cleaned doc & friends provided with display names

doc/user/friend.md

@@ -0,0 +1,155 @@
+# Friend
+
+Available endpoints:
+- POST `/users/:userId/friends`
+- GET `/users/:userId/friends`
+- GET `/users/:userId/friends/count`
+- DELETE `/users/:userId/friends`
+- DELETE `/users/:userId/friends/:friendId`
+
+Common return:
+- 500 with response 
+```json
+{
+	"error": "Internal server error"
+}
+```
+
+## POST `/users/:userId/friends/:friendId`
+
+Used to add a friend to an user
+
+Can return:
+- 200 with response
+```json
+{
+	"msg": "Friend added successfully"
+}
+```
+- 400 with response (if no user is specified in header, or friend is the user specified in header, or friend is already added)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 404 with response (if user does not exist, or friend does not exist)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 401 with response (if user specified in header is neither admin nor user)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+
+## GET `/users/:userId/friends?iStart=<starting index (included)>&iEnd=<ending index (excluded)>`
+
+Used to get the friends of an user
+
+Can return:
+- 200 with response (list of friend objects (between iStart and iEnd))
+```json
+{
+	"friends":
+	[
+		{
+			"friendName": "<the friend's username>",
+			"friendDisplayName": "<the friend's display name>"
+		},
+		...
+	]
+}
+```
+- 400 with response (if iStart/iEnd is missing, or iEnd < iStart)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 404 with response (if user does not exist, or no friends exist in the selected range)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+
+## GET `/users/:userId/friends/count`
+
+Used to get the number of friends of an user
+
+Can return:
+- 200 with response
+```json
+{
+	"n_friends": <number of friends>
+}
+```
+- 404 with response (if user does not exist)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+
+## DELETE `/users/:userId/friends`
+
+Used to delete the friends of an user
+
+Can return:
+- 200 with response
+```json
+{
+	"msg": "Friends deleted successfully"
+}
+```
+- 400 with response (if user specified in header is neither admin nor user)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 401 with response (if user specified in header is neither admin nor user)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 404 with response (if user does not exist)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+
+## DELETE `/users/:userId/friends/:friendId`
+
+Used to delete a friend of an user
+
+Can return:
+- 200 with response
+```json
+{
+	"msg": "Friend deleted successfully"
+}
+```
+- 400 with response (if user specified in header is neither admin nor user)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 401 with response (if user specified in header is neither admin nor user)
+```json
+{
+	"error": "<corresponding error>"
+}
+```
+- 404 with response (if user does not exist, or friend does not exist)
+```json
+{
+	"error": "<corresponding error>"
+}
+```