Meeting statistics (single and multiple meeting counts)

src/main/java/seedu/address/commons/MonthAndYear.java

@@ -0,0 +1,48 @@
+package seedu.address.commons;
+
+import static java.util.Objects.requireNonNull;
+
+import java.time.Month;
+import java.time.Year;
+import java.util.Objects;
+
+/**
+ * Store a month and year.
+ */
+public class MonthAndYear {
+
+    private Month month;
+    private Year year;
+
+    /**
+     * Creates a MonthAndYear Object from the given {@code month} and {@code year}
+     */
+    public MonthAndYear(Month month, Year year) {
+        requireNonNull(month);
+        requireNonNull(year);
+
+        this.month = month;
+        this.year = year;
+    }
+
+    public Month getMonth() {
+        return month;
+    }
+
+    public Year getYear() {
+        return year;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.month, this.year);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return other == this
+                || (other instanceof MonthAndYear // instanceof handles nulls
+                && this.month.equals(((MonthAndYear) other).month)
+                && this.year.equals(((MonthAndYear) other).year));
+    }
+}

src/main/java/seedu/address/commons/MonthlyCountData.java

@@ -0,0 +1,45 @@
+package seedu.address.commons;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Store a data object for monthly count data statistic.
+ */
+public class MonthlyCountData {
+
+    private final MonthAndYear monthAndYear;
+
+    private final int count;
+
+    /**
+     * Creates MonthlyCountData Object from the given {@code monthAndYear} and {@code count}.
+     */
+    public MonthlyCountData(MonthAndYear monthAndYear, int count) {
+        requireNonNull(monthAndYear);
+
+        this.monthAndYear = monthAndYear;
+        this.count = count;
+    }
+
+    /**
+     * Returns the String representation of MonthAndYear.
+     */
+    public String getMonthAndYearAsStr() {
+        return String.format("%s %s", monthAndYear.getMonth(), monthAndYear.getYear());
+    }
+
+    /**
+     * Returns the number of counts related to MonthAndYear object.
+     */
+    public int getCount() {
+        return count;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return other == this
+                || (other instanceof MonthlyCountData // instanceof handles nulls
+                && this.monthAndYear.equals(((MonthlyCountData) other).monthAndYear)
+                && this.count == ((MonthlyCountData) other).count);
+    }
+}

