package command

import (
	"bytes"
	"encoding/gob"
	"fmt"
	"strings"

	"github.com/hashicorp/nomad/api"
	"github.com/hashicorp/nomad/jobspec"
	"github.com/hashicorp/nomad/nomad/structs"
)

type RunCommand struct {
	Meta
}

func (c *RunCommand) Help() string {
	helpText := `
Usage: nomad run [options] <file>

  Starts running a new job using the definition located at <file>.
  This is the main command used to invoke new work in Nomad.

General Options:

  ` + generalOptionsUsage()
	return strings.TrimSpace(helpText)
}

func (c *RunCommand) Synopsis() string {
	return "Run a new job"
}

func (c *RunCommand) Run(args []string) int {
	flags := c.Meta.FlagSet("run", FlagSetClient)
	flags.Usage = func() { c.Ui.Output(c.Help()) }
	if err := flags.Parse(args); err != nil {
		return 1
	}

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

	// Parse the job file
	job, err := jobspec.ParseFile(file)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error parsing job file %s: %s", file, err))
		return 1
	}

	// Convert it to something we can use
	apiJob, err := convertJob(job)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error converting job: %s", err))
		return 1
	}

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

	// Submit the job
	evalID, _, err := client.Jobs().Register(apiJob, nil)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error submitting job: %s", err))
		return 1
	}

	c.Ui.Info("Job registered successfully!\n")
	c.Ui.Info("JobID  = " + job.ID)
	c.Ui.Info("EvalID = " + evalID)
	return 0
}

// convertJob is used to take a *structs.Job and convert it to an *api.Job.
// This function is just a hammer and probably needs to be revisited.
func convertJob(in *structs.Job) (*api.Job, error) {
	var apiJob *api.Job
	buf := new(bytes.Buffer)
	if err := gob.NewEncoder(buf).Encode(in); err != nil {
		return nil, err
	}
	if err := gob.NewDecoder(buf).Decode(&apiJob); err != nil {
		return nil, err
	}
	return apiJob, nil
}