'use strict';
/* This is modified from remix-lib/astWalker.js to use the newer solc AST format
*/

/**
 * Crawl the given AST through the function walk(ast, callback)
 */
function AstWalker () {
}

/**
 * visit all the AST nodes
 *
 * @param {Object} ast  - AST node
 * @param {Object or Function} callback  - if (Function) the function will be called for every node.
 *                                       - if (Object) callback[<Node Type>] will be called for
 *                                         every node of type <Node Type>. callback["*"] will be called fo all other nodes.
 *                                         in each case, if the callback returns false it does not descend into children.
 *                                         If no callback for the current type, children are visited.
 */
AstWalker.prototype.walk = function (ast, callback) {
    if (callback instanceof Function) {
        callback = {'*': callback};
    }
    if (!('*' in callback)) {
        callback['*'] = function () { return true; };
    }
    if (manageCallBack(ast, callback) && ast.nodes && ast.nodes.length > 0) {
        for (const child of ast.nodes) {
            this.walk(child, callback);
        }
    }
};

/**
 * walk the given @astList
 *
 * @param {Object} sourcesList - sources list (containing root AST node)
 * @param {Function} - callback used by AstWalker to compute response
 */
AstWalker.prototype.walkAstList = function (sourcesList, callback) {
    const walker = new AstWalker();
    for (const source of sourcesList) {
        walker.walk(source.ast, callback);
    }
};

function manageCallBack (node, callback) {
    if (node.nodeType in callback) {
        return callback[node.nodeType](node);
    } else {
        return callback['*'](node);
    }
}

module.exports = AstWalker;