var UNKNOWN_FUNCTION = '<unknown>';

var StackTraceParser = {
  /**
   * This parses the different stack traces and puts them into one format
   * This borrows heavily from TraceKit (https://github.com/occ/TraceKit)
   */
  parse: function(stackString) {
    var chrome = /^\s*at (?:(?:(?:Anonymous function)?|((?:\[object object\])?\S+(?: \[as \S+\])?)) )?\(?((?:file|http|https):.*?):(\d+)(?::(\d+))?\)?\s*$/i,
        gecko = /^(?:\s*([^@]*)(?:\((.*?)\))?@)?(\S.*?):(\d+)(?::(\d+))?\s*$/i,
        node  = /^\s*at (?:((?:\[object object\])?\S+(?: \[as \S+\])?) )?\(?(.*?):(\d+)(?::(\d+))?\)?\s*$/i,
        lines = stackString.split('\n'),
        stack = [],
        parts,
        element;

    for (var i = 0, j = lines.length; i < j; ++i) {
        if ((parts = gecko.exec(lines[i]))) {
            element = {
                'file': parts[3],
                'methodName': parts[1] || UNKNOWN_FUNCTION,
                'lineNumber': +parts[4],
                'column': parts[5] ? +parts[5] : null
            };
        } else if ((parts = chrome.exec(lines[i]))) {
            element = {
                'file': parts[2],
                'methodName': parts[1] || UNKNOWN_FUNCTION,
                'lineNumber': +parts[3],
                'column': parts[4] ? +parts[4] : null
            };
        } else if ((parts = node.exec(lines[i]))) {
            element = {
                'file': parts[2],
                'methodName': parts[1] || UNKNOWN_FUNCTION,
                'lineNumber': +parts[3],
                'column': parts[4] ? +parts[4] : null
            };
        } else {
            continue;
        }

        stack.push(element);
    }

    return stack;
  }
};


module.exports = StackTraceParser;