From bb9be306d9c6752028f21287a652fd200a40a5e7 Mon Sep 17 00:00:00 2001
From: Dmitriy Pleshevskiy <dmitriy@ideascup.me>
Date: Sun, 30 May 2021 23:28:06 +0300
Subject: [PATCH] refac: mysql client with core lib

---
 migra-cli/src/database/clients/mysql.rs | 121 ++++++++++++++++--------
 migra-cli/src/error.rs                  |   3 +
 migra-cli/src/main.rs                   |   2 +
 3 files changed, 88 insertions(+), 38 deletions(-)

diff --git a/migra-cli/src/database/clients/mysql.rs b/migra-cli/src/database/clients/mysql.rs
index 6453230..a490214 100644
--- a/migra-cli/src/database/clients/mysql.rs
+++ b/migra-cli/src/database/clients/mysql.rs
@@ -1,53 +1,98 @@
-use crate::database::builder::merge_query_with_params;
-use crate::database::prelude::*;
-use crate::error::StdResult;
+use crate::error::MigraResult;
+use migra::managers::{ManageMigrations, ManageTransaction};
+use migra::migration;
 use mysql::prelude::*;
 use mysql::{Pool, PooledConn};
 
-pub struct MySqlConnection {
+pub struct MySqlClient {
     conn: PooledConn,
+    migrations_table_name: String,
 }
 
-impl OpenDatabaseConnection for MySqlConnection {
-    fn open(connection_string: &str) -> StdResult<Self> {
-        let pool = Pool::new_manual(1, 1, connection_string)?;
-        let conn = pool.get_conn()?;
-        Ok(MySqlConnection { conn })
+impl MySqlClient {
+    fn new(connection_string: &str, migrations_table_name: &str) -> MigraResult<Self> {
+        let conn = Pool::new_manual(1, 1, connection_string)
+            .and_then(|pool| pool.get_conn())
+            .map_err(|_| crate::Error::FailedDatabaseConnection)?;
+
+        Ok(MySqlClient {
+            conn,
+            migrations_table_name: migrations_table_name.to_owned(),
+        })
     }
 }
 
-impl DatabaseStatements for MySqlConnection {
-    fn create_migration_table_stmt(&self, migrations_table_name: &str) -> String {
-        format!(
+impl ManageTransaction for MySqlClient {
+    fn begin_transaction(&mut self) -> migra::Result<()> {
+        self.conn
+            .query_drop("BEGIN")
+            .map_err(|_| migra::Error::FailedOpenTransaction)
+    }
+
+    fn rollback_transaction(&mut self) -> migra::Result<()> {
+        self.conn
+            .query_drop("ROLLBACK")
+            .map_err(|_| migra::Error::FailedRollbackTransaction)
+    }
+
+    fn commit_transaction(&mut self) -> migra::Result<()> {
+        self.conn
+            .query_drop("COMMIT")
+            .map_err(|_| migra::Error::FailedCommitTransaction)
+    }
+}
+
+impl ManageMigrations for MySqlClient {
+    fn apply_sql(&mut self, sql_content: &str) -> migra::Result<()> {
+        self.conn
+            .query_drop(sql_content)
+            .map_err(|_| migra::Error::FailedApplySql)
+    }
+
+    fn create_migrations_table(&mut self) -> migra::Result<()> {
+        let stmt = format!(
             r#"CREATE TABLE IF NOT EXISTS {} (
                 id      int             AUTO_INCREMENT PRIMARY KEY,
                 name    varchar(256)    NOT NULL UNIQUE
             )"#,
-            migrations_table_name
-        )
-    }
-}
-
-impl SupportsTransactionalDdl for MySqlConnection {}
-
-impl DatabaseConnection for MySqlConnection {
-    fn batch_execute(&mut self, query: &str) -> StdResult<()> {
-        self.conn.query_drop(query)?;
-        Ok(())
-    }
-
-    fn execute<'b>(&mut self, query: &str, params: ToSqlParams<'b>) -> StdResult<u64> {
-        let stmt = merge_query_with_params(query, params);
-
-        let res = self.conn.query_first(stmt)?.unwrap_or_default();
-        Ok(res)
-    }
-
-    fn query<'b>(&mut self, query: &str, params: ToSqlParams<'b>) -> StdResult<Vec<Vec<String>>> {
-        let stmt = merge_query_with_params(query, params);
-
-        let res = self.conn.query_map(stmt, |(column,)| vec![column])?;
-
-        Ok(res)
+            &self.migrations_table_name
+        );
+
+        self.conn
+            .query_drop(stmt)
+            .map_err(|_| migra::Error::FailedCreateMigrationsTable)
+    }
+
+    fn insert_migration(&mut self, name: &str) -> migra::Result<u64> {
+        let stmt = format!(
+            "INSERT INTO {} (name) VALUES ($1)",
+            &self.migrations_table_name
+        );
+
+        self.conn
+            .exec_first(&stmt, (name,))
+            .map(|res| res.unwrap_or_default())
+            .map_err(|_| migra::Error::FailedInsertMigration)
+    }
+
+    fn delete_migration(&mut self, name: &str) -> migra::Result<u64> {
+        let stmt = format!(
+            "DELETE FROM {} WHERE name = $1",
+            &self.migrations_table_name
+        );
+
+        self.conn
+            .exec_first(&stmt, (name,))
+            .map(|res| res.unwrap_or_default())
+            .map_err(|_| migra::Error::FailedDeleteMigration)
+    }
+
+    fn applied_migrations(&mut self) -> migra::Result<migration::List> {
+        let stmt = format!("SELECT name FROM {}", &self.migrations_table_name);
+
+        self.conn
+            .query::<String, _>(stmt)
+            .map(From::from)
+            .map_err(|_| migra::Error::FailedGetAppliedMigrations)
     }
 }
diff --git a/migra-cli/src/error.rs b/migra-cli/src/error.rs
index 45c53c7..ddcd6ae 100644
--- a/migra-cli/src/error.rs
+++ b/migra-cli/src/error.rs
@@ -9,6 +9,8 @@ pub type MigraResult<T> = result::Result<T, Error>;
 
 #[derive(Debug)]
 pub enum Error {
+    FailedDatabaseConnection,
+
     RootNotFound,
     MissedEnvVar(String),
 
@@ -22,6 +24,7 @@ impl fmt::Display for Error {
             Error::MissedEnvVar(ref name) => {
                 write!(fmt, r#"Missed "{}" environment variable"#, name)
             }
+            Error::FailedDatabaseConnection => fmt.write_str("Failed database connection"),
             Error::Io(ref error) => write!(fmt, "{}", error),
         }
     }
diff --git a/migra-cli/src/main.rs b/migra-cli/src/main.rs
index f9f77da..026d663 100644
--- a/migra-cli/src/main.rs
+++ b/migra-cli/src/main.rs
@@ -12,6 +12,8 @@ mod commands;
 mod config;
 mod database;
 mod error;
+pub use error::Error;
+
 mod opts;
 
 use crate::error::StdResult;