package commands

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"os"
	"strings"
)

const destroyUsage = `Remove a deployed server instance

Usage:
  congo destroy <name> [flags]

Flags:
  --force    Skip confirmation prompt

Stops all services, deletes the server from the cloud provider,
and removes the instance from infra.json.

Examples:
  congo destroy web-1           # with confirmation
  congo destroy web-1 --force   # skip confirmation
`

func Destroy() {
	fs := flag.NewFlagSet("destroy", flag.ExitOnError)
	fs.Usage = func() { fmt.Print(destroyUsage) }

	force := fs.Bool("force", false, "Skip confirmation prompt")
	fs.Parse(os.Args[2:])

	name := fs.Arg(0)
	if name == "" {
		fs.Usage()
		os.Exit(1)
	}

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

	// Find the instance.
	var target *Instance
	var serverType string
	var instanceIdx int
	for st, instances := range cfg.Instances {
		found := false
		for i := range instances {
			if instances[i].Name == name {
				target = &instances[i]
				serverType = st
				instanceIdx = i
				found = true
				break
			}
		}
		if found {
			break
		}
	}

	if target == nil {
		var names []string
		for _, instances := range cfg.Instances {
			for _, inst := range instances {
				names = append(names, inst.Name)
			}
		}
		if len(names) == 0 {
			log.Fatal("No instances deployed.")
		}
		fmt.Fprintf(os.Stderr, "Instance %q not found. Available instances:\n", name)
		for _, n := range names {
			fmt.Fprintf(os.Stderr, "  %s\n", n)
		}
		os.Exit(1)
	}

	// Confirmation.
	if !*force {
		fmt.Printf("This will permanently delete %s (%s).\n", target.Name, target.IP)
		fmt.Print("Type the instance name to confirm: ")

		scanner := bufio.NewScanner(os.Stdin)
		scanner.Scan()
		if strings.TrimSpace(scanner.Text()) != name {
			fmt.Println("Aborted.")
			return
		}
	}

	p, err := initProvider(cfg.Platform)
	if err != nil {
		log.Fatal(err)
	}

	// Stop containers on the server before deleting.
	if target.IP != "" {
		server := target.toServer()
		fmt.Printf("Stopping services on %s...\n", target.Name)
		server.SSH("bash", "-c", "docker stop $(docker ps -q) 2>/dev/null")
	}

	// Delete from cloud provider.
	if target.ID != "" {
		fmt.Printf("Deleting server from %s...\n", cfg.Platform.Provider)
		if err := p.DeleteServer(target.ID); err != nil {
			log.Fatalf("delete server: %v", err)
		}
	}

	// Remove from infra.json.
	instances := cfg.Instances[serverType]
	cfg.Instances[serverType] = append(instances[:instanceIdx], instances[instanceIdx+1:]...)
	if len(cfg.Instances[serverType]) == 0 {
		delete(cfg.Instances, serverType)
	}
	if err := cfg.save("."); err != nil {
		log.Fatalf("save infra.json: %v", err)
	}

	fmt.Printf("Destroyed %s.\n", name)
}