package command

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"

	"github.com/hashicorp/atlas-go/archive"
	"github.com/hashicorp/atlas-go/v1"
)

type PushCommand struct {
	Meta

	// client is the client to use for the actual push operations.
	// If this isn't set, then the Atlas client is used. This should
	// really only be set for testing reasons (and is hence not exported).
	client pushClient
}

func (c *PushCommand) Run(args []string) int {
	var atlasAddress, atlasToken string
	var archiveVCS, moduleUpload bool
	var name string
	args = c.Meta.process(args, true)
	cmdFlags := c.Meta.flagSet("push")
	cmdFlags.StringVar(&atlasAddress, "atlas-address", "", "")
	cmdFlags.StringVar(&c.Meta.statePath, "state", DefaultStateFilename, "path")
	cmdFlags.StringVar(&atlasToken, "token", "", "")
	cmdFlags.BoolVar(&moduleUpload, "upload-modules", true, "")
	cmdFlags.StringVar(&name, "name", "", "")
	cmdFlags.BoolVar(&archiveVCS, "vcs", true, "")
	cmdFlags.Usage = func() { c.Ui.Error(c.Help()) }
	if err := cmdFlags.Parse(args); err != nil {
		return 1
	}

	// The pwd is used for the configuration path if one is not given
	pwd, err := os.Getwd()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error getting pwd: %s", err))
		return 1
	}

	// Get the path to the configuration depending on the args.
	var configPath string
	args = cmdFlags.Args()
	if len(args) > 1 {
		c.Ui.Error("The apply command expects at most one argument.")
		cmdFlags.Usage()
		return 1
	} else if len(args) == 1 {
		configPath = args[0]
	} else {
		configPath = pwd
	}

	// Verify the state is remote, we can't push without a remote state
	s, err := c.State()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Failed to read state: %s", err))
		return 1
	}
	if !s.State().IsRemote() {
		c.Ui.Error(
			"Remote state is not enabled. For Atlas to run Terraform\n" +
				"for you, remote state must be used and configured. Remote\n" +
				"state via any backend is accepted, not just Atlas. To\n" +
				"configure remote state, use the `terraform remote config`\n" +
				"command.")
		return 1
	}

	// Build the context based on the arguments given
	ctx, planned, err := c.Context(contextOpts{
		Path:      configPath,
		StatePath: c.Meta.statePath,
	})
	if err != nil {
		c.Ui.Error(err.Error())
		return 1
	}
	if planned {
		c.Ui.Error(
			"A plan file cannot be given as the path to the configuration.\n" +
				"A path to a module (directory with configuration) must be given.")
		return 1
	}

	// Get the configuration
	config := ctx.Module().Config()
	if name == "" {
		if config.Atlas == nil || config.Atlas.Name == "" {
			c.Ui.Error(
				"The name of this Terraform configuration in Atlas must be\n" +
					"specified within your configuration or the command-line. To\n" +
					"set it on the command-line, use the `-name` parameter.")
			return 1
		}
		name = config.Atlas.Name
	}

	// Initialize the client if it isn't given.
	if c.client == nil {
		// Make sure to nil out our client so our token isn't sitting around
		defer func() { c.client = nil }()

		// Initialize it to the default client, we set custom settings later
		client := atlas.DefaultClient()
		if atlasAddress != "" {
			client, err = atlas.NewClient(atlasAddress)
			if err != nil {
				c.Ui.Error(fmt.Sprintf("Error initializing Atlas client: %s", err))
				return 1
			}
		}

		if atlasToken != "" {
			client.Token = atlasToken
		}

		c.client = &atlasPushClient{Client: client}
	}

	// Get the variables we might already have
	vars, err := c.client.Get(name)
	if err != nil {
		c.Ui.Error(fmt.Sprintf(
			"Error looking up previously pushed configuration: %s", err))
		return 1
	}
	for k, v := range vars {
		// Local variables override remote ones
		if _, exists := ctx.Variables()[k]; exists {
			continue
		}
		ctx.SetVariable(k, v)
	}

	// Ask for input
	if err := ctx.Input(c.InputMode()); err != nil {
		c.Ui.Error(fmt.Sprintf(
			"Error while asking for variable input:\n\n%s", err))
		return 1
	}

