Fix Xiaohang PPP (#278)

docs/team/kelly9373.adoc

@@ -57,6 +57,8 @@ This section shows my contribution to the LoanBook's development.
 
 ** added censoring function in Nric, Phone and Email class to enable hiding sensitive information feature in LoanCard UI. (Pull request https://github.com/CS2103-AY1819S1-F10-2/main/pull/125[#125])
 
+* *Code Contributed*: https://nus-cs2103-ay1819s1.github.io/cs2103-dashboard/#=undefined&search=xiaohang&sort=displayName&since=2018-09-12&until=2018-11-11&timeframe=day&reverse=false&repoSort=true[Reposense]
+
 * *Other contributions*:
 
 ** Project management:
@@ -93,14 +95,194 @@ This section shows my contribution to the LoanBook's development.
 
 == Contributions to the User Guide
 
+|===
 This section shows the contributions I made to the User Guide. The following instructions show how to use the send email functionality.
+|===
+
+=== Check your email: `checkemail`
+
+Checks whether you have set your email or not, and displays the censored email address if you have set it before. +
+[big]#*Format*: `checkemail`#
+
+=== Set your email: `setemail`
+
+Sets the email address to send reminder emails from. +
+[big]#*Format*: `setemail e/NEWEMAIL x/PASSWORDFORAPP`#
+
+[big red]#List of Parameters#:
+
+`e/NEWEMAIL`: The new user email that you want to set to the app. +
+`x/PASSWORDFORAPP`: The password you set for the app. Not your email password.
+
+Some things to take note of for first time users:
+
+* `NEWEMAIL` cannot the same as the user email you have already set to the app.
+* `NEWEMAIL` must be a valid Gmail address.
+
+[NOTE]
+Only Gmail is accepted!
+
+Examples:
+
+* `setemail e/\new.email@gmail.com x/a12345`
+
+=== Send reminder email: `remind`
+
+Sends a reminder email to the customer. +
+[big]#*Format*: `remind pw/EMAILPASSWORD id/LOAN_ID`#
+
+[big red]#List of Parameters#:
+
+`pw/PASSWORD`: Password of the email address you are sending the messages from. +
+`id/LOAN_ID`: LoanID of the loan you want to remind +
+
+* `LOANID` is the ID of the loan, not the index.
+* `EMAILPASSWORD` must be correct.
+
+[NOTE]
+*[IMPORTANT] Before using this command, please go to https://www.google.com/settings/security/lesssecureapps[Less Secure Apps] , enable it and restart the app! [red]#However! If your help page does not respond when enabling, please copy this link: \https://www.google.com/settings/security/lesssecureapps and access it in your browser. Then enable the less secure app setting and refresh the setting page!#* +
+[NOTE]
+*[IMPORTANT] Please do not connect to eduroam network when using this functionality!*
 
-include::../UserGuide.adoc[tag=sendemail]
+Examples:
+
+* `remind pw/samplepassword id/0`
 
