Partially restored header logic, added suggestions for properties

src/content/header.js

@@ -0,0 +1,7 @@
+import {initializeSiteHeader} from "$lib/components/SiteHeaderWrapper.js";
+
+const siteHeader = document.querySelector('.header');
+
+if (siteHeader) {
+  initializeSiteHeader(siteHeader);
+}

src/lib/components/SearchWrapper.js

@@ -0,0 +1,290 @@
+import {BaseComponent} from "$lib/components/base/BaseComponent.js";
+import {QueryLexer, QuotedTermToken, TermToken, Token} from "$lib/booru/search/QueryLexer.js";
+
+export class SearchWrapper extends BaseComponent {
+  /** @type {HTMLInputElement|null} */
+  #searchField = null;
+  /** @type {string|null} */
+  #lastParsedSearchValue = null;
+  /** @type {Token[]} */
+  #cachedParsedQuery = [];
+
+  build() {
+    this.#searchField = this.container.querySelector('input[name=q]');
+  }
+
+  init() {
+    this.#searchField.addEventListener('input', this.#onInputFindProperties.bind(this));
+  }
+
+  /**
+   * Catch the user input and execute suggestions logic.
+   * @param {InputEvent} event Source event to find the input element from.
+   */
+  #onInputFindProperties(event) {
+    const currentFragment = this.#findCurrentTagFragment();
+
+    if (!currentFragment) {
+      return;
+    }
+
+    this.#renderSuggestions(
+      SearchWrapper.#resolveSuggestionsFromTerm(currentFragment),
+      event.currentTarget
+    );
+  }
+
+  /**
+   * Get the selection position in the search field.
+   * @return {number}
+   */
+  #getInputUserSelection() {
+    return Math.min(
+      this.#searchField.selectionStart,
+      this.#searchField.selectionEnd
+    );
+  }
+
+  /**
+   * Parse the search query and return the list of parsed tokens. Result will be cached for current search query.
+   * @return {Token[]}
+   */
+  #resolveQueryTokens() {
+    const searchValue = this.#searchField.value;
+
+    if (searchValue === this.#lastParsedSearchValue && this.#cachedParsedQuery) {
+      return this.#cachedParsedQuery;
+    }
+
+    this.#lastParsedSearchValue = searchValue;
+    this.#cachedParsedQuery = new QueryLexer(searchValue).parse();
+
+    return this.#cachedParsedQuery;
+  }
+
+  /**
+   * Find the currently selected term.
+   * @return {string|null} Selected term or null if none found.
+   */
+  #findCurrentTagFragment() {
+    if (!this.#searchField) {
+      return null;
+    }
+
+    let searchValue = this.#searchField.value;
+
+    if (!searchValue) {
+      return null;
+    }
+
+    const token = SearchWrapper.#findActiveSearchTermPosition(
+      this.#resolveQueryTokens(),
+      this.#getInputUserSelection(),
+    );
+
+    if (token instanceof TermToken) {
+      return token.value;
+    }
+
+    if (token instanceof QuotedTermToken) {
+      return token.decodedValue;
+    }
+
+    return searchValue;
+  }
+
+  /**
+   * Render the list of suggestions into the existing popup or create and populate a new one.
+   * @param {string[]} suggestions List of suggestion to render the popup from.
+   * @param {HTMLInputElement} targetInput Target input to attach the popup to.
+   */
+  #renderSuggestions(suggestions, targetInput) {
+    /** @type {HTMLElement[]} */
+    const suggestedListItems = suggestions
+      .map(suggestedTerm => SearchWrapper.#renderTermSuggestion(suggestedTerm));
+
+    requestAnimationFrame(() => {
+      const autocompleteContainer = document.querySelector('.autocomplete') ?? SearchWrapper.#renderAutocompleteContainer();
+
+      for (let existingTerm of autocompleteContainer.querySelectorAll('.autocomplete__item--property')) {
+        existingTerm.remove();
+      }
+
