elliotchance/gedcom

package gedcom

// EventNode is a noteworthy happening related to an individual, a group, or an
// organization.
type EventNode struct {
    *SimpleNode
}

// EventNode creates a new EVEN node.
func NewEventNode(value string, children ...Node) *EventNode {
    return &EventNode{
        newSimpleNode(TagEvent, value, "", children...),
    }
}

// Dates returns zero or more dates associated with the event.
//
// When more than one date is returned you should not assume that the order has
// any significance for the importance of the dates.
//
// If the node is nil the result will also be nil.
func (node *EventNode) Dates() DateNodes {
    return Dates(node)
}

// Equal tests if two events are the same.
//
// Two events are considered equal if:
//
// 1. They both contain the same date. If either or both contain more than one
// date only a single date must match both sides.
//
// 2. They both do not have any dates, but all other attributes are the same.
//
// If either node is nil (including both) or if the right side is not a
// EventNode then false is always returned.
func (node *EventNode) Equals(node2 Node) bool {
    if IsNil(node) {
        return false
    }

    if IsNil(node2) {
        return false
    }

    if n2, ok := node2.(*EventNode); ok {
        leftDates := node.Dates()
        rightDates := n2.Dates()

        for _, left := range leftDates {
            for _, right := range rightDates {
                if left.Equals(right) {
                    return true
                }
            }
        }

        if len(leftDates) == 0 && len(rightDates) == 0 && node.Value() == node2.Value() {
            return DeepEqualNodes(node.Nodes(), node2.Nodes())
        }
    }

    return false
}

// Years returns the Years value of the minimum date node in the node.
func (node *EventNode) Years() float64 {
    if min := node.Dates().Minimum(); min != nil {
        return Years(min)
    }

    return 0
}