package mongo

import (
	"errors"
	"strings"

	mongodriver "go.mongodb.org/mongo-driver/v2/mongo"
)

// IsDuplicateKeyError reports whether err is a MongoDB E11000 duplicate key error.
func IsDuplicateKeyError(err error) bool {
	if err == nil {
		return false
	}
	if strings.Contains(err.Error(), "E11000") || strings.Contains(err.Error(), "duplicate key") {
		return true
	}
	var we mongodriver.WriteException
	if errors.As(err, &we) {
		for _, wErr := range we.WriteErrors {
			if wErr.Code == 11000 {
				return true
			}
		}
	}
	return false
}

// DuplicateKeyMatchesField reports whether a duplicate key error involves the given field
// (e.g. "phone" matches index phone_idx or dup key { phone: "..." }).
func DuplicateKeyMatchesField(err error, field string) bool {
	if err == nil || field == "" {
		return false
	}
	msg := strings.ToLower(err.Error())
	field = strings.ToLower(field)
	if strings.Contains(msg, field+"_idx") {
		return true
	}
	if strings.Contains(msg, "dup key") && strings.Contains(msg, field) {
		return true
	}
	return strings.Contains(msg, `"`+field+`"`) || strings.Contains(msg, field+":")
}