	// Build the archiving options, which includes everything it can
	// by default according to VCS rules but forcing the data directory.
	archiveOpts := &archive.ArchiveOpts{
		VCS: archiveVCS,
		Extra: map[string]string{
			DefaultDataDir: c.DataDir(),
		},
	}
	if !moduleUpload {
		// If we're not uploading modules, then exclude the modules dir.
		archiveOpts.Exclude = append(
			archiveOpts.Exclude,
			filepath.Join(c.DataDir(), "modules"))
	}

	archiveR, err := archive.CreateArchive(configPath, archiveOpts)
	if err != nil {
		c.Ui.Error(fmt.Sprintf(
			"An error has occurred while archiving the module for uploading:\n"+
				"%s", err))
		return 1
	}

	// Upsert!
	opts := &pushUpsertOptions{
		Name:      name,
		Archive:   archiveR,
		Variables: ctx.Variables(),
	}
	vsn, err := c.client.Upsert(opts)
	if err != nil {
		c.Ui.Error(fmt.Sprintf(
			"An error occurred while uploading the module:\n\n%s", err))
		return 1
	}

	c.Ui.Output(c.Colorize().Color(fmt.Sprintf(
		"[reset][bold][green]Configuration %q uploaded! (v%d)",
		name, vsn)))
	return 0
}

func (c *PushCommand) Help() string {
	helpText := `
Usage: terraform push [options] [DIR]

  Upload this Terraform module to an Atlas server for remote
  infrastructure management.

Options:

  -atlas-address=<url> An alternate address to an Atlas instance. Defaults
                       to https://atlas.hashicorp.com

  -upload-modules=true If true (default), then the modules are locked at
                       their current checkout and uploaded completely. This
                       prevents Atlas from running "terraform get".

  -name=<name>         Name of the configuration in Atlas. This can also
                       be set in the configuration itself. Format is
                       typically: "username/name".

  -token=<token>       Access token to use to upload. If blank or unspecified,
                       the ATLAS_TOKEN environmental variable will be used.

  -vcs=true            If true (default), push will upload only files
                       comitted to your VCS, if detected.

`
	return strings.TrimSpace(helpText)
}

func (c *PushCommand) Synopsis() string {
	return "Upload this Terraform module to Atlas to run"
}

// pushClient is implementd internally to control where pushes go. This is
// either to Atlas or a mock for testing.
type pushClient interface {
	Get(string) (map[string]string, error)
	Upsert(*pushUpsertOptions) (int, error)
}

type pushUpsertOptions struct {
	Name      string
	Archive   *archive.Archive
	Variables map[string]string
}

type atlasPushClient struct {
	Client *atlas.Client
}

func (c *atlasPushClient) Get(name string) (map[string]string, error) {
	user, name, err := atlas.ParseSlug(name)
	if err != nil {
		return nil, err
	}

	version, err := c.Client.TerraformConfigLatest(user, name)
	if err != nil {
		return nil, err
	}

	var variables map[string]string
	if version != nil {
		variables = version.Variables
	}

	return variables, nil
}

func (c *atlasPushClient) Upsert(opts *pushUpsertOptions) (int, error) {
	user, name, err := atlas.ParseSlug(opts.Name)
	if err != nil {
		return 0, err
	}

	data := &atlas.TerraformConfigVersion{
		Variables: opts.Variables,
	}

	version, err := c.Client.CreateTerraformConfigVersion(
		user, name, data, opts.Archive, opts.Archive.Size)
	if err != nil {
		return 0, err
	}

	return version, nil
}

type mockPushClient struct {
	File string

	GetCalled bool
	GetName   string
	GetResult map[string]string
	GetError  error

	UpsertCalled  bool
	UpsertOptions *pushUpsertOptions
	UpsertVersion int
	UpsertError   error
}

func (c *mockPushClient) Get(name string) (map[string]string, error) {
	c.GetCalled = true
	c.GetName = name
	return c.GetResult, c.GetError
}

func (c *mockPushClient) Upsert(opts *pushUpsertOptions) (int, error) {
	f, err := os.Create(c.File)
	if err != nil {
		return 0, err
	}
	defer f.Close()

	data := opts.Archive
	size := opts.Archive.Size
	if _, err := io.CopyN(f, data, size); err != nil {
		return 0, err
	}

	c.UpsertCalled = true
	c.UpsertOptions = opts
	return c.UpsertVersion, c.UpsertError
}