Fixes #71 Implement Analytics class

src/main/java/seedu/address/commons/util/DateUtil.java

@@ -40,4 +40,17 @@
         return DATE_FORMATTER.format(date);
     }
 
+    /**
+     * Adds a number of days to a Date object.
+     *
+     * @param date The Date object to add days to.
+     * @param days The number of days to add.
+     * @return The new Date object.
+     */
+    public static Date addDay(Date date, int days) {
+        long time = date.getTime();
+        time += days * 24 * 60 * 60 * 1000;
+        return new Date(time);
+    }
+
 }

src/main/java/seedu/address/model/person/Analytics.java

@@ -0,0 +1,225 @@
+package seedu.address.model.person;
+
+import java.util.Date;
+
+/**
+ * Represents the analytics of a LoanRecords object.
+ */
+public class Analytics {
+
+    private int numLoans; // total number of loans
+    private int numOverdueLoans; // total number of overdue loans
+    private int numActiveLoans; // total number of active loans
+
+    private float propOverdueLoans; // proportion of loans that are overdue over active loans
+    private float propActiveLoans; // proportion of loans that are active over total loans
+
+    private float totalValueLoaned; // total value of all loans
+    private float totalValueOverdue; // total value of all overdue loans
+    private float totalValueActive; // total value of all active loans
+
+    private float averageLoanValue; // average loan value of all loans
+    private float averageOverdueValue; // average loan value of all overdue loans
+    private float averageActiveValue; // average loan value of all active loans
+
+    private Date earliestLoanDate; // earliest loan date of all loans
+    private Date earliestReturnDate; // earliest return date of active loans
+    private Date latestLoanDate; // latest loan date of all loans
+    private Date latestReturnDate; // latest return date of active loans
+
+    private Analytics() {
+        this.numLoans = 0;
+        this.numOverdueLoans = 0;
+        this.numActiveLoans = 0;
+
+        this.propOverdueLoans = 0;
+        this.propActiveLoans = 0;
+
+        this.totalValueLoaned = 0;
+        this.totalValueOverdue = 0;
+        this.totalValueActive = 0;
+
+        this.averageLoanValue = 0;
+        this.averageOverdueValue = 0;
+        this.averageActiveValue = 0;
+
+        this.earliestLoanDate = null;
+        this.earliestReturnDate = null;
+        this.latestLoanDate = null;
+        this.latestReturnDate = null;
+    }
+
+    /**
+     * Updates the fields that count the number of various loans.
+     * @param loan The loan to update the fields with.
+     */
+    private void updateNumFields(Loan loan) {
+        this.numLoans++;
+        if (loan.isOverdue()) {
+            this.numOverdueLoans++;
+        }
+        if (loan.isActive()) {
+            this.numActiveLoans++;
+        }
+    }
+
+    /**
+     * Updates the fields that calculate the proportion of various loans.
+     * This method should be called after the fields that count the number of various loans have been updated.
+     */
+    private void updatePropFields() {
+        if (this.numActiveLoans > 0 && this.numLoans > 0) {
+            this.propActiveLoans = (float) this.numActiveLoans / this.numLoans;
+            this.propOverdueLoans = (float) this.numOverdueLoans / this.numActiveLoans;
+        }
+    }
+
+    /**
+     * Updates the fields that calculate the total value of various loans.
+     * @param loan The loan to update the fields with.
+     */
+    private void updateValueFields(Loan loan) {
+        this.totalValueLoaned += loan.getValue();
+        if (loan.isOverdue()) {
+            this.totalValueOverdue += loan.getValue();
+        }
+        if (loan.isActive()) {
+            this.totalValueActive += loan.getValue();
+        }
+    }
+
+    /**
+     * Updates the fields that calculate the average value of various loans.
+     * This method should be called after the fields that calculate the total value of various loans have been updated.
+     */
+    private void updateAverageFields() {
+        if (this.numActiveLoans > 0) {
+            this.averageActiveValue = this.totalValueActive / this.numActiveLoans;
+        }
+        if (this.numOverdueLoans > 0) {
+            this.averageOverdueValue = this.totalValueOverdue / this.numOverdueLoans;
+        }
+        if (this.numLoans > 0) {
+            this.averageLoanValue = this.totalValueLoaned / this.numLoans;
+        }
+    }
+
+    /**
+     * Updates the fields that calculate the earliest and latest dates of various loans.
+     * @param loan The loan to update the fields with.
+     */
+    private void updateDateFields(Loan loan) {
