#!/usr/bin/env bash

set -e -u

TERMUX_SCRIPTDIR=$(realpath "$(dirname "$0")/../")

check_package_license() {
	local pkg_licenses=$1
	local license
	local license_ok=true
	local IFS

	IFS=","
	for license in $pkg_licenses; do
		license=$(echo "$license" | sed -r 's/^\s*(\S+(\s+\S+)*)\s*$/\1/')

		case "$license" in
			AFL-2.1|AFL-3.0|AGPL-V3|APL-1.0|APSL-2.0|Apache-1.0|Apache-1.1);;
			Apache-2.0|Artistic-License-2.0|Attribution|BSD|"BSD 2-Clause");;
			"BSD 3-Clause"|"BSD New"|"BSD Simplified"|BSL-1.0|Bouncy-Castle);;
			CA-TOSL-1.1|CC0-1.0|CDDL-1.0|CDDL-1.1|CPAL-1.0|CPL-1.0|CPOL);;
			CPOL-1.02|CUAOFFICE-1.0|CeCILL-1|CeCILL-2|CeCILL-2.1|CeCILL-B);;
			CeCILL-C|Codehaus|Copyfree|curl|Day|Day-Addendum|ECL2|EPL-1.0|EPL-2.0);;
			EUDATAGRID|EUPL-1.1|EUPL-1.2|Eiffel-2.0|Entessa-1.0);;
			Facebook-Platform|Fair|Frameworx-1.0|GPL-2.0|GPL-3.0|GPL-3.0-only);;
			GPL-3.0-or-later|Go|HSQLDB|Historical|IBMPL-1.0|IJG|IPAFont-1.0);;
			ISC|IU-Extreme-1.1.1|ImageMagick|JA-SIG|JSON|JTidy|LGPL-2.0);;
			LGPL-2.1|LGPL-3.0|LPPL-1.0|Libpng|Lucent-1.02|MIT|MPL-2.0|MS-PL);;
			MS-RL|MirOS|Motosoto-0.9.1|Mozilla-1.1|Multics|NASA-1.3|NAUMEN);;
			NCSA|NOSL-3.0|NTP|NUnit-2.6.3|NUnit-Test-Adapter-2.6.3|Nethack);;
			Nokia-1.0a|OCLC-2.0|OSL-3.0|OpenLDAP|OpenSSL|Openfont-1.1);;
			Opengroup|PHP-3.0|PHP-3.01|PostgreSQL|"Public Domain"|"Public Domain - SUN");;
			PythonPL|PythonSoftFoundation|QTPL-1.0|RPL-1.5|Real-1.0|RicohPL);;
			SUNPublic-1.0|Scala|SimPL-2.0|Sleepycat|Sybase-1.0|TMate|UPL-1.0);;
			Unicode-DFS-2015|Unlicense|UoI-NCSA|"VIM License"|VovidaPL-1.0|W3C);;
			WTFPL|Xnet|ZLIB|ZPL-2.0|wxWindows|X11);;

			*)
				license_ok=false
				break
				;;
		esac
	done

	if ! "$license_ok"; then
		return 1
	fi

	return 0
}

check_package_name() {
	local pkg_name="$1"
	echo -n "Package name '${pkg_name}': "
	if (( ${#pkg_name} < 2 )); then
		echo "INVALID (less than two characters long)"
		return 1
	fi

	if ! grep -qP '^[0-9a-z][0-9a-z+\-\.]+$' <<< "${pkg_name}"; then
		echo "INVALID (contains characters that are not allowed)"
		return 1
	fi

	echo "PASS"
	return 0
}

check_indentation() {
	local pkg_script="$1"
	local line='' heredoc_terminator='' in_array=0 i=0
	local -a issues=('' '') bad_lines=('FAILED')

	# parse leading whitespace
	while IFS=$'\n' read -r line; do
		((i++))

		# make sure it's a heredoc, not a herestring
		if ! [[ "$line" == *'<<<'* ]]; then
			# Skip this check in entirely within heredocs
			# (see packages/ghc-libs for an example of why)
				[[ "$line" =~ [^\(]\<{2}-?[\'\"]?([^\'\"]+) ]] && {
				heredoc_terminator="${BASH_REMATCH[1]}"
			}

			(( ${#heredoc_terminator} )) && \
			grep -qP "^\s*${heredoc_terminator}" <<< "$line" && {
				heredoc_terminator=''
			}
			(( ${#heredoc_terminator} )) && continue
		fi

		# check for mixed indentation
		grep -qP '^(\t+ +| +\t+)' <<< "$line" && {
			issues[0]='Mixed indentation'
			bad_lines[$i]="${pkg_script}:${i}:$line"
		}

