feat: initial functional release of Stock Pignon

app/src/main/java/com/stock/pignon/CartActionHelper.java

@@ -0,0 +1,207 @@
+// CartActionHelper.java
+package com.stock.pignon;
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.Environment;
+import android.text.Html;
+import android.util.Log;
+import android.view.View;
+import android.widget.GridLayout;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.ImageView;
+
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.bumptech.glide.Glide;
+
+/**
+ * Action on shopping cart: validation, clearing, and persistence
+ */
+public class CartActionHelper {
+
+    private static final String TAG = "CartActionHelper";
+
+    /**
+     * Resets the cart data and refreshes UI
+     */
+    public static void emptyCart(LinearLayout cartList, Context activity) {
+        CartManager.clear();
+        CartViewHelper.updateCartView(cartList, activity);
+
+        if (activity instanceof MainActivity) {
+            GridLayout grid = ((MainActivity) activity).findViewById(R.id.gridPieces);
+            refreshGridQuantities(grid);
+        }
+    }
+
+    /**
+     * Handles checkout process: shows summary, saves to disk on confirmation
+     * and redirects the user after a success message
+     */
+    public static void validateCart(LinearLayout cartList, Context activity) {
+        List<CartItem> items = CartManager.getItems();
+        if (items.isEmpty()) return;
+
+        // Build a readable HTML summary for the confirmation dialog
+        StringBuilder recap = new StringBuilder();
+
+        // Show a line for each item
+        for (CartItem item : items) {
+            recap.append(activity.getString(R.string.popup_item,
+                    item.getQuantity(),
+                    item.getName(),
+                    item.getTotalMin(),
+                    item.getTotalMax()));
+        }
+
+        // Show total price range
+        recap.append(activity.getString(R.string.popup_total,
+                CartManager.getGlobalTotalMin(),
+                CartManager.getGlobalTotalMax()));
+
+        // Build dialog with HTML summary and buttons
+        new AlertDialog.Builder(activity)
+                .setTitle(activity.getString(R.string.popup_name))
+                .setMessage(Html.fromHtml(recap.toString()))
+                .setPositiveButton("Oui", (dialog, which) -> {
+                    // Save to storage
+                    saveCartToExternalFile(items);
+
+                    // Clear current session
+                    CartManager.clear();
+                    CartViewHelper.updateCartView(cartList, activity);
+
+                    // Show success message and close
+                    showSuccessAndRedirect(activity);
+                })
+                .setNegativeButton("Non", null)
+                .show();
+    }
+
+    /**
+     * Displays a thank you popup and returns to the main menu after 2 seconds.
+     */
+    private static void showSuccessAndRedirect(Context activity) {
+        AlertDialog merciDialog = new AlertDialog.Builder(activity)
+                .setMessage(activity.getString(R.string.popup_end))
+                // Info popup, not cancelable
+                .setCancelable(false)
+                .create();
+        merciDialog.show();
+
+
+        new Handler().postDelayed(() -> {
+            // Close dialog
+            merciDialog.dismiss();
+            // Go to home if not already
+            if (!(activity instanceof MainActivity)) {
+                Intent intent = new Intent(activity, MainActivity.class);
+                // Clear the backstack so the user can't "go back" to a validated cart
+                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
+                activity.startActivity(intent);
+            }
+        }, 2000);
+    }
+
+    /**
+     * Merges current cart items with the existing stock file on the SD Card.
+     */
+    private static void saveCartToExternalFile(List<CartItem> cartItems) {
+        File stockFile = new File(Environment.getExternalStorageDirectory(), Config.STOCK_FILE_NAME);
+        Gson gson = new Gson();
+        Map<String, Integer> stockMap;
+
+        // Load data into a Map (Key: Item Name, Value: Total Quantity)
+        stockMap = loadExistingStock(stockFile, gson);
+
+        // Merge with new items from current cart
+        for (CartItem item : cartItems) {
+            // Get previous quantity
+            Integer qtyObj = stockMap.get(item.getName());
+            int currentQty = (qtyObj != null) ? qtyObj : 0;
+            // Add
+            stockMap.put(item.getName(), currentQty + item.getQuantity());
+        }
+
+        // Overwrite the file with updated data
+        // Needs WRITE_EXTERNAL_STORAGE permission
+        try (FileOutputStream fos = new FileOutputStream(stockFile);
+             @SuppressWarnings("CharsetObjectCanBeUsed")
+             OutputStreamWriter writer = new OutputStreamWriter(fos, "UTF-8")) {
+
+            // Writing directly to the stream
+            gson.toJson(stockMap, writer);
+            Log.i(TAG, "Stock updated successfully at: " + stockFile.getAbsolutePath());
+
+        } catch (Exception e) {
+            Log.e(TAG, "Failed to write stock file", e);
+        }
+    }
+
+    /**
+     * Reads the current stock file. If the file is missing or corrupted, returns an empty map.
+     */
+    private static Map<String, Integer> loadExistingStock(File stockFile, Gson gson) {
+        if (!stockFile.exists()) return new HashMap<>();
+
+        try (FileInputStream fis = new FileInputStream(stockFile);
+             @SuppressWarnings("CharsetObjectCanBeUsed")
+             InputStreamReader reader = new InputStreamReader(fis, "UTF-8")) {
+
+            // Type definition for Map required by GSON : <String, Integer>
+            Type type = new TypeToken<Map<String, Integer>>(){}.getType();
+            // Read and fill map
+            Map<String, Integer> result = gson.fromJson(reader, type);
+
+            return (result != null) ? result : new HashMap<>();
+
+        } catch (Exception e) {
+            Log.e(TAG, "Error reading existing stock, starting fresh", e);
+            return new HashMap<>();
+        }
+    }
+
+    /**
+     * Updates the UI grid to reflect quantities.
+     */
+    public static void refreshGridQuantities(GridLayout grid) {
+        if (grid == null) return;
+
+        // Iterate through all child views in the grid
+        for (int i = 0; i < grid.getChildCount(); i++) {
+            View itemView = grid.getChildAt(i);
+
+            // Locate the name and quantity views inside the current item layout
+            TextView nameView = itemView.findViewById(R.id.itemName);
+            TextView qtyView = itemView.findViewById(R.id.qtyView);
+
+
+            if (nameView != null && qtyView != null) {
+                // Match names
+                String itemName = nameView.getText().toString();
+
+                // Fetch current quantity from centralized CartManager
+                CartItem cartItem = CartManager.getItemByName(itemName);
+                int quantity = (cartItem != null) ? cartItem.getQuantity() : 0;
+
+                // Update the visual counter
+                qtyView.setText(String.valueOf(quantity));
+            }
+        }
+    }
+}