const { TemplatePath } = require("@11ty/eleventy-utils");

const TemplateEngineManager = require("./TemplateEngineManager");
const TemplateConfig = require("./TemplateConfig");
const EleventyBaseError = require("./EleventyBaseError");

class EleventyExtensionMapConfigError extends EleventyBaseError {}

class EleventyExtensionMap {
  constructor(formatKeys, config) {
    if (!config) {
      throw new EleventyExtensionMapConfigError("Missing `config` argument.");
    }
    if (config instanceof TemplateConfig) {
      this.eleventyConfig = config;
    }
    this._config = config;

    this.formatKeys = formatKeys;

    this.setFormats(formatKeys);

    this._spiderJsDepsCache = {};
  }

  setFormats(formatKeys = []) {
    this.unfilteredFormatKeys = formatKeys.map(function (key) {
      return key.trim().toLowerCase();
    });

    this.validTemplateLanguageKeys = this.unfilteredFormatKeys.filter((key) =>
      this.hasExtension(key)
    );

    this.passthroughCopyKeys = this.unfilteredFormatKeys.filter((key) => !this.hasExtension(key));
  }

  set config(cfg) {
    this._config = cfg;
  }

  get config() {
    if (this._config instanceof TemplateConfig) {
      return this._config.getConfig();
    }
    return this._config;
  }

  get engineManager() {
    if (!this._engineManager) {
      this._engineManager = new TemplateEngineManager(this.eleventyConfig);
    }

    return this._engineManager;
  }

  reset() {
    this.engineManager.reset();
  }

  /* Used for layout path resolution */
  getFileList(path, dir) {
    if (!path) {
      return [];
    }

    let files = [];
    this.validTemplateLanguageKeys.forEach(
      function (key) {
        this.getExtensionsFromKey(key).forEach(function (extension) {
          files.push((dir ? dir + "/" : "") + path + "." + extension);
        });
      }.bind(this)
    );

    return files;
  }

  // Warning: this would false positive on an include, but is only used
  // on paths found from the file system glob search.
  // TODO: Method name might just need to be renamed to something more accurate.
  isFullTemplateFilePath(path) {
    for (let extension of this.validTemplateLanguageKeys) {
      if (path.endsWith(`.${extension}`)) {
        return true;
      }
    }
    return false;
  }

  getCustomExtensionEntry(extension) {
    if (!this.config.extensionMap) {
      return;
    }

    for (let entry of this.config.extensionMap) {
      if (entry.extension === extension) {
        return entry;
      }
    }
  }

  getValidExtensionsForPath(path) {
    let extensions = new Set();
    for (let extension in this.extensionToKeyMap) {
      if (path.endsWith(`.${extension}`)) {
        extensions.add(extension);
      }
    }

    // if multiple extensions are valid, sort from longest to shortest
    // e.g. .11ty.js and .js
    let sorted = Array.from(extensions)
      .filter((extension) => this.validTemplateLanguageKeys.includes(extension))
      .sort((a, b) => b.length - a.length);

    return sorted;
  }

  shouldSpiderJavaScriptDependencies(path) {
    let extensions = this.getValidExtensionsForPath(path);
    for (let extension of extensions) {
      if (extension in this._spiderJsDepsCache) {
        return this._spiderJsDepsCache[extension];
      }

      let cls = this.engineManager.getEngineClassByExtension(extension);
      if (cls) {
        let entry = this.getCustomExtensionEntry(extension);
        let shouldSpider = cls.shouldSpiderJavaScriptDependencies(entry);
        this._spiderJsDepsCache[extension] = shouldSpider;
        return shouldSpider;
      }
    }

    return false;
  }

  getPassthroughCopyGlobs(inputDir) {
    return this._getGlobs(this.passthroughCopyKeys, inputDir);
  }

  getValidGlobs(inputDir) {
    return this._getGlobs(this.validTemplateLanguageKeys, inputDir);
  }

  getGlobs(inputDir) {
    return this._getGlobs(this.unfilteredFormatKeys, inputDir);
  }

  _getGlobs(formatKeys, inputDir) {
    let dir = TemplatePath.convertToRecursiveGlobSync(inputDir);
    let extensions = [];
    for (let key of formatKeys) {
      if (this.hasExtension(key)) {
        for (let extension of this.getExtensionsFromKey(key)) {
          extensions.push(extension);
        }
      } else {
        extensions.push(key);
      }
    }

    let globs = [];
    if (extensions.length === 1) {
      globs.push(`${dir}/*.${extensions[0]}`);
    } else if (extensions.length > 1) {
      globs.push(`${dir}/*.{${extensions.join(",")}}`);
    }

    return globs;
  }

  hasExtension(key) {
    for (var extension in this.extensionToKeyMap) {
      if (this.extensionToKeyMap[extension] === key) {
        return true;
      }
    }
    return false;
  }

  getExtensionsFromKey(key) {
    let extensions = [];
    for (var extension in this.extensionToKeyMap) {
      if (this.extensionToKeyMap[extension] === key) {
        extensions.push(extension);
      }
    }
    return extensions;
  }

  // Only `addExtension` configuration API extensions
  getExtensionEntriesFromKey(key) {
    let entries = [];
    if ("extensionMap" in this.config) {
      for (let entry of this.config.extensionMap) {
        if (entry.key === key) {
          entries.push(entry);
        }
      }
    }
    return entries;
  }

  hasEngine(pathOrKey) {
    return !!this.getKey(pathOrKey);
  }

  getKey(pathOrKey) {
    pathOrKey = (pathOrKey || "").toLowerCase();

    for (var extension in this.extensionToKeyMap) {
      let key = this.extensionToKeyMap[extension];
      if (pathOrKey === extension) {
        return key;
      } else if (pathOrKey.endsWith("." + extension)) {
        return key;
      }
    }
  }

  removeTemplateExtension(path) {
    for (var extension in this.extensionToKeyMap) {
      if (path === extension || path.endsWith("." + extension)) {
        return path.slice(
          0,
          path.length - 1 - extension.length < 0 ? 0 : path.length - 1 - extension.length
        );
      }
    }
    return path;
  }

  // keys are file extensions
  // values are template language keys
  get extensionToKeyMap() {
    if (!this._extensionToKeyMap) {
      this._extensionToKeyMap = {
        ejs: "ejs",
        md: "md",
        html: "html",
        hbs: "hbs",
        mustache: "mustache",
        haml: "haml",
        pug: "pug",
        njk: "njk",
        liquid: "liquid",
        "11ty.js": "11ty.js",
        "11ty.cjs": "11ty.js",
      };

      if ("extensionMap" in this.config) {
        for (let entry of this.config.extensionMap) {
          this._extensionToKeyMap[entry.extension] = entry.key;
        }
      }
    }

    return this._extensionToKeyMap;
  }

  getReadableFileExtensions() {
    return Object.keys(this.extensionToKeyMap).join(" ");
  }
}

module.exports = EleventyExtensionMap;