use crate::database::Database;
use crate::error::Result;
use crate::migration::migration_2::PosAndNetherMigration;
use crate::migration::migration_3::TunnelToPortalMigration;
use crate::migration::migration_4::OutOfStockVoting;
use geoffrey_models::models::db_metadata::DBMetadata;

mod migration_2;
mod migration_3;
mod migration_4;

trait Migration {
    fn up(db: &Database) -> Result<()>;
    fn down(db: &Database) -> Result<()>;
    fn version() -> u64;
}

pub(crate) fn upgrade(db: &Database, current_version: u64, target_version: u64) -> Result<()> {
    for ver in current_version + 1..=target_version {
        match ver {
            2 => PosAndNetherMigration::up(db)?,
            3 => TunnelToPortalMigration::up(db)?,
            4 => OutOfStockVoting::up(db)?,
            _ => (),
        }
    }

    Ok(())
}

pub(crate) fn downgrade(db: &Database, current_version: u64, target_version: u64) -> Result<()> {
    for ver in (target_version..current_version).rev() {
        match ver {
            2 => PosAndNetherMigration::down(db)?,
            3 => TunnelToPortalMigration::down(db)?,
            4 => OutOfStockVoting::down(db)?,
            _ => (),
        }
    }

    Ok(())
}

pub fn do_migration(db: &Database, target_version: u64) -> Result<()> {
    let current_version = db.version().unwrap_or(0);

    #[allow(clippy::comparison_chain)]
    if target_version > current_version {
        upgrade(db, current_version, target_version)?;
    } else if target_version < current_version {
        downgrade(db, current_version, target_version)?;
    }

    let metadata = DBMetadata {
        version: target_version,
    };

    db.insert(metadata)?;

    Ok(())
}