use sea_orm_migration::prelude::*;

#[derive(DeriveMigrationName)]
pub struct Migration;

#[async_trait::async_trait]
impl MigrationTrait for Migration {
    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
        manager
            .create_table(
                Table::create()
                    .table(ProcessVariables::Table)
                    .if_not_exists()
                    .col(
                        ColumnDef::new(ProcessVariables::Id)
                            .uuid()
                            .not_null()
                            .primary_key(),
                    )
                    .col(ColumnDef::new(ProcessVariables::TenantId).uuid().not_null())
                    .col(
                        ColumnDef::new(ProcessVariables::InstanceId)
                            .uuid()
                            .not_null(),
                    )
                    .col(ColumnDef::new(ProcessVariables::Name).string().not_null())
                    .col(
                        ColumnDef::new(ProcessVariables::VarType)
                            .string()
                            .not_null()
                            .default("string"),
                    )
                    .col(ColumnDef::new(ProcessVariables::ValueString).text().null())
                    .col(
                        ColumnDef::new(ProcessVariables::ValueNumber)
                            .double()
                            .null(),
                    )
                    .col(
                        ColumnDef::new(ProcessVariables::ValueBoolean)
                            .boolean()
                            .null(),
                    )
                    .col(
                        ColumnDef::new(ProcessVariables::ValueDate)
                            .timestamp_with_time_zone()
                            .null(),
                    )
                    .to_owned(),
            )
            .await?;

        manager.get_connection().execute(sea_orm::Statement::from_string(
            sea_orm::DatabaseBackend::Postgres,
            "CREATE UNIQUE INDEX idx_process_variables_instance_name ON process_variables (instance_id, name)".to_string(),
        )).await.map_err(|e| DbErr::Custom(e.to_string()))?;

        manager
            .create_foreign_key(
                ForeignKey::create()
                    .name("fk_variables_instance")
                    .from(ProcessVariables::Table, ProcessVariables::InstanceId)
                    .to(ProcessInstances::Table, ProcessInstances::Id)
                    .to_owned(),
            )
            .await?;

        Ok(())
    }

    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
        manager
            .drop_table(Table::drop().table(ProcessVariables::Table).to_owned())
            .await
    }
}

#[derive(DeriveIden)]
enum ProcessVariables {
    Table,
    Id,
    TenantId,
    InstanceId,
    Name,
    VarType,
    ValueString,
    ValueNumber,
    ValueBoolean,
    ValueDate,
}

#[derive(DeriveIden)]
enum ProcessInstances {
    Table,
    Id,
}
