Add group creation. Sync channels to clients on creation.

src/routes/channels/group_create.rs

@@ -0,0 +1,74 @@
+use crate::database::*;
+use crate::util::result::{Error, Result};
+use crate::util::variables::MAX_GROUP_SIZE;
+
+use mongodb::bson::doc;
+use rocket_contrib::json::{Json, JsonValue};
+use serde::{Deserialize, Serialize};
+use std::collections::HashSet;
+use std::iter::FromIterator;
+use ulid::Ulid;
+use validator::Validate;
+
+#[derive(Validate, Serialize, Deserialize)]
+pub struct Data {
+    #[validate(length(min = 1, max = 32))]
+    name: String,
+    #[validate(length(min = 0, max = 1024))]
+    description: Option<String>,
+    // Maximum length of 36 allows both ULIDs and UUIDs.
+    #[validate(length(min = 1, max = 36))]
+    nonce: String,
+    users: Vec<String>
+}
+
+#[post("/create", data = "<info>")]
+pub async fn req(user: User, info: Json<Data>) -> Result<JsonValue> {
+    info
+        .validate()
+        .map_err(|error| Error::FailedValidation { error })?;
+    
+    let mut set: HashSet<String> = HashSet::from_iter(info.users.iter().cloned());
+    set.insert(user.id.clone());
+
+    if set.len() > *MAX_GROUP_SIZE {
+        Err(Error::GroupTooLarge { max: *MAX_GROUP_SIZE })?
+    }
+
+    if get_collection("channels")
+        .find_one(
+            doc! {
+                "nonce": &info.nonce
+            },
+            None,
+        )
+        .await
+        .map_err(|_| Error::DatabaseError {
+            operation: "find_one",
+            with: "channel",
+        })?
+        .is_some()
+    {
+        Err(Error::DuplicateNonce)?
+    }
+
+    for target in &set {
+        if get_relationship(&user, target) != RelationshipStatus::Friend {
+            Err(Error::NotFriends)?
+        }
+    }
+
+    let id = Ulid::new().to_string();
+    let channel = Channel::Group {
+        id,
+        nonce: Some(info.nonce.clone()),
+        name: info.name.clone(),
+        description: info.description.clone().unwrap_or_else(|| "A group.".to_string()),
+        owner: user.id,
+        recipients: set.into_iter().collect::<Vec<String>>()
+    };
+
+    channel.clone().publish().await?;
+
+    Ok(json!(channel))
+}