'use strict';

var traverse = module.exports = function (schema, opts, cb) {

// Legacy support for v0.3.1 and earlier.
if (typeof opts == 'function') {
  cb = opts;
  opts = {};
}

cb = opts.cb || cb;
var pre = (typeof cb == 'function') ? cb : cb.pre || function() {};
var post = cb.post || function() {};

_traverse(opts, pre, post, schema, '', schema);

};

traverse.keywords = {

additionalItems: true,
items: true,
contains: true,
additionalProperties: true,
propertyNames: true,
not: true

};

traverse.arrayKeywords = {

items: true,
allOf: true,
anyOf: true,
oneOf: true

};

traverse.propsKeywords = {

definitions: true,
properties: true,
patternProperties: true,
dependencies: true

};

traverse.skipKeywords = {

default: true,
enum: true,
const: true,
required: true,
maximum: true,
minimum: true,
exclusiveMaximum: true,
exclusiveMinimum: true,
multipleOf: true,
maxLength: true,
minLength: true,
pattern: true,
format: true,
maxItems: true,
minItems: true,
uniqueItems: true,
maxProperties: true,
minProperties: true

};

function _traverse(opts, pre, post, schema, jsonPtr, rootSchema, parentJsonPtr, parentKeyword, parentSchema, keyIndex) {

if (schema && typeof schema == 'object' && !Array.isArray(schema)) {
  pre(schema, jsonPtr, rootSchema, parentJsonPtr, parentKeyword, parentSchema, keyIndex);
  for (var key in schema) {
    var sch = schema[key];
    if (Array.isArray(sch)) {
      if (key in traverse.arrayKeywords) {
        for (var i=0; i<sch.length; i++)
          _traverse(opts, pre, post, sch[i], jsonPtr + '/' + key + '/' + i, rootSchema, jsonPtr, key, schema, i);
      }
    } else if (key in traverse.propsKeywords) {
      if (sch && typeof sch == 'object') {
        for (var prop in sch)
          _traverse(opts, pre, post, sch[prop], jsonPtr + '/' + key + '/' + escapeJsonPtr(prop), rootSchema, jsonPtr, key, schema, prop);
      }
    } else if (key in traverse.keywords || (opts.allKeys && !(key in traverse.skipKeywords))) {
      _traverse(opts, pre, post, sch, jsonPtr + '/' + key, rootSchema, jsonPtr, key, schema);
    }
  }
  post(schema, jsonPtr, rootSchema, parentJsonPtr, parentKeyword, parentSchema, keyIndex);
}

}

function escapeJsonPtr(str) {

return str.replace(/~/g, '~0').replace(/\//g, '~1');

}