// CharmArchiveURL returns the URL, corresponding to the charm archive
// (bundle) in the provider storage for each given charm URL, along
// with the DisableSSLHostnameVerification flag.
func (u *UniterAPI) CharmArchiveURL(args params.CharmURLs) (params.CharmArchiveURLResults, error) {
	result := params.CharmArchiveURLResults{
		Results: make([]params.CharmArchiveURLResult, len(args.URLs)),
	}
	// Get the SSL hostname verification environment setting.
	envConfig, err := u.st.EnvironConfig()
	if err != nil {
		return result, err
	}
	// SSLHostnameVerification defaults to true, so we need to
	// invert that, for backwards-compatibility (older versions
	// will have DisableSSLHostnameVerification: false by default).
	disableSSLHostnameVerification := !envConfig.SSLHostnameVerification()
	for i, arg := range args.URLs {
		curl, err := charm.ParseURL(arg.URL)
		if err != nil {
			err = common.ErrPerm
		} else {
			var sch *state.Charm
			sch, err = u.st.Charm(curl)
			if errors.IsNotFound(err) {
				err = common.ErrPerm
			}
			if err == nil {
				result.Results[i].Result = sch.BundleURL().String()
				result.Results[i].DisableSSLHostnameVerification = disableSSLHostnameVerification
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

// parseSettingsCompatible parses setting strings in a way that is
// compatible with the behavior before this CL based on the issue
// http://pad.lv/1194945. Until then setting an option to an empty
// string caused it to reset to the default value. We now allow
// empty strings as actual values, but we want to preserve the API
// behavior.
func parseSettingsCompatible(ch *state.Charm, settings map[string]string) (charm.Settings, error) {
	setSettings := map[string]string{}
	unsetSettings := charm.Settings{}
	// Split settings into those which set and those which unset a value.
	for name, value := range settings {
		if value == "" {
			unsetSettings[name] = nil
			continue
		}
		setSettings[name] = value
	}
	// Validate the settings.
	changes, err := ch.Config().ParseSettingsStrings(setSettings)
	if err != nil {
		return nil, err
	}
	// Validate the unsettings and merge them into the changes.
	unsetSettings, err = ch.Config().ValidateSettings(unsetSettings)
	if err != nil {
		return nil, err
	}
	for name := range unsetSettings {
		changes[name] = nil
	}
	return changes, nil
}

func assertCustomCharm(c *gc.C, ch *state.Charm, series string, meta *charm.Meta, config *charm.Config, revision int) {
	// Check Charm interface method results.
	c.Assert(ch.Meta(), gc.DeepEquals, meta)
	c.Assert(ch.Config(), gc.DeepEquals, config)
	c.Assert(ch.Revision(), gc.DeepEquals, revision)

	// Test URL matches charm and expected series.
	url := ch.URL()
	c.Assert(url.Series, gc.Equals, series)
	c.Assert(url.Revision, gc.Equals, ch.Revision())

	// Ignore the BundleURL and BundleSHA256 methods, they're irrelevant.
}

func (s *ServiceSuite) TestSetCharmConfig(c *gc.C) {
	charms := map[string]*state.Charm{
		stringConfig:    s.AddConfigCharm(c, "wordpress", stringConfig, 1),
		emptyConfig:     s.AddConfigCharm(c, "wordpress", emptyConfig, 2),
		floatConfig:     s.AddConfigCharm(c, "wordpress", floatConfig, 3),
		newStringConfig: s.AddConfigCharm(c, "wordpress", newStringConfig, 4),
	}

	for i, t := range setCharmConfigTests {
		c.Logf("test %d: %s", i, t.summary)

		origCh := charms[t.startconfig]
		svc := s.AddTestingService(c, "wordpress", origCh)
		err := svc.UpdateConfigSettings(t.startvalues)
		c.Assert(err, gc.IsNil)

		newCh := charms[t.endconfig]
		err = svc.SetCharm(newCh, false)
		var expectVals charm.Settings
		var expectCh *state.Charm
		if t.err != "" {
			c.Assert(err, gc.ErrorMatches, t.err)
			expectCh = origCh
			expectVals = t.startvalues
		} else {
			c.Assert(err, gc.IsNil)
			expectCh = newCh
			expectVals = t.endvalues
		}

		sch, _, err := svc.Charm()
		c.Assert(err, gc.IsNil)
		c.Assert(sch.URL(), gc.DeepEquals, expectCh.URL())
		settings, err := svc.ConfigSettings()
		c.Assert(err, gc.IsNil)
		if len(expectVals) == 0 {
			c.Assert(settings, gc.HasLen, 0)
		} else {
			c.Assert(settings, gc.DeepEquals, expectVals)
		}

		err = svc.Destroy()
		c.Assert(err, gc.IsNil)
	}
}

// CharmArchiveSha256 returns the SHA256 digest of the charm archive
// (bundle) data for each charm url in the given parameters.
func (u *UniterAPIV3) CharmArchiveSha256(args params.CharmURLs) (params.StringResults, error) {
	result := params.StringResults{
		Results: make([]params.StringResult, len(args.URLs)),
	}
	for i, arg := range args.URLs {
		curl, err := charm.ParseURL(arg.URL)
		if err != nil {
			err = common.ErrPerm
		} else {
			var sch *state.Charm
			sch, err = u.st.Charm(curl)
			if errors.IsNotFound(err) {
				err = common.ErrPerm
			}
			if err == nil {
				result.Results[i].Result = sch.BundleSha256()
			}
		}
		result.Results[i].Error = common.ServerError(err)
	}
	return result, nil
}

func assertStandardCharm(c *gc.C, ch *state.Charm, series string) {
	chd := testcharms.Repo.CharmDir(ch.Meta().Name)
	assertCustomCharm(c, ch, series, chd.Meta(), chd.Config(), chd.Metrics(), chd.Revision())
}