#!/usr/bin/env zsh
DOTWRYN_SETUP__SETUP_DIR="${0:a:h}"
#####################################################################

DOTWRYN_SETUP__FORCE_ROOT=false
DOTWRYN_SETUP__OVERWRITE_EXISTING=false
DOTWRYN_SETUP__USE_LOGFILE=true
DOTWRYN_SETUP__STRICT=false
DOTWRYN_SETUP__INSTALLATION_PROFILE=default
DOTWRYN_SETUP__EXCLUDE=()
DOTWRYN_SETUP__STEPS=(filesystem packages config)


setup.run._.usage() {
	local run_file="${DOTWRYN_SETUP__SETUP_DIR}/run"
	local line flags description

	local found_function=false
	while read -r line
	do
		case "${found_function}" in
			( false ) [[ "${line}" == '() {' ]] && found_function=true ;;
			( true  )
				[[ "${line}" =~ '^[[:space:]]*#[[:space:]]?(.*)$' ]] || break
				echo "${match[1]}"
				;;
		esac
	done < "${run_file}"

	echo
	echo 'options:'

	while read -r line
	do
		[[ "${line}" =~ '^[[:space:]]*\([[:space:]]*(-[^)]*)\)[^#]*#[[:space:]]*(.*)$' ]] || continue

		flags="${(j: :)${(z)match[1]}}"
		flags="${flags// | /, }"
		description="${match[2]}"

		[[ "${description}" =~ '^(<[^>]*>)[[:space:]]+(.*)$' ]] \
			&& flags="${flags} ${match[1]}" \
			&& description="${match[2]}"

		printf '  %-38s %s\n' "${flags}" "${description}"
	done < "${run_file}"

	echo
	echo "steps: ${(j:, :)DOTWRYN_SETUP__STEPS}"
	echo
}

#####################################################################

() {
	# set up this machine from the .wryn dotfiles repository
	#
	# usage: setup/run [...options...]
	local -a skip_steps only_steps

	setup.run._.error() { echo "ERROR::${*}" >&2; return 1; }

	local _s
	while [[ "${#}" -gt 0 ]]
	do
		_s=1
		case "${1}" in
			( -h | --help )  # display this message and exit
				setup.run._.usage
				return 0
				;;

			( -p | --installation-profile ) _s=2  # <profile> only install dependencies belonging to <profile>
				DOTWRYN_SETUP__INSTALLATION_PROFILE="${2}"
				;;

			( --min )  # shorthand for '--installation-profile min'
				DOTWRYN_SETUP__INSTALLATION_PROFILE=min
				;;

			( --skip ) _s=2  # <step> don't run <step>; repeatable, incompatible with --only
				skip_steps+=("${2}")
				;;

			( --only ) _s=2  # <step> only run <step>; repeatable, incompatible with --skip
				only_steps+=("${2}")
				;;

			( --exclude ) _s=2  # <dependencies> comma-separated dependencies to neither install nor verify; repeatable
				DOTWRYN_SETUP__EXCLUDE+=("${(s:,:)2}")
				;;

			( --overwrite )  # replace existing local configuration
				DOTWRYN_SETUP__OVERWRITE_EXISTING=true
				;;

			( --force-root )  # allow setup to run as root
				DOTWRYN_SETUP__FORCE_ROOT=true
				;;

			( --ci )  # automation mode; never prompts (pair with '--skip packages' to also skip installs)
				export CI=true
				;;

			( --no-logfile )  # don't write a logfile for this run
				DOTWRYN_SETUP__USE_LOGFILE=false
				;;

			( --strict )  # treat unresolved dependencies as a failure instead of prompting
				DOTWRYN_SETUP__STRICT=true
				;;

			( * )
				setup.run._.error "unknown option '${1}'; try '--help'"
				return 2
				;;
		esac
		shift "${_s}"
	done
	unset _s

	#####################################################################

	[[ "${#skip_steps[@]}" -eq 0 ]] || [[ "${#only_steps[@]}" -eq 0 ]] \
		|| setup.run._.error "'--skip' and '--only' cannot be used together" \
		|| return 2

	local named_step
	for named_step in "${skip_steps[@]}" "${only_steps[@]}"
	do
		(( ${DOTWRYN_SETUP__STEPS[(Ie)${named_step}]} )) \
			|| setup.run._.error "no such setup step '${named_step}' (steps: ${(j:, :)DOTWRYN_SETUP__STEPS})" \
			|| return 2
	done
	unset named_step

	local -a steps
	local step
	for step in "${DOTWRYN_SETUP__STEPS[@]}"
	do
		case "${#only_steps[@]}" in
			( 0 ) (( ${skip_steps[(Ie)${step}]} )) && continue ;;
			( * ) (( ${only_steps[(Ie)${step}]} )) || continue ;;
		esac
		steps+=("${step}")
	done

	[[ "${#steps[@]}" -gt 0 ]] \
		|| setup.run._.error 'every setup step was excluded; nothing to do' \
		|| return 2

	unset -f setup.run._.error

	#####################################################################

	source "${DOTWRYN_SETUP__SETUP_DIR}/prepare-zsh-utilities.zsh" || return 1

	local -a installation_profiles
	installation_profiles=("${(f)$(setup.packages.list-installation-profiles)}")
	(( ${installation_profiles[(Ie)${DOTWRYN_SETUP__INSTALLATION_PROFILE}]} )) \
		|| echo.error "no such installation profile '${DOTWRYN_SETUP__INSTALLATION_PROFILE}' (available: ${(j:, :)installation_profiles})" \
		|| return 2

	#####################################################################

	local ERRORS=0
	local logfile
	case "${DOTWRYN_SETUP__USE_LOGFILE}" in
		( true  ) logfile="${DOTWRYN_SETUP__STATE_DIR}/setup.$(date +%Y-%m-%dT%H%M%S).log" ;;
		( false ) logfile=/dev/null ;;
	esac

	echo.status "installation start : $(date)" 2>> "${logfile}"
	echo.status "setup steps        : ${(j:, :)steps}"

	for step in "${steps[@]}"
	do
		setup.${step} > >(tee -a "${logfile}") 2>&1 \
			|| echo.error "failed during ${step} setup (see above)" \
			|| return ${ERRORS}
	done

	echo.status "installation complete: $(date)" 2>> "${logfile}"

	[[ "${logfile}" == /dev/null ]] \
		|| echo.reminder "logfile can be found at:\n\t${logfile}"

	#####################################################################

	echo.success "\n.wryn setup complete; have a nice day :)\n "
} "${@}"