testthat_init <- function() {
	options(timeout = 3600)
	options(sparklyr.connect.timeout = 300)
	options(livy.session.start.timeout = 300)
	suppressPackageStartupMessages(library(sparklyr))
	suppressPackageStartupMessages(library(dplyr))
	if (using_arrow()) {
		suppressPackageStartupMessages(library(arrow))
	}
	testthat_addl_libraries()
}

testthat_spark_connection <- function() {
	suppressMessages(
		if (!testthat_spark_connection_open()) {
			testthat_init()
			tp <- testthat_spark_connection_type()
			if (tp == "method") sc <- testthat_method_connection()
			if (tp == "databricks")
				sc <- testthat_shell_connection(method = "databricks")
			if (tp == "synapse") sc <- testthat_shell_connection(method = "synapse")
			if (tp == "local") sc <- testthat_shell_connection()
			if (tp == "livy") sc <- testthat_livy_connection()
		} else {
			sc <- testthat_spark_connection_object()
		}
	)

	sc
}

testthat_method_connection <- function() {
	sc <- sparklyr::spark_connect(
		master = using_master_get(),
		method = using_method_get()
	)
	testthat_spark_connection_object(sc)
	sc
}

testthat_shell_connection <- function(method = "shell") {
	connected <- testthat_spark_connection_open()
	spark_version <- testthat_spark_env_version()

	if (connected) {
		sc <- testthat_spark_connection_object()
		connected <- sparklyr::connection_is_open(sc)
	}

	if (Sys.getenv("INSTALL_WINUTILS") == "true") {
		spark_install_winutils(spark_version)
	}

	if (!connected) {
		options(sparklyr.sanitize.column.names.verbose = TRUE)
		options(sparklyr.verbose = TRUE)
		options(sparklyr.na.omit.verbose = TRUE)
		options(sparklyr.na.action.verbose = TRUE)

		config <- sparklyr::spark_config()
		config[["sparklyr.shell.driver-memory"]] <- "3G"
		config[["sparklyr.apply.env.foo"]] <- "env-test"
		config[["spark.sql.warehouse.dir"]] <- get_spark_warehouse_dir()
		if (identical(.Platform$OS.type, "windows")) {
			# TODO: investigate why there are Windows-specific timezone portability issues
			config[["spark.sql.session.timeZone"]] <- "UTC"
		}
		config$`sparklyr.sdf_collect.persistence_level` <- "NONE"

		packages <- NULL
		if (spark_version >= "2.4.2") packages <- c(packages, "delta")

		sc <- sparklyr::spark_connect(
			master = "local",
			method = method,
			version = spark_version,
			config = config,
			packages = packages
		)

		testthat_spark_connection_object(sc)
	}
	sc
}

testthat_livy_connection <- function() {
	if (!testthat_spark_connection_open()) {
		if (Sys.getenv("INSTALL_WINUTILS") == "true") {
			spark_install_winutils(version)
		}

		spark_version <- testthat_spark_env_version()

		sparklyr::livy_service_start(
			version = using_livy_version(),
			spark_version = spark_version
		)

		wait_for_svc(
			svc_name = "livy",
			port = 8998,
			timeout_s = 30
		)

		sc <- sparklyr::spark_connect(
			master = "http://localhost:8998",
			method = "livy",
			version = spark_version
		)

		testthat_spark_connection_object(sc)
	}

	testthat_spark_connection_object()
}

wait_for_svc <- function(svc_name, port, timeout_s) {
	suppressWarnings({
		socket <- NULL
		on.exit(
			if (!is.null(socket)) {
				close(socket)
			}
		)
		for (t in 1:timeout_s) {
			try(
				socket <- socketConnection(
					host = "localhost",
					port = port,
					server = FALSE,
					open = "r+"
				),
				silent = TRUE
			)
			if (is.null(socket)) {
				sprintf("Waiting for %s socket to be in listening state...", svc_name)
				Sys.sleep(1)
			} else {
				break
			}
		}
	})
}

get_spark_warehouse_dir <- function() {
	ifelse(.Platform$OS.type == "windows", Sys.getenv("TEMP"), tempfile())
}

spark_install_winutils <- function(version) {
	hadoop_version <- if (version < "2.0.0") "2.6" else "2.7"
	spark_dir <- paste("spark-", version, "-bin-hadoop", hadoop_version, sep = "")
	winutils_dir <- file.path(
		Sys.getenv("LOCALAPPDATA"),
		"spark",
		spark_dir,
		"tmp",
		"hadoop",
		"bin",
		fsep = "\\"
	)

	if (!dir.exists(winutils_dir)) {
		message("Installing winutils...")

		dir.create(winutils_dir, recursive = TRUE)
		winutils_path <- file.path(winutils_dir, "winutils.exe", fsep = "\\")

		download.file(
			"https://github.com/steveloughran/winutils/raw/master/hadoop-2.6.0/bin/winutils.exe",
			winutils_path,
			mode = "wb"
		)

		message("Installed winutils in ", winutils_path)
	}
}

testthat_addl_libraries <- function() {
	libs <- Sys.getenv("TEST_SPARKLYR_LIBRARIES", unset = NA)
	if (!is.na(libs)) {
		sep_libs <- unlist(strsplit(libs, ";"))
		invisible(
			lapply(sep_libs, function(x) {
				c_libs <- trimws(x)
				suppressPackageStartupMessages(
					library(c_libs, character.only = TRUE)
				)
			})
		)
	}
}