model

type BuildableConfig interface {
	ReaderWriter
	Setup
	Compound
}

type Compound interface {
	UnmarshalKey(key string, rawVal interface{}, opts ...func(*mapstructure.DecoderConfig)) error

	ReadInConfig() error
	ReadConfig(in io.Reader) error
	MergeConfig(in io.Reader) error
	MergeFleetPolicy(configPath string) error

	// Revert a finished configuration so that more can be build on top of it.
	// When building is completed, the caller should call BuildSchema.
	// NOTE: This method should not be used by any new callsites, it is needed
	// currently because of the unique requirements of OTel's configuration.
	RevertFinishedBackToBuilder() BuildableConfig
}

type Config interface {
	ReaderWriter
	Compound
	// TODO: This method shouldn't be here, but it is depended upon by an external repository
	// https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/e7c3295769637e61558c6892be732398840dd5f5/pkg/datadog/agentcomponents/agentcomponents.go#L166
	SetKnown(key string)
}

type NotificationReceiver func(setting string, source Source, oldValue, newValue any, sequenceID uint64)

type Proxy struct {
	HTTP    string   `mapstructure:"http"`
	HTTPS   string   `mapstructure:"https"`
	NoProxy []string `mapstructure:"no_proxy"`
}

type Reader interface {
	Get(key string) interface{}
	GetString(key string) string
	GetBool(key string) bool
	GetInt(key string) int
	GetInt32(key string) int32
	GetInt64(key string) int64
	GetFloat64(key string) float64
	GetDuration(key string) time.Duration
	GetStringSlice(key string) []string
	GetFloat64Slice(key string) []float64
	GetStringMap(key string) map[string]interface{}
	GetStringMapString(key string) map[string]string
	GetStringMapStringSlice(key string) map[string][]string
	GetSizeInBytes(key string) uint
	GetProxies() *Proxy
	GetSequenceID() uint64

	GetSource(key string) Source
	GetAllSources(key string) []ValueWithSource
	GetSubfields(key string) []string

	ConfigFileUsed() string
	ExtraConfigFilesUsed() []string

	AllSettings() map[string]interface{}
	AllSettingsWithoutDefault() map[string]interface{}
	AllSettingsBySource() map[Source]interface{}
	// AllKeysLowercased returns all config keys in the config, no matter how they are set.
	// Note that it returns the keys lowercased.
	AllKeysLowercased() []string
	AllSettingsWithSequenceID() (map[string]interface{}, uint64)

	// SetTestOnlyDynamicSchema is used by tests to disable validation of the config schema
	// This lets tests use the config is more flexible ways (can add to the schema at any point,
	// can modify env vars and the config will rebuild itself, etc)
	SetTestOnlyDynamicSchema(allow bool)

	// IsSet return true if a non nil values is found in the configuration, including defaults. This is legacy
	// behavior from viper and don't answer the need to know if something was set by the user (see IsConfigured for
	// this).
	//
	// Deprecated: this method will be removed once all settings have a default, use 'IsConfigured' instead.
	IsSet(key string) bool
	// IsConfigured returns true if a setting exists, has a value and doesn't come from the defaults (ie: was
	// configured by the user). If a setting is configured by the user with the same value than the defaults this
	// method will still return true as it tests the source of a setting not its value.
	IsConfigured(key string) bool

	// UnmarshalKey Unmarshal a configuration key into a struct
	UnmarshalKey(key string, rawVal interface{}, opts ...func(*mapstructure.DecoderConfig)) error

	// IsKnown returns whether this key is known
	IsKnown(key string) bool

	// GetKnownKeysLowercased returns all the keys that meet at least one of these criteria:
	// 1) have a default, 2) have an environment variable binded, 3) are an alias or 4) have been SetKnown()
	// Note that it returns the keys lowercased.
	GetKnownKeysLowercased() map[string]interface{}

	// GetEnvVars returns a list of the env vars that the config supports.
	// These have had the EnvPrefix applied, as well as the EnvKeyReplacer.
	GetEnvVars() []string

	// Warnings returns pointer to a list of warnings (completes config.Component interface)
	Warnings() *Warnings

	// Object returns Reader to config (completes config.Component interface)
	Object() Reader

	// OnUpdate adds a callback to the list receivers to be called each time a value is change in the configuration
	// by a call to the 'Set' method. The configuration will sequentially call each receiver.
	OnUpdate(callback NotificationReceiver)

	// Stringify stringifies the config, only available if "test" build tag is enabled
	Stringify(source Source, opts ...StringifyOption) string
}

type ReaderWriter interface {
	Reader
	Writer
}

type Setup interface {

	// BuildSchema should be called when Setup is done, it builds the schema making the config ready for use
	BuildSchema()

	SetDefault(key string, value interface{})

	SetEnvPrefix(in string)
	BindEnv(key string, envvars ...string)
	SetEnvKeyReplacer(r *strings.Replacer)

	// The following helpers allow a type to be enforce when parsing environment variables. Most of them exists to
	// support historic behavior. Refrain from adding more as it's most likely a sign of poorly design configuration
	// layout.
	ParseEnvAsStringSlice(key string, fx func(string) []string)
	ParseEnvAsMapStringInterface(key string, fx func(string) map[string]interface{})
	ParseEnvAsSliceMapString(key string, fx func(string) []map[string]string)
	ParseEnvAsSlice(key string, fx func(string) []interface{})

	// SetKnown adds a key to the set of known valid config keys
	SetKnown(key string)

	// BindEnvAndSetDefault sets the default value for a config parameter and adds an env binding
	// in one call, used for most config options.
	//
	// If env is provided, it will override the name of the environment variable used for this
	// config key
	BindEnvAndSetDefault(key string, val interface{}, env ...string)

	AddConfigPath(in string)
	AddExtraConfigPaths(in []string) error
	SetConfigName(in string)
	SetConfigFile(in string)
	SetConfigType(in string)
}

type Source string

type StringifyConfig struct {
	DedupPointerAddr bool
	OmitPointerAddr  bool
	SettingFilters   []string
}

type StringifyOption func(*StringifyConfig)

type ValueWithSource struct {
	Source Source
	Value  interface{}
}

type Warnings struct {
	Errors []error
}

type Writer interface {
	Set(key string, value interface{}, source Source)
	SetWithoutSource(key string, value interface{})
	UnsetForSource(key string, source Source)
}