#!/usr/bin/env bash
# Scribe plugin — SessionStart push channel.
#
# Curls the operator's Scribe instance for always-on rules + active-project
# context and emits it as SessionStart `additionalContext`. Config comes from
# the plugin's userConfig, which Claude Code exports to hook subprocesses as
# CLAUDE_PLUGIN_OPTION_<key> env vars:
#   CLAUDE_PLUGIN_OPTION_api_endpoint  base URL, no trailing slash
#   CLAUDE_PLUGIN_OPTION_api_token     fmcp_ API key (sensitive)
#   CLAUDE_PLUGIN_OPTION_project_id    optional numeric project id
#
# IMPORTANT: do NOT pass these via `${user_config.*}` substitution in
# hooks.json — sensitive userConfig values (api_token) are kept in the keychain
# and are never spliced into a hook command line, so the placeholder arrives
# unexpanded. The harness env vars above are the supported channel. SCRIBE_URL
# / SCRIBE_TOKEN / SCRIBE_PROJECT_ID still override, for the settings.json
# dogfooding path where the hook is wired up by hand.
#
# FAIL-OPEN: any missing tool/config, network error, or unreachable instance
# injects nothing and exits 0. A session must never be blocked by Scribe.
set -uo pipefail

command -v jq   >/dev/null 2>&1 || exit 0
command -v curl >/dev/null 2>&1 || exit 0

url=${SCRIBE_URL:-${CLAUDE_PLUGIN_OPTION_api_endpoint:-}}
token=${SCRIBE_TOKEN:-${CLAUDE_PLUGIN_OPTION_api_token:-}}
project_id=${SCRIBE_PROJECT_ID:-${CLAUDE_PLUGIN_OPTION_project_id:-}}

# Guard against an unexpanded `${...}` placeholder reaching us as a literal — it
# would otherwise be sent as a garbage Bearer token and 401. Treat as unset.
case "$url"   in *'${'*) url="" ;;  esac
case "$token" in *'${'*) token="" ;; esac
case "$project_id" in *'${'*) project_id="" ;; esac

[ -n "$url" ] && [ -n "$token" ] || exit 0

q=""
[ -n "$project_id" ] && q="?project_id=${project_id}"

body=$(curl -fsS --max-time 8 \
  -H "Authorization: Bearer ${token}" \
  "${url%/}/api/plugin/context${q}" 2>/dev/null) || exit 0

text=$(printf '%s' "$body" | jq -r '.context // empty' 2>/dev/null) || exit 0
[ -n "$text" ] || exit 0

jq -n --arg c "$text" \
  '{hookSpecificOutput: {hookEventName: "SessionStart", additionalContext: $c}}'
exit 0