#!/usr/bin/env bash
#
# @license Apache-2.0
#
# Copyright (c) 2021 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 installation tests on [GitHub][1].
#
# [1]: https://help.github.com/en/articles/about-github-actions

# shellcheck disable=SC2181,SC2129

# 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 desired package manager as the first argument to the build script:
pm="$1"

# Get the path to the local installation directory as the second argument to the build script:
install_dir="$2"

# Get the path to a log file as the third argument to the build script:
log_file="$3"

# Define the package to install:
pkg_name='@stdlib/stdlib'

# Define the package repository:
pkg_github_url='git+https://git@github.com/stdlib-js/stdlib.git'

# Define the repository tag/commit/branch to install:
pkg_github_tag='develop'

# Define the package version to install:
pkg_version='latest'

# 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=""

# Get the current working directory:
working_dir=$(pwd)

# Get the Node.js major version:
node_major_version=$(node -e 'var proc = ( typeof process !== "undefined" ) ? process : require( "process" ); console.log( proc.version.substring( 1 ).split( "." )[ 0 ] );' | tr -d '\n')


# 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
}

# Performs local installation initialization tasks.
install_init() {
	echo "Creating installation directory: ${install_dir}..." >> "${log_file}" 2>&1
	mkdir -p "${install_dir}" || return 1

	echo 'Navigating to installation directory...' >> "${log_file}" 2>&1
	cd "${install_dir}" || return 1

	echo 'Creating package.json...' >> "${log_file}" 2>&1
	echo '{"name":"test-install","version":"0.0.0","private":true}' > "${install_dir}/package.json"
	echo 'package.json:' >> "${log_file}" 2>&1
	cat "${install_dir}/package.json" >> "${log_file}" 2>&1

	return 0
}

# Tests that a local installation works as expected.
install_test() {
	echo 'Testing installation...' >> "${log_file}" 2>&1

	echo 'Creating test script (require global namespace)...' >> "${log_file}" 2>&1
	echo 'var stdlib = require( "@stdlib/stdlib" ); console.log( stdlib.math.base.special.sin( 3.14 ) );' > "${install_dir}/script.js"
	echo 'script:' >> "${log_file}" 2>&1
	cat "${install_dir}/script.js" >> "${log_file}" 2>&1

	echo 'Running test script...' >> "${log_file}" 2>&1
	node "${install_dir}/script.js" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when running test script." >> "${log_file}" 2>&1
		return 1
	fi
	echo '' >> "${log_file}" 2>&1
	echo 'Successfully ran test script.' >> "${log_file}" 2>&1

	echo 'Creating test script (require individual package)...' >> "${log_file}" 2>&1
	echo 'var sin = require( "@stdlib/math/base/special/sin" ); console.log( sin( 3.14 ) );' > "${install_dir}/script.js"
	echo 'script:' >> "${log_file}" 2>&1
	cat "${install_dir}/script.js" >> "${log_file}" 2>&1

	echo 'Running test script...' >> "${log_file}" 2>&1
	node "${install_dir}/script.js" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when running test script." >> "${log_file}" 2>&1
		return 1
	fi
	echo '' >> "${log_file}" 2>&1
	echo 'Successfully ran test script.' >> "${log_file}" 2>&1

	# Test `import` syntax on more recent Node.js versions which support ES modules without having to set flags to enable experimental support...
	if [[ "${node_major_version}" -gt 13 ]]; then
		echo 'Creating test script (import global namespace)...' >> "${log_file}" 2>&1
		echo 'import stdlib from "@stdlib/stdlib"; console.log( stdlib.math.base.special.sin( 3.14 ) );' > "${install_dir}/script.mjs"
		echo 'script:' >> "${log_file}" 2>&1
		cat "${install_dir}/script.mjs" >> "${log_file}" 2>&1

		echo 'Running test script...' >> "${log_file}" 2>&1
		node "${install_dir}/script.mjs" >> "${log_file}" 2>&1
		if [[ "$?" -ne 0 ]]; then
			echo "Encountered an error when running test script." >> "${log_file}" 2>&1
			return 1
		fi
		echo '' >> "${log_file}" 2>&1
		echo 'Successfully ran test script.' >> "${log_file}" 2>&1

		# FIMXE: uncomment once we've figured out our package.json `exports` strategy...
		# echo 'Creating test script (import individual package)...' >> "${log_file}" 2>&1
		# echo 'import sin from "@stdlib/math/base/special/sin"; console.log( sin( 3.14 ) );' > "${install_dir}/script.mjs"
		# echo 'script:' >> "${log_file}" 2>&1
		# cat "${install_dir}/script.mjs" >> "${log_file}" 2>&1

		# echo 'Running test script...' >> "${log_file}" 2>&1
		# node "${install_dir}/script.mjs" >> "${log_file}" 2>&1
		# if [[ "$?" -ne 0 ]]; then
		# 	echo "Encountered an error when running test script." >> "${log_file}" 2>&1
		# 	return 1
		# fi
		# echo '' >> "${log_file}" 2>&1
		# echo 'Successfully ran test script.' >> "${log_file}" 2>&1
	fi
	return 0
}

