import { readdir, access } from "node:fs/promises";
import path from "node:path";
import { composeStatus, type StackRunState } from "./docker";
import { readEnvFile, readEnvValue } from "./env-file";
import { RESERVED_SLUGS } from "./slug";

export { isValidSlug, suggestSlug } from "./slug";

export interface BusinessStackSummary {
  slug: string;
  /** BUSINESS_NAME from the business's own .env — null for a business provisioned before this field existed, until it's next edited. */
  name: string | null;
  domain: string | null;
  databaseName: string | null;
  containerName: string;
  status: StackRunState;
}

export function stacksRoot(): string {
  const dir = process.env.STACKS_DIR;
  if (!dir) throw new Error("STACKS_DIR must be set.");
  return dir;
}

export function stackDir(slug: string): string {
  return path.join(stacksRoot(), slug);
}

export async function listBusinessStacks(): Promise<BusinessStackSummary[]> {
  const root = stacksRoot();
  let entries: string[];
  try {
    entries = await readdir(root);
  } catch {
    return [];
  }

  const stacks: BusinessStackSummary[] = [];
  for (const slug of entries) {
    if (RESERVED_SLUGS.has(slug)) continue;
    const dir = path.join(root, slug);
    const composePath = path.join(dir, "compose.yaml");
    try {
      await access(composePath);
    } catch {
      continue;
    }

    // Only ever reads specific known-safe fields — never the rest of a
    // business's .env (database password, AUTH_SECRET, etc.) — see
    // env-file.ts's readEnvValue.
    const envContent = await readEnvFile(path.join(dir, ".env"));
    const name = envContent ? readEnvValue(envContent, "BUSINESS_NAME") : null;
    const domain = envContent ? readEnvValue(envContent, "DOMAIN") : null;
    const databaseName = envContent ? readEnvValue(envContent, "DATABASE_NAME") : null;
    const status = await composeStatus(dir);
    stacks.push({ slug, name, domain, databaseName, containerName: `next-chair-${slug}`, status });
  }

  return stacks.sort((a, b) => a.slug.localeCompare(b.slug));
}

export async function stackExists(slug: string): Promise<boolean> {
  try {
    await access(path.join(stackDir(slug), "compose.yaml"));
    return true;
  } catch {
    return false;
  }
}