package consumers

import (
	"errors"
	"io/fs"

	configkit "gitea.maximumdirect.net/eric/ConfigKit"
)

// VersionedServiceConfig demonstrates a mounted main input whose source-local
// schema version is retained at the effective service path.
type VersionedServiceConfig struct {
	Service struct {
		Version  string `yaml:"version"`
		Name     string `yaml:"name"`
		Endpoint string `yaml:"endpoint"`
		Metadata struct {
			Release string `yaml:"release"`
		} `yaml:"metadata"`
	} `yaml:"service"`
}

// LoadVersionedService checks the main and underlay declarations with one
// application policy. The local rule path is "version" for each source; the
// main input's destination places its protected value at /service/version.
// Optional CLI overrides are passed through to ConfigKit for normal protection.
func LoadVersionedService(mode configkit.SourceVersionMode, overrides ...configkit.Override) (*configkit.Result[VersionedServiceConfig], error) {
	files, err := fs.Sub(bundledFiles, "testdata/source-version")
	if err != nil {
		return nil, err
	}
	main, err := fs.ReadFile(files, "main.yml")
	if err != nil {
		return nil, err
	}
	underlay, err := fs.ReadFile(files, "underlay.yml")
	if err != nil {
		return nil, err
	}
	definition := configkit.Definition[VersionedServiceConfig]{
		Version: &configkit.VersionRule{
			Path: configkit.Keys("version"),
			Check: func(version configkit.Version, _ *configkit.Validation) error {
				if !version.Present || version.Null || version.Text == "" {
					return errors.New("a nonempty source version is required")
				}
				return nil
			},
		},
		Secret: func(path configkit.Path) bool {
			return path.String() == "/service/version"
		},
	}
	return configkit.LoadLayered(configkit.Input{
		Source: configkit.Bytes("service main", main), Destination: configkit.Keys("service"),
	}, configkit.LayeredOptions[VersionedServiceConfig]{
		Definition:        definition,
		SourceVersionMode: mode,
		Overrides:         overrides,
		Underlays: []configkit.Underlay{{Inputs: []configkit.Input{{
			Source: configkit.Bytes("service defaults", underlay), Destination: configkit.Keys("service"),
		}}}},
	})
}