#!/usr/bin/env bash
#
# show-impact.sh — Display accumulated impact metrics from the log.
#
# Usage: ./show-impact.sh [session_id]
#   Without arguments: shows summary across all sessions.
#   With session_id: shows entries for that session only.

set -euo pipefail

PROJECT_DIR="${CLAUDE_PROJECT_DIR:-$(cd "$(dirname "$0")/../.." && pwd)}"
LOG_FILE="$PROJECT_DIR/.claude/impact/impact-log.jsonl"

if [ ! -f "$LOG_FILE" ]; then
  echo "No impact log found at $LOG_FILE"
  echo "The PreCompact hook will create it on first context compaction."
  exit 0
fi

FILTER="${1:-.}"

echo "=== Impact Log ==="
echo ""

while IFS= read -r line; do
  sid=$(echo "$line" | jq -r '.session_id')
  if ! echo "$sid" | grep -q "$FILTER"; then
    continue
  fi

  ts=$(echo "$line" | jq -r '.timestamp')
  trigger=$(echo "$line" | jq -r '.trigger')
  turns=$(echo "$line" | jq -r '.assistant_turns')
  tools=$(echo "$line" | jq -r '.tool_uses')
  source=$(echo "$line" | jq -r '.token_source // "heuristic"')
  cum_input=$(echo "$line" | jq -r '.cumulative_input_tokens')
  # Support both old field name and new field name
  output=$(echo "$line" | jq -r '.output_tokens // .estimated_output_tokens')
  cache_create=$(echo "$line" | jq -r '.cache_creation_tokens // 0')
  cache_read=$(echo "$line" | jq -r '.cache_read_tokens // 0')
  energy=$(echo "$line" | jq -r '.energy_wh')
  co2=$(echo "$line" | jq -r '.co2_g')
  cost=$(echo "$line" | jq -r '.cost_cents')

  printf "%s [%s] session=%s\n" "$ts" "$trigger" "${sid:0:12}..."
  printf "  Turns: %s  Tool uses: %s  Token source: %s\n" "$turns" "$tools" "$source"
  printf "  Input tokens (cache-weighted): %s  Output tokens: %s\n" "$cum_input" "$output"
  if [ "$cache_create" != "0" ] || [ "$cache_read" != "0" ]; then
    printf "  Cache: %s created, %s read\n" "$cache_create" "$cache_read"
  fi
  LC_NUMERIC=C printf "  Energy: ~%s Wh  CO2: ~%sg  Cost: ~\$%.2f\n" "$energy" "$co2" "$(echo "$cost / 100" | bc -l 2>/dev/null || echo "$cost cents")"
  echo ""
done < "$LOG_FILE"

# Totals
TOTAL_ENERGY=$(jq -s '[.[].energy_wh] | add' "$LOG_FILE")
TOTAL_CO2=$(jq -s '[.[].co2_g] | add' "$LOG_FILE")
TOTAL_COST=$(jq -s '[.[].cost_cents] | add' "$LOG_FILE")
TOTAL_ENTRIES=$(wc -l < "$LOG_FILE")

echo "=== Totals ($TOTAL_ENTRIES snapshots) ==="
LC_NUMERIC=C printf "  Energy: ~%s Wh  CO2: ~%sg  Cost: ~\$%.2f\n" \
  "$TOTAL_ENERGY" "$TOTAL_CO2" \
  "$(echo "$TOTAL_COST / 100" | bc -l 2>/dev/null || echo "$TOTAL_COST cents")"