src/main/java/seedu/address/commons/MonthlyList.java

@@ -0,0 +1,126 @@
+package seedu.address.commons;
+
+import java.time.Month;
+import java.time.Year;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Stores a list of items of type T based on the key of < month, year >
+ */
+public class MonthlyList<T> {
+
+    private final Map<MonthAndYear, List<T>> monthlyList;
+
+    public MonthlyList() {
+        this.monthlyList = new HashMap<>();
+    }
+
+    /**
+     * Adds {@code item} of type T to an item list
+     * based on the key of {@code month} and {@code year}.
+     *
+     * @param month a valid month number
+     * @param year a valid year number
+     * @param item item of type T
+     */
+    public void addItem(Month month, Year year, T item) {
+        MonthAndYear key = new MonthAndYear(month, year);
+        if (this.monthlyList.containsKey(key)) {
+            this.monthlyList.get(key).add(item);
+        } else {
+            this.monthlyList.put(key, new ArrayList<>(Collections.singleton(item)));
+        }
+    }
+
+    /**
+     * Removes {@code item} of type T from an item list
+     * based on the key of {@code month} and {@code year} if exists.
+     *
+     * @param month a valid month number
+     * @param year a valid year number
+     * @param item item of type T
+     */
+    public void removeItem(Month month, Year year, T item) {
+        MonthAndYear key = new MonthAndYear(month, year);
+        if (this.monthlyList.containsKey(key)) {
+            if (this.monthlyList.get(key).size() == 1) {
+                this.monthlyList.remove(key);
+            } else {
+                this.monthlyList.get(key).remove(item);
+            }
+        }
+    }
+
+    /**
+     * Gets the number of items in an item list
+     * based on the key of {@code month} and {@code year}.
+     * If the key of {@code month} and {@code year} does not exist, the number is 0.
+     *
+     * @param month a valid month number
+     * @param year a valid year number
+     * @return the number of items in that month and year
+     */
+    public int getItemCount(Month month, Year year) {
+        MonthAndYear key = new MonthAndYear(month, year);
+        if (this.monthlyList.containsKey(key)) {
+            return this.monthlyList.get(key).size();
+        }
+        return 0;
+    }
+
+    /**
+     * Removes all entries in the monthlyList.
+     */
+    public void clear() {
+        this.monthlyList.clear();
+    }
+
+    /**
+     * Gets the item counts in the item list for {@code month}, {@code year}
+     * and the previous @{numberOfMonths} - 1 months.
+     * @param month valid month
+     * @param year  valid year
+     * @param numberOfMonths  non-negative integer
+     * @return list of MonthlyCountData objects, ordered by non-decreasing year and month
+     */
+    public List<MonthlyCountData> getMultipleMonthCount(Month month, Year year, int numberOfMonths) {
+        List<MonthlyCountData> result = new ArrayList<>();
+
+        MonthAndYear currentMonthAndYear = new MonthAndYear(month, year);
+        result.add(new MonthlyCountData(currentMonthAndYear,
+                this.monthlyList.getOrDefault(currentMonthAndYear, Collections.emptyList()).size()));
+
+        for (int i = 1; i < numberOfMonths; i++) {
+            MonthAndYear previousMonthAndYear = getPreviousMonthAndYear(month, year);
+            result.add(new MonthlyCountData(previousMonthAndYear,
+                    this.monthlyList.getOrDefault(previousMonthAndYear, Collections.emptyList()).size()));
+            month = previousMonthAndYear.getMonth();
+            year = previousMonthAndYear.getYear();
+        }
+
+        Collections.reverse(result);
+        return result;
+    }
+
+    /**
+     * Gets the month and year for
+     * one month before {@code month} and {@code year}.
+     * @param month valid month
+     * @param year valid year
+     * @return MonthAndYear object that is one month before the {@code month} and {@code year}
+     */
+    private MonthAndYear getPreviousMonthAndYear(Month month, Year year) {
+        Year yearResult = year;
+        int monthResult = month.getValue() - 1;
+        if (monthResult <= 0) {
+            monthResult += 12;
+            yearResult = year.minusYears(1);
+        }
+        Month previousMonth = Month.of(monthResult);
+        return new MonthAndYear(previousMonth, yearResult);
+    }
+}

src/main/java/seedu/address/commons/core/Messages.java

@@ -19,6 +19,11 @@ public class Messages {
     public static final String MESSAGE_INVALID_TAG_DISPLAYED_INDEX = "The tag index provided is invalid";
     public static final String MESSAGE_INVALID_MEETING_DISPLAYED_INDEX = "The meeting index provided is invalid";
     public static final String MESSAGE_INVALID_SALE_DISPLAYED_INDEX = "The sale index provided is invalid";
+    public static final String MESSAGE_INVALID_MONTH =
+            "Month must be an integer value in between 1 and 12 inclusive.";
+    public static final String MESSAGE_INVALID_YEAR = "Year must be an non negative integer.";
+    public static final String MESSAGE_INVALID_NUMBER_OF_MONTHS =
+            "The number of months must be an integer value in between 2 and 6 inclusive.";
     public static final String MESSAGE_SALE_TAGS_NOT_FOUND = "The provided sales tag(s) do not exist yet";
     public static final String MESSAGE_CONTACT_TAGS_NOT_FOUND = "The provided contact tag(s) do not exist yet";
 

src/main/java/seedu/address/logic/commands/CommandResult.java

@@ -2,8 +2,11 @@
 
 import static java.util.Objects.requireNonNull;
 
+import java.util.List;
 import java.util.Objects;
 
+import seedu.address.commons.MonthlyCountData;
+
 /**
  * Represents the result of a command execution.
  */
@@ -20,14 +23,35 @@ public class CommandResult {
     /** The chat box should be cleared. */
     private final boolean clear;
 
