#!/usr/bin/env bash
#
# @license Apache-2.0
#
# Copyright (c) 2019 The Stdlib Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Build script to run continuous integration tasks on [GitHub][1].
#
# [1]: https://help.github.com/en/articles/about-github-actions

# shellcheck disable=SC2181

# Ensure that the exit status of pipelines is non-zero in the event that at least one of the commands in a pipeline fails:
set -o pipefail


# VARIABLES #

# Get the name of the build task as the first argument to the build script:
task="$1"

# Get the path to a log file as the second argument to the build script:
log_file="$2"

# Define a heartbeat interval to periodically print messages in order to prevent CI from prematurely ending a build due to long running commands:
heartbeat_interval='30s'

# Declare a variable for storing the heartbeat process id:
heartbeat_pid=""


# FUNCTIONS #

# Error handler.
#
# $1 - error status
on_error() {
	echo 'ERROR: An error was encountered during execution.' >&2
	cleanup
	exit "$1"
}

# Runs clean-up tasks.
cleanup() {
	stop_heartbeat
}

# Starts a heartbeat.
#
# $1 - heartbeat interval
start_heartbeat() {
	echo 'Starting heartbeat...' >&2

	# Create a heartbeat and send to background:
	heartbeat "$1" &

	# Capture the heartbeat pid:
	heartbeat_pid=$!
	echo "Heartbeat pid: ${heartbeat_pid}" >&2
}

# Runs an infinite print loop.
#
# $1 - heartbeat interval
heartbeat() {
	while true; do
		echo "$(date) - heartbeat..." >&2;
		sleep "$1";
	done
}

# Stops the heartbeat print loop.
stop_heartbeat() {
	echo 'Stopping heartbeat...' >&2
	kill "${heartbeat_pid}"
}

# Prints a success message.
print_success() {
	echo 'Success!' >&2
}

# Runs benchmarks.
#
# $1 - log file
benchmark() {
	echo 'Running benchmarks...' >&2
	make NODE_FLAGS='--no-deprecation' benchmark >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Benchmarks failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Running benchmarks...' >&2
		make NODE_FLAGS='--no-deprecation' benchmark >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Benchmarks failed.' >&2
			return 1
		fi
	fi
	echo 'Successfully ran benchmarks.' >&2
	return 0
}

# Checks dependencies.
#
# $1 - log file
check_deps() {
	echo 'Checking dependencies...' >&2
	make check-deps >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Dependencies are out-of-date.' >&2
		return 1
	fi
	echo 'Dependencies are up-to-date.' >&2
	return 0
}

# Checks licenses.
#
# $1 - log file
check_licenses() {
	echo 'Checking licenses...' >&2
	make check-licenses-production >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Detected dependency licensing issues.' >&2
		return 1
	fi
	echo 'No dependency licensing issues detected.' >&2
	return 0
}

# Runs examples.
#
# $1 - log file
examples() {
	echo 'Running examples...' >&2
	make NODE_FLAGS='--no-deprecation' examples >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Examples failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Running examples...' >&2
		make NODE_FLAGS='--no-deprecation' examples >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Examples failed.' >&2
			return 1
		fi
	fi
	echo 'Successfully ran examples.' >&2
	return 0
}

# Performs install tasks.
#
# $1 - log file
install() {
	echo 'Installing...' >&2
	make install >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Error occurred during install.' >&2
		echo 'Retry 1 of 2...' >&2
		sleep 15s
		echo 'Installing...' >&2
		make install >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Error occurred during install.' >&2
			echo 'Retry 2 of 2...' >&2
			sleep 30s
			echo 'Installing...' >&2
			make install >> "$1" 2>&1
			if [[ "$?" -ne 0 ]]; then
				echo 'Error occurred during install.' >&2
				echo 'Failed to install 3 times. Aborting install.' >&2
				return 1
			fi
		fi
	fi
	echo 'Install successful.' >&2
	return 0
}

