#!/usr/bin/env bash
# =============================================================================
# Airflow DAG Monitor - Setup Script
#
# Creates virtual environment, installs dependencies, prepares directories,
# and installs systemd service.
#
# По умолчанию устанавливает в /opt/airflow-monitor.
# Если запущен из другого каталога — копирует файлы в /opt/airflow-monitor.
# =============================================================================
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
INSTALL_DIR="/opt/airflow-monitor"

# Copy project files to /opt/airflow-monitor if running from another location
if [ "$SCRIPT_DIR" != "$INSTALL_DIR" ]; then
    echo "Copying project to $INSTALL_DIR..."
    sudo mkdir -p "$INSTALL_DIR"
    sudo chown "$(whoami):$(id -gn)" "$INSTALL_DIR"
    cp -r "$SCRIPT_DIR/airflow_monitor"          "$INSTALL_DIR/"
    cp    "$SCRIPT_DIR/config.yaml"               "$INSTALL_DIR/"
    cp    "$SCRIPT_DIR/requirements.txt"          "$INSTALL_DIR/"
    cp    "$SCRIPT_DIR/airflow-monitor.service"   "$INSTALL_DIR/"
    cp    "$SCRIPT_DIR/README.md"                 "$INSTALL_DIR/"
    [ -f "$SCRIPT_DIR/setup.sh" ] && cp "$SCRIPT_DIR/setup.sh" "$INSTALL_DIR/"
    [ -f "$SCRIPT_DIR/build.sh" ] && cp "$SCRIPT_DIR/build.sh" "$INSTALL_DIR/"
    [ -d "$SCRIPT_DIR/zabbix" ]   && cp -r "$SCRIPT_DIR/zabbix" "$INSTALL_DIR/"
fi

VENV_DIR="$INSTALL_DIR/venv"
SERVICE_NAME="airflow-monitor"
SERVICE_FILE="$INSTALL_DIR/${SERVICE_NAME}.service"

echo "=== Airflow DAG Monitor Setup ==="
echo "Install directory: $INSTALL_DIR"
echo ""

# --- Step 1: Create virtual environment ---
echo "[1/4] Creating Python virtual environment..."
if [ -d "$VENV_DIR" ]; then
    echo "  Virtual environment already exists, recreating..."
    rm -rf "$VENV_DIR"
fi
python3 -m venv "$VENV_DIR"
echo "  Created: $VENV_DIR"

# --- Step 2: Install dependencies ---
echo "[2/4] Installing dependencies..."
"$VENV_DIR/bin/pip" install --upgrade pip --quiet
"$VENV_DIR/bin/pip" install -r "$INSTALL_DIR/requirements.txt" --quiet
echo "  Installed: $(cat "$INSTALL_DIR/requirements.txt" | grep -v '^#' | tr '\n' ' ')"

# --- Step 3: Create required directories ---
echo "[3/4] Creating directories..."

STATE_DIR="/var/lib/airflow-monitor"
LOG_DIR="/var/log/airflow-monitor"

for dir in "$STATE_DIR" "$LOG_DIR"; do
    if [ ! -d "$dir" ]; then
        sudo mkdir -p "$dir"
        sudo chown "$(whoami):$(id -gn)" "$dir"
        echo "  Created: $dir"
    else
        echo "  Exists:  $dir"
    fi
done

# --- Step 4: Install systemd service ---
echo "[4/5] Installing systemd service..."
if [ -f "$SERVICE_FILE" ]; then
    sudo cp "$SERVICE_FILE" /etc/systemd/system/
    sudo systemctl daemon-reload
    echo "  Installed: /etc/systemd/system/${SERVICE_NAME}.service"
else
    echo "  WARNING: ${SERVICE_FILE} not found, skipping service install"
fi

# --- Step 5: Install Zabbix agent config ---
echo "[5/5] Installing Zabbix agent config..."
ZABBIX_CONF_SRC="$INSTALL_DIR/zabbix/airflow-monitor.conf"
ZABBIX_CONF_DST="/etc/zabbix/zabbix_agentd.conf.d/airflow-monitor.conf"

if [ -f "$ZABBIX_CONF_SRC" ]; then
    if [ -d "/etc/zabbix/zabbix_agentd.conf.d" ]; then
        sudo cp "$ZABBIX_CONF_SRC" "$ZABBIX_CONF_DST"
        # Zabbix agent must be able to read data files
        sudo chmod 644 "$ZABBIX_CONF_DST"
        echo "  Installed: $ZABBIX_CONF_DST"
        # Restart zabbix agent to pick up new UserParameters
        if systemctl is-active zabbix-agent >/dev/null 2>&1; then
            sudo systemctl restart zabbix-agent
            echo "  Restarted: zabbix-agent"
        elif systemctl is-active zabbix-agent2 >/dev/null 2>&1; then
            sudo systemctl restart zabbix-agent2
            echo "  Restarted: zabbix-agent2"
        else
            echo "  WARNING: zabbix-agent not running, restart it manually"
        fi
    else
        echo "  WARNING: /etc/zabbix/zabbix_agentd.conf.d/ not found"
        echo "  Copy manually: cp $ZABBIX_CONF_SRC $ZABBIX_CONF_DST"
    fi
else
    echo "  WARNING: zabbix config not found at $ZABBIX_CONF_SRC"
fi

# Ensure data directory is readable by zabbix agent
sudo chmod 755 "$STATE_DIR"

echo ""
echo "=== Setup Complete ==="
echo ""
echo "Next steps:"
echo "  1. Edit config.yaml:"
echo "     vim $INSTALL_DIR/config.yaml"
echo "  2. Test manually:"
echo "     $VENV_DIR/bin/python -m airflow_monitor --discover -c $INSTALL_DIR/config.yaml"
echo "  3. Enable and start:"
echo "     sudo systemctl enable --now $SERVICE_NAME"
echo "  4. Check logs:"
echo "     journalctl -u $SERVICE_NAME -f"
echo "  5. Verify Zabbix agent reads data:"
echo "     zabbix_agentd -t airflow.monitor.heartbeat"
echo "     zabbix_agentd -t airflow.dag.problems.count"