shit

#!/bin/bash
#
# shit – Short Git.
#
# Makes commit indexes from git-linearize ("Extremely Linear Git History") usable with git.
#
# "shit show 14" -> "git show 00000140"
# "shit log 10..14" -> "git log 00000100..00000140"

# Final program to execute, arguments will be added to this array
X=("git")

# Convert arguments matching this format
SINGLE='^[0-9]{1,7}$'

# Range formats matching: "shit log 10..14"
RANGE='^([0-9]{1,7})(\.{2,3})([0-9]{1,7})$'

# Format to convert to
# Set EL_FORMAT externally to override
EL_FORMAT="${EL_FORMAT:-%07d0}"

function expand() {
	# shellcheck disable=SC2059 # Disabled because EL_FORMAT contains the format
	padded=$(printf "$EL_FORMAT" "$1")

	# Find commit with the given prefix reachable from HEAD
	reachable=$(git rev-list HEAD | grep --max-count 1 "$padded" | head -n1)
	if [[ $reachable ]]; then
		echo "$reachable"
		return 0
	fi

	# Fallback to using the prefix
	echo "$padded"
}

for arg in "$@"; do
	if [[ $arg =~ $SINGLE ]]; then
		# Looks like a number, add padding
		out=$(expand "$arg")
		X+=("$out")
	elif [[ $arg =~ $RANGE ]]; then
		# Convert ranges like "10..14" to "00000100..00000140"
		first=$(expand "${BASH_REMATCH[1]}")
		dots=${BASH_REMATCH[2]}
		second=$(expand "${BASH_REMATCH[3]}")
		X+=("${first}${dots}${second}")
	else
		# Not a number, keep as-is
		X+=("$arg")
	fi
done

"${X[@]}"