package command

import (
	"fmt"
	"strings"

	"github.com/hashicorp/nomad/api/contexts"
	"github.com/posener/complete"
)

type StopCommand struct {
	Meta
}

func (c *StopCommand) Help() string {
	helpText := `
Usage: nomad stop [options] <job>

  Stop an existing job. This command is used to signal allocations
  to shut down for the given job ID. Upon successful deregistration,
  an interactive monitor session will start to display log lines as
  the job unwinds its allocations and completes shutting down. It
  is safe to exit the monitor early using ctrl+c.

General Options:

  ` + generalOptionsUsage() + `

Stop Options:

  -detach
    Return immediately instead of entering monitor mode. After the
    deregister command is submitted, a new evaluation ID is printed to the
    screen, which can be used to examine the evaluation using the eval-status
    command.

  -purge
    Purge is used to stop the job and purge it from the system. If not set, the
    job will still be queryable and will be purged by the garbage collector.

  -yes
    Automatic yes to prompts.

  -verbose
    Display full information.
`
	return strings.TrimSpace(helpText)
}

func (c *StopCommand) Synopsis() string {
	return "Stop a running job"
}

func (c *StopCommand) AutocompleteFlags() complete.Flags {
	return mergeAutocompleteFlags(c.Meta.AutocompleteFlags(FlagSetClient),
		complete.Flags{
			"-detach":  complete.PredictNothing,
			"-purge":   complete.PredictNothing,
			"-yes":     complete.PredictNothing,
			"-verbose": complete.PredictNothing,
		})
}

func (c *StopCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictFunc(func(a complete.Args) []string {
		client, err := c.Meta.Client()
		if err != nil {
			return nil
		}

		resp, _, err := client.Search().PrefixSearch(a.Last, contexts.Jobs, nil)
		if err != nil {
			return []string{}
		}
		return resp.Matches[contexts.Jobs]
	})
}

func (c *StopCommand) Run(args []string) int {
	var detach, purge, verbose, autoYes bool

	flags := c.Meta.FlagSet("stop", FlagSetClient)
	flags.Usage = func() { c.Ui.Output(c.Help()) }
	flags.BoolVar(&detach, "detach", false, "")
	flags.BoolVar(&verbose, "verbose", false, "")
	flags.BoolVar(&autoYes, "yes", false, "")
	flags.BoolVar(&purge, "purge", false, "")

	if err := flags.Parse(args); err != nil {
		return 1
	}

	// Truncate the id unless full length is requested
	length := shortId
	if verbose {
		length = fullId
	}

	// Check that we got exactly one job
	args = flags.Args()
	if len(args) != 1 {
		c.Ui.Error(c.Help())
		return 1
	}
	jobID := args[0]

	// Get the HTTP client
	client, err := c.Meta.Client()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error initializing client: %s", err))
		return 1
	}

	// Check if the job exists
	jobs, _, err := client.Jobs().PrefixList(jobID)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error deregistering job: %s", err))
		return 1
	}
	if len(jobs) == 0 {
		c.Ui.Error(fmt.Sprintf("No job(s) with prefix or id %q found", jobID))
		return 1
	}
	if len(jobs) > 1 && strings.TrimSpace(jobID) != jobs[0].ID {
		c.Ui.Error(fmt.Sprintf("Prefix matched multiple jobs\n\n%s", createStatusListOutput(jobs)))
		return 1
	}
	// Prefix lookup matched a single job
	job, _, err := client.Jobs().Info(jobs[0].ID, nil)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error deregistering job: %s", err))
		return 1
	}

	// Confirm the stop if the job was a prefix match.
	if jobID != *job.ID && !autoYes {
		question := fmt.Sprintf("Are you sure you want to stop job %q? [y/N]", *job.ID)
		answer, err := c.Ui.Ask(question)
		if err != nil {
			c.Ui.Error(fmt.Sprintf("Failed to parse answer: %v", err))
			return 1
		}

		if answer == "" || strings.ToLower(answer)[0] == 'n' {
			// No case
			c.Ui.Output("Cancelling job stop")
			return 0
		} else if strings.ToLower(answer)[0] == 'y' && len(answer) > 1 {
			// Non exact match yes
			c.Ui.Output("For confirmation, an exact ‘y’ is required.")
			return 0
		} else if answer != "y" {
			c.Ui.Output("No confirmation detected. For confirmation, an exact 'y' is required.")
			return 1
		}
	}

	// Invoke the stop
	evalID, _, err := client.Jobs().Deregister(*job.ID, purge, nil)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error deregistering job: %s", err))
		return 1
	}

	// If we are stopping a periodic job there won't be an evalID.
	if evalID == "" {
		return 0
	}

	if detach {
		c.Ui.Output(evalID)
		return 0
	}

	// Start monitoring the stop eval
	mon := newMonitor(c.Ui, client, length)
	return mon.monitor(evalID, false)
}