# Performs lint tasks.
#
# $1 - log file
lint() {
	echo 'Initializing development environment...' >&2
	make init >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Linting failed as unable to initialize development environment.' >&2
		return 1
	fi
	echo 'Initialization successful.' >&2

	echo 'Linting filenames...' >&2
	make lint-filenames >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Linting filenames failed.' >&2
		return 1
	fi
	make lint-header-filenames >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Linting filenames failed.' >&2
		return 1
	fi
	echo 'Linting package.json files...' >&2
	make lint-pkg-json >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Linting package.json failed.' >&2
		return 1
	fi
	# FIXME: linting of Markdown files takes too long; need to speed-up via distributed tasks or only linting files which changed
	# echo 'Linting Markdown files...' >&2
	# make lint-markdown >> "$1" 2>&1
	# if [[ "$?" -ne 0 ]]; then
	# 	echo 'Linting Markdown failed.' >&2
	# 	return 1
	# fi
	echo 'Linting passed.' >&2
	return 0
}

# Runs unit tests.
#
# $1 - log file
tests() {
	echo 'Running tests...' >&2
	make NODE_FLAGS='--no-deprecation' test >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Tests failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Running tests...' >&2
		make NODE_FLAGS='--no-deprecation' test >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Tests failed.' >&2
			return 1
		fi
	fi
	echo 'Tests passed.' >&2
	return 0
}

# Runs test coverage.
#
# $1 - log file
test_coverage() {
	echo 'Running test coverage...' >&2
	make NODE_FLAGS='--no-deprecation' test-cov >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Tests failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Running test coverage...' >&2
		make NODE_FLAGS='--no-deprecation' test-cov >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Tests failed.' >&2
			return 1
		fi
	fi
	echo 'Tests passed.' >&2
	return 0
}

# Sends test coverage report to coverage service.
#
# $1 - report title
# $2 - log file
test_coverage_report() {
	echo 'Sending coverage report to coverage service...' >&2
	make COVERAGE_NAME="$1" coverage >> "$2" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Sending coverage report to coverage service failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Sending coverage report to coverage service...' >&2
		make COVERAGE_NAME="$1" coverage >> "$2" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Sending coverage report to coverage service failed.' >&2
			return 1
		fi
	fi
	echo 'Coverage report sent to coverage service.' >&2
	return 0
}

# Tests whether the project successfully installs via `npm`.
#
# $1 - log file
test_npm_install() {
	echo 'Testing npm install...' >&2
	make test-npm-install >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Installation failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Testing npm install...' >&2
		make test-npm-install >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Installation failed.' >&2
			return 1
		fi
	fi
	echo 'Successfully installed.' >&2

	echo 'Testing npm install (via GitHub)...' >&2
	make test-npm-install-github >> "$1" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo 'Installation (via GitHub) failed.' >&2
		echo 'Retry 1 of 1...' >&2
		sleep 15s
		echo 'Testing npm install (via GitHub)...' >&2
		make test-npm-install-github >> "$1" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo 'Installation (via GitHub) failed.' >&2
			return 1
		fi
	fi
	echo 'Successfully installed (via GitHub).' >&2

	return 0
}

# Main execution sequence.
main() {
	start_heartbeat "${heartbeat_interval}"

	echo "Task: ${task}." >&2

	# Note: please keep tasks in alphabetical order...
	if [[ "${task}" = "benchmark" ]]; then
		benchmark "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "check_deps" ]]; then
		check_deps "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "check_licenses" ]]; then
		check_licenses "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "examples" ]]; then
		examples "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "install" ]]; then
		install "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "lint" ]]; then
		lint "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "test" ]]; then
		tests "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "test-coverage" ]]; then
		test_coverage "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
		test_coverage_report "unit_test" "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	elif [[ "${task}" = "test-npm-install" ]]; then
		test_npm_install "${log_file}"
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	else
		echo "ERROR: unknown task: ${task}." >&2
		on_error 1
	fi
	cleanup
	print_success
	exit 0
}

# Set an error handler to print captured output and perform any clean-up tasks:
trap 'on_error' ERR

# Run main:
main