// appendArchives collects all matching Juju GUI archive metadata information.
func appendArchives(
	source simplestreams.DataSource,
	matchingItems []interface{},
	items map[string]interface{},
	cons simplestreams.LookupConstraint,
) ([]interface{}, error) {
	var majorVersion int
	if guiConstraint, ok := cons.(*constraint); ok {
		majorVersion = guiConstraint.majorVersion
	}
	for _, item := range items {
		meta := item.(*Metadata)
		if majorVersion != 0 && majorVersion != meta.JujuMajorVersion {
			continue
		}
		fullPath, err := source.URL(meta.Path)
		if err != nil {
			return nil, errors.Annotate(err, "cannot retrieve metadata full path")
		}
		meta.FullPath = fullPath
		vers, err := version.Parse(meta.StringVersion)
		if err != nil {
			return nil, errors.Annotate(err, "cannot parse metadata version")
		}
		meta.Version = vers
		meta.Source = source
		matchingItems = append(matchingItems, meta)
	}
	return matchingItems, nil
}

func assertSourceContents(c *gc.C, source simplestreams.DataSource, filename string, content []byte) {
	rc, _, err := source.Fetch(filename)
	c.Assert(err, gc.IsNil)
	defer rc.Close()
	retrieved, err := ioutil.ReadAll(rc)
	c.Assert(err, gc.IsNil)
	c.Assert(retrieved, gc.DeepEquals, content)
}

func appendMatchingFunc(source simplestreams.DataSource, matchingImages []interface{},
	images map[string]interface{}, cons simplestreams.LookupConstraint) ([]interface{}, error) {

	for _, val := range images {
		file := val.(*OvaFileMetadata)
		if file.FileType == "ova" {
			//ignore error for url data source
			url, _ := source.URL(file.Path)
			file.Url = url
			matchingImages = append(matchingImages, file)
		}
	}
	return matchingImages, nil
}

// appendMatchingTools updates matchingTools with tools metadata records from tools which belong to the
// specified series. If a tools record already exists in matchingTools, it is not overwritten.
func appendMatchingTools(source simplestreams.DataSource, matchingTools []interface{},
	tools map[string]interface{}, cons simplestreams.LookupConstraint) ([]interface{}, error) {

	toolsMap := make(map[version.Binary]*ToolsMetadata, len(matchingTools))
	for _, val := range matchingTools {
		tm := val.(*ToolsMetadata)
		binary, err := tm.binary()
		if err != nil {
			return nil, errors.Trace(err)
		}
		toolsMap[binary] = tm
	}
	for _, val := range tools {
		tm := val.(*ToolsMetadata)
		if !set.NewStrings(cons.Params().Series...).Contains(tm.Release) {
			continue
		}
		if toolsConstraint, ok := cons.(*ToolsConstraint); ok {
			tmNumber := version.MustParse(tm.Version)
			if toolsConstraint.Version == version.Zero {
				if toolsConstraint.MajorVersion >= 0 && toolsConstraint.MajorVersion != tmNumber.Major {
					continue
				}
				if toolsConstraint.MinorVersion >= 0 && toolsConstraint.MinorVersion != tmNumber.Minor {
					continue
				}
			} else {
				if toolsConstraint.Version != tmNumber {
					continue
				}
			}
		}
		binary, err := tm.binary()
		if err != nil {
			return nil, errors.Trace(err)
		}
		if _, ok := toolsMap[binary]; !ok {
			tm.FullPath, _ = source.URL(tm.Path)
			matchingTools = append(matchingTools, tm)
		}
	}
	return matchingTools, nil
}

// storeImageMetadataFromFiles puts image metadata found in sources into state.
func storeImageMetadataFromFiles(st *state.State, env environs.Environ, source simplestreams.DataSource) error {
	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	if inst, ok := env.(simplestreams.HasRegion); ok {
		// If we can determine current region,
		// we want only metadata specific to this region.
		cloud, err := inst.Region()
		if err != nil {
			return err
		}
		imageConstraint.CloudSpec = cloud
	}

	existingMetadata, info, err := imagemetadata.Fetch([]simplestreams.DataSource{source}, imageConstraint)
	if err != nil && !errors.IsNotFound(err) {
		return errors.Annotate(err, "cannot read image metadata")
	}
	return storeImageMetadataInState(st, info.Source, source.Priority(), existingMetadata)
}