mod migrator;
use migrator::Migrator;

use sea_orm::{ConnectOptions, ConnectionTrait, Database, DbBackend, DbErr, Statement};
use sea_orm_migration::prelude::*;

#[async_std::test]
async fn main() -> Result<(), DbErr> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::DEBUG)
        .with_test_writer()
        .init();

    let url = &std::env::var("DATABASE_URL").expect("Environment variable 'DATABASE_URL' not set");

    run_migration(url, "sea_orm_migration", "public").await?;

    run_migration(url, "sea_orm_migration_schema", "my_schema").await?;

    Ok(())
}

async fn run_migration(url: &str, db_name: &str, schema: &str) -> Result<(), DbErr> {
    let db_connect = |url: String| async {
        let connect_options = ConnectOptions::new(url)
            .set_schema_search_path(schema.to_owned())
            .to_owned();

        Database::connect(connect_options).await
    };

    let db = db_connect(url.to_owned()).await?;

    let db = &match db.get_database_backend() {
        DbBackend::MySql => {
            db.execute(Statement::from_string(
                db.get_database_backend(),
                format!("CREATE DATABASE IF NOT EXISTS `{db_name}`;"),
            ))
            .await?;

            let url = format!("{url}/{db_name}");
            db_connect(url).await?
        }
        DbBackend::Postgres => {
            db.execute(Statement::from_string(
                db.get_database_backend(),
                format!("DROP DATABASE IF EXISTS \"{db_name}\";"),
            ))
            .await?;
            db.execute(Statement::from_string(
                db.get_database_backend(),
                format!("CREATE DATABASE \"{db_name}\";"),
            ))
            .await?;

            let url = format!("{url}/{db_name}");
            let db = db_connect(url).await?;

            db.execute(Statement::from_string(
                db.get_database_backend(),
                format!("CREATE SCHEMA IF NOT EXISTS \"{schema}\";"),
            ))
            .await?;

            db
        }
        DbBackend::Sqlite => db,
    };
    let manager = SchemaManager::new(db);

    println!("\nMigrator::status");
    Migrator::status(db).await?;

    println!("\nMigrator::install");
    Migrator::install(db).await?;

    assert!(manager.has_table("seaql_migrations").await?);

    println!("\nMigrator::reset");
    Migrator::reset(db).await?;

    assert!(!manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::up");
    Migrator::up(db, Some(0)).await?;

    assert!(!manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::up");
    Migrator::up(db, Some(1)).await?;

    assert!(manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::down");
    Migrator::down(db, Some(0)).await?;

    assert!(manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::down");
    Migrator::down(db, Some(1)).await?;

    assert!(!manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    // Tests rolling back changes of "migrate up" when running migration on Postgres
    if matches!(db.get_database_backend(), DbBackend::Postgres) {
        println!("\nRoll back changes when encounter errors");

        // Set a flag to throw error inside `m20230109_000001_seed_cake_table.rs`
        std::env::set_var("ABORT_MIGRATION", "YES");

        // Should throw an error
        println!("\nMigrator::up");
        assert_eq!(
            Migrator::up(db, None).await,
            Err(DbErr::Migration(
                "Abort migration and rollback changes".into()
            ))
        );

        println!("\nMigrator::status");
        Migrator::status(db).await?;

        // Check migrations have been rolled back
        assert!(!manager.has_table("cake").await?);
        assert!(!manager.has_table("fruit").await?);

        // Unset the flag
        std::env::remove_var("ABORT_MIGRATION");
    }

    println!("\nMigrator::up");
    Migrator::up(db, None).await?;

    println!("\nMigrator::status");
    Migrator::status(db).await?;

    assert!(manager.has_table("cake").await?);
    assert!(manager.has_table("fruit").await?);

    assert!(manager.has_column("cake", "name").await?);
    assert!(manager.has_column("fruit", "cake_id").await?);

    // Tests rolling back changes of "migrate down" when running migration on Postgres
    if matches!(db.get_database_backend(), DbBackend::Postgres) {
        println!("\nRoll back changes when encounter errors");

        // Set a flag to throw error inside `m20230109_000001_seed_cake_table.rs`
        std::env::set_var("ABORT_MIGRATION", "YES");

        // Should throw an error
        println!("\nMigrator::down");
        assert_eq!(
            Migrator::down(db, None).await,
            Err(DbErr::Migration(
                "Abort migration and rollback changes".into()
            ))
        );

        println!("\nMigrator::status");
        Migrator::status(db).await?;

        // Check migrations have been rolled back
        assert!(manager.has_table("cake").await?);
        assert!(manager.has_table("fruit").await?);

        // Unset the flag
        std::env::remove_var("ABORT_MIGRATION");
    }

    println!("\nMigrator::down");
    Migrator::down(db, None).await?;

    assert!(manager.has_table("seaql_migrations").await?);
    assert!(!manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::fresh");
    Migrator::fresh(db).await?;

    assert!(manager.has_table("cake").await?);
    assert!(manager.has_table("fruit").await?);

    println!("\nMigrator::refresh");
    Migrator::refresh(db).await?;

    assert!(manager.has_table("cake").await?);
    assert!(manager.has_table("fruit").await?);

    println!("\nMigrator::reset");
    Migrator::reset(db).await?;

    assert!(!manager.has_table("cake").await?);
    assert!(!manager.has_table("fruit").await?);

    println!("\nMigrator::status");
    Migrator::status(db).await?;

    Ok(())
}