? "").trim();
  if (!/^[0-9a-f]{40,64}$/u.test(normalized)) {
    throw new SourceProvenanceError("commit_invalid");
  }
  return Object.freeze({
    BUILD_SHA: normalized,
    VITE_BUILD_SHA: normalized.slice(0, 12),
  });
}

function runGit(rootDir, args) {
  return spawnSync("git", args, {
    cwd: rootDir,
    encoding: "utf8",
    stdio: ["ignore", "pipe", "pipe"],
  });
}

function gitText(rootDir, args, failureCode) {
  const result = runGit(rootDir, args);
  if (result.status !== 0) {
    throw new SourceProvenanceError(failureCode);
  }
  return result.stdout.trim();
}

export function collectSourceProvenance({ rootDir, allowUnpublished = false }) {
  const inside = gitText(rootDir, ["rev-parse", "--is-inside-work-tree"], "not_a_git_worktree");
  if (inside !== "true") {
    throw new SourceProvenanceError("not_a_git_worktree");
  }

  const dirty = gitText(
    rootDir,
    ["status", "--porcelain=v1", "--untracked-files=all"],
    "git_status_failed",
  );
  if (dirty) {
    throw new SourceProvenanceError("dirty_worktree");
  }

  const commit = gitText(rootDir, ["rev-parse", "--verify", "HEAD"], "commit_unavailable");
  const buildEnv = deriveCandidateBuildEnv(commit);
  const branch = gitText(rootDir, ["branch", "--show-current"], "branch_unavailable") || "detached";
  const upstreamResult = runGit(rootDir, ["rev-parse", "--abbrev-ref", "--symbolic-full-name", "@{upstream}"]);
  const upstream = upstreamResult.status === 0 ? upstreamResult.stdout.trim() : null;
  if (!upstream && !allowUnpublished) {
    throw new SourceProvenanceError("upstream_missing");
  }

  const published = Boolean(upstream) && runGit(rootDir, ["merge-base", "--is-ancestor", commit, upstream]).status === 0;
  if (!published && !allowUnpublished) {
    throw new SourceProvenanceError("commit_not_in_upstream");
  }

  return {
    status: "PASS",
    commit: buildEnv.BUILD_SHA,
    shortCommit: buildEnv.VITE_BUILD_SHA,
    buildEnv,
    branch,
    upstream,
    published,
    overrideUsed: !published,
  };
}

export function refreshUpstreamRef({ rootDir, allowFailure = false }) {
  const branch = gitText(rootDir, ["branch", "--show-current"], "branch_unavailable");
  const upstreamResult = runGit(rootDir, ["rev-parse", "--abbrev-ref", "--symbolic-full-name", "@{upstream}"]);
  const upstream = upstreamResult.status === 0 ? upstreamResult.stdout.trim() : null;
  if (!upstream) {
    if (allowFailure) {
      return { refreshed: false, upstream: null, remote: null, code: "upstream_missing" };
    }
    throw new SourceProvenanceError("upstream_missing");
  }

  const remoteResult = runGit(rootDir, ["config", "--get", `branch.${branch}.remote`]);
  const remote = remoteResult.status === 0 ? remoteResult.stdout.trim() : null;
  if (!remote || remote === ".") {
    if (allowFailure) {
      return { refreshed: false, upstream, remote: null, code: "upstream_remote_missing" };
    }
    throw new SourceProvenanceError("upstream_remote_missing");
  }

  const fetchResult = runGit(rootDir, ["fetch", "--quiet", "--prune", remote]);
  if (fetchResult.status !== 0) {
    if (allowFailure) {
      return { refreshed: false, upstream, remote, code: "upstream_refresh_failed" };
    }
    throw new SourceProvenanceError("upstream_refresh_failed");
  }
  return { refreshed: true, upstream, remote, code: null };
}

function parseRootArg(argv) {
  const item = argv.find((value) => value.startsWith("--root="));
  if (item) {
    return path.resolve(item.slice("--root=".length));
  }
  return path.resolve(new URL("../..", import.meta.url).pathname);
}

function main() {
  try {
    const rootDir = parseRootArg(process.argv.slice(2));
    const allowUnpublished = process.env.DEPLOY_ALLOW_UNPUBLISHED_COMMIT === "1";
    const overrideReason = String(process.env.DEPLOY_UNPUBLISHED_REASON ?? "").trim();
    if (allowUnpublished && !ALLOWED_UNPUBLISHED_REASONS.has(overrideReason)) {
      throw new SourceProvenanceError("unpublished_override_reason_invalid");
    }

    collectSourceProvenance({ rootDir, allowUnpublished: true });
    const refresh = refreshUpstreamRef({ rootDir, allowFailure: allowUnpublished });
    const result = collectSourceProvenance({ rootDir, allowUnpublished });
    console.log(JSON.stringify({
      ...result,
      remoteVerified: refresh.refreshed,
      upstreamRefreshCode: refresh.code,
      overrideRequested: allowUnpublished,
      overrideReason: allowUnpublished ? overrideReason : null,
    }));
  } catch (error) {
    const code = error instanceof SourceProvenanceError ? error.code : "unexpected_error";
    console.error(JSON.stringify({ status: "FAIL", code }));
    process.exitCode = 1;
  }
}

const isMain = process.argv[1] && path.resolve(process.argv[1]) === fileURLToPath(import.meta.url);
if (isMain) {
  main();
}