package cli

import (
	"errors"
	"os"

	"forge.lclr.dev/AI/mcp-framework/secretstore"
)

type KeyLookupFunc func(key string) (string, bool, error)

type ResolveLookupOptions struct {
	Flag   KeyLookupFunc
	Env    KeyLookupFunc
	Config KeyLookupFunc
	Secret KeyLookupFunc
}

func ResolveLookup(options ResolveLookupOptions) LookupFunc {
	return func(source ValueSource, key string) (string, bool, error) {
		switch source {
		case SourceFlag:
			return runKeyLookup(options.Flag, key)
		case SourceEnv:
			return runKeyLookup(options.Env, key)
		case SourceConfig:
			return runKeyLookup(options.Config, key)
		case SourceSecret:
			return runKeyLookup(options.Secret, key)
		case SourceDefault:
			return "", false, nil
		default:
			return "", false, nil
		}
	}
}

func runKeyLookup(lookup KeyLookupFunc, key string) (string, bool, error) {
	if lookup == nil {
		return "", false, nil
	}
	if key == "" {
		return "", false, nil
	}
	return lookup(key)
}

func MapLookup(values map[string]string) KeyLookupFunc {
	return func(key string) (string, bool, error) {
		value, ok := values[key]
		return value, ok, nil
	}
}

func EnvLookup(lookup func(string) (string, bool)) KeyLookupFunc {
	reader := lookup
	if reader == nil {
		reader = os.LookupEnv
	}

	return func(key string) (string, bool, error) {
		value, ok := reader(key)
		return value, ok, nil
	}
}

func ConfigMap(values map[string]string) KeyLookupFunc {
	return MapLookup(values)
}

func SecretStore(store secretstore.Store) KeyLookupFunc {
	if store == nil {
		return nil
	}

	return func(key string) (string, bool, error) {
		value, err := store.GetSecret(key)
		switch {
		case err == nil:
			return value, true, nil
		case errors.Is(err, secretstore.ErrNotFound):
			return "", false, nil
		default:
			return "", false, err
		}
	}
}