#!/bin/bash

set -f +o posix && shopt -s extglob || exit

function die {
	printf '%s\n' "$1"
	exit "${2-1}"
}

function get_common_prefix {
	local a b i IFS=/
	a=($1) b=($2) i=0

	for (( ; i < ${#a[@]}; ++i )); do
		[[ ${a[i]} == "${b[i]}" ]] || break
	done

	__=${a[*]:0:i}
}

function get_common_prefix_multi {
	__=${1%/*}

	while shift; [[ ${1+.} ]]; do
		get_common_prefix "$__" "${1%/*}"
	done
}

function check_commit_cleanup {
	local value

	if ! value=$(git config commit.cleanup); then
		echo "WARNING: Failed to get value of 'commit.cleanup'."
		echo
	elif [[ ${value} != strip ]]; then
		echo "WARNING: Git's config variable 'commit.cleanup' is not set to 'strip'."
		echo
	fi
}

function call {
	local x q m=

	for x do
		printf -v q %q "$x"

		if [[ $q == "$x" ]]; then
			m+=" $x"
		elif [[ $x == *\'* ]]; then
			m+=" $q"
		else
			m+=" '$x'"
		fi
	done

	printf '> %s\n' "${m# }"
	command "$@"
}

function all_files_deleted {
	local dir=$1
	[[ -z $(git ls-files --cached -- "${dir}") ]] # Simple solution discovered and shared by osse
}

function main {
	local copyright_year current_year ebuilds files status test_dir= value __

	check_commit_cleanup
	status=$(git status --porcelain --find-renames="100%")

	# Check copyright year in ebuilds; ignore pure renames.

	readarray -t files < <(printf '%s' "${status}" | \
			gawk 'match($0, /^[ACMT]. (.* -> )?(.*\.ebuild)$/, a) { print a[2] }')
	printf -v current_year '%(%Y)T'

	for f in "${files[@]}"; do
		copyright_year=$(git show ":./$f" | gawk 'match($0,
				/^# Copyright ([[:digit:]]+-)?([[:digit:]]+) /, a) { print a[2]; exit }')
		[[ ${copyright_year} != "${current_year}" ]] && \
			die "Copyright year of '$f' is invalid: ${copyright_year}"
	done

	# Immediately check for unindexed files that belong to a package starting
	# from where the git command was executed.

	readarray -t unindexed < <(printf '%s' "${status}" | \
			gawk 'BEGIN { p = ENVIRON["GIT_PREFIX"] } !/^. / && !/^!!/ &&
					match($0, /^(.. )(.*)/, a) && substr(a[2], 0, length(p)) == p &&
					a[2] ~ /^[^/-]+-[^/-]+\/[^/-]+/ { print a[1] a[2] }')

	if [[ ${#unindexed[@]} -gt 0 ]]; then
		local IFS=$'\n' __
		printf -v __ 'Unindexed modifications found: \n\n%s\n' "${unindexed[*]/#/  }"
		die "$__"
	fi

	# Following tests are worktree based.
	#
	# The first step is to get the common prefix.

	readarray -t files < <(printf '%s' "${status}" | \
			gawk 'match($0, /^[ACDMRT]. (.* -> )?(.*)/, a) { print a[2] }')

	if [[ ${#files[@]} -gt 0 ]]; then
		get_common_prefix_multi "${files[@]}"

		if [[ -z $__ || $__ == +([!/-])-+([!/-]) || $__ == +([!/-])-+([!/-])/* ]]; then
			if [[ $__ ]]; then
				local IFS=/
				set -- $__
				test_dir="${*:1:2}"
			fi

			# We can't allow unindexed modifications in "${test_dir}" because the main tests will be
			# affected by those.
			#
			# The "not all files are currently deleted but directory doesn't exist in worktree" test
			# below might be overshadowed by this but we'll keep the test anyway for the sake of
			# consistency.
			#
			# Don't exclude directories since files within it do not appear when the directory
			# itself isn't indexed.

			readarray -t unindexed < <(git status --porcelain -- "${test_dir:-.}" | \
					gawk '!/^. / && !/^!!/')

			if [[ ${#unindexed[@]} -gt 0 ]]; then
				local IFS=$'\n' __
				printf -v __ 'Unindexed modifications found: \n\n%s\n' "${unindexed[*]/#/  }"
				die "$__"
			fi

			# Test directory not existing means whole category or package was deleted.
			#
			# It can also be another non-category/non-package directory but its parent
			# directory doesn't need to be tested for it.

			if [[ -z ${test_dir} ]] || ! all_files_deleted "${test_dir}"; then
				[[ -z ${test_dir} || -e ${test_dir} ]] || \
					die "Not all files are currently deleted but directory doesn't exist in worktree: ${test_dir}"
				[[ -z ${test_dir} || -d ${test_dir} ]] || \
					die "Unexpectedly not a directory: ${test_dir}"

				readarray -t ebuilds < <(find "${test_dir:-.}" -name '*.ebuild' -exec grep -Ple \
						"KEYWORDS=.*[ \"'=][[:lower:]][[:alnum:]-]+" -- '{}' +)

				if [[ ${#ebuilds[@]} -gt 0 ]]; then
					echo "The following ebuilds have stable keywords: "
					printf '%s\n' "${ebuilds[@]}"
					return 1
				fi

				if [[ ${GIT_PRE_COMMIT_SKIP_REPOMAN-} != @(true|1) ]] &&
						type -P repoman >/dev/null; then
					echo Repoman:
					echo "Set GIT_PRE_COMMIT_SKIP_REPOMAN to 'true' to disable."
					( [[ -z ${test_dir} ]] || cd -- "${test_dir}" && call repoman ) || return 1
					echo
				fi

				if [[ ${GIT_PRE_COMMIT_SKIP_PKGCHECK_SCAN-} != @(true|1) ]] &&
						type -P pkgcheck >/dev/null; then
					local pkgcheck=(pkgcheck scan --exit=error)

					if [[ -e helpers/profiles.mask ]]; then
						readarray -t profiles < helpers/profiles.mask || return 1
						IFS=, eval 'pkgcheck+=("--profiles=${profiles[*]/#/-}")'
					fi

					echo "Pkgcheck scan:"
					echo "Set GIT_PRE_COMMIT_SKIP_PKGCHECK_SCAN to 'true' to disable."
					( [[ -z ${test_dir} ]] || cd -- "${test_dir}" && call "${pkgcheck[@]}" ) || \
						return 1
					echo
				fi
			fi
		fi
	fi

	return 0
}

main