partial implementation of community profile page - next, straighten out left menus

database/category.go

@@ -0,0 +1,115 @@
+/*
+ * Amsterdam Web Communities System
+ * Copyright (c) 2025 Erbosoft Metaverse Design Solutions, All Rights Reserved
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+// The database package contains database management and storage logic.
+package database
+
+import (
+	"errors"
+	"sync"
+)
+
+// Category is the structure defining a category.
+type Category struct {
+	CatId         int32  `db:"catid"`
+	Parent        int32  `db:"parent"`
+	SymLink       int32  `db:"symlink"`
+	HideDirectory int32  `db:"hide_dir"`
+	HideSearch    int32  `db:"hide_search"`
+	Name          string `db:"name"`
+}
+
+// allCategories is the list of all categories loaded from the database.
+var allCategories []Category
+
+// categoryIdMap maps IDs to categories.
+var categoryIdMap map[int32]*Category = make(map[int32]*Category)
+
+// categoryMutex syncs the loading of the categories.
+var categoryMutex sync.Mutex
+
+// loadCategories loads the categories list from the database.
+func loadCategories() error {
+	categoryMutex.Lock()
+	defer categoryMutex.Unlock()
+	if allCategories == nil {
+		rs, err := amdb.Query("SELECT COUNT(*) FROM refcategory")
+		if err != nil {
+			return err
+		}
+		if !rs.Next() {
+			return errors.New("internal error loading categories")
+		}
+		var ncats int32
+		rs.Scan(&ncats)
+		allCategories = make([]Category, 0, ncats)
+		err = amdb.Select(&allCategories, "SELECT * FROM refcategory ORDER BY parent, name")
+		if err != nil {
+			return err
+		}
+		for i, c := range allCategories {
+			categoryIdMap[c.CatId] = &(allCategories[i])
+		}
+	}
+	return nil
+}
+
+/* AmGetCategory returns the category for the given name.
+ * Parameters:
+ *     catid - The ID of the category to get.
+ * Returns:
+ *     Pointer to the appropriate Category, or nil.
+ *     Standard Go error status.
+ */
+func AmGetCategory(catid int32) (*Category, error) {
+	err := loadCategories()
+	if err != nil {
+		return nil, err
+	}
+	c := categoryIdMap[catid]
+	d := 5
+	for c.SymLink != -1 {
+		d--
+		if d == 0 {
+			return nil, errors.New("symlink resolution error")
+		}
+		c = categoryIdMap[c.SymLink]
+	}
+	return c, nil
+}
+
+/* AmGetCategoryHierarchy returns the category hierarchy for the given ID.
+ * Parameters:
+ *     catid - The ID of the category to get.
+ * Returns:
+ *     Array of pointers to the categories in hierarchical order, or nil.
+ *     Standard Go error status.
+ */
+func AmGetCategoryHierarchy(catid int32) ([]*Category, error) {
+	err := loadCategories()
+	if err != nil {
+		return nil, err
+	}
+	// walk all the way to the "root" (parent = -1)
+	p := catid
+	ia := make([]*Category, 0, 3)
+	for p != -1 {
+		c := categoryIdMap[p]
+		for c.SymLink != -1 {
+			c = categoryIdMap[c.SymLink]
+		}
+		ia = append(ia, c)
+		p = c.Parent
+	}
+	// reverse the array for return
+	rc := make([]*Category, 0, len(ia))
+	for i := range ia {
+		rc = append(rc, ia[len(ia)-(i+1)])
+	}
+	return rc, nil
+}