/*
<MODULE_CONTRACT>
<purpose>
RFC-0840: Persist and restore root-level operator config files between mission workpiece and cache clone.
Provides persistOperatorConfigFiles (mission.close) and restoreOperatorConfigFiles (mission.materialize).
Follows the same pattern as env-persist.ts (RFC-0822) but for non-env operator config files.
</purpose>
<non-goals>
  <item>Do not git-commit operator config files — they are untracked artifacts in the cache clone.</item>
  <item>Do not modify file contents during restore — unlike env restoration which rewrites PUBLIC_IMAGE_PROVIDER.</item>
  <item>Do not add generated build outputs to OPERATOR_CONFIG_FILES — those are regenerated by build.prepare.</item>
  <item>Do not add .env* files — those are already handled by RFC-0822.</item>
</non-goals>
</MODULE_CONTRACT>
<CHANGE_SUMMARY>
  <item>RFC-0840: initial operator-config-files module with OPERATOR_CONFIG_FILES, persistOperatorConfigFiles, and restoreOperatorConfigFiles.</item>
  <item>warpgogol-m000170: OPTIONAL_OPERATOR_CONFIG_FILES — src/image-variants.config.yaml persists/restores like the required entries but stays opt-in (presence check + MAT-CONFIG-02 keep covering only the required list).</item>
</CHANGE_SUMMARY>
*/

import path from "node:path";
import { createDefaultIO, type WorkspaceIO } from "@warpgogol/werkstatt-shared/kernel/workspace-io";

export interface OperatorConfigPersistResult {
  copied: string[];
  skipped: string[];
}

export const OPERATOR_CONFIG_FILES = [
  ".lighthouse-budget-ignore",
  "src/image-delivery.config.yaml",
] as const;

/**
 * m000170: optional operator configs — persisted/restored like
 * OPERATOR_CONFIG_FILES when present, but NOT required by
 * workpiece.config.presence.check (a site may simply never need the knob).
 * Excluded from MAT-CONFIG-02's dead-entry scan for the same reason.
 */
export const OPTIONAL_OPERATOR_CONFIG_FILES = ["src/image-variants.config.yaml"] as const;

const ALL_OPERATOR_CONFIG_FILES: readonly string[] = [
  ...OPERATOR_CONFIG_FILES,
  ...OPTIONAL_OPERATOR_CONFIG_FILES,
];

export async function persistOperatorConfigFiles(
  workpieceDir: string,
  cacheCloneDir: string,
  io: WorkspaceIO = createDefaultIO().io,
): Promise<OperatorConfigPersistResult> {
  const copied: string[] = [];
  const skipped: string[] = [];

  for (const entry of ALL_OPERATOR_CONFIG_FILES) {
    const src = path.join(workpieceDir, entry);
    const dest = path.join(cacheCloneDir, entry);
    if (!(await io.exists(src))) continue;
    try {
      await io.mkdir(path.dirname(dest));
      await io.copyFile(src, dest);
      copied.push(entry);
    } catch {
      skipped.push(entry);
    }
  }

  return { copied, skipped };
}

export async function restoreOperatorConfigFiles(
  cacheCloneDir: string,
  workpieceDir: string,
  io: WorkspaceIO = createDefaultIO().io,
): Promise<OperatorConfigPersistResult> {
  const copied: string[] = [];
  const skipped: string[] = [];

  for (const entry of ALL_OPERATOR_CONFIG_FILES) {
    const src = path.join(cacheCloneDir, entry);
    const dest = path.join(workpieceDir, entry);
    if (!(await io.exists(src))) continue;
    try {
      await io.mkdir(path.dirname(dest));
      await io.copyFile(src, dest);
      copied.push(entry);
    } catch {
      skipped.push(entry);
    }
  }

  return { copied, skipped };
}