#!/usr/bin/env bash
# Cross-platform path normalization helpers (Bash 3.2+).
# Fallback chain: realpath -m -> realpath -> readlink -f -> manual collapse.
# Manual collapse resolves "."/".." relative to $PWD without requiring the path
# to exist. Default mode collapses then resolves symlinks when possible (physical).
set -euo pipefail
# Collapse . and .. components. For relative input, collapse relative to $PWD
# and return an absolute path; empty input becomes "." (relative result) before
# absolute expansion. Double slashes are squashed. Clamps at root for leading ..
mcp_path_collapse() {
local raw="${1-}"
[ -z "${raw}" ] && raw="."
if [[ "${raw}" != /* ]]; then
local base="${PWD:-.}"
raw="${base%/}/${raw}"
fi
# squash multiple slashes
raw="$(printf '%s' "${raw}" | tr -s '/')"
# read -a requires bash (not zsh); arrays are Bash 3.2-compatible.
IFS='/' read -r -a parts <<<"${raw}"
local -a stack=() # Bash 3.2 arrays are ok; prefer array for clarity
local comp
for comp in "${parts[@]}"; do
case "${comp}" in
"" | ".") continue ;;
"..")
if [ "${#stack[@]}" -gt 0 ]; then
unset "stack[${#stack[@]}-1]"
fi
;;
*)
stack+=("${comp}")
;;
esac
done
local joined="/"
if [ "${#stack[@]}" -gt 0 ]; then
local idx
for idx in "${!stack[@]}"; do
joined="${joined%/}/${stack[$idx]}"
done
fi
[ -z "${joined}" ] && joined="/"
printf '%s' "${joined}"
}
# Normalize a path with optional mode:
# --physical (default): collapse, then resolve symlinks when resolver exists.
# --logical: collapse only (no final symlink resolution).
# Empty input yields $PWD when a resolver exists; otherwise collapse result.
mcp_path_normalize() {
local mode="physical"
while [ "$#" -gt 0 ]; do
case "$1" in
--physical) mode="physical" ;;
--logical) mode="logical" ;;
--)
shift
break
;;
-*) break ;;
*) break ;;
esac
shift
done
local raw="${1-}"
[ -z "${raw}" ] && raw="."
local resolver=""
local realpath_supports_m="false"
if command -v realpath >/dev/null 2>&1; then
if realpath -m "/" >/dev/null 2>&1; then
realpath_supports_m="true"
fi
fi
local normalized=""
if [ "${realpath_supports_m}" = "true" ]; then
normalized="$(realpath -m "${raw}" 2>/dev/null || true)"
resolver="realpath -m"
elif command -v realpath >/dev/null 2>&1; then
normalized="$(realpath "${raw}" 2>/dev/null || true)"
resolver="realpath"
elif command -v readlink >/dev/null 2>&1; then
if readlink -f / >/dev/null 2>&1; then
normalized="$(readlink -f "${raw}" 2>/dev/null || true)"
resolver="readlink -f"
fi
fi
if [ -z "${normalized}" ]; then
normalized="$(mcp_path_collapse "${raw}")"
resolver="collapse"
fi
if [ "${mode}" = "physical" ]; then
if [ "${resolver}" = "collapse" ]; then
if [ "${realpath_supports_m}" = "true" ]; then
local tmp
tmp="$(realpath -m "${normalized}" 2>/dev/null || true)"
[ -n "${tmp}" ] && normalized="${tmp}" && resolver="collapse+realpath -m"
elif command -v realpath >/dev/null 2>&1; then
local tmp
tmp="$(realpath "${normalized}" 2>/dev/null || true)"
[ -n "${tmp}" ] && normalized="${tmp}" && resolver="collapse+realpath"
elif command -v readlink >/dev/null 2>&1; then
if readlink -f / >/dev/null 2>&1; then
local tmp
tmp="$(readlink -f "${normalized}" 2>/dev/null || true)"
[ -n "${tmp}" ] && normalized="${tmp}" && resolver="collapse+readlink -f"
fi
fi
fi
fi
[ -z "${normalized}" ] && normalized="${raw}"
if [[ "${normalized}" != "/" ]]; then
normalized="${normalized%/}"
[ -z "${normalized}" ] && normalized="/"
fi
# Normalize drive letter case for Windows/MSYS-style paths.
# Examples: /c/Users -> /C/Users, c:\tmp -> C:\tmp
if [[ "${normalized}" =~ ^/([a-z])(/.*)?$ ]]; then
local drive="${BASH_REMATCH[1]}"
local rest="${BASH_REMATCH[2]:-}"
local drive_upper
drive_upper="$(printf '%s' "${drive}" | tr '[:lower:]' '[:upper:]')"
normalized="/${drive_upper}${rest}"
elif [[ "${normalized}" =~ ^([a-z]): ]]; then
local drive_letter="${BASH_REMATCH[1]}"
local drive_upper
drive_upper="$(printf '%s' "${drive_letter}" | tr '[:lower:]' '[:upper:]')"
normalized="${drive_upper}${normalized:1}"
fi
# On Windows/MSYS, canonicalize paths through Windows format and back to Unix format.
# This resolves: (1) MSYS virtual paths like /tmp -> /c/Users/.../Temp,
# (2) 8.3 short names like RUNNER~1 -> runneradmin, ensuring consistent path comparison.
# The -l flag expands 8.3 short names to long names.
if [[ "${OSTYPE:-}" == msys* || "${OSTYPE:-}" == cygwin* ]] && command -v cygpath >/dev/null 2>&1; then
local win_path unix_path
win_path="$(cygpath -w -l "${normalized}" 2>/dev/null || true)"
if [ -n "${win_path}" ]; then
unix_path="$(cygpath -u "${win_path}" 2>/dev/null || true)"
[ -n "${unix_path}" ] && normalized="${unix_path}"
fi
fi
if [ "${MCP_PATH_DEBUG:-0}" = "1" ]; then
printf 'mcp_path_normalize: %s -> %s\n' "${raw}" "${resolver}" >&2
fi
printf '%s' "${normalized}"
}
