package main

import (
	"fmt"
	"reflect"
)

func printStructTags(f reflect.Value) {
	for i := 0; i < f.NumField(); i++ {
		field := f.Type().Field(i)
		tag := field.Tag
		fmt.Printf("Field: %v.\nEnvironment variable: %v.\n", field.Name, tag.Get("env"))
	}
}

func setField(obj interface{}, name string, value interface{}) error {
	v := reflect.ValueOf(obj)

	if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
		return fmt.Errorf("expected pointer to a struct")
	}

	v = v.Elem()
	field := v.FieldByName(name)

	if !field.IsValid() {
		return fmt.Errorf("no such field: %s", name)
	}
	if !field.CanSet() {
		return fmt.Errorf("cannot set field: %s", name)
	}

	val := reflect.ValueOf(value)

	if field.Type() != val.Type() {
		return fmt.Errorf("provided value type (%s) doesn't match field type (%s)", val.Type(), field.Type())
	}

	field.Set(val)
	return nil
}