+      const listContainer = autocompleteContainer.querySelector('ul');
+      listContainer.prepend(...suggestedListItems);
+
+      autocompleteContainer.style.position = 'absolute';
+      autocompleteContainer.style.left = `${targetInput.offsetLeft}px`;
+      autocompleteContainer.style.top = `${targetInput.offsetTop + targetInput.offsetHeight - targetInput.parentElement.scrollTop}px`;
+
+      document.body.append(autocompleteContainer);
+    })
+  }
+
+  /**
+   * Loosely estimate where current selected search term is located and return it if found.
+   * @param {Token[]} tokens Search value to find the actively selected term from.
+   * @param {number} userSelectionIndex The index of the user selection.
+   * @return {Token|null} Search term object or NULL if nothing found.
+   */
+  static #findActiveSearchTermPosition(tokens, userSelectionIndex) {
+    return tokens.find(
+      token => token.index < userSelectionIndex && token.index + token.value.length >= userSelectionIndex
+    );
+  }
+
+  /**
+   * Regular expression to search the properties' syntax.
+   * @type {RegExp}
+   */
+  static #propertySearchTermHeadingRegExp = /^(?<name>[a-z\d_]+)(?<op_syntax>\.(?<op>[a-z]*))?(?<value_syntax>:(?<value>.*))?$/;
+
+  /**
+   * Create a list of suggested elements using the input received from the user.
+   * @param {string} searchTermValue Original decoded term received from the user.
+   * @return {string[]} List of suggestions. Could be empty.
+   */
+  static #resolveSuggestionsFromTerm(searchTermValue) {
+    /** @type {string[]} */
+    const suggestionsList = [];
+
+    this.#propertySearchTermHeadingRegExp.lastIndex = 0;
+    const parsedResult = this.#propertySearchTermHeadingRegExp.exec(searchTermValue);
+
+    if (!parsedResult) {
+      return suggestionsList;
+    }
+
+    const propertyName = parsedResult.groups.name;
+    const hasOperatorSyntax = Boolean(parsedResult.groups.op_syntax);
+    const hasValueSyntax = Boolean(parsedResult.groups.value_syntax);
+
+
+    // No suggestions for values for now, maybe could add suggestions for namespaces like my:*
+    if (hasValueSyntax) {
+      return suggestionsList;
+    }
+
+    // If at least one dot placed, start suggesting operators
+    if (hasOperatorSyntax) {
+      const propertyType = this.#properties.get(propertyName);
+
+      if (this.#typeOperators.has(propertyType)) {
+        const operatorName = parsedResult.groups.op;
+
+        for (let candidateOperator of this.#typeOperators.get(propertyType)) {
+          if (operatorName && !candidateOperator.startsWith(operatorName)) {
+            continue;
+          }
+
+          suggestionsList.push(`${propertyName}.${candidateOperator}:`);
+        }
+      }
+
+      return suggestionsList;
+    }
+
+    // Otherwise, search for properties with names starting with the term
+    for (let [candidateProperty] of this.#properties) {
+      if (propertyName && !candidateProperty.startsWith(propertyName)) {
+        continue;
+      }
+
+      suggestionsList.push(candidateProperty);
+    }
+
+    return suggestionsList;
+  }
+
+  /**
+   * Render a new autocomplete container similar to the one generated by website. Might be sensitive to the updates
+   * made to the Philomena.
+   * @return {HTMLElement}
+   */
+  static #renderAutocompleteContainer() {
+    const autocompleteContainer = document.createElement('div');
+    autocompleteContainer.className = 'autocomplete';
+
+    const innerListContainer = document.createElement('ul');
+    innerListContainer.className = 'autocomplete__list';
+
+    autocompleteContainer.append(innerListContainer);
+
+    return autocompleteContainer;
