package oauth

import (
	"encoding/json"
	"fmt"
	"strings"
)

//go:generate stringer -type=Provider
type Provider int

const (
	Unknown Provider = iota
	Credentials
	Google
	GitHub
	Linkedin
	Mock
)

// UnmarshalJSON implements json.Unmarshaler so Provider accepts string in JSON (e.g. "mock", "google")
func (p *Provider) UnmarshalJSON(data []byte) error {
	var s string
	if err := json.Unmarshal(data, &s); err != nil {
		return err
	}
	parsed, err := ParseProvider(s)
	if err != nil {
		return err
	}
	*p = parsed
	return nil
}

// ParseProvider parses a provider string and returns the corresponding Provider enum
func ParseProvider(provider string) (Provider, error) {
	switch strings.ToLower(provider) {
	case "credentials":
		return Credentials, nil
	case "google":
		return Google, nil
	case "github":
		return GitHub, nil
	case "linkedin":
		return Linkedin, nil
	case "mock":
		return Mock, nil
	default:
		return Unknown, fmt.Errorf("unknown provider: %s", provider)
	}
}