#!/usr/bin/env bash
# Scribe plugin — SessionStart push channel (two tiers + compaction re-grounding).
#
# Tier 1 (STATIC, always fires, no auth, no network): injects a bundled
# behavioral mandate (scribe_static_context.md) so a fresh session knows to
# reach for Scribe — record work, recall before acting — even when the instance
# is unreachable OR the API token never reached this hook. The latter is a known
# Claude Code gap: sensitive userConfig values aren't always exported to the
# hook subprocess, so the dynamic tier can silently get nothing. The static tier
# is the load-bearing floor that does not depend on the key or the network.
#
# Tier 2 (DYNAMIC, best-effort enrichment): curls the operator's Scribe instance
# for always-on rules + active-project context and appends it. Config comes from
# the plugin's userConfig, exported to hooks as:
#   CLAUDE_PLUGIN_OPTION_api_endpoint  base URL, no trailing slash
#   CLAUDE_PLUGIN_OPTION_api_token     fmcp_ API key (sensitive)
# The active project is resolved server-side from the working repo's git remote
# (see services/repo_bindings); bind each repo once with the bind_repo MCP tool.
#
# COMPACTION RE-GROUNDING: this hook is registered matcher-less, so it ALSO
# fires after a compaction (SessionStart input `source` == "compact"), when
# earlier turns have just been summarized and in-flight state is most at risk.
# On that source we lead with a banner telling the model to reload project +
# in-flight tasks from Scribe. (PreCompact is the wrong tool here — a host hook
# can't make the model flush, and can't know the in-flight task ids; the durable
# path is record-as-you-go + this post-compaction reload.)
#
# IMPORTANT: do NOT pass config via `${user_config.*}` substitution in
# hooks.json — sensitive values are kept in the keychain and 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 override for
# the settings.json dogfooding path.
#
# FAIL-OPEN, BUT NOT SILENT: the dynamic tier never blocks a session. A *failed*
# dynamic fetch is surfaced as a short status line (not swallowed). A fully
# unconfigured install (no url AND no token) is the intended static-only mode
# and stays quiet.
set -uo pipefail

command -v jq >/dev/null 2>&1 || exit 0   # needed to emit the JSON envelope safely

here=$(CDPATH= cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd) || exit 0

# SessionStart delivers a JSON event on stdin; `source` is startup|resume|compact|clear.
event=$(cat 2>/dev/null || true)
source=$(printf '%s' "$event" | jq -r '.source // empty' 2>/dev/null) || source=""

out=""
# Append $1 to $out, separated by a horizontal rule when $out already has content.
append() { if [ -n "$out" ]; then out="${out}"$'\n\n---\n\n'"$1"; else out="$1"; fi; }
# Prepend $1 above $out (used for the compaction banner so it's seen first).
prepend() { if [ -n "$out" ]; then out="$1"$'\n\n---\n\n'"${out}"; else out="$1"; fi; }

# --- Tier 1: static behavioral mandate (always, keyless, networkless) ---
[ -f "$here/scribe_static_context.md" ] && out=$(cat "$here/scribe_static_context.md")

# --- Tier 2: dynamic rules + active-project context (best-effort) ---
url=${SCRIBE_URL:-${CLAUDE_PLUGIN_OPTION_api_endpoint:-}}
token=${SCRIBE_TOKEN:-${CLAUDE_PLUGIN_OPTION_api_token:-}}

# 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

dyn=""
status=""
if [ -n "$url" ] && [ -n "$token" ] && command -v curl >/dev/null 2>&1; then
  # Resolve the working repo's remote so the server can map it to a project.
  repo_dir=${CLAUDE_PROJECT_DIR:-$PWD}
  repo=$(git -C "$repo_dir" remote get-url origin 2>/dev/null || true)
  q=""
  if [ -n "$repo" ]; then
    enc=$(printf '%s' "$repo" | jq -rR '@uri' 2>/dev/null) || enc=""
    [ -n "$enc" ] && q="?repo=${enc}"
  fi
  body=$(curl -fsS --max-time 8 \
    -H "Authorization: Bearer ${token}" \
    "${url%/}/api/plugin/context${q}" 2>/dev/null) || body=""
  [ -n "$body" ] && dyn=$(printf '%s' "$body" | jq -r '.context // empty' 2>/dev/null)
  [ -z "$dyn" ] && status="> ⚠️ Scribe: live rules/project context could not be loaded this session (instance unreachable or request failed). The standing guidance above still applies — pull rules with \`list_always_on_rules()\` and project context with \`enter_project()\` as needed."
elif [ -n "$url" ] && [ -z "$token" ]; then
  # Endpoint configured but token absent: the signature of the known Claude Code
  # userConfig export gap (sensitive values not always reaching the hook).
  status="> ⚠️ Scribe: live context disabled this session — the API token did not reach this hook (a known Claude Code plugin-config gap). Tools still work; pull rules with \`list_always_on_rules()\` and project context with \`enter_project()\`."
fi

[ -n "$dyn" ]    && append "$dyn"
[ -n "$status" ] && append "$status"

# Compaction re-grounding: lead with a reload banner when this fire is a compact.
if [ "$source" = "compact" ]; then
  prepend "> ⟳ This session was just COMPACTED — earlier turns are now a summary, so in-flight detail may be lost. Before continuing, reload your bearings from Scribe: re-pull the operator's binding rules with \`list_always_on_rules()\` (a compaction can summarize them out of context, leaving only generic harness defaults in their place), re-run \`enter_project()\` for the active project, check its open tasks and recent notes, and reconcile what you're mid-way through against what Scribe records. Don't trust half-remembered state — Scribe is the record."
fi

# Nothing at all to inject → stay silent.
[ -n "$out" ] || exit 0

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