package command

import (
	"context"
	"strings"

	"github.com/hashicorp/packer/packer"

	"github.com/posener/complete"
)

type ValidateCommand struct {
	Meta
}

func (c *ValidateCommand) Run(args []string) int {
	ctx, cleanup := handleTermInterrupt(c.Ui)
	defer cleanup()

	cfg, ret := c.ParseArgs(args)
	if ret != 0 {
		return ret
	}

	return c.RunContext(ctx, cfg)
}

func (c *ValidateCommand) ParseArgs(args []string) (*ValidateArgs, int) {
	var cfg ValidateArgs

	flags := c.Meta.FlagSet("validate", FlagSetBuildFilter|FlagSetVars)
	flags.Usage = func() { c.Ui.Say(c.Help()) }
	cfg.AddFlagSets(flags)
	if err := flags.Parse(args); err != nil {
		return &cfg, 1
	}

	args = flags.Args()
	if len(args) != 1 {
		flags.Usage()
		return &cfg, 1
	}
	cfg.Path = args[0]
	return &cfg, 0
}

func (c *ValidateCommand) RunContext(ctx context.Context, cla *ValidateArgs) int {
	packerStarter, ret := c.GetConfig(&cla.MetaArgs)
	if ret != 0 {
		return 1
	}

	// If we're only checking syntax, then we're done already
	if cla.SyntaxOnly {
		c.Ui.Say("Syntax-only check passed. Everything looks okay.")
		return 0
	}

	diags := packerStarter.Initialize(packer.InitializeOptions{
		SkipDatasourcesExecution: true,
	})
	ret = writeDiags(c.Ui, nil, diags)
	if ret != 0 {
		return ret
	}

	_, diags = packerStarter.GetBuilds(packer.GetBuildsOptions{
		Only:   cla.Only,
		Except: cla.Except,
	})

	fixerDiags := packerStarter.FixConfig(packer.FixConfigOptions{
		Mode: packer.Diff,
	})
	diags = append(diags, fixerDiags...)

	return writeDiags(c.Ui, nil, diags)
}

func (*ValidateCommand) Help() string {
	helpText := `
Usage: packer validate [options] TEMPLATE

  Checks the template is valid by parsing the template and also
  checking the configuration with the various builders, provisioners, etc.

  If it is not valid, the errors will be shown and the command will exit
  with a non-zero exit status. If it is valid, it will exit with a zero
  exit status.

Options:

  -syntax-only           Only check syntax. Do not verify config of the template.
  -except=foo,bar,baz    Validate all builds other than these.
  -machine-readable      Produce machine-readable output.
  -only=foo,bar,baz      Validate only these builds.
  -var 'key=value'       Variable for templates, can be used multiple times.
  -var-file=path         JSON or HCL2 file containing user variables.
`

	return strings.TrimSpace(helpText)
}

func (*ValidateCommand) Synopsis() string {
	return "check that a template is valid"
}

func (*ValidateCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictNothing
}

func (*ValidateCommand) AutocompleteFlags() complete.Flags {
	return complete.Flags{
		"-syntax-only":      complete.PredictNothing,
		"-except":           complete.PredictNothing,
		"-only":             complete.PredictNothing,
		"-var":              complete.PredictNothing,
		"-machine-readable": complete.PredictNothing,
		"-var-file":         complete.PredictNothing,
	}
}