db, add item and functions to get items

Creates item. It's pretty barebowns until I implement fetching.

I also added get functions for feed and channel to get items with.

koucha/src/db/item.rs

@@ -0,0 +1,122 @@
+use crate::{
+  Result,
+  AdapterPool,
+  db::{
+    ChannelKey,
+    ItemKey,
+  },
+};
+use chrono::{DateTime, Utc};
+
+pub struct UnparsedItem {
+  pub id: i64,
+  pub channel_id: i64,
+  pub fetched_at: Option<String>,
+
+  pub title: Option<String>,
+  pub description: Option<String>,
+  pub content: Option<String>,
+}
+
+impl UnparsedItem {
+  pub fn parse(self) -> Result<Item> {
+    Ok(Item {
+      key: ItemKey(self.id),
+      channel_id: ChannelKey(self.channel_id),
+      fetched_at: match self.fetched_at {
+        Some(dt_str) => Some(DateTime::parse_from_rfc2822(&dt_str)?
+          .with_timezone(&Utc)),
+        None => None,
+      },
+
+      title: self.title,
+      description: self.description,
+      content: self.content,
+    })
+  }
+}
+
+pub struct Item {
+  key: ItemKey,
+  channel_id: ChannelKey,
+
+  fetched_at: Option<DateTime<Utc>>,
+  title: Option<String>,
+  description: Option<String>,
+  content: Option<String>,
+}
+
+impl Item {
+  pub fn key(&self) -> ItemKey { self.key }
+  pub fn channel(&self) -> ChannelKey { self.channel_id }
+  pub fn title(&self) -> Option<&str> { self.title.as_deref() }
+  pub fn description(&self) -> Option<&str> { self.description.as_deref() }
+  pub fn content(&self) -> Option<&str> { self.content.as_deref() }
+
+  pub async fn get_or_create(
+    pool: &AdapterPool, from_channel: ChannelKey, guid: &str
+  ) -> Result<Self> {
+
+    let item = sqlx::query_as!(
+      UnparsedItem,
+      "INSERT INTO items (channel_id, guid)
+       VALUES (?, ?)
+       ON CONFLICT(channel_id, guid) DO UPDATE SET channel_id = channel_id
+       RETURNING id as `id!`, channel_id, fetched_at, title, description,
+         content",
+      from_channel.0, guid
+    ).fetch_one(&pool.0).await?.parse();
+
+    item
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crate::test_utils::{
+    ITEM_GUID, ITEM_TITLE, ITEM_DESC, ITEM_CONT,
+    setup_adapter,
+    setup_channel,
+  };
+  use chrono::TimeZone;
+
+  // UnparsedItem tests
+  #[test]
+  fn parse_unparsed_item() {
+    const ITEM_ID: i64 = 1;
+    const CHANNEL_ID: i64 = 1;
+
+    let date: DateTime<Utc> = Utc.with_ymd_and_hms(2020,1,1,0,0,0).unwrap();
+    let raw_item = UnparsedItem {
+      id: ITEM_ID,
+      channel_id: CHANNEL_ID,
+      fetched_at: Some(date.to_rfc2822()),
+      title: Some(ITEM_TITLE.to_string()),
+      description: Some(ITEM_DESC.to_string()),
+      content: Some(ITEM_CONT.to_string()),
+    };
+    let item = raw_item.parse().unwrap();
+    
+    assert_eq!(item.key.0, ITEM_ID);
+    assert_eq!(item.channel_id.0, CHANNEL_ID);
+    assert_eq!(item.fetched_at, Some(date));
+    assert_eq!(item.title, Some(ITEM_TITLE.to_string()));
+    assert_eq!(item.description, Some(ITEM_DESC.to_string()));
+    assert_eq!(item.content, Some(ITEM_CONT.to_string()));
+
+  }
+
+  // Item Tests
+  #[tokio::test]
+  async fn get_or_create_duplicate() {
+    let adapter = setup_adapter().await;
+    let pool = adapter.get_pool();
+    let channel = setup_channel(pool).await;
+
+    let item1 = Item::get_or_create(pool, channel.key(), ITEM_GUID).await.unwrap();
+    let item2 = Item::get_or_create(pool, channel.key(), ITEM_GUID).await.unwrap();
+
+    assert_eq!(item1.key(), item2.key());
+  }
+}