		[[ "$line" == *'=('* ]] && in_array=1
		if (( ! in_array )); then # spaces for indentation are okay for aligning arrays
			grep -qP '^ +' <<< "$line" && { # check for spaces as indentation
				issues[1]='Use tabs for indentation'
				bad_lines[$i]="${pkg_script}:${i}:$line"
			}
		fi
		[[ "$line" == *')' ]] && in_array=0
	done < "$pkg_script"

	# if we found problems print them out and throw an error
	(( ${#issues[0]} || ${#issues[1]} )) && {
		printf '%s\n' "${bad_lines[@]}"
		printf '%s\n' "${issues[@]}"
		return 1
	}
	return 0
}

lint_package() {
	local package_script
	local package_name

	package_script="$1"
	package_name="$(basename "$(dirname "$package_script")")"

	echo "================================================================"
	echo
	echo "Package: $package_name"
	echo

	check_package_name "$package_name" || return 1
	local subpkg_script
	for subpkg_script in $(dirname "$package_script")/*.subpackage.sh; do
		test ! -f "$subpkg_script" && continue
		local subpkg_name=$(basename "${subpkg_script%.subpackage.sh}")
		check_package_name "$subpkg_name" || return 1
	done

	echo -n "End of line check: "
	local last2octet
	last2octet=$(xxd -s -2 "$package_script" | awk '{ print $2 }')
	if [[ "$last2octet" == "0a0a" ]]; then
		echo -e "FAILED (duplicate newlines at the end)\n"
		tail -n5 "$package_script" | sed -e "s|^|  |" -e "5s|^  |>>|"
		return 1
	fi
	if [[ "$last2octet" != *"0a" ]]; then
		echo -e "FAILED (no newline terminated)\n"
		xxd -s -2 "$package_script"
		return 1
	fi
	echo "PASS"

	echo -n "File permission check: "
	local file_permission
	file_permission=$(stat -c "%A" "$package_script")
	if [[ "$file_permission" == *"x"* ]]; then
		echo -e "FAILED (executable bit is set)\n"
		echo "${file_permission}"
		return 1
	fi
	echo "PASS"

	echo -n "Indentation check: "
	local script
	for script in "$package_script" $(dirname "$package_script")/*.subpackage.sh; do
		test ! -f "$script" && continue
		check_indentation "$script" || return 1
	done
	echo "PASS"

	echo -n "Syntax check: "
	local syntax_errors
	syntax_errors=$(bash -n "$package_script" 2>&1)
	if (( ${#syntax_errors} )); then
		echo "FAILED"
		echo
		echo "$syntax_errors"
		echo
		return 1
	fi
	echo "PASS"

	echo -n "Trailing whitespace check: "
	local trailing_whitespace
	trailing_whitespace=$(grep -Hn ' $' "$package_script")
	if (( ${#trailing_whitespace} )); then
		echo -e "FAILED\n\n${trailing_whitespace}\n"
		return 1
	fi
	echo "PASS"
	echo

	# Fields checking is done in subshell since we will source build.sh.
	(set +e +u
		local pkg_lint_error

		# Certain fields may be API-specific.
		# Using API 24 here.
		TERMUX_PKG_API_LEVEL=24

		if [[ -f "$TERMUX_SCRIPTDIR/scripts/properties.sh" ]]; then
			. "$TERMUX_SCRIPTDIR/scripts/properties.sh"
		fi

		. "$package_script"

		pkg_lint_error=false

		echo -n "TERMUX_PKG_HOMEPAGE: "
		if (( ${#TERMUX_PKG_HOMEPAGE} )); then
			if ! grep -qP '^https://.+' <<< "$TERMUX_PKG_HOMEPAGE"; then
				echo "NON-HTTPS (acceptable)"
			else
				echo "PASS"
			fi
		else
			echo "NOT SET"
			pkg_lint_error=true
		fi

		echo -n "TERMUX_PKG_DESCRIPTION: "
		if (( ${#TERMUX_PKG_DESCRIPTION} )); then

			if (( ${#TERMUX_PKG_DESCRIPTION} > 100 )); then
				echo "TOO LONG (allowed: 100 characters max)"
			else
				echo "PASS"
			fi

		else
			echo "NOT SET"
			pkg_lint_error=true
		fi

		echo -n "TERMUX_PKG_LICENSE: "
		if (( ${#TERMUX_PKG_LICENSE} )); then
			if [[ "$TERMUX_PKG_LICENSE" == 'custom' ]]; then
				echo "CUSTOM"
			elif [[ "$TERMUX_PKG_LICENSE" == 'non-free' ]]; then
				echo "NON-FREE"
			else
				if check_package_license "$TERMUX_PKG_LICENSE"; then
					echo "PASS"
				else
					echo "INVALID"
					pkg_lint_error=true
				fi
			fi
		else
			echo "NOT SET"
			pkg_lint_error=true
		fi

