/**
 * The application (SPEC.md §9).
 *
 * One call assembles it. REST CRUD, the OpenAPI document, the API Explorer, the SDK
 * and the Schema Registry follow from the modules listed below; policies, revisions,
 * the audit log and change sets are not options at all, because an application
 * without them silently throws its history away.
 *
 * Nothing is declared yet — no model, no resource, no block. That is the starting
 * state on purpose: everything above is machinery, and what a project is about is the
 * first thing you add to `src/modules/content.ts`.
 *
 * `createApp()` hands back an application that has **not** been booted, because two
 * callers need one and neither should get the other's: `src/server.ts`, which serves
 * it, and `assemora.config.ts`, through which the `assemora` command boots it to
 * describe the real application rather than a parse of this source (ADR-0021).
 */
// assemora:if pages
import { join } from 'node:path'

// assemora:end
import { auth } from '@assemora/auth'
import { createMemoryAdapter, type DatabaseAdapter } from '@assemora/database'
import { postgres } from '@assemora/database-postgres'
// assemora:if pages
import { pages } from '@assemora/pages'
// assemora:end
import { collections } from '@assemora/resources'
import { type AssemoraApplication, assemora } from 'assemora'

import manifest from '../package.json' with { type: 'json' }
import { ENV_FILE } from './env.ts'
import { content } from './modules/content.ts'

/**
 * `.env`, read before anything asks what is in it.
 *
 * Node does not read `.env` on its own, and `assemora dev`, `assemora db:migrate` and
 * every other command reach this file through `assemora.config.ts`. Loading it here
 * rather than in `server.ts` is what makes one `.env` serve all of them — a migration
 * run against a different database than the server uses is a long afternoon.
 *
 * It never overwrites a variable the environment already has, so a container's
 * configuration still wins.
 */
try {
  process.loadEnvFile(ENV_FILE)
} catch {
  // There is no .env, which is the ordinary case in a deployment.
}

/**
 * Where this project's data lives, or `undefined` when nowhere yet.
 *
 * Exported because `src/server.ts` asks the same question for a different reason:
 * the in-memory fallback is the one database a seed may create an account on
 * (see `src/seed.ts`), and both answers have to come from one place.
 */
export const databaseUrl = (): string | undefined => {
  const url = process.env.DATABASE_URL

  return url === undefined || url === '' ? undefined : url
}

/**
 * A real database when there is one, and a loud fallback when there is not.
 *
 * `pnpm create assemora demo && pnpm dev` has to show something working before
 * anybody has provisioned PostgreSQL, and a first run that dies on a connection error
 * loses people. The bargain is that it says so on every single boot: an in-memory
 * database is honest only while it is announcing itself.
 */
const database = (): DatabaseAdapter => {
  const url = databaseUrl()

  if (url !== undefined) return postgres({ url })

  console.warn(
    'DATABASE_URL is not set: this project is running on an in-memory database, and ' +
      'everything in it disappears when the process restarts. Put a URL in .env, then ' +
      'run `pnpm db:generate initial && pnpm db:migrate`.',
  )

  return createMemoryAdapter()
}

export const createApp = (): AssemoraApplication =>
  assemora({
    database: database(),
    modules: [
      // Users, sessions, roles, permissions and policies. Authorization denies by
      // default, so without this nobody — including you — could do anything at all.
      auth(),
      // assemora:if pages
      // The page builder. A block type reaches its palette by being listed here, and
      // by nothing else — `blocks: [Hero]` once `assemora make:block hero` has written
      // one. Until then the palette is empty, which is the truth about this project.
      pages(),
      // assemora:end
      // A collection is a resource made in Studio rather than in TypeScript, stored as
      // a definition and registered while the application boots (SPEC.md §37). It is
      // what makes the first thing in an empty project something a person can make
      // without opening an editor.
      collections(),
      content(),
    ],
    // Read from package.json so the three places that ask agree: the OpenAPI title,
    // the name the MCP server announces over the protocol, and what
    // `assemora.describe` tells an agent this project is.
    project: { name: manifest.name, version: manifest.version },
    // assemora:if studio
    // Studio, served at /studio on this same origin, so its session cookie and CSRF
    // protection are first-party. The bundle comes from `@assemora/studio`, which
    // this project depends on and the framework deliberately does not.
    //
    // `languages` is which languages Studio offers to be *read* in — never the
    // languages of the content, which is `locales` (SPEC.md §131, ADR-0034). The bundle
    // speaks English, Ukrainian and Russian; this project offers English, because that
    // is the one a new project can be sure of, and a switcher offering languages nobody
    // in the room reads is furniture. Widen it — `['en', 'uk']` — or delete the line to
    // offer everything the bundle has. A language the bundle never had is a directory
    // of JSON: `studio: { languagePacks: './i18n' }`.
    studio: { languages: ['en'] },
    // assemora:end
    // assemora:if mcp
    // An agent proposes; a person applies (SPEC.md §75). `mutations: 'direct'` is the
    // deliberate opt-out, and it belongs here where it can be seen.
    mcp: true,
    // assemora:end
    // assemora:if pages
    // The bundle `pnpm build` writes. Studio's canvas frames it at /preview, so what
    // an editor sees is this site's own components rather than an imitation of them
    // (SPEC.md §59).
    frontend: { root: join(import.meta.dirname, '../app/dist') },
    // assemora:end
  })