package commands

import (
	"flag"
	"fmt"
	"log"
	"os"

	"congo.gg/cmd/internal"
)

const logsUsage = `Stream logs from a deployed service

Usage:
  congo logs [flags] [service]

Flags:
  --server <name>  Instance to read from (auto-selects if only one)
  --tail <n>       Number of lines to show (default: 100)
  --follow         Follow log output (Ctrl+C to stop)

Examples:
  congo logs                   # list services on default instance
  congo logs web-app           # show recent logs for web-app
  congo logs web-app --follow  # stream logs
  congo logs --server web-1    # target a specific instance
`

func Logs() {
	fs := flag.NewFlagSet("logs", flag.ExitOnError)
	fs.Usage = func() { fmt.Print(logsUsage) }

	serverName := fs.String("server", "", "Instance to read from")
	tail := fs.String("tail", "100", "Number of lines")
	follow := fs.Bool("follow", false, "Follow log output")

	fs.Parse(os.Args[2:])

	cfg, err := scaffold.LoadInfraConfig(".")
	if err != nil {
		log.Fatalf("load infra.json: %v", err)
	}

	target, err := scaffold.FindInstanceOrDefault(cfg, *serverName)
	if err != nil {
		if multi, ok := err.(*scaffold.MultipleInstancesError); ok {
			fmt.Println("Multiple instances found. Use --server <name>:")
			for _, inst := range multi.Instances {
				fmt.Printf("  %s (%s)\n", inst.Name, inst.IP)
			}
			os.Exit(1)
		}
		log.Fatal(err)
	}

	server := target.ToServer()
	service := fs.Arg(0)

	if service == "" {
		fmt.Printf("Services on %s (%s):\n\n", target.Name, target.IP)
		out, err := server.SSH("docker", "ps", "--format", "table {{.Names}}\t{{.Status}}\t{{.Ports}}")
		if err != nil {
			log.Fatalf("docker ps: %v", err)
		}
		fmt.Println(out)
		fmt.Println("\nUsage: congo logs <service-name>")
		return
	}

	args := []string{"docker", "logs"}
	if *follow {
		args = append(args, "-f")
	}
	args = append(args, "--tail", *tail, service)

	if *follow {
		fmt.Printf("Streaming logs from %s on %s...\n\n", service, target.Name)
		if err := server.Connect(args...); err != nil {
			os.Exit(1)
		}
	} else {
		out, err := server.SSH(args...)
		if err != nil {
			log.Fatalf("logs: %v", err)
		}
		fmt.Print(out)
	}
}