+        if (this.earliestLoanDate == null || loan.getStartDate().before(this.earliestLoanDate)) {
+            this.earliestLoanDate = loan.getStartDate();
+        }
+        if (this.latestLoanDate == null || loan.getStartDate().after(this.latestLoanDate)) {
+            this.latestLoanDate = loan.getStartDate();
+        }
+        if (!loan.isReturned()) {
+            if (this.earliestReturnDate == null || loan.getReturnDate().before(this.earliestReturnDate)) {
+                this.earliestReturnDate = loan.getReturnDate();
+            }
+            if (this.latestReturnDate == null || loan.getReturnDate().after(this.latestReturnDate)) {
+                this.latestReturnDate = loan.getReturnDate();
+            }
+        }
+    }
+
+    /**
+     * Returns an Analytics object that represents the analytics of a LoanRecords object.
+     * @param loanRecords The LoanRecords object to get the analytics from.
+     * @return The Analytics object that represents the analytics of the LoanRecords object.
+     */
+    public static Analytics getAnalytics(LoanRecords loanRecords) {
+        Analytics analytics = new Analytics();
+        for (int i = 0; i < loanRecords.size(); i++) {
+            Loan loan = loanRecords.getLoan(i);
+            analytics.updateNumFields(loan);
+            analytics.updateValueFields(loan);
+            analytics.updateDateFields(loan);
+        }
+        analytics.updatePropFields();
+        analytics.updateAverageFields();
+        return analytics;
+    }
+
+    public int getNumLoans() {
+        return numLoans;
+    }
+
+    public int getNumOverdueLoans() {
+        return numOverdueLoans;
+    }
+
+    public int getNumActiveLoans() {
+        return numActiveLoans;
+    }
+
+    public float getPropOverdueLoans() {
+        return propOverdueLoans;
+    }
+
+    public float getPropActiveLoans() {
+        return propActiveLoans;
+    }
+
+    public float getTotalValueLoaned() {
+        return totalValueLoaned;
+    }
+
+    public float getTotalValueOverdue() {
+        return totalValueOverdue;
+    }
+
+    public float getTotalValueActive() {
+        return totalValueActive;
+    }
+
+    public float getAverageLoanValue() {
+        return averageLoanValue;
+    }
+
+    public float getAverageOverdueValue() {
+        return averageOverdueValue;
+    }
+
+    public float getAverageActiveValue() {
+        return averageActiveValue;
+    }
+
+    public Date getEarliestLoanDate() {
+        return earliestLoanDate;
+    }
+
+    public Date getEarliestReturnDate() {
+        return earliestReturnDate;
+    }
+
+    public Date getLatestLoanDate() {
+        return latestLoanDate;
+    }
+
+    public Date getLatestReturnDate() {
+        return latestReturnDate;
+    }
+
+    @Override
+    public String toString() {
+        return "Number of loans: " + numLoans + "\n"
+                + "Number of overdue loans: " + numOverdueLoans + "\n"
+                + "Number of active loans: " + numActiveLoans + "\n"
+                + "Proportion of overdue loans: " + propOverdueLoans + "\n"
+                + "Proportion of active loans: " + propActiveLoans + "\n"
+                + "Total value loaned: " + totalValueLoaned + "\n"
+                + "Total value of overdue loans: " + totalValueOverdue + "\n"
+                + "Total value of active loans: " + totalValueActive + "\n"
+                + "Average loan value: " + averageLoanValue + "\n"
+                + "Average value of overdue loans: " + averageOverdueValue + "\n"
+                + "Average value of active loans: " + averageActiveValue + "\n"
+                + "Earliest loan date: " + earliestLoanDate + "\n"
+                + "Earliest return date: " + earliestReturnDate + "\n"
+                + "Latest loan date: " + latestLoanDate + "\n"
+                + "Latest return date: " + latestReturnDate + "\n";
+    }
+
+}

src/main/java/seedu/address/model/person/Loan.java

@@ -96,6 +96,15 @@
         return !isReturned;
     }
 
+    /**
+     * Returns true if the loan is overdue.
+     */
+    public boolean isOverdue() {
+        // shift return date to the next day
+        Date returnDateNextDay = DateUtil.addDay(returnDate, 1);
+        return !isReturned && new Date().after(returnDateNextDay);
+    }
+
     /**
      * Marks the loan as returned.
      */

src/main/java/seedu/address/model/person/Person.java

@@ -57,6 +57,10 @@
         return address;
     }
 
+    public Analytics getAnalytics() {
+        return Analytics.getAnalytics(loanRecords);
+    }
+
     /**
      * Returns an immutable tag set, which throws {@code UnsupportedOperationException}
      * if modification is attempted.