# Performs local installation cleanup tasks.
install_clean() {
	echo "Returning to original directory: ${working_dir}..." >> "${log_file}" 2>&1
	cd "${working_dir}" || return 1

	echo "Removing installation directory: ${install_dir}..." >> "${log_file}" 2>&1
	rm -rf "${install_dir}" || return 1

	return 0
}

# Installs a package via `npm`.
npm_install() {
	install_init
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing pre-install initialization tasks." >> "${log_file}" 2>&1
		return 1
	fi
	echo "Installing ${pkg_name}@${pkg_version}..." >> "${log_file}" 2>&1
	npm install "${pkg_name}@${pkg_version}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when installing ${pkg_name}@${pkg_version} via npm." >> "${log_file}" 2>&1
		cat "${working_dir}/npm-debug.log" >> "${log_file}" 2>&1
		return 1
	fi
	echo "Successfully installed ${pkg_name}@${pkg_version}." >> "${log_file}" 2>&1

	install_test
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when testing installation." >> "${log_file}" 2>&1
		return 1
	fi
	install_clean
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing post-install cleanup tasks." >> "${log_file}" 2>&1
		return 1
	fi
	return 0
}

# Installs a package via `npm` from GitHub.
npm_install_from_github() {
	install_init
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing pre-install initialization tasks." >> "${log_file}" 2>&1
		return 1
	fi
	echo "Installing ${pkg_github_url}#${pkg_github_tag}..." >> "${log_file}" 2>&1
	npm install "${pkg_github_url}#${pkg_github_tag}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when installing ${pkg_github_url}#${pkg_github_tag} via npm." >> "${log_file}" 2>&1
		cat "${working_dir}/npm-debug.log" >> "${log_file}" 2>&1
		return 1
	fi
	echo "Successfully installed ${pkg_github_url}#${pkg_github_tag}." >> "${log_file}" 2>&1

	install_test
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when testing installation." >> "${log_file}" 2>&1
		return 1
	fi
	install_clean
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing post-install cleanup tasks." >> "${log_file}" 2>&1
		return 1
	fi
	return 0
}

# Installs a package globally via `npm`.
npm_install_global() {
	echo "Installing ${pkg_name}@${pkg_version} as a global package..." >> "${log_file}" 2>&1
	npm install -g "${pkg_name}@${pkg_version}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when installing ${pkg_name}@${pkg_version} as a global package via npm." >> "${log_file}" 2>&1
		cat "${working_dir}/npm-debug.log" >> "${log_file}" 2>&1
		return 1
	fi
	npm list -g --depth=0 >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when attempting to list globally installed packages via npm." >> "${log_file}" 2>&1
		return 1
	fi
	echo "Successfully installed ${pkg_name}@${pkg_version}." >> "${log_file}" 2>&1

	echo 'Testing global installation...' >> "${log_file}" 2>&1
	stdlib --help >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when testing installation." >> "${log_file}" 2>&1
		return 1
	fi
	echo 'Successfully tested global installation...' >> "${log_file}" 2>&1

	echo 'Removing global installation...' >> "${log_file}" 2>&1
	npm uninstall -g "${pkg_name}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing post-install cleanup tasks." >> "${log_file}" 2>&1
		return 1
	fi
	npm list -g --depth=0 >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when attempting to list globally installed packages via npm." >> "${log_file}" 2>&1
		return 1
	fi
	echo 'Successfully removed global installation...' >> "${log_file}" 2>&1
	return 0
}

# Installs a package globally via `npm` from GitHub.
npm_install_global_github() {
	echo "Installing ${pkg_github_url}#${pkg_github_tag} as a global package..." >> "${log_file}" 2>&1
	npm install -g "${pkg_github_url}#${pkg_github_tag}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when installing ${pkg_github_url}#${pkg_github_tag} as a global package via npm." >> "${log_file}" 2>&1
		cat "${working_dir}/npm-debug.log" >> "${log_file}" 2>&1
		return 1
	fi
	npm list -g --depth=0 >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when attempting to list globally installed packages via npm." >> "${log_file}" 2>&1
		return 1
	fi
	echo "Successfully installed ${pkg_github_url}#${pkg_github_tag}." >> "${log_file}" 2>&1

	echo 'Testing global installation...' >> "${log_file}" 2>&1
	stdlib --help >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when testing installation." >> "${log_file}" 2>&1
		return 1
	fi
	echo 'Successfully tested global installation...' >> "${log_file}" 2>&1

	echo 'Removing global installation...' >> "${log_file}" 2>&1
	npm uninstall -g "${pkg_name}" >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when performing post-install cleanup tasks." >> "${log_file}" 2>&1
		return 1
	fi
	npm list -g --depth=0 >> "${log_file}" 2>&1
	if [[ "$?" -ne 0 ]]; then
		echo "Encountered an error when attempting to list globally installed packages via npm." >> "${log_file}" 2>&1
		return 1
	fi
	echo 'Successfully removed global installation...' >> "${log_file}" 2>&1
	return 0
}

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

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

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

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

	return 0
}

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

	echo "Package manager: ${pm}." >&2

	# Note: please keep the list of package managers in alphabetical order...
	if [[ "${pm}" = "npm" ]]; then
		test_npm_install
		if [[ "$?" -ne 0 ]]; then
			on_error 1
		fi
	else
		echo "ERROR: unknown package manager: ${pm}." >&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