#!/usr/bin/env bash
# ==============================================================================
# remove.sh — Multi-Agent Mux (MAM) Orchestration Uninstaller
# ==============================================================================
# Safely removes MAM orchestration skills, virtual environment, and metadata.
# Leaves pre-existing user configurations and files untouched by reading
# the installation manifest (.mam/install_manifest.txt).
# ==============================================================================
set -euo pipefail

TARGET_DIR=""
FORCE=0
PURGE_ENV=0

# Parse arguments
while [[ $# -gt 0 ]]; do
  case "$1" in
    -y|--yes|--force)
      FORCE=1
      shift
      ;;
    --purge-env)
      PURGE_ENV=1
      shift
      ;;
    *)
      TARGET_DIR="$1"
      shift
      ;;
  esac
done

if [ -z "$TARGET_DIR" ]; then
  TARGET_DIR="$(pwd)"
fi

echo "===================================================================="
echo "⚡ Starting Multi-Agent Mux (MAM) Uninstallation"
echo "📂 Target Workspace: $TARGET_DIR"
echo "===================================================================="

if [ ! -d "$TARGET_DIR" ]; then
  echo "❌ Error: Target directory '$TARGET_DIR' does not exist." >&2
  exit 1
fi

cd "$TARGET_DIR"

# 1. Non-interactive input safety guard (set -e read crash prevention)
if [ ! -t 0 ] && [ $FORCE -eq 0 ]; then
  echo "❌ Error: Non-interactive terminal detected. Please run with -y/--yes/--force." >&2
  exit 1
fi

# Check if there is anything to remove
MANIFEST_FILE=".mam/install_manifest.txt"
any_exist=0
manifest_files=()

# Load the install manifest if it exists
if [ -f "$MANIFEST_FILE" ]; then
  any_exist=1
  while IFS= read -r line; do
    if [ -n "$line" ]; then
      manifest_files+=("$line")
    fi
  done < "$MANIFEST_FILE"
else
  # Fallback to the core MAM directories to check if any exist
  fallback_assets=(
    ".agents/skills/lib.sh"
    ".agents/skills/multi-agent-mux-create"
    ".agents/skills/multi-agent-mux-delegate-job"
    ".agents/skills/multi-agent-mux-monitor"
    ".agents/skills/multi-agent-mux-resume"
    ".agents/skills/multi-agent-mux-status"
    ".agents/skills/multi-agent-mux-stop"
    ".venv"
    ".mam"
  )
  for asset in "${fallback_assets[@]}"; do
    if [ -e "$asset" ] || [ -h "$asset" ]; then
      any_exist=1
      break
    fi
  done
fi

if [ $any_exist -eq 0 ]; then
  echo "ℹ️  No MAM assets detected in '$TARGET_DIR'. Nothing to do."
  exit 0
fi

# Request confirmation if not forced
if [ $FORCE -eq 0 ]; then
  echo "⚠️  WARNING: This will permanently remove the MAM orchestration skills, "
  echo "   virtual environment (.venv), local metadata (.mam), and docs."
  echo "   (Your own custom files inside .agents/ will NOT be touched)."
  
  if ! read -p "❓ Are you sure you want to proceed? [y/N]: " -r response; then
    response="n"
  fi
  if [[ ! "$response" =~ ^[yY](es)?$ ]]; then
    echo "❌ Uninstallation cancelled by user."
    exit 0
  fi
fi

delete_asset() {
  local asset="$1"
  if [ -e "$asset" ] || [ -h "$asset" ]; then
    echo "🗑️  Removing: $asset"
    rm -rf "$asset"
  fi
}

# 2. Uninstall files using the manifest if present
if [ ${#manifest_files[@]} -gt 0 ]; then
  echo "📜 Manifest found. Reversing installer-created files..."
  for f in ${manifest_files[@]+"${manifest_files[@]}"}; do
    # Skip .env and remove.sh for now, they are handled separately
    if [ "$f" = ".env" ] || [ "$f" = "remove.sh" ]; then
      continue
    fi
    delete_asset "$f"
  done
  else
    # Fallback: Delete MAM skills manually (only if manifest is missing)
    echo "⚠️  No manifest found. Deleting standard MAM skills..."
    delete_asset ".agents/skills/lib.sh"
    delete_asset ".agents/skills/multi-agent-mux-create"
    delete_asset ".agents/skills/multi-agent-mux-delegate-job"
    delete_asset ".agents/skills/multi-agent-mux-monitor"
    delete_asset ".agents/skills/multi-agent-mux-resume"
    delete_asset ".agents/skills/multi-agent-mux-status"
    delete_asset ".agents/skills/multi-agent-mux-stop"
  fi

# 3. Clean up empty parent directories under .agents recursively to avoid littering
if [ -d ".agents" ]; then
  find .agents -depth -type d -exec rmdir {} + 2>/dev/null || true
fi

# 4. Remove virtual environment, monitor cache, and metadata database
delete_asset ".venv"
delete_asset ".cache/multi-agent-mux-monitor"
delete_asset ".mam"  # Deletes manifest file too

# 5. Clean up .env file (Only if created by installer, or forced with --purge-env)
# If .env is in manifest, it means MAM created it.
env_created_by_mam=0
for f in ${manifest_files[@]+"${manifest_files[@]}"}; do
  if [ "$f" = ".env" ]; then
    env_created_by_mam=1
    break
  fi
done

if [ -f ".env" ]; then
  should_delete_env=0
  if [ $PURGE_ENV -eq 1 ]; then
    should_delete_env=1
  elif [ $env_created_by_mam -eq 1 ]; then
    # Even if MAM created it, ask or rename to backup to prevent loss of custom secrets
    if [ $FORCE -eq 1 ]; then
      should_delete_env=1
    else
      if ! read -p "❓ MAM-created '.env' found. Delete it? (Saying No preserves it) [y/N]: " -r env_response; then
        env_response="n"
      fi
      if [[ "$env_response" =~ ^[yY](es)?$ ]]; then
        should_delete_env=1
      fi
    fi
  fi

  if [ $should_delete_env -eq 1 ]; then
    delete_asset ".env"
  else
    if [ $env_created_by_mam -eq 1 ]; then
      backup_name=".env.mam-backup"
      if [ -e "$backup_name" ]; then
        backup_name=".env.mam-backup.$(date +%Y%m%d%H%M%S)"
      fi
      echo "💾 Backing up .env configuration to $backup_name..."
      mv ".env" "$backup_name"
    else
      echo "ℹ️  Preserving user-owned .env configuration."
    fi
  fi
fi

# 6. Remove uninstaller file itself (if we are in the target root)
# Simple check: only delete remove.sh if it is recorded in the manifest
remove_in_manifest=0
for f in ${manifest_files[@]+"${manifest_files[@]}"}; do
  if [ "$f" = "remove.sh" ]; then
    remove_in_manifest=1
    break
  fi
done

if [ -f "remove.sh" ] && [ $remove_in_manifest -eq 1 ]; then
  echo "🗑️  Removing uninstaller: remove.sh"
  # Self-delete is the final action
  rm -f "remove.sh"
fi

echo "===================================================================="
echo "🎉 Uninstallation complete!"
echo "===================================================================="