db/mod.rs: Add functions to read scripts for migration

1 files changed, 54 insertions, 0 deletions

diff --git a/src/db/mod.rs b/src/db/mod.rs
new file mode 100644
index 0000000..1a60ce3
--- /dev/null
+++ b/src/db/mod.rs
@@ -0,0 +1,54 @@
+use miette::Diagnostic;
+use thiserror::Error;
+
+pub struct Migration {
+    pub filename: String,
+    pub directory: String,
+    pub script_contents: String,
+}
+
+const DB_MIGRATION_DIR: &str = "./src/db/";
+
+/// To prevent accidental error coersion in other modules, std::io::Error gets cast as Migration Error here
+#[derive(Debug, Diagnostic, Error)]
+pub enum MigrationError {
+    #[error("IO error")]
+    IOMigrationError(#[from] std::io::Error),
+}
+
+type Result<T> = std::result::Result<T, MigrationError>;
+
+/// Reads the filesystem for sql files in the DB migration directory
+fn get_script_filenames() -> Result<Vec<String>> {
+    let results = std::fs::read_dir(DB_MIGRATION_DIR)?;
+
+    Ok(results
+        .flat_map(|entry| entry.unwrap().file_name().into_string())
+        .filter(|s| s.ends_with(".sql"))
+        .collect())
+}
+
+/// Gets SQL files from the DB migration directory to provide instructions for setting up the database
+pub fn get_migration_scripts() -> Result<Vec<Migration>> {
+    let files = get_script_filenames()?;
+    let mut migrations = vec![];
+
+    for file in files {
+        let filename = String::from(DB_MIGRATION_DIR) + &file;
+        tracing::event!(
+            tracing::Level::TRACE,
+            filename = filename,
+            "Found migration script."
+        );
+
+        let contents = std::fs::read_to_string(filename)?;
+
+        migrations.push(Migration {
+            filename: file,
+            directory: DB_MIGRATION_DIR.into(),
+            script_contents: contents,
+        });
+    }
+
+    Ok(migrations)
+}