#!/usr/bin/env bash
# ==============================================================================
# install.sh — Multi-Agent Mux (MAM) Orchestration Installer
# ==============================================================================
# Idempotent, robust installer to bootstrap MAM orchestration skills
# and Python backplane dependencies on any local workspace.
# ==============================================================================
set -euo pipefail

# --- Configuration & Defaults ---
TARGET_DIR="${1:-$(pwd)}"
VENV_NAME=".venv"
MIN_PYTHON_VERSION="3.9"

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

# --- 1. System Requirements Validation ---
echo "🔍 Checking system dependencies..."

check_cmd() {
  local cmd="$1"
  if ! command -v "$cmd" &>/dev/null; then
    echo "❌ Error: '$cmd' is not installed. Please install it first." >&2
    exit 1
  fi
}

check_cmd tmux
check_cmd python3

# Verify Python Version
PYTHON_VERSION=$(python3 -c 'import sys; print(f"{sys.version_info.major}.{sys.version_info.minor}")')
PYTHON_MAJOR="${MIN_PYTHON_VERSION%%.*}"
PYTHON_MINOR="${MIN_PYTHON_VERSION##*.}"
if python3 -c "import sys; exit(0 if sys.version_info >= ($PYTHON_MAJOR, $PYTHON_MINOR) else 1)"; then
  echo "✅ Python $PYTHON_VERSION detected."
else
  echo "❌ Error: Python version must be $MIN_PYTHON_VERSION or higher. Detected: $PYTHON_VERSION" >&2
  exit 1
fi

# --- 2. Workspace Setup ---
cd "$TARGET_DIR"
echo "📂 Ensuring metadata directory structure (.mam/)..."
mkdir -p .mam/jobs .mam/delegate_job_logs

# File permission lockdown on database directory (if owned by the current user to prevent multi-user system issues)
if [ -O .mam ]; then
  chmod 0700 .mam
fi

# --- 3. Check Network File System (NFS) Warnings ---
echo "💾 Detecting file system mount type..."
if command -v df &>/dev/null && command -v mount &>/dev/null; then
  MOUNTPOINT="$(df --output=target . 2>/dev/null | tail -1 || echo "")"
  if [ -n "$MOUNTPOINT" ]; then
    if mount | grep -q "$MOUNTPOINT.*nfs\|$MOUNTPOINT.*cifs\|$MOUNTPOINT.*fuse.sshfs"; then
      echo "⚠️  WARNING: Target directory is on a network filesystem (NFS/CIFS/SSHFS)."
      echo "   File locks (fcntl.flock) are UNRELIABLE on network storage."
      echo "   The sqlite3 registry will fall back to 'DELETE' journaling instead of WAL."
    else
      echo "✅ File system supports WAL (Local storage detected)."
    fi
  fi
fi

# --- 4. Python Virtual Environment Setup ---
echo "🐍 Bootstrapping Python virtual environment (.venv)..."
if [ ! -d "$VENV_NAME" ]; then
  python3 -m venv "$VENV_NAME"
  echo "✅ Virtual environment created."
else
  echo "ℹ️  Virtual environment (.venv) already exists. Skipping creation."
fi

# Activate virtual environment
# shellcheck disable=SC1091
source "$VENV_NAME"/bin/activate

# Upgrade pip
pip install --upgrade pip

# Install requirements
REQ_FILE=".agents/skills/multi-agent-mux-delegate-job/requirements.txt"
if [ -f "$REQ_FILE" ]; then
  echo "📦 Installing backplane dependencies from $REQ_FILE..."
  pip install -r "$REQ_FILE"
  echo "✅ Dependencies installed successfully."
else
  echo "⚠️  WARNING: Could not find requirements file: $REQ_FILE"
  echo "   Installing default packages (paho-mqtt, pyyaml) manually..."
  pip install "paho-mqtt>=2.0.0" pyyaml
fi

# --- 5. Generate Environment Template ---
ENV_FILE=".env"
ENV_EXAMPLE=".env.example"
if [ ! -f "$ENV_FILE" ]; then
  if [ -f "$ENV_EXAMPLE" ]; then
    echo "📝 Creating configuration from $ENV_EXAMPLE..."
    cp "$ENV_EXAMPLE" "$ENV_FILE"
  else
    echo "📝 Creating default $ENV_FILE..."
    touch "$ENV_FILE"
  fi
  
  # Always append the active defaults to ensure they are set and not commented out
  cat <<EOF >> "$ENV_FILE"

# === Installer-applied active defaults ===
MQTT_BROKER=broker.hivemq.com
MQTT_PORT=1883
MQTT_TLS=0
MQTT_CLIENT_ID_PREFIX=mam-agent
TMUX_SERVER_NAME=default
EOF
  chmod 0600 "$ENV_FILE"
  echo "✅ Config file .env initialized with chmod 0600."
else
  echo "ℹ️  $ENV_FILE already exists. Skipping config override."
fi

echo "===================================================================="
echo "🎉 Installation complete!"
echo "✨ You can now run the status or monitor skills."
echo "💡 Hint: Try executing: .venv/bin/python .agents/skills/multi-agent-mux-delegate-job/scripts/registry.py list"
echo "===================================================================="