#!/bin/sh
# Validate an UNTRUSTED model id against the live catalog.
#
# This is the one gate that stands between an agent-written model string and an
# unquoted `--model $MODEL` expansion in the pipelines, so it lives in a single
# tested place (see scripts/ci/test-model-selection.sh) rather than inline in a
# Woodpecker `commands:` block. Written in POSIX sh (run as `sh`), matching the
# other scripts/ci/ helpers added alongside it.
#
# Echoes the id on stdout IFF it is BOTH:
#   1. a single safe token — only [A-Za-z0-9._-] AND not starting with a dash, so
#      a value carrying a newline or a space, or one that looks like an option
#      (e.g. "--dangerously-skip-permissions", or
#      "claude-x\n--dangerously-skip-permissions"), can never pass and then
#      word-split into an injected CLI flag; and
#   2. present in column 1 of the catalog read on stdin (fetch-models.sh --table
#      output, or a bare id-per-line list).
# Otherwise echoes nothing. Always exits 0 so callers can use $(...) under set -e.
# The two checks are independent: step 1 alone makes the value safe to pass to a
# command line even if a caller supplies no catalog.
#
# Usage:  printf '%s\n' "$TABLE" | valid-model.sh "$candidate"
set -eu

CAND="${1:-}"

# 1. shape check — reject empty, a leading dash (option-like), or any char
#    outside the safe set. A real model id never starts with '-'.
case "$CAND" in ""|-*|*[!A-Za-z0-9._-]*) exit 0 ;; esac

# 2. membership check — must be a currently-available id (catalog on stdin).
CATALOG="$(cat)"
[ -n "$CATALOG" ] || exit 0
printf '%s\n' "$CATALOG" | cut -f1 | grep -qxF -- "$CAND" || exit 0

printf '%s\n' "$CAND"