//- Mixins and associated functions

mixin makeExample(filePath, region, title, stylePatterns)
  - var language = attributes.language || getExtn(filePath);
  - var format = attributes.format || "linenums";
  - var frag = getFrag(filePath, region);
  if (title)
    .example-title #{title}
  code-example(language="#{language}" format="#{format}")
    != styleString(frag, stylePatterns)

mixin makeTabs(filePaths, regions, tabNames, stylePatterns)
  - filePaths = strSplit(filePaths);
  - regions = strSplit(regions, filePaths.length);
  - tabNames = strSplit(tabNames, filePaths.length);

  code-tabs
      each filePath,index in filePaths
        - var region = regions[index].trim();
        - var tabName = tabNames[index].trim();
        - var language = attributes.language || getExtn(filePath);
        - var format = attributes.format || "linenums";

        - var frag = getFrag(filePath, region);
        - var sps = Array.isArray(stylePatterns) ? stylePatterns[index] : stylePatterns;
        code-pane(language="#{language}" name="#{tabName}" format="#{format}")
            != styleString(frag, sps)

mixin makeJson( filePath, jsonConfig, title, stylePatterns)
  - var language = attributes.language || getExtn(filePath);
  - var format = attributes.format || "linenums";
  - var frag = getFrag(filePath, '');
  - var json = unescapeHtml(frag);
  - var jsonExtract = extractJson(json, jsonConfig);

  if (title)
    .example-title #{title}
  code-example(language="#{language}" format="#{format}")
    if (jsonExtract == 'ERROR')
      err ERROR: Unable to extract json using config: "#{jsonConfig.toString()}"
    else
      != styleString(jsonExtract, stylePatterns)


//---------------------------------------------------------------------------------------------------------

- var EMPTY_STRINGS = [ '','','','','','',''];

- var strSplit = function(str, length) {
-   var res;
-   str = str || '';
-   if (!length) {
-     res = str.split(",");
-   } else {
-     res = str.split(",");
-     if (res.length < length) {
-       res = res.concat(EMPTY_STRINGS.slice(0, length - res.length));
-     }
-   }
-   return res;
- }

- var getFrag = function(filePath, region) {
-   var fullFileName = getFragFilePath(filePath, region);
-   var frag = partial(fullFileName);
-   if (frag == null) {
-     return "BAD FILENAME: " + fullFileName + "   Current path: " + current.path +  " PathToDocs: " + getPathToDocs();
-   } else {
-     // ``` gets translated to <pre><code>.....</code></pre> and we need
-     // to remove this from the fragment prefix is 11 long and suffix is 13 long
-     frag = frag.substring(11, frag.length-13);
-     // Uncomment next line for debugging.
-     // frag = "FileName: " + fullFileName + "   Current path: " + current.path +  " PathToDocs: " + getPathToDocs() + "\n" + frag;
-     return frag;
-   }
- }

- var extractJson = function(json, jsonConfig ) {
-   try {
-     if (jsonConfig) {
-       return extractJsonFragment(json, jsonConfig.rootPath || null, jsonConfig.paths || [], jsonConfig.space || "  ");
-     } else {
-       return json;
-     }
-   } catch (e) {
-     return "ERROR";
-     // return json;
-   }
- }

- var unescapeHtml = function(s) {
-   // can't break across multiple lines because of jade limitations.
-   return s.replace(/&amp;/g, '&').replace(/&lt;/g, '<').replace(/&gt;/g, '>').replace(/&quot;/g, '"').replace(/&#039/g, "'");
- }

- var styleString = function(source, stylePatterns) {
-   if (stylePatterns) {
-      for (var styleName in stylePatterns) {
-        var rxs = stylePatterns[styleName];
-        rxs = Array.isArray(rxs) ? rxs : [rxs];
-        rxs.forEach(function(rx) {
-          source = applyStyle(source, styleName, rx );
-        });
-      }
-   }
-  return source;
- }

- var getFragFilePath = function (filePath, region) {
-   filePath = filePath.trim();
-   var extn = getExtn(filePath);
-   var fileBase = filePath.substr(0,filePath.length - (extn.length + 1));
-   var regionPad = (region && region.length) ? '-' + region.toString() : '';
-   var fullFileName = getPathToFrags() + fileBase + regionPad + "." + extn + '.md';
-   return fullFileName;
- }

//- styles a string according to a regular expression.
//- The match groups resulting from the regexp application are what is styled
//- (not the whole regexp).
- var applyStyle = function(str, styleName, rx) {
-   var repls = {};
-   var matches;
-   do {
-     matches = rx.exec(str);
-     if (matches) {
-       matches.slice(1).forEach(function(match) {
-         var repl = '<span class="' + styleName + '">' + match + '</span>';
-         repls[match] = { repl: repl, isGlobal: rx.global };
-       });
-     }
-   } while (matches != null && rx.global );
-   for (var match in repls) {
-     var repl = repls[match];
-     // var escapedMatch = match.replace(/\\/g,'\\').replace(/\(/g,'\(').replace(/\)/g, '\)').replace(/\./,'\.');
-     // var rx2 = new RegExp(escapedMatch, repl.isGlobal ? "g" : "");
-     var rx2 = match;
-     str = str.replace(rx2, repl.repl);
-   };
-   return str;
- }

- var getExtn = function(fileName) {
-   var ix = fileName.lastIndexOf('.');
-   return ix > 0 ? fileName.substr(ix+1) : "";
- }

- var getPathToDocs = function() {
-   // simple way to only take as many '../' sections as we need to back up to the 'docs' dir
-   // from the current document
-   // we will almost certainly never go 10 or 11 deep but ...
-   return current.pathToDocs || "../../../../../../../../../../../".substr(0, (current.path.length-2)*3);
- }

- var getPathToFrags = function() {
-   return getPathToDocs() + "_fragments/";
- }

- var getPathToExamples = function() {
-   return getPathToDocs() + "_examples/";
- }

//- Extract a subset of a json file in a specified order defined
//- by extractPaths while retaining original order for any
//- unspecified subobjects.
//-
//- based on the principle that JSON.parse(source) constructs objects
//- in order from the top down in 'source' and JSON.stringify(source) iterates 'source'
//- properties according to the order in which they were inserted.  ( the spec actually
//- discourages this assumption but this method will only
//- run on node (v8) and the assumption seems safe there. )
- function extractJsonFragment(source, rootPath, extractPaths, space) {
-   var objSource = JSON.parse(source);
-   if (rootPath && rootPath.length > 0) {
-     objSource = getSubObject(objSource, rootPath);
-   }
-   var objDest = {};
-   extractPaths.trim().split(",").forEach(function(dotPath) {
-     processPath(objSource, objDest, dotPath );
-   });
-   var result = JSON.stringify(objDest, null, space || "  ");
-   return result;

-   function getSubObject(source, path) {
-     var nextSource = source;
-     var pathParts = path.trim().split(".");
-     while (pathParts.length > 0) {
-       var nextProp = pathParts.shift();
-       nextSource = nextSource[nextProp];
-     }
-     return nextSource;
-   }

-   function processPath(source, dest, dotPath) {
-     var nextSource = source;
-     var nextDest = dest;
-     var pathParts = dotPath.trim().split(".");
-     while (pathParts.length > 0) {
-       var nextProp = pathParts.shift();
-       nextSource = nextSource[nextProp];
-       if (pathParts.length > 0) {
-         var val = nextDest[nextProp] || {};
-         nextDest[nextProp] = val;
-         nextDest = val;
-       } else {
-         nextDest[nextProp] = nextSource;
-       }
-     }
-   }
- }