== ERModel Current version ==
== Diagram ==
[[Image(KristinaSrbinoskaER.4.jpg)]]

== Data requirements ==
=== ENTITIES ===


{{{USER}}}
[[BR]]
Represents each individual user at the platform. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{user_id}}} – numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{user_id}}} – numeric, required. Primary key.
* {{{username}}} – text, required, unique.
* {{{email}}} – text, required, unique.
* {{{name}}} – text, required.
* {{{surname}}} – text, required.
* {{{password}}} – hash value, required.
[[BR]]
----

{{{ADMIN}}}
[[BR]]
Represents the admin user (full access of the system). Inherited from USER.
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{user_id}}} – inherited primary key.
[[BR]]
'''[[span(style=color: #9A0000, Inheritance:)]]'''
Inherits all attributes from USER.
[[BR]]
----

{{{REGULAR_USER}}}
[[BR]]
Represents regular users. Inherited from USER.
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{user_id}}} – inherited primary key.
[[BR]]
'''[[span(style=color: #9A0000, Inheritance:)]]'''
Inherits all attributes from USER 
[[BR]]
----

{{{WRITER}}}
[[BR]]
Represents writers. Inherited from USER.
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{user_id}}} – inherited primary key.
[[BR]]
'''[[span(style=color: #9A0000, Inheritance:)]]'''
Inherits all attributes from USER 
[[BR]]
----

{{{STORY}}}
[[BR]]
Represents every story that is written in the platform. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{story_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{story_id}}} – numeric, required. Auto-generated primary key.
* {{{mature_content}}} – boolean, required. Indicates if story contains mature content.
* {{{short_description}}} – text, required. Brief description of the story.
* {{{content}}} – text, required. Full content of the story.
* {{{status}}} – multi-valued text, required. Publication status (draft, published, archived). A story can have multiple status values over time.
* {{{image}}} – text, optional. URL or path to story cover image.
[[BR]]
----

{{{CHAPTER}}}
[[BR]]
Represents a chapter, which is part of a story.
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{chapter_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{chapter_id}}} – numeric, required. Auto-generated primary key.
* {{{chapter_number}}} – numeric, required. Order number of the chapter within the story.
* {{{chapter_name}}} – text, required. Name of the chapter.
* {{{title}}} – text, required. Title of the chapter.
* {{{content}}} – text, required. Content of the chapter.
* {{{word_count}}} – numeric, optional. Number of words in the chapter.
* {{{rating}}} – numeric, optional. Rating of the chapter.
* {{{published_at}}} – timestamp, required. Publication date and time.
* {{{view_count}}} – numeric, optional. Number of views.
[[BR]]
----

{{{GENRE}}}
[[BR]]
Represents a genre category for stories. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{genre_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{genre_id}}} – numeric, required. Auto-generated primary key.
* {{{name}}} – text, required, unique. Name of the genre.
[[BR]]
----

{{{READING_LIST}}}
[[BR]]
Represents a reading list created by users. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{list_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{list_id}}} – numeric, required. Auto-generated primary key.
* {{{name}}} – text, required. Name of the reading list.
* {{{content}}} – text, optional. Description of the reading list.
* {{{is_public}}} – boolean, required. Visibility of the reading list.
[[BR]]
----

{{{NOTIFICATION}}}
[[BR]]
Represents notifications sent to users. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{notification_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{notification_id}}} – numeric, required. Auto-generated primary key.
* {{{content}}} – text, required. Content of the notification.
* {{{content_type}}} – multi-valued text, required. Type of notification content. A notification can belong to multiple content types.
* {{{is_read}}} – boolean, required. Indicates whether the notification has been read. Default: false.

[[BR]]
----

{{{AI_SUGGESTION}}}
[[BR]]
Represents AI-generated suggestions for story improvements.
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{suggestion_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{suggestion_id}}} – numeric, required. Auto-generated primary key.
* {{{original_text}}} – text, required. Original text from the story.
* {{{suggested_text}}} – text, required. AI-suggested improvement.
* {{{suggestion_type}}} – multi-valued text, required. Type of suggestion (grammar, style, etc.). A suggestion can belong to multiple types.
* {{{accepted}}} – boolean, required. Whether the suggestion was accepted.
[[BR]]
----

{{{LIKE}}}
[[BR]]
Represents likes given by users to stories. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* Composite key: ({{{user_id}}}, {{{story_id}}}).
[[BR]]
----

