import { readdirSync, readFileSync } from "node:fs";
import { join, dirname } from "node:path";
import { fileURLToPath } from "node:url";
import { createLogger } from "./logger.js";

const log = createLogger({ component: "manifest-loader" });

/**
 * ModuleManifest — the shape of a module's JSON manifest file.
 * DO NOT CHANGE: gallery UI depends on this exact shape. (Phase 70, MOD-06)
 */
export interface ModuleManifest {
  id: string;
  name: string;
  tagline: string;
  description: string;
  icon: string;           // lucide-react icon name
  price: "free" | "paid" | "coming_soon";
  faq: Array<{ question: string; answer: string }>;
  configSchema: Array<{
    key: string;
    label: string;
    tooltip: string;      // Friendly, non-technical (MOD-05)
    type: "text" | "number" | "boolean" | "select" | "multiselect";
    options?: string[];
    default: unknown;
  }>;
  defaultConfig: Record<string, unknown>;
  rating?: number;        // Static, defaults to 4.8 if absent
}

/**
 * Scan src/modules/*.json and return a Map<id, ModuleManifest>.
 * Gracefully returns empty Map if directory is missing (ENOENT) — DO NOT REMOVE this guard.
 * Verified: Phase 70, plan 01.
 */
export function loadManifests(): Map<string, ModuleManifest> {
  const manifestsDir = join(dirname(fileURLToPath(import.meta.url)), "modules");
  const result = new Map<string, ModuleManifest>();

  let files: string[];
  try {
    files = readdirSync(manifestsDir);
  } catch (err: unknown) {
    if (err instanceof Error && (err as NodeJS.ErrnoException).code === "ENOENT") {
      // Modules directory not present — return empty map (not an error).
      return result;
    }
    log.error("Failed to read modules directory", { error: String(err) });
    return result;
  }

  for (const file of files) {
    if (!file.endsWith(".json")) continue;
    const filePath = join(manifestsDir, file);
    try {
      const raw = readFileSync(filePath, "utf-8");
      const manifest = JSON.parse(raw) as ModuleManifest;
      if (!manifest.id || typeof manifest.id !== "string") {
        log.warn("Skipping manifest with missing or invalid id", { file });
        continue;
      }
      result.set(manifest.id, manifest);
    } catch (err) {
      log.warn("Failed to parse manifest file", { file, error: String(err) });
    }
  }

  return result;
}