+  }
+
+  /**
+   * Render a single suggestion item and connect required events to interact with the user.
+   * @param {string} suggestedTerm Term to use for suggestion item.
+   * @return {HTMLElement} Resulting element.
+   */
+  static #renderTermSuggestion(suggestedTerm) {
+    /** @type {HTMLElement} */
+    const suggestionItem = document.createElement('li');
+    suggestionItem.classList.add('autocomplete__item', 'autocomplete__item--property');
+    suggestionItem.dataset.value = suggestedTerm;
+    suggestionItem.innerText = suggestedTerm;
+
+    suggestionItem.addEventListener('mouseover', () => {
+      this.#findAndResetSelectedSuggestion(suggestionItem);
+      suggestionItem.classList.add('autocomplete__item--selected');
+    });
+
+    suggestionItem.addEventListener('mouseout', () => {
+      this.#findAndResetSelectedSuggestion(suggestionItem);
+    })
+
+    return suggestionItem;
+  }
+
+  /**
+   * Find the selected suggestion item(s) and unselect them. Similar to the logic implemented by the Philomena's
+   * front-end.
+   * @param {HTMLElement} suggestedElement Target element to search from. If element is disconnected from the DOM,
+   * search will be halted.
+   */
+  static #findAndResetSelectedSuggestion(suggestedElement) {
+    if (!suggestedElement.parentElement) {
+      return;
+    }
+
+    for (let selectedElement of suggestedElement.parentElement.querySelectorAll('.autocomplete__item--selected')) {
+      selectedElement.classList.remove('autocomplete__item--selected');
+    }
+  }
+
+  static #typeNumeric = Symbol();
+  static #typeDate = Symbol();
+  static #typeLiteral = Symbol();
+  static #typePersonal = Symbol();
+
+  static #properties = new Map([
+    ['aspect_ratio', SearchWrapper.#typeNumeric],
+    ['comment_count', SearchWrapper.#typeNumeric],
+    ['created_at', SearchWrapper.#typeDate],
+    ['description', SearchWrapper.#typeLiteral],
+    ['downvotes', SearchWrapper.#typeNumeric],
+    ['faved_by', SearchWrapper.#typeLiteral],
+    ['faves', SearchWrapper.#typeNumeric],
+    ['first_seen_at', SearchWrapper.#typeDate],
+    ['height', SearchWrapper.#typeNumeric],
+    ['id', SearchWrapper.#typeNumeric],
+    ['orig_sha512_hash', SearchWrapper.#typeLiteral],
+    ['score', SearchWrapper.#typeNumeric],
+    ['sha512_hash', SearchWrapper.#typeLiteral],
+    ['source_url', SearchWrapper.#typeLiteral],
+    ['tag_count', SearchWrapper.#typeNumeric],
+    ['uploader', SearchWrapper.#typeLiteral],
+    ['upvotes', SearchWrapper.#typeNumeric],
+    ['width', SearchWrapper.#typeNumeric],
+    ['wilson_score', SearchWrapper.#typeNumeric],
+    ['my', SearchWrapper.#typePersonal],
+  ]);
+
+  static #comparisonOperators = ['gt', 'gte', 'lt', 'lte'];
+
+  static #typeOperators = new Map([
+    [SearchWrapper.#typeNumeric, SearchWrapper.#comparisonOperators],
+    [SearchWrapper.#typeDate, SearchWrapper.#comparisonOperators],
+  ]);
+}

src/lib/components/SiteHeaderWrapper.js

@@ -0,0 +1,23 @@
+import {BaseComponent} from "$lib/components/base/BaseComponent.js";
+import {SearchWrapper} from "$lib/components/SearchWrapper.js";
+
+class SiteHeaderWrapper extends BaseComponent {
+  /** @type {SearchWrapper|null} */
+  #searchWrapper = null;
+
+  build() {
+    const searchForm = this.container.querySelector('.header__search');
+    this.#searchWrapper = searchForm && new SearchWrapper(searchForm) || null;
+  }
+
+  init() {
+    if (this.#searchWrapper) {
+      this.#searchWrapper.initialize();
+    }
+  }
+}
+
+export function initializeSiteHeader(siteHeaderElement) {
+  new SiteHeaderWrapper(siteHeaderElement)
+    .initialize();
+}