import { renderRemote } from "../../render-remote";
import { type GeneratedArtifact } from "../artifact";
import { VIEW_COMPONENTS, type InterfaceType } from "./interface";

/** Subdirectory under the federation runtime dir where view artifacts are written. */
const VIEWS_DIR_NAME = "views";

/**
 * An interface to generate render artifacts for. The `src` file default-exports
 * an `unstable_defineView(...)` result; the build emits one render-contract
 * artifact per component the interface type exposes.
 * @public
 */
export interface InterfaceArtifact {
  /** Interface type — selects which components the build expands. */
  type: InterfaceType;
  /** Interface name, unique within the app. */
  name: string;
  /** Path to the interface `src` file, relative to the app root (or absolute). */
  src: string;
}

/**
 * Expand each view into one generated artifact per component it exposes. A
 * panel's `title` and `panel` each become their own render-contract module and
 * module-federation expose, so the host renders each as an independent island.
 *
 * Each artifact binds its component as the `App` the render contract renders —
 * a single-component view exports a bare function, a multi-component one keys by
 * name — behind an HMR boundary so view edits re-render through the new module.
 */
export function viewArtifacts(
  views: readonly InterfaceArtifact[],
): GeneratedArtifact[] {
  const artifacts: GeneratedArtifact[] = [];
  for (const view of views) {
    for (const component of VIEW_COMPONENTS[view.type]) {
      artifacts.push({
        path: `${VIEWS_DIR_NAME}/${view.name}/${component}.js`,
        expose: `./${VIEWS_DIR_NAME}/${view.name}/${component}`,
        source: ({ resolveImport }) =>
          renderRemote({
            preamble: `import view from ${JSON.stringify(resolveImport(view.src))}`,
            app: `typeof view.components === 'function' ? view.components : view.components[${JSON.stringify(component)}]`,
            version: `view.version`,
            hmr: true,
          }),
      });
    }
  }
  return artifacts;
}