package engine

import "gitea.maximumdirect.net/eric/ConfigKit/internal/document"

func appendInheritanceExplanation(explanation *Explanation, working **document.Node, query Path, operations []inheritanceOperation, secrets map[string]bool) {
	for _, operation := range operations {
		changes := projectedInheritanceChanges(query, operation)
		if operation.control != nil {
			if !pathsIntersect(operation.control.path, query) {
				continue
			}
			before := valueSnapshot(*working, query, secrets)
			replaceHistoryPath(working, operation.control.path, nil)
			after := valueSnapshot(*working, query, secrets)
			if len(changes) != 0 {
				explanation.History = append(explanation.History, ValueChange{
					Before: before, After: after, Origin: cloneOrigin(changes[0].Origin),
					Dependencies: clonePaths(changes[0].Dependencies),
				})
			}
			continue
		}
		if operation.transfer == nil {
			continue
		}
		before := valueSnapshot(*working, query, secrets)
		replaceHistoryPath(working, operation.transfer.to, operation.parent)
		// A record keeps its own identity throughout inheritance. Restore it
		// before taking enclosing snapshots as well as direct field snapshots.
		for _, field := range operation.identityFields {
			identity, _ := documentAtPath(operation.effective, Keys(field))
			replaceHistoryPath(working, operation.transfer.to.Key(field), identity)
		}
		afterParent := valueSnapshot(*working, query, secrets)
		parent, parentPresent := transferredOperationOrigin(operation, operationPathForQuery(operation.transfer.to, query))
		if pathsIntersect(operation.transfer.to, query) && parentPresent {
			parent.Operation = ChangeInheritance
			parent.Inheritance = projectInheritanceSteps(parent)
			explanation.History = append(explanation.History, ValueChange{
				Before: before, After: afterParent, Origin: parent,
				Dependencies: []Path{operation.transfer.from.clone(), operation.transfer.reference.clone()},
			})
		}
		replaceHistoryPath(working, operation.transfer.to, operation.effective)
		if !pathsIntersect(operation.transfer.to, query) {
			continue
		}
		afterChild := valueSnapshot(*working, query, secrets)
		if len(changes) != 0 {
			last := changes[len(changes)-1]
			if !parentPresent || len(changes) > 1 {
				explanation.History = append(explanation.History, ValueChange{
					Before: afterParent, After: afterChild, Origin: cloneOrigin(last.Origin),
					Dependencies: clonePaths(last.Dependencies),
				})
			}
		}
	}
}

func operationPathForQuery(root, query Path) Path {
	if pathContains(query, root) {
		return root
	}
	return query
}