/**
 * Generates src/generated/versionInfo.json with the project's current version,
 * git tag/describe info, and the last commit's metadata. Consumed by the admin
 * VersionOverlay via GET /api/version (the file is read at runtime so a fresh
 * post-bump regeneration rsync'd to the server shows up without a rebuild).
 *
 * Git metadata resolution order (first non-empty wins):
 *   1. Environment variables — explicit overrides for CI systems that inject
 *      metadata as env vars:
 *        GIT_TAG, GIT_DESCRIBE, GIT_COMMIT_HASH, GIT_COMMIT_DATE, GIT_COMMIT_SUBJECT
 *   2. SOURCE_COMMIT — the commit SHA Coolify injects as a build arg when
 *      "Include Source Commit in Build" is enabled (application settings →
 *      Advanced). Coolify strips `.git` from the build context, so `git` is
 *      unavailable there. Only the SHA is provided — tags, date, and subject
 *      have no Coolify equivalent and stay null in that case.
 *   3. `git` from the project root — the local-dev path (and any build context
 *      that still contains .git, e.g. a local `docker build`).
 *
 * Gracefully no-ops on missing git metadata (no .git, no tags, no env) so the
 * JSON always exists with whatever fields are resolvable.
 */
import { execSync } from "node:child_process";
import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const here = path.dirname(fileURLToPath(import.meta.url));
const projectRoot = path.resolve(here, "..", "..");

function git(args: string): string | null {
  try {
    const out = execSync(`git ${args}`, { cwd: projectRoot, encoding: "utf8" });
    const trimmed = out.trim();
    return trimmed.length > 0 ? trimmed : null;
  } catch {
    return null;
  }
}

function envVar(name: string): string | null {
  const value = process.env[name];
  return typeof value === "string" && value.length > 0 ? value : null;
}

function shortCommit(sha: string): string {
  return sha.length > 7 ? sha.slice(0, 7) : sha;
}

function readPackageVersion(): string | null {
  try {
    const pkg = JSON.parse(readFileSync(path.join(projectRoot, "package.json"), "utf8"));
    return typeof pkg?.version === "string" && pkg.version.length > 0 ? pkg.version : null;
  } catch {
    return null;
  }
}

function main(): void {
  const version = readPackageVersion();
  const tag = envVar("GIT_TAG") ?? git("describe --tags --always --abbrev=0");
  const gitDescribe = envVar("GIT_DESCRIBE") ?? git("describe --tags --always --abbrev=7");
  const rawCommit = envVar("GIT_COMMIT_HASH") ?? envVar("SOURCE_COMMIT");
  const commitHash = rawCommit ? shortCommit(rawCommit) : git("rev-parse --short HEAD");
  const commitDate = envVar("GIT_COMMIT_DATE") ?? git("log -1 --format=%cI");
  const commitSubject = envVar("GIT_COMMIT_SUBJECT") ?? git("log -1 --format=%s");
  const buildTime = new Date().toISOString();

  const info = {
    version,
    tag,
    gitDescribe,
    commitHash,
    commitDate,
    commitSubject,
    lastUpdated: commitDate ?? buildTime,
    commitMessage: commitSubject,
    buildTime,
  };

  const outDir = path.join(projectRoot, "src", "generated");
  if (!existsSync(outDir)) {
    mkdirSync(outDir, { recursive: true });
  }
  writeFileSync(
    path.join(outDir, "versionInfo.json"),
    `${JSON.stringify(info, null, 2)}\n`,
    "utf8",
  );

  const label = gitDescribe ?? tag ?? version ?? "unknown";
  console.log(`[version-info] wrote src/generated/versionInfo.json (${label})`);
}

main();