#!/bin/bash
# evaluate.sh - Stop hook: evaluate session for skill-worthy workflows
#
# Suggests skill creation only when a session shows genuine workflow complexity:
#   - 8+ mutating tool calls (high threshold, reduces noise)
#   - 4+ distinct mutating tool types (diversity = workflow, not repetitive edits)
#   - No skill was loaded (novel work, not following existing procedure)
#   - Per-session cooldown file prevents re-fire on resume
#
# Toggle: touch ~/.claude/auto-skill.disable   (global off)
#         touch .claude/auto-skill.disable      (project off)
#         rm either file to re-enable
#
# CRITICAL: This hook must NEVER fail visibly. All errors suppressed.

{
  INPUT=$(cat)
  SESSION_ID=$(printf '%s' "$INPUT" | jq -r '.session_id // empty' 2>/dev/null)

  [ -z "$SESSION_ID" ] && exit 0

  SHORT_ID="${SESSION_ID:0:8}"
  TRACK_FILE="/tmp/claude_autoskill_${SHORT_ID}"

  # No tracking file = no tool calls recorded
  [ -f "$TRACK_FILE" ] || exit 0

  # --- Toggle: global or project disable ---
  if [ -f "$HOME/.claude/auto-skill.disable" ] || [ -f ".claude/auto-skill.disable" ]; then
    rm -f "$TRACK_FILE"
    exit 0
  fi

  # --- Per-session cooldown: only suggest once per session ---
  SUGGESTED_FILE="/tmp/claude_autoskill_suggested_${SHORT_ID}"
  if [ -f "$SUGGESTED_FILE" ]; then
    rm -f "$TRACK_FILE"
    exit 0
  fi

  # --- Classify tools ---
  READ_ONLY_LIST=" Read Glob Grep LS NotebookRead TaskList TaskGet TaskCreate TaskUpdate TaskOutput TaskStop "
  SKILL_LOADED=false
  TOTAL=0
  WRITES=0
  UNIQUE_TYPES=""

  while IFS= read -r tool; do
    [ -z "$tool" ] && continue
    TOTAL=$((TOTAL + 1))

    # Check if a skill was loaded
    [ "$tool" = "Skill" ] && SKILL_LOADED=true

    # Check if read-only (space-padded list for exact word match)
    case "$READ_ONLY_LIST" in
      *" ${tool} "*) continue ;;
    esac

    # Skip Skill tool itself
    [ "$tool" = "Skill" ] && continue

    WRITES=$((WRITES + 1))

    # Track unique mutating tool types
    case " $UNIQUE_TYPES " in
      *" ${tool} "*) ;;  # already seen
      *) UNIQUE_TYPES="${UNIQUE_TYPES} ${tool}" ;;
    esac
  done < "$TRACK_FILE"

  # Count unique types (count words in UNIQUE_TYPES)
  UNIQUE_COUNT=0
  for _ in $UNIQUE_TYPES; do
    UNIQUE_COUNT=$((UNIQUE_COUNT + 1))
  done

  # Build tool summary before cleanup
  TOOL_SUMMARY=$(sort "$TRACK_FILE" | uniq -c | sort -rn | head -6 | awk '{printf "%s(%d) ", $2, $1}')

  # Clean up tracking file
  rm -f "$TRACK_FILE"

  # --- Gate 1: Skill was loaded = not novel work ---
  [ "$SKILL_LOADED" = true ] && exit 0

  # --- Gate 2: Minimum 8 mutating operations ---
  [ "$WRITES" -lt 8 ] && exit 0

  # --- Gate 3: Minimum 4 distinct mutating tool types ---
  [ "$UNIQUE_COUNT" -lt 4 ] && exit 0

  # --- All gates passed: suggest ---

  # Mark this session as suggested (prevents repeat on resume)
  touch "$SUGGESTED_FILE" 2>/dev/null

  MSG="Skill-worthy session: ${WRITES} mutating ops across ${UNIQUE_COUNT} tool types (${TOTAL} total): ${TOOL_SUMMARY}- run /auto-skill to capture this workflow."

  ESCAPED=$(printf '%s' "$MSG" | sed 's/"/\\"/g' | tr '\n' ' ')
  printf '{"systemMessage":"%s"}\n' "$ESCAPED"

} 2>/dev/null

exit 0