#!/usr/bin/env bash
#
# install.sh — Install the impact tracking toolkit for Claude Code.
#
# Copies hook scripts and configures the PreCompact hook in your
# Claude Code settings. Safe to run multiple times (idempotent).
#
# Usage: ./install.sh [--user | --project]
#   --user     Install to user-level settings (~/.claude/settings.json)
#   --project  Install to project-level settings (.claude/settings.json)
#   Default: --project

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SCOPE="${1:---project}"

# Check dependencies
if ! command -v jq &>/dev/null; then
  echo "Error: jq is required but not installed."
  echo "Install it with: apt install jq / brew install jq / etc."
  exit 1
fi

if ! command -v python3 &>/dev/null; then
  echo "Error: python3 is required for token extraction."
  echo "Install Python 3 or ensure it is on your PATH."
  exit 1
fi

# Determine target directories
if [ "$SCOPE" = "--user" ]; then
  SETTINGS_DIR="$HOME/.claude"
  HOOKS_DIR="$SETTINGS_DIR/hooks"
  echo "Installing to user-level settings ($SETTINGS_DIR)"
else
  # Project-level: use current working directory
  SETTINGS_DIR="$(pwd)/.claude"
  HOOKS_DIR="$SETTINGS_DIR/hooks"
  echo "Installing to project-level settings ($SETTINGS_DIR)"
fi

# Create directories
mkdir -p "$HOOKS_DIR"
mkdir -p "$SETTINGS_DIR/impact"

# Copy hook scripts
cp "$SCRIPT_DIR/hooks/pre-compact-snapshot.sh" "$HOOKS_DIR/"
cp "$SCRIPT_DIR/hooks/show-impact.sh" "$HOOKS_DIR/"
cp "$SCRIPT_DIR/hooks/show-aggregate.sh" "$HOOKS_DIR/"
chmod +x "$HOOKS_DIR/pre-compact-snapshot.sh"
chmod +x "$HOOKS_DIR/show-impact.sh"
chmod +x "$HOOKS_DIR/show-aggregate.sh"

echo "Copied hook scripts to $HOOKS_DIR"

# Configure settings.json
SETTINGS_FILE="$SETTINGS_DIR/settings.json"
HOOK_CMD="$HOOKS_DIR/pre-compact-snapshot.sh"

if [ -f "$SETTINGS_FILE" ]; then
  # Check if PreCompact hook already configured
  if jq -e '.hooks.PreCompact' "$SETTINGS_FILE" &>/dev/null; then
    echo "PreCompact hook already configured in $SETTINGS_FILE — skipping."
  else
    # Add hooks to existing settings
    jq --arg cmd "$HOOK_CMD" \
      '.hooks.PreCompact = [{"hooks": [{"type": "command", "command": $cmd}]}]' \
      "$SETTINGS_FILE" > "${SETTINGS_FILE}.tmp" && mv "${SETTINGS_FILE}.tmp" "$SETTINGS_FILE"
    echo "Added PreCompact hook to $SETTINGS_FILE"
  fi
else
  # Create new settings file
  jq -n --arg cmd "$HOOK_CMD" \
    '{"hooks": {"PreCompact": [{"hooks": [{"type": "command", "command": $cmd}]}]}}' \
    > "$SETTINGS_FILE"
  echo "Created $SETTINGS_FILE with PreCompact hook"
fi

echo ""
echo "Installation complete."
echo "Impact metrics will be logged to $SETTINGS_DIR/impact/impact-log.jsonl"
echo "on each context compaction."
echo ""
echo "To view per-session impact:  $HOOKS_DIR/show-impact.sh"
echo "To view aggregate dashboard: $HOOKS_DIR/show-aggregate.sh"