sqlx_migrator 0.9.0

use sqlx::MySql;

use super::{DatabaseOperation, Migrate, Migrator};
use crate::error::Error;
use crate::migration::{AppliedMigrationSqlRow, Migration};

/// create migrator table query
#[must_use]
pub(crate) fn create_migrator_table_query() -> &'static str {
    "CREATE TABLE IF NOT EXISTS _sqlx_migrator_migrations (
        id INT PRIMARY KEY NOT NULL AUTO_INCREMENT,
        app VARCHAR(384) NOT NULL,
        name VARCHAR(384) NOT NULL,
        applied_time TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
        UNIQUE (app, name)
    )"
}

/// Drop table query
#[must_use]
pub(crate) fn drop_table_query() -> &'static str {
    "DROP TABLE IF EXISTS _sqlx_migrator_migrations"
}

/// fetch rows
pub(crate) fn fetch_rows_query() -> &'static str {
    "SELECT id, app, name, DATE_FORMAT(applied_time, '%Y-%m-%d %H:%i:%s') AS applied_time FROM \
     _sqlx_migrator_migrations"
}

/// add migration query
#[must_use]
pub(crate) fn add_migration_query() -> &'static str {
    "INSERT INTO _sqlx_migrator_migrations(app, name) VALUES (?, ?)"
}

/// delete migration query
#[must_use]
pub(crate) fn delete_migration_query() -> &'static str {
    "DELETE FROM _sqlx_migrator_migrations WHERE app = ? AND name = ?"
}

/// get current database query
pub(crate) fn current_database_query() -> &'static str {
    "SELECT DATABASE()"
}

/// get lock database query
/// # Errors
/// Failed to lock database
pub(crate) fn lock_database_query() -> &'static str {
    "SELECT GET_LOCK(?, -1)"
}

/// get lock database query
/// # Errors
/// Failed to lock database
pub(crate) fn unlock_database_query() -> &'static str {
    "SELECT RELEASE_LOCK(?)"
}

/// generate lock id
pub(crate) fn get_lock_id_for_database(database_name: &str) -> String {
    crc32fast::hash(database_name.as_bytes()).to_string()
}

#[async_trait::async_trait]
impl DatabaseOperation<MySql> for Migrator<MySql> {
    async fn ensure_migration_table_exists(
        &self,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        sqlx::query(create_migrator_table_query())
            .execute(connection)
            .await?;
        Ok(())
    }

    async fn drop_migration_table_if_exists(
        &self,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        sqlx::query(drop_table_query()).execute(connection).await?;
        Ok(())
    }

    async fn add_migration_to_db_table(
        &self,
        migration: &Box<dyn Migration<MySql>>,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        sqlx::query(add_migration_query())
            .bind(migration.app())
            .bind(migration.name())
            .execute(connection)
            .await?;
        Ok(())
    }

    async fn delete_migration_from_db_table(
        &self,
        migration: &Box<dyn Migration<MySql>>,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        sqlx::query(delete_migration_query())
            .bind(migration.app())
            .bind(migration.name())
            .execute(connection)
            .await?;
        Ok(())
    }

    async fn fetch_applied_migration_from_db(
        &self,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<Vec<AppliedMigrationSqlRow>, Error> {
        Ok(
            sqlx::query_as::<_, AppliedMigrationSqlRow>(fetch_rows_query())
                .fetch_all(connection)
                .await?,
        )
    }

    async fn lock(
        &self,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        let (database_name,): (String,) = sqlx::query_as(current_database_query())
            .fetch_one(&mut *connection)
            .await?;
        let lock_id = get_lock_id_for_database(&database_name);
        sqlx::query(lock_database_query())
            .bind(lock_id)
            .execute(connection)
            .await?;
        Ok(())
    }

    async fn unlock(
        &self,
        connection: &mut <MySql as sqlx::Database>::Connection,
    ) -> Result<(), Error> {
        let (database_name,): (String,) = sqlx::query_as(current_database_query())
            .fetch_one(&mut *connection)
            .await?;
        let lock_id = get_lock_id_for_database(&database_name);
        sqlx::query(unlock_database_query())
            .bind(lock_id)
            .execute(connection)
            .await?;
        Ok(())
    }
}

impl Migrate<MySql> for Migrator<MySql> {}