add getSalaryInfo logic

src/main/java/core/basesyntax/SalaryInfo.java

@@ -1,7 +1,59 @@
 package core.basesyntax;
 
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+
 public class SalaryInfo {
+    private static final DateTimeFormatter FORMATTER =
+            DateTimeFormatter.ofPattern("dd.MM.yyyy");
+    private static final int FORMATTER_LENGTH = 10;
+
     public String getSalaryInfo(String[] names, String[] data, String dateFrom, String dateTo) {
-        return null;
+        StringBuilder builder = new StringBuilder("Report for period ");
+        LocalDate startDate = getLocalDate(dateFrom);
+        LocalDate endDate = getLocalDate(dateTo);
+
+        builder.append(dateFrom).append(" - ")
+                .append(dateTo);
+
+        for (String name : names) {
+            int totalSalary = 0;
+
+            for (String record : data) {
+                if (record.contains(name)) {
+                    LocalDate recordDate = getLocalDate(record.substring(0, FORMATTER_LENGTH));
+
+                    if ((recordDate.isAfter(startDate) && recordDate.isBefore(endDate)
+                            || (recordDate.isEqual(startDate) || recordDate.isEqual(endDate)))) {
+                        int salaryPerPeriod = getSalaryPerPeriod(record);
+
+                        totalSalary += salaryPerPeriod;
+                    }
+                }
+
+            }
+            builder.append(System.lineSeparator())
+                    .append(name)
+                    .append(" - ")
+                    .append(totalSalary);
+        }
+
+        return builder.toString();
+    }
+
+    private static LocalDate getLocalDate(String date) {
+        return LocalDate.parse(date, FORMATTER);
+    }
+
+    private static int getSalaryPerPeriod(String record) {
+        int lastSpaceIndex = record.lastIndexOf(" ");
+        int secondLastSpaceIndex = record.lastIndexOf(" ", lastSpaceIndex - 1);
+        int workingHours = Integer.parseInt(
+                record.substring(secondLastSpaceIndex, lastSpaceIndex)
+                .trim()
+        );
+        int incomePerHour = Integer.parseInt(record.substring(lastSpaceIndex).trim());
+
+        return incomePerHour * workingHours;
     }
 }