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> {
        let db = manager.get_connection();

        db.execute_unprepared(
            r#"
            CREATE TABLE IF NOT EXISTS ble_gateways (
                id UUID PRIMARY KEY,
                tenant_id UUID NOT NULL,
                gateway_id VARCHAR NOT NULL UNIQUE,
                name VARCHAR NOT NULL,
                api_key_hash VARCHAR NOT NULL,
                api_key_prefix VARCHAR NOT NULL,
                status VARCHAR NOT NULL DEFAULT 'active',
                firmware_version VARCHAR,
                ip_address VARCHAR,
                last_heartbeat_at TIMESTAMPTZ,
                metadata JSON,
                created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
                updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
                created_by UUID,
                updated_by UUID,
                deleted_at TIMESTAMPTZ,
                version INTEGER NOT NULL DEFAULT 1
            );

            CREATE TABLE IF NOT EXISTS gateway_patient_bindings (
                id UUID PRIMARY KEY,
                tenant_id UUID NOT NULL,
                gateway_id_fk UUID NOT NULL,
                patient_id UUID NOT NULL,
                peripheral_mac VARCHAR,
                device_type VARCHAR,
                status VARCHAR NOT NULL DEFAULT 'active',
                created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
                updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
                created_by UUID,
                updated_by UUID,
                deleted_at TIMESTAMPTZ,
                version INTEGER NOT NULL DEFAULT 1
            );
            "#,
        )
        .await?;

        // 索引（幂等）
        let indexes = [
            (
                "idx_ble_gateways_tenant_id",
                "CREATE INDEX IF NOT EXISTS idx_ble_gateways_tenant_id ON ble_gateways (tenant_id)",
            ),
            (
                "idx_ble_gateways_api_key_prefix",
                "CREATE INDEX IF NOT EXISTS idx_ble_gateways_api_key_prefix ON ble_gateways (api_key_prefix)",
            ),
            (
                "idx_gateway_patient_bindings_gateway",
                "CREATE INDEX IF NOT EXISTS idx_gateway_patient_bindings_gateway ON gateway_patient_bindings (gateway_id_fk)",
            ),
            (
                "idx_gateway_patient_bindings_patient",
                "CREATE INDEX IF NOT EXISTS idx_gateway_patient_bindings_patient ON gateway_patient_bindings (patient_id)",
            ),
        ];
        for (_, sql) in &indexes {
            db.execute_unprepared(sql).await.ok();
        }

        // 外键约束（幂等）
        let fks = [
            (
                "fk_gpb_gateway",
                "ALTER TABLE gateway_patient_bindings ADD CONSTRAINT fk_gpb_gateway FOREIGN KEY (gateway_id_fk) REFERENCES ble_gateways(id) ON DELETE CASCADE",
            ),
            (
                "fk_gpb_patient",
                "ALTER TABLE gateway_patient_bindings ADD CONSTRAINT fk_gpb_patient FOREIGN KEY (patient_id) REFERENCES patient(id) ON DELETE CASCADE",
            ),
        ];
        for (name, sql) in &fks {
            let check = format!(
                "SELECT COUNT(*) FROM information_schema.table_constraints WHERE constraint_name = '{name}'"
            );
            let result = db
                .query_one(sea_orm::Statement::from_string(
                    sea_orm::DatabaseBackend::Postgres,
                    check,
                ))
                .await?;
            let count: i64 = result.unwrap().try_get_by_index::<i64>(0).unwrap_or(0);
            if count == 0 {
                db.execute_unprepared(sql).await?;
            }
        }

        Ok(())
    }

    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
        let db = manager.get_connection();
        db.execute_unprepared("DROP TABLE IF EXISTS gateway_patient_bindings")
            .await?;
        db.execute_unprepared("DROP TABLE IF EXISTS ble_gateways")
            .await?;
        Ok(())
    }
}