Add Discussions GraphQL query

Close #171

Author: Goder-0

CHANGELOG.md

@@ -11,6 +11,8 @@ this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Tracing with a filter set by `RUST_LOG` environment variable.
 - Added support for passing the SSH passphrase through the `SSH_PASSPHRASE`
   environment variable.
+- Exposed a new `discussions` query in the server’s GraphQL API to query the
+  stored discussion data.
 
 ### Changed
 

src/database.rs

@@ -5,38 +5,47 @@ use regex::Regex;
 use serde::Serialize;
 use sled::{Db, Tree};
 
+pub mod discussion;
+
+pub(crate) use discussion::DiscussionDbSchema;
+
 use crate::{
     github::{GitHubIssue, GitHubPullRequests},
     graphql::{Issue, PullRequest},
 };
+
 const ISSUE_TREE_NAME: &str = "issues";
 const PULL_REQUEST_TREE_NAME: &str = "pull_requests";
+const DISCUSSION_TREE_NAME: &str = "discussions";
 
 #[derive(Clone)]
 pub(crate) struct Database {
     db: Db,
     issue_tree: Tree,
     pull_request_tree: Tree,
+    discussion_tree: Tree,
 }
 
 impl Database {
     fn connect_db(path: &Path) -> Result<Db> {
         Ok(sled::open(path)?)
     }
 
-    fn connect_trees(db: &Db) -> Result<(Tree, Tree)> {
+    fn connect_trees(db: &Db) -> Result<(Tree, Tree, Tree)> {
         let issue_tree = db.open_tree(ISSUE_TREE_NAME)?;
         let pull_request_tree = db.open_tree(PULL_REQUEST_TREE_NAME)?;
-        Ok((issue_tree, pull_request_tree))
+        let discussion_tree = db.open_tree(DISCUSSION_TREE_NAME)?;
+        Ok((issue_tree, pull_request_tree, discussion_tree))
     }
 
     pub(crate) fn connect(db_path: &Path) -> Result<Database> {
         let db = Database::connect_db(db_path)?;
-        let (issue_tree, pull_request_tree) = Database::connect_trees(&db)?;
+        let (issue_tree, pull_request_tree, discussion_tree) = Database::connect_trees(&db)?;
         Ok(Database {
             db,
             issue_tree,
             pull_request_tree,
+            discussion_tree,
         })
     }
 
@@ -155,7 +164,7 @@ impl<T: TryFromKeyValue> DoubleEndedIterator for Iter<T> {
     }
 }
 
-pub(crate) fn parse_key(key: &[u8]) -> Result<(String, String, i64)> {
+pub(crate) fn parse_key(key: &[u8]) -> Result<(String, String, i32)> {
     let re = Regex::new(r"(?P<owner>\S+)/(?P<name>\S+)#(?P<number>[0-9]+)").expect("valid regex");
     if let Some(caps) = re.captures(
         String::from_utf8(key.to_vec())
@@ -176,7 +185,7 @@ pub(crate) fn parse_key(key: &[u8]) -> Result<(String, String, i64)> {
             .name("number")
             .ok_or_else(|| anyhow!("invalid key"))?
             .as_str()
-            .parse::<i64>()
+            .parse::<i32>()
             .context("invalid key")?;
         Ok((owner, name, number))
     } else {