import { types, NodePath } from '@babel/core';

export function ensureImport(t: typeof types, program: NodePath<types.Node>, importSpecifier: string, importSource: string)
export function ensureImport(t, program, importSpecifier, importSource) {
    // check to see if we've already added the real import line to this file
    const foundImport =
        program.get("body").filter((x) => {
            if (t.isImportDeclaration(x) && x.node.source.value === importSource) {
                return (
                    x.node.specifiers.filter(
                        (s) => s.local.name === importSpecifier
                    ).length > 0
                )
            }
            return false
        }).length > 0

    // if not, add it, i.e.:
    // import { importSpecifier } from importSource
    if (!foundImport) {
        program.unshiftContainer(
            "body",
            t.importDeclaration(
                [
                    t.importSpecifier(
                        t.identifier(importSpecifier),
                        t.identifier(importSpecifier)
                    )
                ],
                t.stringLiteral(importSource)
            )
        )
    }
}