		echo -n "TERMUX_PKG_MAINTAINER: "
		if (( ${#TERMUX_PKG_MAINTAINER} )); then
			echo "PASS"
		else
			echo "NOT SET"
			pkg_lint_error=true
		fi

		if (( ${#TERMUX_PKG_API_LEVEL} )); then
		echo -n "TERMUX_PKG_API_LEVEL: "

			if grep -qP '^[1-9][0-9]$' <<< "$TERMUX_PKG_API_LEVEL"; then
				if (( TERMUX_PKG_API_LEVEL < 24 || TERMUX_PKG_API_LEVEL > 28 )); then
					echo "INVALID (allowed: number in range 24 - 28)"
					pkg_lint_error=true
				else
					echo "PASS"
				fi
			else
				echo "INVALID (allowed: number in range 24 - 28)"
				pkg_lint_error=true
			fi
		fi

		echo -n "TERMUX_PKG_VERSION: "
		if (( ${#TERMUX_PKG_VERSION} )); then
			if grep -qiP '^([0-9]+\:)?[0-9][0-9a-z+\-\.\~]*$' <<< "${TERMUX_PKG_VERSION}"; then
				echo "PASS"
			else
				echo "INVALID (contains characters that are not allowed)"
				pkg_lint_error=true
			fi
		else
			echo "NOT SET"
			pkg_lint_error=true
		fi

		if (( ${#TERMUX_PKG_REVISION} )); then
		echo -n "TERMUX_PKG_REVISION: "

			if (( TERMUX_PKG_REVISION > 1 || TERMUX_PKG_REVISION < 999999999 )); then
				echo "PASS"
			else
				echo "INVALID (allowed: number in range 1 - 999999999)"
				pkg_lint_error=true
			fi
		fi

		if (( ${#TERMUX_PKG_SKIP_SRC_EXTRACT} )); then
		echo -n "TERMUX_PKG_SKIP_SRC_EXTRACT: "

			case "$TERMUX_PKG_SKIP_SRC_EXTRACT" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		echo -n "TERMUX_PKG_SRCURL: "
		if (( ${#TERMUX_PKG_SRCURL} )); then
			urls_ok=true
			for url in "${TERMUX_PKG_SRCURL[@]}"; do
				if (( ${#url} )); then
					if ! grep -qP '^git\+https://.+' <<< "$url" && ! grep -qP '^https://.+' <<< "$url"; then
						echo "NON-HTTPS (acceptable)"
						urls_ok=false
						break
					fi
				else
					echo "NOT SET (one of the array elements)"
					urls_ok=false
					pkg_lint_error=true
					break
				fi
			done
			unset url

			if "$urls_ok"; then
				echo "PASS"
			fi
			unset urls_ok

			echo -n "TERMUX_PKG_SHA256: "
			if (( ${#TERMUX_PKG_SHA256} )); then
				if (( ${#TERMUX_PKG_SRCURL[@]} == ${#TERMUX_PKG_SHA256[@]} )); then
					sha256_ok=true

					for sha256 in "${TERMUX_PKG_SHA256[@]}"; do
						if ! grep -qP '^[0-9a-fA-F]{64}$' <<< "${sha256}" && [[ "$sha256" != 'SKIP_CHECKSUM' ]]; then
							echo "MALFORMED (SHA-256 should contain 64 hexadecimal numbers)"
							sha256_ok=false
							pkg_lint_error=true
							break
						fi
					done
					unset sha256

					if $sha256_ok; then
						echo "PASS"
					fi
					unset sha256_ok
				else
					echo "LENGTHS OF 'TERMUX_PKG_SRCURL' AND 'TERMUX_PKG_SHA256' ARE NOT EQUAL"
					pkg_lint_error=true
				fi
			elif [[ "${TERMUX_PKG_SRCURL:0:4}" == 'git+' ]]; then
				echo "NOT SET (acceptable since TERMUX_PKG_SRCURL is git repo)"
			else
				echo "NOT SET"
				pkg_lint_error=true
			fi
		else
			echo -n "NOT SET"
			if [[ "$TERMUX_PKG_SKIP_SRC_EXTRACT" != 'true' ]] && ! declare -F termux_step_extract_package > /dev/null 2>&1; then
				echo " (set TERMUX_PKG_SKIP_SRC_EXTRACT to 'true' if no sources downloaded)"
				pkg_lint_error=true
			else
				echo " (acceptable since TERMUX_PKG_SKIP_SRC_EXTRACT is true)"
			fi
		fi

