payments/internal/models/config.go

package models

import (
	"encoding/json"
	"time"
)

// since the json unmarshaller is case-insensitive this generic interface will be used to receive back the unmarshaled struct from a plugin
// then we can remarshal the payload and enforce the case we expect (eg. clientID vs clientId) rather than blindly trusting the raw user input
type PluginInternalConfig interface{}

// Config is the generic configuration that all connectors share
// Note that the PollingPeriod defined here is often overwritten by the connector-specific configuration
type Config struct {
	Name          string        `json:"name" validate:"required,gte=3,lte=500"`
	PollingPeriod time.Duration `json:"pollingPeriod" validate:"required"`
}

func (c Config) MarshalJSON() ([]byte, error) {
	return json.Marshal(struct {
		Name          string `json:"name"`
		PollingPeriod string `json:"pollingPeriod"`
	}{
		Name:          c.Name,
		PollingPeriod: c.PollingPeriod.String(),
	})
}

func (c *Config) UnmarshalJSON(data []byte) error {
	var raw struct {
		Name          string `json:"name"`
		PollingPeriod string `json:"pollingPeriod"`
	}

	if err := json.Unmarshal(data, &raw); err != nil {
		return err
	}

	var pollingPeriod time.Duration
	if raw.PollingPeriod != "" {
		p, err := time.ParseDuration(raw.PollingPeriod)
		if err != nil {
			return err
		}
		pollingPeriod = p
	}

	c.Name = raw.Name

	if pollingPeriod > 0 {
		c.PollingPeriod = pollingPeriod
	}

	return nil
}