init geek calc

state.js

@@ -0,0 +1,117 @@
+// State management module
+const StateManager = (function() {
+    class StateManager {
+        constructor() {
+            this.history = [];
+            this.settings = {
+                theme: 'dark',
+                mode: 'standard', // 'standard' or 'rpn'
+                historyLimit: 50
+            };
+            this.loadFromStorage();
+        }
+
+        // Add a calculation to history
+        addToHistory(expression, result) {
+            const entry = {
+                id: Date.now().toString(),
+                expression: expression,
+                result: result,
+                timestamp: new Date()
+            };
+
+            this.history.unshift(entry); // Add to beginning of array
+
+            // Limit history size
+            if (this.history.length > this.settings.historyLimit) {
+                this.history = this.history.slice(0, this.settings.historyLimit);
+            }
+
+            this.saveToStorage();
+        }
+
+        // Get calculation history
+        getHistory() {
+            return [...this.history]; // Return a copy to prevent external modification
+        }
+
+        // Get settings
+        getSettings() {
+            return { ...this.settings }; // Return a copy
+        }
+
+        // Update settings
+        updateSettings(newSettings) {
+            this.settings = { ...this.settings, ...newSettings };
+            this.saveToStorage();
+        }
+
+        // Toggle calculator mode (standard/RPN)
+        toggleMode() {
+            this.settings.mode = this.settings.mode === 'standard' ? 'rpn' : 'standard';
+            this.saveToStorage();
+            return this.settings.mode;
+        }
+
+        // Get current mode
+        getMode() {
+            return this.settings.mode;
+        }
+
+        // Clear history
+        clearHistory() {
+            this.history = [];
+            this.saveToStorage();
+        }
+
+        // Save state to localStorage
+        saveToStorage() {
+            try {
+                const stateData = {
+                    history: this.history,
+                    settings: this.settings
+                };
+                localStorage.setItem('geekCalculatorState', JSON.stringify(stateData));
+            } catch (error) {
+                console.error('Failed to save state to localStorage:', error);
+            }
+        }
+
+        // Load state from localStorage
+        loadFromStorage() {
+            try {
+                const stateData = localStorage.getItem('geekCalculatorState');
+                if (stateData) {
+                    const parsedData = JSON.parse(stateData);
+                    this.history = Array.isArray(parsedData.history) ? parsedData.history : [];
+                    this.settings = parsedData.settings || this.settings;
+                }
+            } catch (error) {
+                console.error('Failed to load state from localStorage:', error);
+                // If loading fails, keep default state
+            }
+        }
+
+        // Get the last calculation result
+        getLastResult() {
+            if (this.history.length > 0) {
+                return this.history[0].result; // First item is the most recent
+            }
+            return null;
+        }
+
+        // Re-run a specific calculation from history
+        rerunCalculation(id) {
+            const entry = this.history.find(item => item.id === id);
+            if (entry) {
+                return {
+                    expression: entry.expression,
+                    result: entry.result
+                };
+            }
+            return null;
+        }
+    }
+
+    return { StateManager };
+})();