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import { Exception } from "./errors.ts";import Extensions from "./extensions.ts";
import type { Data } from "../core.ts";
export interface Options {  /** Extra data to be passed to the engines */  globalData: Data;}
/** * Class to render the pages * using different template engines. */export default class Engines {  /** Template engines by extension */  engines = new Extensions<Engine>();
  /** Extra data to be passed to the engines */  globalData: Data;
  /** The registered helpers */  helpers = new Map<string, [Helper, HelperOptions]>();
  constructor(options: Options) {    this.globalData = options.globalData || {};  }
  /** Delete a cached template */  deleteCache(file: string): void {    for (const engine of this.engines.values()) {      engine.deleteCache(file);    }  }
  /** Register a new template engine */  addEngine(extensions: string[], engine: Engine) {    extensions.forEach((extension) => this.engines.set(extension, engine));
    for (const [name, helper] of this.helpers) {      engine.addHelper(name, ...helper);    }  }
  /** Register a new helper used by the template engines */  addHelper(name: string, fn: Helper, options: HelperOptions) {    this.helpers.set(name, [fn, options]);
    for (const engine of this.engines.values()) {      engine.addHelper(name, fn, options);    }
    return this;  }
  /** Render a template */  async render(    content: unknown,    data: Data,    filename: string,  ): Promise<unknown> {    const engines = this.getEngine(filename, data);
    if (engines) {      data = { ...this.globalData, ...data };
      for (const engine of engines) {        content = await engine.render(content, data, filename);      }    }
    return content;  }
  /** Render a template synchronous */  renderSync(content: unknown, data: Data, filename: string): unknown {    const engines = this.getEngine(filename, data);
    if (engines) {      data = { ...this.globalData, ...data };
      for (const engine of engines) {        content = engine.renderSync(content, data, filename);      }    }
    return content;  }
  /** Get the engines assigned to an extension or configured in the data */  getEngine(path: string, data: Data): Engine[] | undefined {    let { templateEngine } = data;
    if (templateEngine) {      templateEngine = Array.isArray(templateEngine)        ? templateEngine        : templateEngine.split(",");
      return templateEngine.map((name) => {        const engine = this.engines.get(`.${name.trim()}`);
        if (engine) {          return engine;        }
        throw new Exception(          "Invalid value for templateEngine",          { path, templateEngine },        );      });    }
    const result = this.engines.search(path);
    if (result) {      return [result[1]];    }  }}
/** An interface used by all template engines */export interface Engine {  /** Delete a cached template */  deleteCache(file: string): void;
  /** Render a template */  render(    content: unknown,    data?: Data,    filename?: string,  ): unknown | Promise<unknown>;
  /** Render a template synchronous */  renderSync(    content: unknown,    data?: Data,    filename?: string,  ): string;
  /** Add a helper to the template engine */  addHelper(    name: string,    fn: Helper,    options: HelperOptions,  ): void;}
/** A generic helper to be used in template engines */// deno-lint-ignore no-explicit-anyexport type Helper = (...args: any[]) => any;
/** The options for a template helper */export interface HelperOptions {  /** The type of the helper (tag, filter, etc) */  type: string;
  /** Whether the helper returns an instance or not */  async?: boolean;
  /** Whether the helper has a body or not (used for tag types) */  body?: boolean;}