4 files changed, 103 insertions, 6 deletions

diff --git a/src/database/friends.rs b/src/database/friends.rs
new file mode 100644
index 0000000..0b78488
--- /dev/null
+++ b/src/database/friends.rs
@@ -0,0 +1,97 @@
+use tracing::instrument;
+
+use crate::{
+    database::{self, users::user_from_row},
+    types::user::{User, FOLLOWED, FOLLOWING, NO_RELATION},
+};
+
+pub fn init() -> Result<(), rusqlite::Error> {
+    let sql = "
+        CREATE TABLE IF NOT EXISTS friends (
+            follower_id     INTEGER NOT NULL,
+            followee_id     INTEGER NOT NULL,
+            FOREIGN KEY(follower_id) REFERENCES users(user_id),
+            FOREIGN KEY(followee_id) REFERENCES users(user_id),
+            PRIMARY KEY (follower_id, followee_id)
+        );
+    ";
+    let conn = database::connect()?;
+    conn.execute(sql, ())?;
+    Ok(())
+}
+
+#[instrument()]
+pub fn get_friend_status(user_id_1: u64, user_id_2: u64) -> Result<u8, rusqlite::Error> {
+    tracing::trace!("Retrieving friend status");
+    let conn = database::connect()?;
+    let mut stmt = conn.prepare("SELECT * FROM friends WHERE (follower_id = ? AND followee_id = ?) OR (follower_id = ? AND followee_id = ?);")?;
+    let mut status = NO_RELATION;
+    let rows: Vec<u64> = stmt
+        .query_map([user_id_1, user_id_2, user_id_2, user_id_1], |row| {
+            let id: u64 = row.get(0)?;
+            Ok(id)
+        })?
+        .into_iter()
+        .flatten()
+        .collect();
+
+    for follower in rows {
+        if follower == user_id_1 {
+            status |= FOLLOWING;
+        }
+
+        if follower == user_id_2 {
+            status |= FOLLOWED;
+        }
+    }
+
+    Ok(status)
+}
+
+#[instrument()]
+pub fn get_friends(user_id: u64) -> Result<Vec<User>, rusqlite::Error> {
+    tracing::trace!("Retrieving friends");
+    let conn = database::connect()?;
+    let mut stmt = conn.prepare(
+        "
+        SELECT * 
+        FROM users u 
+        WHERE EXISTS (
+            SELECT NULL 
+            FROM friends f 
+            WHERE u.user_id = f.follower_id
+            AND f.followee_id = ?
+        )
+        AND EXISTS (
+            SELECT NULL
+            FROM friends f
+            WHERE u.user_id = f.followee_id
+            AND f.follower_id = ?
+        )
+    ",
+    )?;
+    let row = stmt.query_map([user_id, user_id], |row| {
+        let row = user_from_row(row, true)?;
+        Ok(row)
+    })?;
+    Ok(row.into_iter().flatten().collect())
+}
+
+#[instrument()]
+pub fn set_following(user_id_1: u64, user_id_2: u64) -> Result<bool, rusqlite::Error> {
+    tracing::trace!("Setting following");
+    let conn = database::connect()?;
+    let mut stmt =
+        conn.prepare("INSERT OR REPLACE INTO friends (follower_id, followee_id) VALUES (?,?)")?;
+    let changes = stmt.execute([user_id_1, user_id_2])?;
+    Ok(changes == 1)
+}
+
+#[instrument()]
+pub fn remove_following(user_id_1: u64, user_id_2: u64) -> Result<bool, rusqlite::Error> {
+    tracing::trace!("Removing following");
+    let conn = database::connect()?;
+    let mut stmt = conn.prepare("DELETE FROM friends WHERE follower_id = ? AND followee_id = ?")?;
+    let changes = stmt.execute([user_id_1, user_id_2])?;
+    Ok(changes == 1)
+}
diff --git a/src/database/likes.rs b/src/database/likes.rs
index 6f6939e..f6a130b 100644
--- a/src/database/likes.rs
+++ b/src/database/likes.rs
@@ -37,9 +37,7 @@ pub fn get_liked(user_id: u64, post_id: u64) -> Result<bool, rusqlite::Error> {
     tracing::trace!("Retrieving if liked");
     let conn = database::connect()?;
     let mut stmt = conn.prepare("SELECT * FROM likes WHERE user_id = ? AND post_id = ?")?;
-    let liked = stmt.query_row([user_id, post_id], |_| {
-        Ok(())
-    }).optional()?;
+    let liked = stmt.query_row([user_id, post_id], |_| Ok(())).optional()?;
     Ok(liked.is_some())
 }
 
@@ -49,7 +47,7 @@ pub fn add_liked(user_id: u64, post_id: u64) -> Result<bool, rusqlite::Error> {
     let conn = database::connect()?;
     let mut stmt = conn.prepare("INSERT OR REPLACE INTO likes (user_id, post_id) VALUES (?,?)")?;
     let changes = stmt.execute([user_id, post_id])?;
-    Ok(changes == 1)    
+    Ok(changes == 1)
 }
 
 #[instrument()]
@@ -69,7 +67,7 @@ pub fn get_all_likes() -> Result<Vec<Like>, rusqlite::Error> {
     let row = stmt.query_map([], |row| {
         let like = Like {
             user_id: row.get(0)?,
-            post_id: row.get(1)?
+            post_id: row.get(1)?,
         };
         Ok(like)
     })?;
diff --git a/src/database/mod.rs b/src/database/mod.rs
index 6d4853a..d22a350 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -1,6 +1,7 @@
 use tracing::instrument;
 
 pub mod comments;
+pub mod friends;
 pub mod likes;
 pub mod posts;
 pub mod sessions;
@@ -16,6 +17,7 @@ pub fn init() -> Result<(), rusqlite::Error> {
     sessions::init()?;
     likes::init()?;
     comments::init()?;
+    friends::init()?;
     Ok(())
 }
 
diff --git a/src/database/users.rs b/src/database/users.rs
index 15565f1..6062ea8 100644
--- a/src/database/users.rs
+++ b/src/database/users.rs
@@ -31,7 +31,7 @@ pub fn init() -> Result<(), rusqlite::Error> {
     Ok(())
 }
 
-fn user_from_row(row: &Row, hide_password: bool) -> Result<User, rusqlite::Error> {
+pub fn user_from_row(row: &Row, hide_password: bool) -> Result<User, rusqlite::Error> {
     let user_id = row.get(0)?;
     let firstname = row.get(1)?;
     let lastname = row.get(2)?;