#!/bin/bash

# Generate Promtail configuration for Log Client

# Check required variables
if [ -z "$LOGSERVER_HOST" ] || [ -z "$LOGSERVER_PORT" ] || [ -z "$LOKI_PASSWORD" ]; then
    echo "ERROR: Required environment variables not set"
    echo "  LOGSERVER_HOST: ${LOGSERVER_HOST:-NOT SET}"
    echo "  LOGSERVER_PORT: ${LOGSERVER_PORT:-NOT SET}"
    echo "  LOKI_PASSWORD: ${LOKI_PASSWORD:-NOT SET}"
    echo ""
    echo "Please set these in config/service.env before running install"
    exit 1
fi

# Get actual hostname
ACTUAL_HOSTNAME=${HOSTNAME_LABEL:-${HOSTNAME:-$(hostname 2>/dev/null || echo "unknown")}}

# Determine config directory
CONFIG_DIR="${CONFIG_PATH:-./config}"
mkdir -p "$CONFIG_DIR"

# Generate promtail.yaml configuration
cat > "$CONFIG_DIR/promtail.yaml" << EOF
server:
  http_listen_port: 9080
  grpc_listen_port: 0

positions:
  filename: /tmp/positions/positions.yaml

clients:
  - url: http://${LOKI_USER:-logclient}:${LOKI_PASSWORD}@${LOGSERVER_HOST}:${LOGSERVER_PORT}/loki/api/v1/push
    # Authentication via URL (HTTP Basic Auth)

scrape_configs:
  # Docker container logs via Docker API
  - job_name: docker
    docker_sd_configs:
      - host: unix:///var/run/docker.sock
        refresh_interval: 5s
    relabel_configs:
      - source_labels: ['__meta_docker_container_name']
        regex: '/(.*)'
        target_label: 'container_name'
      - source_labels: ['__meta_docker_container_id']
        target_label: 'container_id'
      - source_labels: ['__meta_docker_container_image']
        target_label: 'image'
      - target_label: 'hostname'
        replacement: '${ACTUAL_HOSTNAME}'
      - target_label: 'job'
        replacement: 'docker'

  # System logs
  - job_name: syslog
    static_configs:
      - targets:
          - localhost
        labels:
          job: syslog
          hostname: ${ACTUAL_HOSTNAME}
          __path__: /var/log/syslog

  - job_name: messages
    static_configs:
      - targets:
          - localhost
        labels:
          job: messages
          hostname: ${ACTUAL_HOSTNAME}
          __path__: /var/log/messages

  - job_name: auth
    static_configs:
      - targets:
          - localhost
        labels:
          job: auth
          hostname: ${ACTUAL_HOSTNAME}
          __path__: /var/log/auth.log

  # Docker container JSON logs (backup method)
  - job_name: containers
    static_configs:
      - targets:
          - localhost
        labels:
          job: containers
          hostname: ${ACTUAL_HOSTNAME}
          __path__: /var/lib/docker/containers/*/*-json.log
    pipeline_stages:
      - json:
          expressions:
            output: log
            stream: stream
            time: time
      - timestamp:
          source: time
          format: RFC3339Nano
      - labels:
          stream:
      - output:
          source: output
EOF

echo "Promtail configuration generated at: $CONFIG_DIR/promtail.yaml"
echo "Configuration:"
echo "  LOGSERVER_HOST: ${LOGSERVER_HOST}"
echo "  LOGSERVER_PORT: ${LOGSERVER_PORT}"
echo "  HOSTNAME: ${ACTUAL_HOSTNAME}"