Create fileDatabase.js

lib/fileDatabase.js

@@ -0,0 +1,97 @@
+const fs = require('fs');
+const path = require('path');
+const base64 = require('base-64');
+
+class FileDatabase {
+    constructor(basePath) {
+        this.basePath = basePath;
+        fs.mkdirSync(this.basePath, { recursive: true });
+    }
+
+    createTable(tableName, columns) {
+        const tablePath = path.join(this.basePath, tableName);
+        fs.mkdirSync(tablePath, { recursive: true });
+
+        // Store table schema inside the table directory
+        fs.writeFileSync(path.join(tablePath, 'schema.json'), JSON.stringify(columns));
+    }
+
+    insertRow(tableName, rowData) {
+        const tablePath = path.join(this.basePath, tableName);
+
+        const rowNumber = fs.readdirSync(tablePath).length + 1;
+        const rowFolder = path.join(tablePath, `${rowNumber}.row`);
+        fs.mkdirSync(rowFolder);
+
+        // Ensure rowData is a string, if it's an array, convert it to a string
+        if (Array.isArray(rowData)) {
+            rowData = rowData.join(','); // Convert array elements to a string
+        }
+
+        // Encode and store row data
+        const encodedData = base64.encode(rowData);
+        fs.writeFileSync(path.join(rowFolder, 'row_content'), encodedData);
+    }
+
+    retrieveRows(tableName) {
+        const tablePath = path.join(this.basePath, tableName);
+        const rows = [];
+
+        fs.readdirSync(tablePath).forEach((folder) => {
+            const rowFolder = path.join(tablePath, folder);
+            if (fs.statSync(rowFolder).isDirectory()) {
+                const encodedData = fs.readFileSync(path.join(rowFolder, 'row_content'), 'utf8');
+                const decodedData = base64.decode(encodedData);
+                rows.push(decodedData);
+            }
+        });
+
+        return rows;
+    }
+
+    deleteTable(tableName) {
+        const tablePath = path.join(this.basePath, tableName);
+        if (fs.existsSync(tablePath)) {
+            fs.rmdirSync(tablePath, { recursive: true });
+        } else {
+            throw new Error(`Table '${tableName}' does not exist.`);
+        }
+    }
+
+    deleteRow(tableName, rowNumber) {
+        const rowFolder = path.join(this.basePath, tableName, `${rowNumber}.row`);
+        if (fs.existsSync(rowFolder)) {
+            fs.rmdirSync(rowFolder, { recursive: true });
+        } else {
+            throw new Error(`Row '${rowNumber}' in table '${tableName}' does not exist.`);
+        }
+    }
+
+    deleteDatabase() {
+        if (fs.existsSync(this.basePath)) {
+            fs.rmdirSync(this.basePath, { recursive: true });
+        } else {
+            throw new Error('Database does not exist.');
+        }
+    }
+
+    selectRows(tableName, conditionFunc) {
+        const tablePath = path.join(this.basePath, tableName);
+        const rows = [];
+
+        fs.readdirSync(tablePath).forEach((folder) => {
+            const rowFolder = path.join(tablePath, folder);
+            if (fs.statSync(rowFolder).isDirectory()) {
+                const encodedData = fs.readFileSync(path.join(rowFolder, 'row_content'), 'utf8');
+                const decodedData = base64.decode(encodedData);
+                if (conditionFunc(decodedData)) {
+                    rows.push(decodedData);
+                }
+            }
+        });
+
+        return rows;
+    }
+}
+
+module.exports = FileDatabase;