Fixed logic in FileHandler to make it OS independent and added more tests

millions/src/main/java/no/ntnu/gruppe53/FileHandler.java

@@ -4,125 +4,135 @@
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.math.BigDecimal;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Handles file operations for the application.
+ * Handles reading and writing of .csv files for stocks.
  */
-
 public class FileHandler {
 
     /**
-     * Writes a list of {@link Stock}s to a text-file. Class is structed for {@code .csv} files.
+     * Writes a list of {@link Stock}s to a CSV file in UTF-8 encoding.
      *
-     * @param stockList the list of stocks to be converted to text
-     * @param path output path for the file
-     * @param filename name of the file (not including extension)
+     * @param stockList the list of stocks to be written
+     * @param path      directory path for the file
+     * @param filename  name of the file (without or with .csv extension)
+     * @throws IllegalArgumentException if stockList, path, or filename is null, or if stockList is empty
      */
     public static void writeStocksToFile(List<Stock> stockList, String path, String filename) {
-        String pathString = path + filename;
-        Path filePath = Paths.get(pathString);
-
-        try (BufferedWriter writer = Files.newBufferedWriter(filePath, Charset.defaultCharset())) {
-            if (!Files.exists(filePath)) {
-                Files.createDirectories(filePath);
+        if (stockList == null) throw new IllegalArgumentException("StockList cannot be null");
+        if (path == null || path.isBlank()) throw new IllegalArgumentException("Path cannot be null or blank");
+        if (filename == null || filename.isBlank()) throw new IllegalArgumentException(
+                "Filename cannot be null or blank");
+
+
+        path = path.trim();
+        filename = filename.trim();
+        String filenameWithExtension = filename.endsWith(".csv") ? filename : filename + ".csv";
+
+        Path filePath = Paths.get(path, filenameWithExtension);
+
+        Path dirPath = filePath.getParent();
+        if (!Files.exists(dirPath)) {
+            try {
+                Files.createDirectories(dirPath);
+            } catch (IOException e) {
+                System.out.println("ERROR: Could not create directories.");
+                e.printStackTrace();
+                return;
             }
+        }
 
+        try (BufferedWriter writer = Files.newBufferedWriter(filePath, StandardCharsets.UTF_8)) {
             writer.write("#Ticker,Name,Price");
             writer.newLine();
-            writer.newLine();
 
             for (Stock stock : stockList) {
-                String line = String.join(",", stock.getSymbol(), stock.getCompany(),
+                if (stock == null) continue;
+                String line = String.join(",",
+                        stock.getSymbol(),
+                        stock.getCompany(),
                         stock.getSalesPrice().toString());
                 writer.write(line);
                 writer.newLine();
             }
 
         } catch (IOException e) {
-            System.out.println("ERROR: Something went wrong while writing the csv file.");
-            System.out.println("Message: " + e.getMessage());
+            System.out.println("ERROR: Something went wrong while writing the CSV file.");
+            e.printStackTrace();
         }
     }
 
     /**
-     * Reads a .csv file and converts it to a list of {@code Stock} objects.
+     * Reads a CSV file and converts it to a list of {@link Stock} objects.
      *
-     * @param path path to the file to be read
-     * @param filename name of the file to be read (including extension)
-     * @return a list of {@code Stock} objects converted from text
+     * @param path     directory path of the CSV file
+     * @param filename CSV file name (with or without .csv extension)
+     * @return list of Stock objects
      */
     public static List<Stock> readStocksFromFile(String path, String filename) {
         List<Stock> stocks = new ArrayList<>();
-        String pathString = path + filename;
-        Path filePath = Paths.get(pathString);
+        if (path == null || path.isBlank()) {
+            throw new IllegalArgumentException("Path cannot be null or blank.");
+        }
+        if (filename == null || filename.isBlank()) {
+            throw new IllegalArgumentException("Filename cannot be null or blank.");
+        }
+
+        path = path.trim();
+        filename = filename.trim();
+        String filenameWithExtension = filename.endsWith(".csv") ? filename : filename + ".csv";
+
+        Path filePath = Paths.get(path, filenameWithExtension);
+
+        if (!Files.exists(filePath)) {
+            System.out.println("ERROR: File not found: " + filePath.toAbsolutePath());
+            return stocks;
+        }
 
-        try (BufferedReader reader = Files.newBufferedReader(filePath, Charset.defaultCharset())) {
+        try (BufferedReader reader = Files.newBufferedReader(filePath, StandardCharsets.UTF_8)) {
             String line;
-            String symbol;
-            String name;
-            BigDecimal price;
 
             while ((line = reader.readLine()) != null) {
-                symbol = null;
-                name = null;
-                price = null;
-                int counter = 0;
-                String trimValue = line.trim();
+                line = line.trim();
 
-                if (trimValue.isBlank() || (line.charAt(0) == '#')) {
+                if (line.isBlank() || line.startsWith("#")) continue;
+
+                String[] values = line.split(",", -1);
+                if (values.length != 3) {
+                    System.out.println("ERROR: Bad line in CSV (expected 3 values): " + line);
                     continue;
                 }
 
-                String[] values = line.split(",");
+                String symbol = values[0].trim();
+                String name = values[1].trim();
+                BigDecimal price;
 
-                if (values.length != 3) {
-                    System.out.println("ERROR: Bad line in csv: ");
-                    System.out.print(line);
-                    System.out.println("There should be 3 values total: " +
-                            "symbol, name, price.");
+                try {
+                    price = new BigDecimal(values[2].trim());
+                } catch (NumberFormatException e) {
+                    System.out.println("ERROR: Price is not a valid number: " + values[2]);
                     continue;
                 }
 
-                for (String value : values) {
-                    trimValue =  value.trim();
-
-                    switch (counter) {
-                        case 0:
-                            symbol = trimValue;
-                            break;
-                        case 1:
-                            name = trimValue;
-                            break;
-                        case 2:
-                            try {
-                                price = new BigDecimal(trimValue);
-                            }
-                            catch (NumberFormatException e) {
-                                System.out.println("ERROR: Not a number. Last column in .csv file " +
-                                        "needs to be the price of the stock (number). Skipping...");
-                                price = null;
-                                break;
-                        }
-                    }
-                    counter++;
-                }
-                if (symbol == null || symbol.isBlank() || name == null || name.isBlank() ||
-                price == null || price.compareTo(BigDecimal.ZERO) <= 0) {
+                if (symbol.isBlank() || name.isBlank() || price.compareTo(BigDecimal.ZERO) <= 0) {
+                    System.out.println("ERROR: Invalid stock data, skipping: " + line);
                     continue;
                 }
+
                 stocks.add(new Stock(symbol, name, price));
             }
+
+        } catch (IOException e) {
+            System.out.println("ERROR: Something went wrong while reading the CSV file.");
+            e.printStackTrace();
         }
-        catch (IOException e) {
-            System.out.println("ERROR: Something went wrong while reading the csv file.");
-            System.out.println("Message: " + e.getMessage());
-        }
+
         return stocks;
     }
-}
+}