feat: Refactor user and thought models to use UUIDs instead of integers

- Updated user and thought models to utilize UUIDs for primary keys.
- Modified persistence functions to accommodate UUIDs for user and thought IDs.
- Implemented tag functionality with new Tag and ThoughtTag models.
- Added migration scripts to create new tables for tags and thought-tag relationships.
- Enhanced thought creation to parse hashtags and link them to thoughts.
- Updated tests to reflect changes in user and thought ID types.

thoughts-backend/migration/src/lib.rs

@@ -3,6 +3,7 @@ pub use sea_orm_migration::prelude::*;
 mod m20240101_000001_init;
 mod m20250905_000001_init;
 mod m20250906_100000_add_profile_fields;
+mod m20250906_130237_add_tags;
 
 pub struct Migrator;
 
@@ -13,6 +14,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20240101_000001_init::Migration),
             Box::new(m20250905_000001_init::Migration),
             Box::new(m20250906_100000_add_profile_fields::Migration),
+            Box::new(m20250906_130237_add_tags::Migration),
         ]
     }
 }

thoughts-backend/migration/src/m20240101_000001_init.rs

@@ -13,10 +13,10 @@ impl MigrationTrait for Migration {
                     .if_not_exists()
                     .col(
                         ColumnDef::new(User::Id)
-                            .integer()
+                            .uuid()
                             .not_null()
-                            .auto_increment()
-                            .primary_key(),
+                            .primary_key()
+                            .default(Expr::cust("gen_random_uuid()")),
                     )
                     .col(
                         ColumnDef::new(User::Username)

thoughts-backend/migration/src/m20250905_000001_init.rs

@@ -13,8 +13,14 @@ impl MigrationTrait for Migration {
                 Table::create()
                     .table(Thought::Table)
                     .if_not_exists()
-                    .col(pk_auto(Thought::Id))
-                    .col(integer(Thought::AuthorId).not_null())
+                    .col(
+                        ColumnDef::new(Thought::Id)
+                            .uuid()
+                            .not_null()
+                            .primary_key()
+                            .default(Expr::cust("gen_random_uuid()")),
+                    )
+                    .col(uuid(Thought::AuthorId).not_null())
                     .foreign_key(
                         ForeignKey::create()
                             .name("fk_thought_author_id")
@@ -39,8 +45,8 @@ impl MigrationTrait for Migration {
                 Table::create()
                     .table(Follow::Table)
                     .if_not_exists()
-                    .col(integer(Follow::FollowerId).not_null())
-                    .col(integer(Follow::FollowedId).not_null())
+                    .col(uuid(Follow::FollowerId).not_null())
+                    .col(uuid(Follow::FollowedId).not_null())
                     // Composite Primary Key to ensure a user can only follow another once
                     .primary_key(
                         Index::create()
@@ -77,7 +83,7 @@ impl MigrationTrait for Migration {
 }
 
 #[derive(DeriveIden)]
-enum Thought {
+pub enum Thought {
     Table,
     Id,
     AuthorId,
@@ -86,7 +92,7 @@ enum Thought {
 }
 
 #[derive(DeriveIden)]
-enum Follow {
+pub enum Follow {
     Table,
     // The user who is initiating the follow
     FollowerId,

thoughts-backend/migration/src/m20250906_100000_add_profile_fields.rs

@@ -36,8 +36,8 @@ impl MigrationTrait for Migration {
                 Table::create()
                     .table(TopFriends::Table)
                     .if_not_exists()
-                    .col(integer(TopFriends::UserId).not_null())
-                    .col(integer(TopFriends::FriendId).not_null())
+                    .col(uuid(TopFriends::UserId).not_null())
+                    .col(uuid(TopFriends::FriendId).not_null())
                     .col(small_integer(TopFriends::Position).not_null())
                     .primary_key(
                         Index::create()

thoughts-backend/migration/src/m20250906_130237_add_tags.rs

@@ -0,0 +1,74 @@
+use super::m20250905_000001_init::Thought;
+use sea_orm_migration::{prelude::*, schema::*};
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_table(
+                Table::create()
+                    .table(Tag::Table)
+                    .if_not_exists()
+                    .col(pk_auto(Tag::Id))
+                    .col(string(Tag::Name).not_null().unique_key())
+                    .to_owned(),
+            )
+            .await?;
+
+        manager
+            .create_table(
+                Table::create()
+                    .table(ThoughtTag::Table)
+                    .if_not_exists()
+                    .col(uuid(ThoughtTag::ThoughtId).not_null())
+                    .col(integer(ThoughtTag::TagId).not_null())
+                    .primary_key(
+                        Index::create()
+                            .col(ThoughtTag::ThoughtId)
+                            .col(ThoughtTag::TagId),
+                    )
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk_thought_tag_thought_id")
+                            .from(ThoughtTag::Table, ThoughtTag::ThoughtId)
+                            .to(Thought::Table, Thought::Id)
+                            .on_delete(ForeignKeyAction::Cascade),
+                    )
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk_thought_tag_tag_id")
+                            .from(ThoughtTag::Table, ThoughtTag::TagId)
+                            .to(Tag::Table, Tag::Id)
+                            .on_delete(ForeignKeyAction::Cascade),
+                    )
+                    .to_owned(),
+            )
+            .await
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .drop_table(Table::drop().table(ThoughtTag::Table).to_owned())
+            .await?;
+        manager
+            .drop_table(Table::drop().table(Tag::Table).to_owned())
+            .await
+    }
+}
+
+#[derive(DeriveIden)]
+enum Tag {
+    Table,
+    Id,
+    Name,
+}
+
+#[derive(DeriveIden)]
+enum ThoughtTag {
+    Table,
+    ThoughtId,
+    TagId,
+}