feat: add subscriptions

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/crunch-traits/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "crunch-traits"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow.workspace = true
+tokio.workspace = true
+thiserror.workspace = true
+async-trait.workspace = true
+uuid.workspace = true

crates/crunch-traits/src/errors.rs

@@ -0,0 +1,43 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum SerializeError {
+    #[error("failed to serialize {0}")]
+    FailedToSerialize(anyhow::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum DeserializeError {
+    #[error("failed to serialize {0}")]
+    FailedToDeserialize(anyhow::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum PublishError {
+    #[error("failed to serialize {0}")]
+    SerializeError(#[source] SerializeError),
+
+    #[error("failed to commit to database {0}")]
+    DbError(#[source] anyhow::Error),
+
+    #[error("transaction failed {0}")]
+    DbTxError(#[source] anyhow::Error),
+
+    #[error("failed to connect to database {0}")]
+    ConnectionError(#[source] anyhow::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum TransportError {
+    #[error("to publish to transport {0}")]
+    Err(anyhow::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum PersistenceError {
+    #[error("failed to get item {0}")]
+    GetErr(anyhow::Error),
+
+    #[error("failed to publish item {0}")]
+    UpdatePublished(anyhow::Error),
+}

crates/crunch-traits/src/lib.rs

@@ -0,0 +1,46 @@
+use std::{fmt::Display, sync::Arc};
+
+use async_trait::async_trait;
+use errors::{DeserializeError, PersistenceError, SerializeError, TransportError};
+
+#[async_trait]
+pub trait Persistence {
+    async fn insert(&self, event_info: &EventInfo, content: Vec<u8>) -> anyhow::Result<()>;
+    async fn next(&self) -> Option<String>;
+    async fn get(&self, event_id: &str) -> Result<Option<(EventInfo, Vec<u8>)>, PersistenceError>;
+    async fn update_published(&self, event_id: &str) -> Result<(), PersistenceError>;
+}
+
+pub trait Serializer {
+    fn serialize(&self) -> Result<Vec<u8>, SerializeError>;
+}
+
+pub trait Deserializer {
+    fn deserialize(raw: Vec<u8>) -> Result<Self, DeserializeError>
+    where
+        Self: Sized;
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct EventInfo {
+    pub domain: &'static str,
+    pub entity_type: &'static str,
+    pub event_name: &'static str,
+}
+
+impl Display for EventInfo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&format!(
+            "domain: {}, entity_type: {}",
+            self.domain, self.entity_type
+        ))
+    }
+}
+
+pub trait Event: Serializer + Deserializer {
+    fn event_info(&self) -> EventInfo;
+}
+
+pub mod errors;
+mod transport;
+pub use transport::*;

crates/crunch-traits/src/transport.rs

@@ -0,0 +1,12 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+
+use crate::{errors::TransportError, EventInfo};
+
+#[async_trait]
+pub trait Transport {
+    async fn publish(&self, event_info: &EventInfo, content: Vec<u8>)
+        -> Result<(), TransportError>;
+}
+pub type DynTransport = Arc<dyn Transport + Send + Sync + 'static>;