muse/src/lib/binding.ts

import path from "node:path";
import { type AnyPlaybillComponent, Playbill } from "@proscenium/playbill";
import { Glob } from "bun";
import z from "zod";
import { loadYAMLFileOrFail } from "#util";
import { ComponentFile } from "./component-file";
import { FileNotFoundError } from "./errors";

// binding.yaml file schema
const BindingSchema = z.object({
  include: z.array(z.string()).default([]),

  name: z.string().default("Unnamed playbill"),
  author: z.string().default("Someone"),
  description: z.string().default("No description provided"),
  version: z.string().default("0.0.0"),

  files: z.array(z.string()).default(["**/*.yaml", "**/*.md"]),
  omitDefaultStyles: z.boolean().default(false),
  styles: z
    .union([z.string(), z.array(z.string())])
    .transform((val) => (Array.isArray(val) ? val : [val]))
    .default([]),
  terms: z.record(z.string(), z.string()).default({}),
});

export interface BoundPlaybill {
  // File information
  bindingFilePath: string;
  bindingFileDirname: string;
  files: string[];
  componentFiles: ComponentFile[];

  // Binding properties
  name: string;
  author: string;
  version: string;
  description: string;

  omitDefaultStyles: boolean;
  styles: string;

  playbill: Playbill;
}

/**
 * Given a path, find the binding.yaml file
 * If the path is to a directory, check for a binding.yaml inside
 * If the path is to a file, check if it exists and is a binding.yaml
 * Otherwise throw an error
 *
 * @param bindingPath - The path to the binding file
 * @returns The absolute resolved path to the binding file
 */
export async function resolveBindingPath(bindingPath: string): Promise<string> {
  // If the path does not specify a filename, use binding.yaml
  const inputLocation = Bun.file(bindingPath);

  // If it is a directory, try again seeking a binding.yaml inside
  const stat = await inputLocation.stat();
  if (stat.isDirectory()) {
    return resolveBindingPath(path.resolve(bindingPath, "binding.yaml"));
  }

  // If it doesnt exist, bail
  if (!(await inputLocation.exists())) {
    throw new FileNotFoundError(bindingPath);
  }

  // Resolve the path
  return path.resolve(bindingPath);
}

export async function loadFromBinding(
  bindingPath: string,
): Promise<BoundPlaybill> {
  const resolvedBindingPath = await resolveBindingPath(bindingPath);
  const yamlContent = await loadYAMLFileOrFail(resolvedBindingPath);
  const binding = BindingSchema.parse(yamlContent);
  const fileGlobs = binding.files;
  const bindingFileDirname = path.dirname(resolvedBindingPath);

  const playbill = new Playbill(
    binding.name,
    binding.author,
    binding.description,
    binding.version,
  );

  // If this is extending another binding, load that first
  for (const includePath of binding.include) {
    const pathFromHere = path.resolve(bindingFileDirname, includePath);
    const extendBindingPath = await resolveBindingPath(pathFromHere);
    const loadedBinding = await loadFromBinding(extendBindingPath);
    playbill.extend(loadedBinding.playbill);
  }

  // Load any specified stylesheets
  const loadedStyles: string[] = [];
  for (const style of binding.styles) {
    const cssFilePath = path.resolve(bindingFileDirname, style);
    const cssFile = Bun.file(cssFilePath);
    const cssFileExists = await cssFile.exists();

    if (cssFileExists) {
      loadedStyles.push(await cssFile.text());
    } else {
      throw new FileNotFoundError(cssFilePath);
    }
  }
  const styles = loadedStyles.join("\n");

  // Scan for all files matching the globs
  const allFilePaths: string[] = [];

  for (const thisGlob of fileGlobs) {
    const glob = new Glob(thisGlob);

    const results = glob.scanSync({
      cwd: bindingFileDirname,
      absolute: true,
      followSymlinks: true,
      onlyFiles: true,
    });

    allFilePaths.push(...results);
  }

  // Exclude the binding.yaml file
  const filePathsWithoutBindingFile = allFilePaths.filter((filePath) => {
    return filePath !== resolvedBindingPath;
  });

  // Load discovered component files
  const componentFiles: ComponentFile[] = [];
  const fileLoadPromises: Promise<void>[] = [];

  for (const filepath of filePathsWithoutBindingFile) {
    const componentFile = new ComponentFile(filepath);
    componentFiles.push(componentFile);
    fileLoadPromises.push(componentFile.load());
  }

  await Promise.all(fileLoadPromises);

  // Aggregate all loaded components
  const loadedComponents: AnyPlaybillComponent[] = [];
  for (const file of componentFiles) {
    loadedComponents.push(...file.components);
  }

  // Add all components to the playbill
  // (This method ensures proper addition order maintain correctness)
  playbill.addManyComponents(loadedComponents);

  // Add all definitions
  for (const [term, definition] of Object.entries(binding.terms)) {
    playbill.addDefinition(term, definition);
  }

  return {
    bindingFilePath: bindingPath,
    bindingFileDirname,
    files: filePathsWithoutBindingFile,
    componentFiles,

    name: binding.name,
    author: binding.author ?? "Anonymous",
    description: binding.description ?? "",
    version: binding.version,

    omitDefaultStyles: binding.omitDefaultStyles,
    styles,

    playbill,
  };
}