import { readFileSync, writeFileSync } from "node:fs";
import { join } from "node:path";

const MANIFEST_FILE = ".skills.json";
const MANIFEST_VERSION = 1;

export interface ManifestEntry {
  version: string;
  installedAt: string;
  platform: string;
  contentHash?: string;
}

export interface Manifest {
  version: number;
  skills: Record<string, ManifestEntry>;
}

function manifestPath(): string {
  return join(process.cwd(), MANIFEST_FILE);
}

export function readManifest(): Manifest {
  try {
    const raw = readFileSync(manifestPath(), "utf-8");
    const parsed = JSON.parse(raw);
    if (!parsed.skills || typeof parsed.skills !== "object") {
      return { version: MANIFEST_VERSION, skills: {} };
    }
    // Ensure version field exists (migrate from old format)
    if (!parsed.version) {
      parsed.version = MANIFEST_VERSION;
    }
    // Ensure all entries have platform field (migrate from old format)
    for (const entry of Object.values(parsed.skills) as ManifestEntry[]) {
      if (!entry.platform) {
        entry.platform = "claude-code";
      }
    }
    return parsed as Manifest;
  } catch {
    return { version: MANIFEST_VERSION, skills: {} };
  }
}

export function writeManifest(manifest: Manifest): void {
  manifest.version = MANIFEST_VERSION;
  writeFileSync(manifestPath(), JSON.stringify(manifest, null, 2) + "\n");
}

export function addToManifest(
  slug: string,
  version: string,
  platform = "claude-code",
  contentHash?: string,
): void {
  const manifest = readManifest();
  manifest.skills[slug] = {
    version,
    installedAt: new Date().toISOString(),
    platform,
    ...(contentHash && { contentHash }),
  };
  writeManifest(manifest);
}

export function removeFromManifest(slug: string): boolean {
  const manifest = readManifest();
  if (!(slug in manifest.skills)) return false;
  delete manifest.skills[slug];
  writeManifest(manifest);
  return true;
}