task-072

Co-authored-by: Joe Carstairs <jcarstairs@scottlogic.com>
Reviewed-on: https://git.joeac.net/joeac/schist/pulls/3
Co-authored-by: Joe Carstairs <me@joeac.net>
Co-committed-by: Joe Carstairs <me@joeac.net>

1 files changed, 71 insertions, 0 deletions

diff --git a/schist_desktop_gui/src/database_connection.rs b/schist_desktop_gui/src/database_connection.rs
new file mode 100644
index 0000000..99fbe2d
--- /dev/null
+++ b/schist_desktop_gui/src/database_connection.rs
@@ -0,0 +1,71 @@
+use std::{fmt, path::PathBuf};
+
+use anyhow::Context;
+use diesel::{Connection, SqliteConnection};
+use diesel_migrations::MigrationHarness;
+use schist_models::migrations::MIGRATIONS;
+
+pub struct DatabaseConnection {
+    pub connection: diesel::SqliteConnection,
+    pub file_path: PathBuf,
+}
+
+impl DatabaseConnection {
+    pub fn establish(file_path: PathBuf) -> DatabaseConnectionResult {
+        DatabaseConnectionResult {
+            connection: Self::establish_sqlite_connection(&file_path),
+            file_path: file_path,
+        }
+    }
+
+    fn establish_sqlite_connection(file_path: &PathBuf) -> anyhow::Result<SqliteConnection> {
+        let file_path_str = file_path
+            .to_str()
+            .with_context(|| format!("Failed to get database path from {:?}", file_path))?;
+        let mut connection = diesel::SqliteConnection::establish(&file_path_str)
+            .with_context(|| format!("Failed to connect to database at {}", file_path_str))?;
+        connection
+            .run_pending_migrations(MIGRATIONS)
+            .map_err(anyhow::Error::from_boxed)
+            .with_context(|| {
+                format!(
+                    "Failed to run pending migrations on database at {}",
+                    file_path_str
+                )
+            })?;
+        Ok(connection)
+    }
+}
+
+impl fmt::Debug for DatabaseConnection {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("SqliteConnection")
+            .field("file_path", &self.file_path)
+            .finish()
+    }
+}
+
+pub struct DatabaseConnectionResult {
+    pub connection: anyhow::Result<SqliteConnection>,
+    pub file_path: PathBuf,
+}
+
+impl DatabaseConnectionResult {
+    pub fn ok(self) -> Result<DatabaseConnection, (PathBuf, anyhow::Error)> {
+        self.try_into()
+    }
+}
+
+impl TryFrom<DatabaseConnectionResult> for DatabaseConnection {
+    type Error = (PathBuf, anyhow::Error);
+
+    fn try_from(result: DatabaseConnectionResult) -> Result<Self, Self::Error> {
+        result
+            .connection
+            .map(|connection| DatabaseConnection {
+                connection,
+                file_path: result.file_path.clone(),
+            })
+            .map_err(|err| (result.file_path, err))
+    }
+}