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 # User Guide
 
-## Features 
+Rattus **is a desktop application that keeps track of various tasks**.
+The application makes use of a Command Line Interface (CLI), while having a
+Graphical User Interface (GUI) to enhance user experience.
 
-### Feature-ABC
+## Quick start
 
-Description of the feature.
+1. [Install](https://www.oracle.com/java/technologies/downloads/#java11) 
+**Java 11** if you have not done so.
+2. [Download](https://github.com/jq1836/ip/releases)
+the latest application file **Rattus.jar**.
+3. Move the file into any folder you would like to use as the home folder for Rattus.
+4. Left click the `Rattus.jar` twice. The application should start up, showing the 
+page below.
+5. Type a command in the text box to the bottom of the application. **Either**
+click on the **Send** button or press the **Enter** key on your keyboard.
+6. Refer to the [Features](#features) section for more details of each command or
+alternatively, take a look at the [Command Summary]() section for a table of all
+commands.
 
-### Feature-XYZ
+![UI](Ui.png)
 
-Description of the feature.
+## Features
 
-## Usage
+**Notes about command formatting:**
+- Words in `UPPERCASE` are the compulsory parameters to be supplied by the user.
+<br> e.g. in `find KEYWORD`, `KEYWORD` is a parameter to be supplied by the user.
+- Strictly **no** other parameters to be supplied.
 
-### `Keyword` - Describe action
+### Adding a todo : `todo`
 
-Describe the action and its outcome.
+Creates a todo task and adds it to the list of current working file.
 
-Example of usage: 
+Format: `todo DESCRIPTION`
+- Adds a todo task with the description `DESCRIPTION` to the list of tasks.
+- The `DESCRIPTION` parameter is a description of the todo task and can be disjoint.
 
-`keyword (optional arguments)`
+Example:
+- `todo Wash the car` is an example where `Wash the car` is a disjoint `DESCRIPTION`.
+<br>
+- `todo Sleep` is an example where `Sleep` is a non-disjoint `DESCRIPTION`.
 
-Expected outcome:
 
