scripts: Add git-resolve tool for full SHA-1 resolution

#!/bin/bash

usage() {

	echo "Usage: $(basename "$0") [--selftest] [--force] <commit-id> [commit-subject]"

	echo "Resolves a short git commit ID to its full SHA-1 hash, particularly useful for fixing references in commit messages."

	echo ""

	echo "Arguments:"

	echo "  --selftest      Run self-tests"

	echo "  --force         Try to find commit by subject if ID lookup fails"

	echo "  commit-id       Short git commit ID to resolve"

	echo "  commit-subject  Optional commit subject to help resolve between multiple matches"

	exit 1

}

# Convert subject with ellipsis to grep pattern

convert_to_grep_pattern() {

	local subject="$1"

	# First escape ALL regex special characters

	local escaped_subject

	escaped_subject=$(printf '%s\n' "$subject" | sed 's/[[\.*^$()+?{}|]/\\&/g')

	# Also escape colons, parentheses, and hyphens as they are special in our context

	escaped_subject=$(echo "$escaped_subject" | sed 's/[:-]/\\&/g')

	# Then convert escaped ... sequence to .*?

	escaped_subject=$(echo "$escaped_subject" | sed 's/\\\.\\\.\\\./.*?/g')

	echo "^${escaped_subject}$"

}

git_resolve_commit() {

	local force=0

	if [ "$1" = "--force" ]; then

		force=1

		shift

	fi

	# Split input into commit ID and subject

	local input="$*"

	local commit_id="${input%% *}"

	local subject=""

	# Extract subject if present (everything after the first space)

	if [[ "$input" == *" "* ]]; then

		subject="${input#* }"

		# Strip the ("...") quotes if present

		subject="${subject#*(\"}"

		subject="${subject%\")*}"

	fi

	# Get all possible matching commit IDs

	local matches

	readarray -t matches < <(git rev-parse --disambiguate="$commit_id" 2>/dev/null)

	# Return immediately if we have exactly one match

	if [ ${#matches[@]} -eq 1 ]; then

		echo "${matches[0]}"

		return 0

	fi

	# If no matches and not in force mode, return failure

	if [ ${#matches[@]} -eq 0 ] && [ $force -eq 0 ]; then

		return 1

	fi

	# If we have a subject, try to find a match with that subject

	if [ -n "$subject" ]; then

		# Convert subject with possible ellipsis to grep pattern

		local grep_pattern

		grep_pattern=$(convert_to_grep_pattern "$subject")

		# In force mode with no ID matches, use git log --grep directly

		if [ ${#matches[@]} -eq 0 ] && [ $force -eq 1 ]; then

			# Use git log to search, but filter to ensure subject matches exactly

			local match

			match=$(git log --format="%H %s" --grep="$grep_pattern" --perl-regexp -10 | \

					while read -r hash subject; do

						if echo "$subject" | grep -qP "$grep_pattern"; then

							echo "$hash"

							break

						fi

					done)

			if [ -n "$match" ]; then

				echo "$match"

				return 0

			fi

		else

			# Normal subject matching for existing matches

			for match in "${matches[@]}"; do

				if git log -1 --format="%s" "$match" | grep -qP "$grep_pattern"; then

					echo "$match"

					return 0

				fi

			done

		fi

	fi

	# No match found

	return 1

}

run_selftest() {

	local test_cases=(

		'00250b5 ("MAINTAINERS: add new Rockchip SoC list")'

		'0037727 ("KVM: selftests: Convert xen_shinfo_test away from VCPU_ID")'

		'ffef737 ("net/tls: Fix skb memory leak when running kTLS traffic")'

		'd3d7 ("cifs: Improve guard for excluding $LXDEV xattr")'

		'dbef ("Rename .data.once to .data..once to fix resetting WARN*_ONCE")'

		'12345678'  # Non-existent commit

		'12345 ("I'\''m a dummy commit")'  # Valid prefix but wrong subject

		'--force 99999999 ("net/tls: Fix skb memory leak when running kTLS traffic")'  # Force mode with non-existent ID but valid subject

		'83be ("firmware: ... auto-update: fix poll_complete() ... errors")'  # Wildcard test

		'--force 999999999999 ("firmware: ... auto-update: fix poll_complete() ... errors")'  # Force mode wildcard test

	)

	local expected=(

		"00250b529313d6262bb0ebbd6bdf0a88c809f6f0"

		"0037727b3989c3fe1929c89a9a1dfe289ad86f58"

		"ffef737fd0372ca462b5be3e7a592a8929a82752"

		"d3d797e326533794c3f707ce1761da7a8895458c"

		"dbefa1f31a91670c9e7dac9b559625336206466f"

		""  # Expect empty output for non-existent commit

		""  # Expect empty output for wrong subject

		"ffef737fd0372ca462b5be3e7a592a8929a82752"  # Should find commit by subject in force mode

		"83beece5aff75879bdfc6df8ba84ea88fd93050e"  # Wildcard test

		"83beece5aff75879bdfc6df8ba84ea88fd93050e"  # Force mode wildcard test

	)

	local expected_exit_codes=(

		0

		0

		0

		0

		0

		1  # Expect failure for non-existent commit

		1  # Expect failure for wrong subject

		0  # Should succeed in force mode

		0  # Should succeed with wildcard

		0  # Should succeed with force mode and wildcard

	)

	local failed=0

	echo "Running self-tests..."

	for i in "${!test_cases[@]}"; do

		# Capture both output and exit code

		local result

		result=$(git_resolve_commit ${test_cases[$i]})  # Removed quotes to allow --force to be parsed

		local exit_code=$?

		# Check both output and exit code

		if [ "$result" != "${expected[$i]}" ] || [ $exit_code != ${expected_exit_codes[$i]} ]; then

			echo "Test case $((i+1)) FAILED"

			echo "Input: ${test_cases[$i]}"

			echo "Expected output: '${expected[$i]}'"

			echo "Got output: '$result'"

			echo "Expected exit code: ${expected_exit_codes[$i]}"

			echo "Got exit code: $exit_code"

			failed=1

		else

			echo "Test case $((i+1)) PASSED"

		fi

	done

	if [ $failed -eq 0 ]; then

		echo "All tests passed!"

		exit 0

	else

		echo "Some tests failed!"

		exit 1

	fi

}

# Check for selftest

if [ "$1" = "--selftest" ]; then

	run_selftest

	exit $?

fi

# Handle --force flag

force=""

if [ "$1" = "--force" ]; then

	force="--force"

	shift

fi

# Verify arguments

if [ $# -eq 0 ]; then

	usage

fi

# Skip validation in force mode

if [ -z "$force" ]; then

	# Validate that the first argument matches at least one git commit

	if [ "$(git rev-parse --disambiguate="$1" 2>/dev/null | wc -l)" -eq 0 ]; then

		echo "Error: '$1' does not match any git commit"

		exit 1

	fi

fi

git_resolve_commit $force "$@"

exit $?