Add DB connection establishing

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

2 files changed, 69 insertions, 0 deletions

diff --git a/src/db/connection.rs b/src/db/connection.rs
new file mode 100644
index 0000000..4e338d0
--- /dev/null
+++ b/src/db/connection.rs
@@ -0,0 +1,67 @@
+use anyhow::Result;
+use anyhow::Error;
+use clap_v3::ArgMatches;
+use diesel::prelude::*;
+use diesel::pg::PgConnection;
+use getset::Getters;
+
+use crate::config::Configuration;
+
+#[derive(Debug, Getters)]
+pub struct DbConnectionConfig {
+    #[getset(get = "pub")]
+    database_host: String,
+
+    #[getset(get = "pub")]
+    database_port: String,
+
+    #[getset(get = "pub")]
+    database_user: String,
+
+    #[getset(get = "pub")]
+    database_password: String,
+
+    #[getset(get = "pub")]
+    database_name: String,
+}
+
+impl Into<String> for DbConnectionConfig {
+    fn into(self) -> String {
+        format!("postgres://{user}:{password}@{host}:{port}/{name}",
+                host     = self.database_host,
+                port     = self.database_port,
+                user     = self.database_user,
+                password = self.database_password,
+                name     = self.database_name)
+    }
+}
+
+pub fn parse_db_connection_config(config: &Configuration, cli: &ArgMatches) -> DbConnectionConfig {
+    fn find_value<F>(cli: &ArgMatches, key: &str, alternative: F) -> String
+        where F: FnOnce() -> String
+    {
+        cli.value_of(key).map(String::from).unwrap_or_else(alternative)
+    }
+
+    let database_host     = find_value(cli, "database_host",      || config.database_host().to_string());
+    let database_port     = find_value(cli, "database_port",     || config.database_port().to_string());
+    let database_user     = find_value(cli, "database_user",     || config.database_user().to_string());
+    let database_password = find_value(cli, "database_password", || config.database_password().to_string());
+    let database_name     = find_value(cli, "database_name",     || config.database_name().to_string());
+
+    DbConnectionConfig {
+        database_host,
+        database_port,
+        database_user,
+        database_password,
+        database_name,
+    }
+
+}
+
+pub fn establish_connection(conn_config: DbConnectionConfig) -> Result<PgConnection> {
+    let database_uri: String = conn_config.into();
+    debug!("Trying to connect to database: {}", database_uri);
+    PgConnection::establish(&database_uri).map_err(Error::from)
+}
+
diff --git a/src/db/mod.rs b/src/db/mod.rs
new file mode 100644
index 0000000..0b0387e
--- /dev/null
+++ b/src/db/mod.rs
@@ -0,0 +1,2 @@
+mod connection;
+pub use connection::*;