-Description of the outcome.
+### Adding an event : `event`
 
-```
-expected output
-```
+Creates a timed event task and adds it to the list of current working file.
+
+Format: `event DESCRIPTION /at DATE TIME`
+- Adds an event task with the description `DESCRIPTION`, the date `DATE` and time
+`TIME` of the event to the list of tasks.
+- For more information about `DESCRIPTION`, click [here](#adding-a-todo--todo).
+- The format of the `DATE` parameter is strictly `YYYY-MM-DD`.
+- The format of the `TIME` parameter is strictly `HHmm`, in 24-hour time notation.
+
+Example:
+- `event Concert /at 2022-09-06 2000` is an example where the `MM` and `DD` are
+1-digit numbers. The `0` in `09` and `06` is compulsory.
+- `event Breakfast with the family /at 2022-11-20 0900` is an example where the
+`HH` in the `TIME` parameter is a 1-digit number. The `0` in `09` is compulsory.
+
+### Adding a deadline : `deadline`
+
+Creates a task with a deadline and adds it to the list of current working file.
+
+Format: `deadline DESCRIPTION /by DATE TIME`
+- Adds a deadline task with the description `DESCRIPTION`, the date `DATE` and time
+`TIME` of the event to the list of tasks.
+- For more information about `DESCRIPTION`, click [here](#adding-a-todo--todo).
+- For more information about `DATE` and `TIME`, click [here](#adding-an-event--event).
+
+Example:
+- `deadline Homework /by 2022-10-21 2359`
+
+### Listing tasks : `list`
+
+Shows all tasks within the current working file.
+
+Format: `list`
+- The tasks are displayed in the format `INDEX. [TYPE][STATUS] CONTENT`
+- The `INDEX` is the index of the task, with the first task having an index of `1`.
+- The `TYPE` is the type of task, `T`, `E` and `D` representing todo, event and
+deadline respectively.
+- The `STATUS` is either empty or `X`.
+- The `CONTENT` includes the description and if applicable, the date and time of
+associated with the task.
+
+Example:
+- `1. [T][] Complete iP` indicates that the task is a todo task, is the first task 
+on the list and that the task has not been completed.
+- `2. [E][] Family gathering (at: Oct 20 2022, 1700hrs)` indicates that the task is
+an event task, is the 2nd task on the list, that the event has not passed and that
+the event is on the 20th of October 2022 at 5:00pm.
+- `3. [D][X] Finish homework (by: Sep 18 2022, 2359hrs)` indicates that the task is
+a deadline task, is the 3rd task on the list, that the task has been completed,
+and that the deadline of the task is on the 18th of September 2022 at 11:59pm.
+
+### Exit from the application : `bye`
+
+Exits the application.
+
+Format: `bye`
+
+### Delete a task : `delete`
+
+Deletes a task within the current working file.
+
+Format: `delete INDEX`
+- The `INDEX` parameter is the index of the task to be deleted.
+- The `INDEX` parameter must be a positive integer that corresponds to an existing
+task in the current working file.
+
+Example:
+- `delete 2` deletes the 2nd task in the current working file.
+- `delete 0` has an invalid `INDEX` input.
+
+### Mark a task : `mark`
+
+Marks a task within the current working file as completed.
+
+Format: `mark INDEX`
+- The `INDEX` parameter is the index of the task to be marked as completed.
+- The `INDEX` parameter must be a positive integer that corresponds to an existing
+task in the current working file.
+
+Example:
+- `mark 3` marks the 3rd task in the current working file as completed.
+
+### Unmark a task : `unmark`
+
+Marks a task within the current working file as not completed.
+
+Format: `unmark INDEX`
+- The `INDEX` parameter is the index of the task to be marked as not completed.
+- The `INDEX` parameter must be a positive integer that corresponds to an existing
+task in the current working file.
+
+Example:
+- `unmark 4` marks the 4th task in the current working file as not completed.
+
+### Find a task with a keyword : `find`
+
+Displays a list of tasks with a description that matches the keyword provided.
+
+Format: `find KEYWORD`
+- The `KEYWORD` parameter is case-sensitive and can be disjoint.
+
+Example:
+- Suppose that your list contains tasks with descriptions:
+  1. `CS2100 assignment`
+  2. `CS2109 assignment`
+- `find assignment` would display both tasks.
+- `find CS2100` would only display task (i).
+- `find CS2109 A` would not display any tasks.
+- `find CS2109 a` would only display task (ii).
+
+### Check a task by date : `check`
+
+Displays a list of timed-tasks with a corresponding date.
+
+Format: `check DATE`
+- The format of the `DATE` parameter is strictly `YYYY-MM-DD`.
+
+Example:
+- Suppose that your list contains timed-tasks with dates:
+  1. `2022-09-10`
+  2. `2022-09-10`
+  3. `2022-09-11`
+  4. `2023-09-10`
+  5. `2022-10-10`
+- `check 2022-09-10` would only display tasks (i) and (ii).
+
+### Saving of tasks
+
+Tasks are saved automatically after each command. The data files are stored within
+the `[home directory]/data` directory. The home directory is the directory with
+`Rattus.jar`.
+
+### Adding a new data file : `filenew`
+
+Creates a new data file. Does not redirect to new file.
+
+Format: `filenew FILENAME`
+- The `FILENAME` parameter is the name of the file to be created.
+- If `FILENAME` parameter is the name of an existing file, no new file is created.
+- The `FILENAME` parameter **should** not include the file type.
+
+Example:
+- `filenew Sem1` creates a new data file `Sem1.txt`.
+- Another `filenew Sem1` command does not result in a new data file being created.
+- `filenew Sem1.txt` creates a new data file `Sem1.txt.txt`, which is still usable.
+
+### Deleting a data file : `filedel`
+
+Deletes the corresponding data file if it exists.
+
+Format: `filedel FILENAME`
+- The `FILENAME` parameter is the name of the file to be deleted.
+- The `FILENAME` parameter **must** not include the file type.
+
+Example:
+- `filedel Sem1` deletes the `Sem1.txt` file.
+
+### Changing to another data file : `filechange`
+
+Changes the working file to another data file if it exists.
+
+Format: `filechange FILENAME`
+- The `FILENAME` parameter is the name of the file to use.
+- The `FILENAME` parameter **must** not include the file type.
+
+Example:
+- `filechange Sem1` changes the current working file to the `Sem1.txt` file.
+
+## Command summary
+
+| Action          | Format, Examples                                                                       |
+|-----------------|----------------------------------------------------------------------------------------|
+| **Todo**        | `todo DESCRIPTION`<br> e.g., `todo Sleep`                                              |
+| **Event**       | `event DESCRIPTION /at DATE TIME`<br> e.g., `event Concert /at 2022-09-06 2000`        |
+| **Deadline**    | `deadline DESCRIPTION /by DATE TIME`<br> e.g., `deadline Homework /by 2022-10-21 2359` |
+| **List**        | `list`                                                                                 |
+| **Exit**        | `bye`                                                                                  |
+| **Delete**      | `delete INDEX`<br> e.g., `delete 1`                                                    |
+| **Mark**        | `mark INDEX`<br> e.g., `mark 2`                                                        |
+| **Unmark**      | `unmark INDEX` <br> e.g., `unmark 3`                                                   |
+| **Find**        | `find KEYWORD`<br> e.g., `find assignment`                                             |
+| **Check**       | `check DATE` <br> e.g., `check 2022-09-16`                                             |
+| **New File**    | `filenew FILENAME` <br> e.g., `filenew Sem1`                                           |
+| **Delete File** | `filedel FILENAME` <br> e.g., `filedel Sem2`                                           |                                            
+| **Change File** | `filechange FILENAME` <br> e.g., `filechange Sem2`                                     |