const { join } = require('path');
const t = require('@babel/types');
const { assert } = require('console');


module.exports = (babel) => {
    return {
        visitor: {
            FunctionDeclaration(path, state) {
                const { cwd } = state;
                const { node } = path;
                if (t.isIdentifier(node.id) && node.id.name === 'oakGetPackageJsonVersion') {
                    const { body } = node;
                    assert(t.isBlockStatement(body));
                    assert(body.body.length === 1);

                    const pkgJson = join(cwd, 'package.json');
                    const { version } = require(pkgJson);

                    body.body = [
                        t.returnStatement(t.stringLiteral(version))
                    ];
                }
            },
        },
    };
};