// addCharmViaAPI calls the appropriate client API calls to add the
// given charm URL to state. Also displays the charm URL of the added
// charm on stdout.
func addCharmViaAPI(client *api.Client, ctx *cmd.Context, curl *charm.URL, repo charm.Repository) (*charm.URL, error) {
	if curl.Revision < 0 {
		latest, err := charm.Latest(repo, curl)
		if err != nil {
			return nil, err
		}
		curl = curl.WithRevision(latest)
	}
	switch curl.Schema {
	case "local":
		ch, err := repo.Get(curl)
		if err != nil {
			return nil, err
		}
		stateCurl, err := client.AddLocalCharm(curl, ch)
		if err != nil {
			return nil, err
		}
		curl = stateCurl
	case "cs":
		err := client.AddCharm(curl)
		if err != nil {
			return nil, err
		}
	default:
		return nil, fmt.Errorf("unsupported charm URL schema: %q", curl.Schema)
	}
	ctx.Infof("Added charm %q to the environment.", curl)
	return curl, nil
}

func getCharmInfo(client *api.Client, charmName string, localRepoPath string, defaultSeries string) (*api.CharmInfo, error) {
	curl, err := resolveCharmURL(client, charmName, defaultSeries)
	if err != nil {
		return nil, err
	}

	repo, err := charm.InferRepository(curl.Reference, localRepoPath)
	if err != nil {
		return nil, err
	}

	//	repo = config.SpecializeCharmRepo(repo, defaultSeries)

	curl, err = addCharmViaAPI(client, curl, repo)
	if err != nil {
		return nil, err
	}

	charmInfo, err := client.CharmInfo(curl.String())
	if err != nil {
		log.Info("Error getting charm info for: %v", curl.String(), err)
		return nil, err
	}
	return charmInfo, nil
}

// resolveCharmURL returns a resolved charm URL, given a charm location string.
// If the series is not resolved, the environment default-series is used, or if
// not set, the series is resolved with the state server.
func resolveCharmURL(client *api.Client, url string, defaultSeries string) (*charm.URL, error) {
	ref, series, err := charm.ParseReference(url)
	if err != nil {
		return nil, err
	}
	// If series is not set, use configured default series
	if series == "" {
		series = defaultSeries
	}
	// Otherwise, look up the best supported series for this charm
	if series == "" {
		return client.ResolveCharm(ref)
	}
	return &charm.URL{Reference: ref, Series: series}, nil
}

func recordMachineInState(
	client *api.Client, machineParams params.AddMachineParams) (machineId string, err error) {
	// Note: we explicitly use AddMachines1dot18 rather than AddMachines to preserve
	// backwards compatibility; we do not require any of the new features of AddMachines
	// here.
	results, err := client.AddMachines1dot18([]params.AddMachineParams{machineParams})
	if err != nil {
		return "", err
	}
	// Currently, only one machine is added, but in future there may be several added in one call.
	machineInfo := results[0]
	if machineInfo.Error != nil {
		return "", machineInfo.Error
	}
	return machineInfo.Machine, nil
}

// initVersions collects state relevant to an upgrade decision. The returned
// agent and client versions, and the list of currently available tools, will
// always be accurate; the chosen version, and the flag indicating development
// mode, may remain blank until uploadTools or validate is called.
func (c *UpgradeJujuCommand) initVersions(client *api.Client, cfg *config.Config) (*upgradeContext, error) {
	agent, ok := cfg.AgentVersion()
	if !ok {
		// Can't happen. In theory.
		return nil, fmt.Errorf("incomplete environment configuration")
	}
	if c.Version == agent {
		return nil, errUpToDate
	}
	clientVersion := version.Current.Number
	findResult, err := client.FindTools(clientVersion.Major, -1, "", "")
	var availableTools coretools.List
	if params.IsCodeNotImplemented(err) {
		availableTools, err = findTools1dot17(cfg)
	} else {
		availableTools = findResult.List
	}
	if err != nil {
		return nil, err
	}
	err = findResult.Error
	if findResult.Error != nil {
		if !params.IsCodeNotFound(err) {
			return nil, err
		}
		if !c.UploadTools {
			// No tools found and we shouldn't upload any, so if we are not asking for a
			// major upgrade, pretend there is no more recent version available.
			if c.Version == version.Zero && agent.Major == clientVersion.Major {
				return nil, errUpToDate
			}
			return nil, err
		}
	}
	return &upgradeContext{
		agent:     agent,
		client:    clientVersion,
		chosen:    c.Version,
		tools:     availableTools,
		apiClient: client,
		config:    cfg,
	}, nil
}

// resolveCharmURL returns a resolved charm URL, given a charm location string.
// If the series is not resolved, the environment default-series is used, or if
// not set, the series is resolved with the state server.
func resolveCharmURL(url string, client *api.Client, conf *config.Config) (*charm.URL, error) {
	ref, series, err := charm.ParseReference(url)
	if err != nil {
		return nil, err
	}
	// If series is not set, use configured default series
	if series == "" {
		if defaultSeries, ok := conf.DefaultSeries(); ok {
			series = defaultSeries
		}
	}
	// Otherwise, look up the best supported series for this charm
	if series == "" {
		if ref.Schema == "local" {
			possibleUrl := &charm.URL{Reference: ref, Series: "precise"}
			logger.Errorf(`The series is not specified in the environment (default-series) or with the charm. Did you mean:
	%s`, possibleUrl.String())
			return nil, fmt.Errorf("cannot resolve series for charm: %q", ref)
		}
		return client.ResolveCharm(ref)
	}
	return &charm.URL{Reference: ref, Series: series}, nil
}

func assertEnvironmentName(c *gc.C, client *api.Client, expectName string) {
	envInfo, err := client.EnvironmentInfo()
	c.Assert(err, gc.IsNil)
	c.Assert(envInfo.Name, gc.Equals, expectName)
}