/**
 * Rebuild what the lab runs, from source, before it runs.
 *
 * **A stale artifact reporting success against old rules is the fault this project keeps writing
 * down** (novox/hq 04-ISSUES/005). The lab consumes a handful of artifacts from two repositories,
 * and they
 * were rebuilt by hand, one at a time, from memory. A rename in the control plane's catalogue needs
 * both the control-plane image *and* the builder binary, because both parse manifests; rebuilding
 * one left a binary eleven hours old refusing a field the mesh had just renamed, and cost a full
 * run to find out.
 *
 * In the repository rather than in a shell script beside it, for the reason 005 is about: a step
 * that lives in somebody's terminal history runs when they remember, and remembering is not a
 * mechanism.
 */

import { spawnSync } from "node:child_process";
import { repositories } from "./repos.ts";

export interface Build {
  /** What it produces, for the log. */
  what: string;
  /** The repository root to run in. */
  in: string;
  argv: string[];
  env?: NodeJS.ProcessEnv;
}

/**
 * planned is what must be built, given where this run has been pointed.
 *
 * Derived from the same environment the suite is configured by, so there is one place that says
 * where a repository is. A repository this run was not pointed at is not built — and, per
 * {@link whatWasTested}, is not claimed in the receipt either.
 */
export function planned(env: NodeJS.ProcessEnv = process.env): Build[] {
  const builds: Build[] = [];
  const where = repositories(env);
  const host = env["MESH_LAB_HOST_BINARY"];
  if (host && where["mesh-host"]) {
    builds.push({
      what: "host",
      in: where["mesh-host"],
      argv: ["go", "build", "-ldflags=-s -w -X main.builtFor=arch", "-o", host, "./cmd/mesh-host"],
      env: { CGO_ENABLED: "0" },
    });
  }
  const control = where["mesh-controller"];
  if (control) {
    // **Every image the lab runs, not only the control plane's.**
    //
    // On 2026-09-01 a suite ran with a control-plane image built that minute and a provisioner
    // image built the day before. The rotation test failed against a real database, and the
    // failure looked exactly like the change under test being wrong — the provisioner was
    // creating logins by a naming rule that had been replaced.
    //
    // This is the same fault the builder line below was added for, one target along. A rebuild
    // that covers most of what a run uses is worse than one that covers none, because the run
    // that follows it is believed.
    builds.push({
      what: "images",
      in: control,
      argv: ["make", "image", "builder-image", "provisioner-image", "objectstore-image",
        "redis-provisioner-image", "proxy-image"],
    });
    const builder = env["MESH_LAB_BUILDER"];
    if (builder) {
      // Both of these parse manifests. Building one and not the other is the eleven-hour-old
      // binary above, so they are one step and not two.
      builds.push({
        what: "builder",
        in: control,
        argv: ["go", "build", "-o", builder, "./cmd/mesh-builder"],
      });
    }
  }

  // **The installer, carrying the control plane's image.**
  //
  // Last, and that is an ordering rather than a preference: `make bootstrap` embeds the output of
  // `docker save <image>`, so the image has to have been built by the step above or the installer
  // carries whatever was lying around — the eleven-hour-old artifact again, this time inside a
  // binary where nothing would ever notice.
  //
  // It is built here at all because the bed now bootstraps THROUGH it (novox/hq ADR 0067): the
  // anchor is brought into existence by running the same program a bare machine runs, rather than
  // by the bed applying a foundation bundle by hand and calling that an install. An installer that
  // was stale would be a bed proving something about last week's procedure.
  const installer = env["MESH_LAB_BOOTSTRAP_BINARY"];
  if (installer && where["mesh-host"]) {
    builds.push({
      what: "installer",
      in: where["mesh-host"],
      argv: ["make", "bootstrap", `IMAGE=${carriedImage(env)}`, `BOOTSTRAP_OUT=${installer}`],
    });
  }
  return builds;
}

/**
 * The image the installer carries.
 *
 * **It is the builder, not the control plane** (novox/hq ADR 0073). The installer used to carry the
 * thing it was going to run and now carries the thing that makes it, so a raised mesh holds a
 * control plane it built from a repository and a commit rather than one it was handed.
 *
 * `mesh-builder:development` is what mesh-controller's `make builder-image` tags — one tag, said in
 * one place. Overridable because a release installer carries a release image, and nothing about
 * that is the lab's business.
 */
export function carriedImage(env: NodeJS.ProcessEnv = process.env): string {
  return env["MESH_LAB_CARRIED_IMAGE"] ?? "mesh-builder:development";
}

/** rebuild runs the plan, and throws on the first failure rather than testing a stale artifact. */
export function rebuild(env: NodeJS.ProcessEnv = process.env): string[] {
  const built: string[] = [];
  for (const build of planned(env)) {
    const [command, ...args] = build.argv;
    const ran = spawnSync(command!, args, {
      cwd: build.in,
      env: { ...env, ...build.env },
      encoding: "utf8",
    });
    if (ran.status !== 0) {
      // Loudly, and stopping. A suite that runs anyway is a suite reporting on code that is not
      // the code in front of you, which is the whole of 005.
      throw new Error(
        `could not build the ${build.what}: ${build.argv.join(" ")} in ${build.in}\n\n` +
          `${(ran.stderr || ran.stdout || String(ran.error)).trim()}`,
      );
    }
    built.push(build.what);
  }
  return built;
}