 == Contributions to the Developer Guide
 
+|===
 This section shows the contributions I made to the Developer Guide. The following instructions show how to the send email functionality is implemented.
+|===
+
+=== Hide private information
+
+Users must provide some important and personal information when adding a loan, e.g. `Nric`, so it is our responsibility to protect their privacy.
+
+As a result, we have added a new feature to hide the private information from the Window. +
+Example: The customer's `Nric` as stored in the database is `Nric: T0248272F`, but our `LoanCard` will only show `Nric: Txxxxx72F`.
+
+image::LoanListPanelView.png[]
+
+==== Current implementation
+
+Hidden private information is facilitated by an interface called `Censor`. It is implemented by classes `Nric`, `Phone` and `Email`.
+
+When showing a new loan, it will do the following operations:
+
+* `LoanCard#LoanCard()` -- the constructor will assign values to each of the labels shown in the LoanCard.
+
+* `Nric#getCensored()` -- censor the Nric value and hide the first five digital numbers. Then it returns the censored String.
+
+* `Nric#doCensoring(int length)` -- Take in the length of the Nric String and return the censored part ("x" part) according to the length.
+
+* `Phone#getCensored()` -- censor the phone number and hide the first five digital numbers. Then it returns the censored String.
+
+* `Phone#doCensoring(int length)` -- Take in the length of the Phone String and return the censored part ("x" part) according to the length.
+
+* `Email#getCensored()` -- censor the email address and hide every characters except the last two characters in the local-part and the domain.
+
+* `Email#doCensoring(int length)` -- Take in the length of the Email String and return the censored part ("x" part) according to the length.
+
+Given below is an example usage scenario and how this mechanism behaves at each step.
+
+**Step1.** The user adds a new loan to the LoanBook. A new `LoanCard` object will be created. +
+The `LoanCard` object will contain information on the loan: `LoanID`, `BikeID`, `Name`, `Nric`, `Phone`, `Email`, `LoanRate` and `LoanTime`.
+
+**Step2.** Assign the value of each of the components to their corresponding labels. +
+For example: `name.setText(loan.getName().value);` will directly assign the name String of this loan to the `name` label. +
+
+However, the values of `Nric`, `Phone` and `Email` need censoring before assigning their values, so they will call their own `getCensored()` method in their class. +
+`getCensored()` in each of these class will call their corresponding `doCensoring(int)` method. Then combine the censored part and remain part and return. +
+For example: `phone.setText(loan.getPhone().getCensored().value);` will censor the value of the phone String of this loan and then assign the censored value to the `phone` label.
+
+The following sequence diagram shows how this operation works:
+
+image::HideInfoSequenceDiagrams.png[]
+
+==== Design Considerations
+
+**Aspect: How to execute getCensored() and doCensoring(int)**
+
+* **Alternative 1 (current choice)**: each class implements from `Censor` interface.
+** Pros: Easy to implement.
+
+* **Alternative 2**: `Loan` class implements from `Censor` interface.
+** Cons: The method might be bulky.
+
+=== Send Reminder Email feature
+
+==== Current Implementation
+
+The email sending mechanism is supported by the https://docs.oracle.com/javaee/7/api/javax/mail/package-summary.html[`JavaMail`] library. This feature is composed of three commands: `checkemail`, `setemail` and `remind`.
+
+* `checkemail` command: display the email address that the user has set to send emails from. The app will censor the email address.
+[NOTE]
+If user has not set an email, the email address will be an invalid email and the app show a "You have not set your email yet!" message.
+
+* `setemail` command: set the email address used for sending reminders to the customers.
+[NOTE]
+Only gmail is accepted by the app.
+
+* `remind` command: automatically generate an email containing some core information about the loan, and send it to the corresponding customer from user's email. This command will use the `JavaMail` library.
+[NOTE]
+The email will contain the `Name`, `BikeId`, `LoanStartTime` and `LoanRate` of the loan.
+
+Given below is an example usage scenario and how the reminder email mechanism behaves at each step.
+
+*Step 1.* The user launches the application for the first time. The user's email address is invalid by default.
+
+*Step 2.* The user executes `checkemail`. The following sequence diagram shows how `checkemail` works:
+
+image::CheckEmailSequenceDiagram.png[]
+
+The command executes `Model#getMyEmail()`, which calls `UserPrefs#getDefaultEmail()` and returns user's email stored in `UserPref`. The app checks if user's email equals to `"default"`. In this case, they are equal, so it throws a `CommandException`.
+
+*Step 3.* The user executes `setemail e/EMAIL x/PASSWORDFORAPP`. This command does a few checks first:
+
+.. The app then checks if `EMAIL` equals to the user email that has been already set to the app. If so, then a `CommandException` is thrown, to warn the user that they are setting the same email as last time.
+
+.. Otherwise, `SetEmailCommand#isValidGmail(EMAIL)` is called to check if `EMAIL` is a valid gmail. If not, a `CommandException` is thrown to warn the user that they are setting invalid email address.
+
+*Step 4.* The user forgets what email has been set before, so the user executes `checkemail` again. The procedure is the same as in *Step 2*. However, the app detects that user's email is not the default invalid string this time, so it creates an `Email(userEmail)` object and executes `Email#getCensored()`. Then, the function returns a `CommandResult` with a success message and the censored user email.
+
+*Step 5.* The user sends a reminder email to a customer by executing `remind pw/EMAILPASSWORD id/LOAN_ID`. This command implements the following operations:
+
+a. Execute `Model#getLoanById()` and return an optional<Loan> object called `targetLoan`.
+
+b. Check if `targetLoan.isPresent()` returns a non-null `loan`, then check if its `LoanStatus` is `ONGOING`.
+
+c. If its `LoanStatus` is `ONGOING`, create a `SendReminder(model, EMAILPASSWORD, loan)` object and execute `SendReminder#send()` to send email. +
+The `SendReminder#send()` method calls `SendReminder#createReminderEmail(session, userEmail)` to create the content of the email, connects user's email using `EMAILPASSWORD` and finally send the email.
+[NOTE]
+For Steps (b), if the next step cannot be executed, a `CommandException` with corresponding failure message will be thrown.
+[NOTE]
+If it throws a `CommandException` with authentication failed message in step (c), please check if user's email and password are correct. If they are, please make sure that the `Less secure apps` setting of user's email is enabled. If it is not, enable it and refresh the page.
+
+==== Design considerations
+*Aspect: use user's personal email vs share an immutable common email*
+
+* *Alternative 1 (current choice):* Use a user-specified email.
+
+** Pros:
+*** The user has a choice of what email address to use.
+*** The user needs to type in the correct password if they want to send a reminder email, which ensures the security and privacy of the email.
+
+** Cons:
+*** The user needs to enable the `Less secure apps` setting, which could be a security concern.
+
+* *Alternative 2:* Use a common email provided by the app.
+
+** Pros:
+*** The user does not need to set their own email when sending reminder emails, reducing hassle when setting up.
+*** The user does not need to type in a password when sending a reminder email.
+
+** Cons:
+*** The common email is less secure, as its password can be found within the program.
+*** The password of the common email can be changed by malicious users.
+*** The email might get overloaded.
+*** Customers might receive spam emails, as the `remind` command does not require a password.
 
-include::../DeveloperGuide.adoc[tag=hideinfo]
+==== Future considerations
+We plan to add a feature that can automatically send an e-receipt to the customer after `return` ing a loan.
 
-include::../DeveloperGuide.adoc[tag=sendemail]
+The e-receipt will contain the `Name`, `BikeID`, `LoanStartTime`, `LoanEndTime` and `TotalCost` of the loan.