+    private final List<MonthlyCountData> statisticResult;
+
     /**
-     * Constructs a {@code CommandResult} with the specified fields.
+     * Constructs a {@code CommandResult} with the specified {@code feedbackToUser},
+     * {@code showHelp}, {@code exit}, {@code clear}
+     * and other fields set to their default value.
      */
     public CommandResult(String feedbackToUser, boolean showHelp, boolean exit, boolean clear) {
+        this(feedbackToUser, showHelp, exit, clear, null);
+    }
+
+    /**
+     * Constructs a {@code CommandResult} with the specified fields.
+     */
+    public CommandResult(String feedbackToUser, boolean showHelp,
+                         boolean exit, boolean clear, List<MonthlyCountData> statisticResult) {
         this.feedbackToUser = requireNonNull(feedbackToUser);
         this.showHelp = showHelp;
         this.exit = exit;
         this.clear = clear;
+        this.statisticResult = statisticResult;
+    }
+
+    /**
+     * Constructs a {@code CommandResult} with the specified {@code statisticResult},
+     * and other fields set to their default value.
+     */
+    public CommandResult(String feedbackToUser, List<MonthlyCountData> statisticResult) {
+        this(feedbackToUser, false, false, false, statisticResult);
     }
 
     /**
@@ -54,6 +78,14 @@ public boolean isClear() {
         return clear;
     }
 
+    public boolean hasStatisticsResult() {
+        return !Objects.isNull(this.statisticResult);
+    }
+
+    public List<MonthlyCountData> getStatisticResult() {
+        return statisticResult;
+    }
+
     @Override
     public boolean equals(Object other) {
         if (other == this) {
@@ -69,12 +101,16 @@ public boolean equals(Object other) {
         return feedbackToUser.equals(otherCommandResult.feedbackToUser)
                 && showHelp == otherCommandResult.showHelp
                 && clear == otherCommandResult.clear
-                && exit == otherCommandResult.exit;
+                && exit == otherCommandResult.exit
+                && ((Objects.isNull(statisticResult)
+                    && Objects.isNull(otherCommandResult.statisticResult))
+                    || (!Objects.isNull(statisticResult)
+                    && statisticResult.equals(otherCommandResult.statisticResult)));
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(feedbackToUser, showHelp, exit, clear);
+        return Objects.hash(feedbackToUser, showHelp, exit, clear, statisticResult);
     }
 
 }

src/main/java/seedu/address/logic/commands/meeting/MultipleMeetingStatsCommand.java

@@ -0,0 +1,58 @@
+package seedu.address.logic.commands.meeting;
+
+import static java.util.Objects.requireNonNull;
+
+import java.time.LocalDate;
+import java.time.Month;
+import java.time.Year;
+import java.time.ZoneId;
+import java.util.List;
+
+import seedu.address.commons.MonthlyCountData;
+import seedu.address.logic.commands.CommandResult;
+import seedu.address.model.Model;
+
+/**
+ * Gets multiple monthly meeting counts
+ */
+public class MultipleMeetingStatsCommand extends StatsCommand {
+
+    public static final String MESSAGE_SUCCESS = "Opened a new window!";
+
+    private final int numberOfMonths;
+
+    /**
+     * Creates a MultipleMeetingStatsCommand with the given {@code numberOfMonths}.
+     */
+    public MultipleMeetingStatsCommand(int numberOfMonths) {
+        this.numberOfMonths = numberOfMonths;
+    }
+
+    /**
+     * Gets multiple monthly meeting counts for months between
+     * the current month and the previous numberOfMonths - 1 months inclusive.
+     *
+     * @param model {@code Model} which the command should operate on
+     * @return CommandResult object storing the success message
+     * and the multiple monthly count result
+     */
+    @Override
+    public CommandResult execute(Model model) {
+        requireNonNull(model);
+
+        Month currentMonth = LocalDate.now(ZoneId.of("Asia/Singapore")).getMonth();
+        Year currentYear = Year.now();
+
+        List<MonthlyCountData> result = model
+                .getMultipleMonthMeetingsCount(currentMonth, currentYear, numberOfMonths);
+
+        return new CommandResult(MESSAGE_SUCCESS, result);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        return other == this
+                || (other instanceof MultipleMeetingStatsCommand
+                && numberOfMonths == (((MultipleMeetingStatsCommand) other).numberOfMonths));
+    }
+}