import { existsSync } from 'node:fs';
import { mkdir, readFile } from 'node:fs/promises';
import { dirname, join } from 'node:path';
import { resolveProjectWorkspace } from './workspace.js';
import { writeTextFileAtomic } from './atomic-write.js';
import type { AssetTagEntry } from './prompt-rules.js';

export interface EnvironmentAssetEntry {
  name: string;
  description: string;
  plateUrl: string;
  plateRef: string;
}

export interface EnvironmentAssetsArtifact {
  schemaVersion: 1;
  projectSlug: string;
  generatedAt: string;
  environments: EnvironmentAssetEntry[];
}

export interface EnvironmentAssetsLookup {
  environments: EnvironmentAssetEntry[];
  /** name (lowercased) -> AssetTagEntry, ready for buildAssetTagLookup's environmentsByName. */
  environmentEntryByName: Map<string, AssetTagEntry>;
}

export function environmentAssetsPathFor(root: string, slug: string): string {
  return join(resolveProjectWorkspace(slug, root).projectDir, 'artifacts', 'environment-assets.json');
}

export async function writeEnvironmentAssets(
  root: string,
  slug: string,
  artifact: EnvironmentAssetsArtifact,
): Promise<void> {
  const path = environmentAssetsPathFor(root, slug);
  await mkdir(dirname(path), { recursive: true });
  await writeTextFileAtomic(path, JSON.stringify(artifact, null, 2) + '\n');
}

/**
 * Read `artifacts/environment-assets.json`. Returns an empty lookup when absent
 * (graceful — `@location` tags then fall through to strip-and-warn). The
 * `environmentEntryByName` map is the AssetTagEntry shape `buildAssetTagLookup`
 * consumes via `environmentsByName`.
 */
export async function readEnvironmentAssets(root: string, slug: string): Promise<EnvironmentAssetsLookup> {
  const path = environmentAssetsPathFor(root, slug);
  if (!existsSync(path)) {
    return { environments: [], environmentEntryByName: new Map() };
  }
  const parsed = JSON.parse(await readFile(path, 'utf-8')) as Partial<EnvironmentAssetsArtifact>;
  const environments = Array.isArray(parsed.environments) ? parsed.environments : [];
  const environmentEntryByName = new Map<string, AssetTagEntry>();
  for (const env of environments) {
    if (!env?.name) continue;
    // Wire the HOSTED plate URL (public R2) as the reference — providers
    // (seedance-direct etc.) require a real HTTP/HTTPS URL or Asset:// URI and
    // reject the internal `gobananas://` plateRef. Fall back to plateRef only if
    // no hosted URL was captured.
    const referencePath = env.plateUrl || env.plateRef;
    environmentEntryByName.set(env.name.toLowerCase(), {
      descriptor: env.description ?? env.name,
      ...(referencePath ? { referencePath } : {}),
    });
  }
  return { environments, environmentEntryByName };
}