1 files changed, 143 insertions, 0 deletions

diff --git a/viewer/src/services/indexfactory.ts b/viewer/src/services/indexfactory.ts
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+/* ldgallery - A static generator which turns a collection of tagged
+--             pictures into a searchable web gallery.
+--
+-- Copyright (C) 2019-2020  Guillaume FOUET
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU Affero General Public License for more details.
+--
+-- You should have received a copy of the GNU Affero General Public License
+-- along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { Operation } from "@/@types/Operation";
+import Navigation from "@/services/navigation";
+
+export default class IndexFactory {
+
+  public static generateTags(root: Gallery.Item | null): Tag.Index {
+    let tagsIndex: Tag.Index = {};
+    if (root) IndexFactory.pushTagsForItem(tagsIndex, root);
+    return tagsIndex;
+  }
+
+  // Pushes all tags for a root item (and its children) to the index
+  private static pushTagsForItem(tagsIndex: Tag.Index, item: Gallery.Item): void {
+    if (item.properties.type === "directory") {
+      item.properties.items.forEach(item => this.pushTagsForItem(tagsIndex, item));
+      return; // Directories are not indexed
+    }
+    for (const tag of item.tags) {
+      const parts = tag.split(":");
+      let lastPart: string | null = null;
+      for (const part of parts) {
+        tagsIndex[part] = IndexFactory.pushPartToIndex(tagsIndex[part], part, item, !Boolean(lastPart));
+        if (lastPart) {
+          const children = tagsIndex[lastPart].children;
+          children[part] = IndexFactory.pushPartToIndex(children[part], part, item, false);
+        }
+        lastPart = part;
+      }
+      if (lastPart) tagsIndex[lastPart].childPart = true;
+    }
+  }
+
+  private static pushPartToIndex(index: Tag.Node, part: string, item: Gallery.Item, rootPart: boolean): Tag.Node {
+    if (!index) index = { tag: part, tagfiltered: Navigation.normalize(part), rootPart, childPart: !rootPart, items: [], children: {} };
+    else if (rootPart) index.rootPart = true;
+    else index.childPart = true;
+
+    if (!index.items.includes(item)) index.items.push(item);
+    return index;
+  }
+
+  // ---
+
+
+  public static searchTags(tagsIndex: Tag.Index, filter: string, strict: boolean): Tag.Search[] {
+    let search: Tag.Search[] = [];
+    if (tagsIndex && filter) {
+      const operation = IndexFactory.extractOperation(filter);
+      if (operation !== Operation.INTERSECTION) filter = filter.slice(1);
+      if (filter.includes(":")) {
+        const filterParts = filter.split(":");
+        search = this.searchTagsFromFilterWithCategory(tagsIndex, operation, filterParts[0], filterParts[1], strict);
+      } else {
+        search = this.searchTagsFromFilter(tagsIndex, operation, filter, strict);
+      }
+    }
+    return search;
+  }
+
+  private static extractOperation(filter: string): Operation {
+    const first = filter.slice(0, 1);
+    switch (first) {
+      case Operation.ADDITION:
+      case Operation.SUBSTRACTION:
+        return first;
+      default:
+        return Operation.INTERSECTION;
+    }
+  }
+
+  private static searchTagsFromFilterWithCategory(
+    tagsIndex: Tag.Index,
+    operation: Operation,
+    category: string,
+    disambiguation: string,
+    strict: boolean
+  ): Tag.Search[] {
+    category = Navigation.normalize(category);
+    disambiguation = Navigation.normalize(disambiguation);
+    return Object.values(tagsIndex)
+      .filter(node => IndexFactory.matches(node, category, strict))
+      .flatMap(node =>
+        Object.values(node.children)
+          .filter(child => IndexFactory.matches(child, disambiguation, strict))
+          .map(child => ({ ...child, parent: node, operation, display: `${operation}${node.tag}:${child.tag}` }))
+      );
+  }
+
+  private static searchTagsFromFilter(tagsIndex: Tag.Index, operation: Operation, filter: string, strict: boolean): Tag.Search[] {
+    filter = Navigation.normalize(filter);
+    return Object.values(tagsIndex)
+      .filter(node => IndexFactory.matches(node, filter, strict))
+      .map(node => ({ ...node, operation, display: `${operation}${node.tag}` }));
+  }
+
+  private static matches(node: Tag.Node, filter: string, strict: boolean): boolean {
+    if (strict) return node.tagfiltered === filter;
+    return node.tagfiltered.includes(filter)
+  }
+
+  // ---
+
+  public static generateCategories(tagsIndex: Tag.Index, categoryTags?: Gallery.RawTag[]): Tag.Category[] {
+    if (!categoryTags?.length) return [{ tag: "", index: tagsIndex }];
+
+    const tagsCategories: Tag.Category[] = [];
+    const tagsRemaining = new Map(Object.entries(tagsIndex));
+    categoryTags
+      .map(tag => ({ tag, index: tagsIndex[tag]?.children }))
+      .filter(category => category.index && Object.keys(category.index).length)
+      .forEach(category => {
+        tagsCategories.push(category);
+        [category.tag, ...Object.values(category.index).map(node => node.tag)]
+          .filter(tag => IndexFactory.isDiscriminantTagOnly(categoryTags, tagsIndex[tag]))
+          .forEach(tag => tagsRemaining.delete(tag));
+      });
+    tagsCategories.push({ tag: "", index: Object.fromEntries(tagsRemaining) });
+    return tagsCategories;
+  }
+
+  private static isDiscriminantTagOnly(tags: Gallery.RawTag[], node: Tag.Node): boolean {
+    return !tags.includes(node.tag) || !node.childPart;
+  }
+}