		if (( ${#TERMUX_PKG_METAPACKAGE} )); then
		echo -n "TERMUX_PKG_METAPACKAGE: "

			case "$TERMUX_PKG_METAPACKAGE" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_ESSENTIAL} )); then
		echo -n "TERMUX_PKG_ESSENTIAL: "

			case "$TERMUX_PKG_ESSENTIAL" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_NO_STATICSPLIT} )); then
		echo -n "TERMUX_PKG_NO_STATICSPLIT: "

			case "$TERMUX_PKG_NO_STATICSPLIT" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_BUILD_IN_SRC} )); then
		echo -n "TERMUX_PKG_BUILD_IN_SRC: "

			case "$TERMUX_PKG_BUILD_IN_SRC" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_HAS_DEBUG} )); then
		echo -n "TERMUX_PKG_HAS_DEBUG: "

			case "$TERMUX_PKG_HAS_DEBUG" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_PLATFORM_INDEPENDENT} )); then
		echo -n "TERMUX_PKG_PLATFORM_INDEPENDENT: "

			case "$TERMUX_PKG_PLATFORM_INDEPENDENT" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_HOSTBUILD} )); then
		echo -n "TERMUX_PKG_HOSTBUILD: "

			case "$TERMUX_PKG_HOSTBUILD" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_FORCE_CMAKE} )); then
		echo -n "TERMUX_PKG_FORCE_CMAKE: "

			case "$TERMUX_PKG_FORCE_CMAKE" in
				'true'|'false')
					echo "PASS";;
				*)
					echo "INVALID (allowed: true / false)"
					pkg_lint_error=true;;
			esac
		fi

		if (( ${#TERMUX_PKG_RM_AFTER_INSTALL} )); then
		echo -n "TERMUX_PKG_RM_AFTER_INSTALL: "
			file_path_ok=true

			while read -r file_path; do
				[[ -z "$file_path" ]] && continue

				if grep -qP '^(\.\.)?/' <<< "$file_path"; then
					echo "INVALID (file path should be relative to prefix)"
					file_path_ok=false
					pkg_lint_error=true
					break
				fi
			done <<< "$TERMUX_PKG_RM_AFTER_INSTALL"
			unset file_path

			if "$file_path_ok"; then
				echo "PASS"
			fi
			unset file_path_ok
		fi

		if (( ${#TERMUX_PKG_CONFFILES} )); then
		echo -n "TERMUX_PKG_CONFFILES: "
			file_path_ok=true

			while read -r file_path; do
				[[ -z "$file_path" ]] && continue

				if grep -qP '^(\.\.)?/' <<< "$file_path"; then
					echo "INVALID (file path should be relative to prefix)"
					file_path_ok=false
					pkg_lint_error=true
					break
				fi
			done <<< "$TERMUX_PKG_CONFFILES"
			unset file_path

			if "$file_path_ok"; then
				echo "PASS"
			fi
			unset file_path_ok
		fi

		if (( ${#TERMUX_PKG_SERVICE_SCRIPT} )); then
		echo -n "TERMUX_PKG_SERVICE_SCRIPT: "

			if (( ${#TERMUX_PKG_SERVICE_SCRIPT[@]} % 2 )); then
				echo "INVALID (TERMUX_PKG_SERVICE_SCRIPT has to be an array of even length)"
				pkg_lint_error=true
			else
				echo "PASS"
			fi
		fi

		if "$pkg_lint_error"; then
			exit 1
		fi
	exit 0
	)

	local ret=$?

	echo

	return "$ret"
}

linter_main() {
	local package_counter=0
	local problems_found=false
	local package_script

	for package_script in "$@"; do
		if ! lint_package "$package_script"; then
			problems_found=true
			break
		fi

		(( package_counter++ ))
	done

	if "$problems_found"; then
		echo "================================================================"
		echo
		echo "A problem has been found in '$(realpath --relative-to="$TERMUX_SCRIPTDIR" "$package_script")'."
		echo "Checked $package_counter packages before the first error was detected."
		echo
		echo "================================================================"

		return 1
	fi

	echo "================================================================"
	echo
	echo "Checked $package_counter packages."
	echo "Everything seems ok."
	echo
	echo "================================================================"

	return 0
}

if (( $# )); then
	linter_main "$@" || exit 1
else
	for repo_dir in $(jq --raw-output 'del(.pkg_format) | keys | .[]' $TERMUX_SCRIPTDIR/repo.json); do
		linter_main $repo_dir/*/build.sh
	done || exit 1
fi