{{{COMMENT}}}
[[BR]]
Represents comments made by users on stories. 
[[BR]]
'''[[span(style=color: #9A0000, Candidate keys:)]]'''
* {{{comment_id}}} – surrogate numeric identifier (primary key).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{comment_id}}} – numeric, required. Auto-generated primary key.
* {{{content}}} – text, required. Content of the comment.
[[BR]]
----

=== RELATIONS ===

{{{has_list (USER – READING_LIST)}}}
[[BR]]
Represents users having reading lists.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
1:N (One user can have many reading lists, each reading list belongs to one user)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Foreign key: {{{user_id}}} in READING_LIST references USER.
[[BR]]
----
{{{reading_list_items (READING_LIST – STORY)}}}
[[BR]]
Represents stories added to reading lists.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
Cardinality: M:N (Many reading lists can contain many stories))
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Keys: Composite key: (list_id, story_id).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{added_at}}} – timestamp, required. Date and time when the story was added to the reading list.

[[BR]]
----

{{{collaboration (USER – STORY)}}}
[[BR]]
Represents users collaborating on stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
M:N (Many users can collaborate on many stories)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Composite key: ({{{user_id}}}, {{{story_id}}}).
[[BR]]
'''[[span(style=color: #9A0000, Attributes:)]]'''
* {{{role}}} – multi-valued text, required. Role of the collaborator.
* {{{permission_level}}} – multi-valued numeric, optional. Level of permission for collaboration.
[[BR]]
----

{{{created_story (WRITER – STORY)}}}
[[BR]]
Represents writers creating stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
1:N (One writer can create many stories, each story is created by one writer)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Foreign key: {{{user_id}}} in STORY references WRITER.
[[BR]]
----

{{{has_genre (STORY – GENRE)}}}
[[BR]]
Represents stories having genres.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
M:N (Many stories can have many genres)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Composite key: ({{{story_id}}}, {{{genre_id}}}).
[[BR]]
----

{{{part_of (CHAPTER – STORY)}}}
[[BR]]
Represents chapters being part of stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
N:1 (Many chapters are part of one story)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Foreign key: {{{story_id}}} in CHAPTER references STORY.
[[BR]]
----

{{{is_liked (USER – LIKE – STORY)}}}
[[BR]]
Represents likes given by users to stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
User 1:N LIKE, Story 1:N LIKE (One user can like many stories, one story can have many likes)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Composite key: (user_id, story_id) in LIKE
Foreign key: {{{user_id}}} in LIKE references USER.
Foreign key: {{{story_id in}}} LIKE references STORY.
[[BR]]
----

{{{is_commented (USER – COMMENT – STORY)}}}
[[BR]]
Represents comments made by users on stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
User 1:N COMMENT, Story 1:N COMMENT (One user can make many comments, one story can have many comments)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Foreign key: {{{user_id}}} in COMMENT references USER.
Foreign key: {{{story_id in}}} COMMENT references STORY.
[[BR]]
----

{{{notify (USER – STORY – NOTIFICATION)}}}
[[BR]]
Represents notifications sent to users about stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
M:N:P (Many users can receive many notifications about many stories)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Composite key: ({{{user_id}}},{{{story_id}}},{{{notification_id}}})
Foreign key: {{{user_id}}} references USER
Foreign key: {{{story_id}}} references STORY.
Foreign key: {{{notification_id}}} references NOTIFICATION.
[[BR]]
----

{{{need_approval (AI_SUGGESTION – STORY – CHAPTER)}}}
[[BR]]
Represents AI suggestions needing approval for specific chapters within stories.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
M:N:P (Many AI suggestions can be made for many stories across many chapters)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Composite key: ({{{suggestion_id}}},{{{story_id}}},{{{chapter_id}}})
Foreign key: {{{suggestion_id}}} references AI_SUGGESTION.
Foreign key: {{{story_id}}} references STORY.
Foreign key: {{{chapter_id}}} references CHAPTER.
[[BR]]
----

{{{suggested (STORY – AI_SUGGESTION)}}}
[[BR]]
Represents stories having AI-generated suggestions.
[[BR]]
'''[[span(style=color: #9A0000, Cardinality:)]]'''
1:N (One story can have many AI suggestions)
[[BR]]
'''[[span(style=color: #9A0000, Keys:)]]'''
Foreign key: {{{story_id}}} in AI_SUGGESTION references STORY.