import * as tsm from 'ts-morph';

export function isGlobalDeclaration({
    declaration,
}: {
    declaration:
        | tsm.VariableDeclaration
        | tsm.FunctionDeclaration
        | tsm.ModuleDeclaration;
}): boolean {
    const isGlobalVariable =
        tsm.Node.isVariableDeclaration(declaration) &&
        declaration.getVariableStatementOrThrow().isAmbient() &&
        !declaration.isExported();

    const isGlobalFunction =
        tsm.Node.isFunctionDeclaration(declaration) &&
        declaration.isAmbient() &&
        declaration.getName() !== undefined &&
        !declaration.isExported();

    const isGlobalNamespace =
        tsm.Node.isModuleDeclaration(declaration) &&
        declaration.isAmbient() &&
        !declaration.isExported() &&
        !declaration.hasModuleKeyword();

    return isGlobalVariable || isGlobalFunction || isGlobalNamespace;
}