// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License.  You may obtain a copy
// of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
// License for the specific language governing permissions and limitations under
// the License.

// mimeparse.js
// http://code.google.com/p/mimeparse/
// Code with comments: http://mimeparse.googlecode.com/svn/trunk/mimeparse.js
// Tests: http://mimeparse.googlecode.com/svn/trunk/mimeparse-js-test.html
// Ported from version 0.1.2

var Mimeparse = (function() {
  function strip(string) {
    return string.replace(/^\s+/, '').replace(/\s+$/, '');
  };
  function parseRanges(ranges) {
    var parsedRanges = [], rangeParts = ranges.split(",");
    for (var i=0; i < rangeParts.length; i++) {
      parsedRanges.push(publicMethods.parseMediaRange(rangeParts[i]));
    };
    return parsedRanges;
  };
  var publicMethods = {
    parseMimeType : function(mimeType) {
      var fullType, typeParts, params = {}, parts = mimeType.split(';');
      for (var i=0; i < parts.length; i++) {
        var p = parts[i].split('=');
        if (p.length == 2) {
          params[strip(p[0])] = strip(p[1]);
        }
      };
      fullType = parts[0].replace(/^\s+/, '').replace(/\s+$/, '');
      if (fullType == '*') fullType = '*/*';
      typeParts = fullType.split('/');
      return [typeParts[0], typeParts[1], params];
    },
    parseMediaRange : function(range) {
      var q, parsedType = this.parseMimeType(range);
      if (!parsedType[2]['q']) {
        parsedType[2]['q'] = '1';
      } else {
        q = parseFloat(parsedType[2]['q']);
        if (isNaN(q)) {
          parsedType[2]['q'] = '1';
        } else if (q > 1 || q < 0) {
          parsedType[2]['q'] = '1';
        }
      }
      return parsedType;
    },
    fitnessAndQualityParsed : function(mimeType, parsedRanges) {
      var bestFitness = -1, bestFitQ = 0, target = this.parseMediaRange(mimeType);
      var targetType = target[0], targetSubtype = target[1], targetParams = target[2];

      for (var i=0; i < parsedRanges.length; i++) {
        var parsed = parsedRanges[i];
        var type = parsed[0], subtype = parsed[1], params = parsed[2];
        if ((type == targetType || type == "*" || targetType == "*") &&
          (subtype == targetSubtype || subtype == "*" || targetSubtype == "*")) {
          var matchCount = 0;
          for (param in targetParams) {
            if (param != 'q' && params[param] && params[param] == targetParams[param]) {
              matchCount += 1;
            }
          }

          var fitness = (type == targetType) ? 100 : 0;
          fitness += (subtype == targetSubtype) ? 10 : 0;
          fitness += matchCount;

          if (fitness > bestFitness) {
            bestFitness = fitness;
            bestFitQ = params["q"];
          }
        }
      };
      return [bestFitness, parseFloat(bestFitQ)];
    },
    qualityParsed : function(mimeType, parsedRanges) {
      return this.fitnessAndQualityParsed(mimeType, parsedRanges)[1];
    },
    quality : function(mimeType, ranges) {
      return this.qualityParsed(mimeType, parseRanges(ranges));
    },

    // Takes a list of supported mime-types and finds the best
    // match for all the media-ranges listed in header. The value of
    // header must be a string that conforms to the format of the
    // HTTP Accept: header. The value of 'supported' is a list of
    // mime-types.
    //
    // >>> bestMatch(['application/xbel+xml', 'text/xml'], 'text/*;q=0.5,*/*; q=0.1')
    // 'text/xml'
    bestMatch : function(supported, header) {
      var parsedHeader = parseRanges(header);
      var weighted = [];
      for (var i=0; i < supported.length; i++) {
        weighted.push([publicMethods.fitnessAndQualityParsed(supported[i], parsedHeader), supported[i]]);
      };
      weighted.sort();
      return weighted[weighted.length-1][0][1] ? weighted[weighted.length-1][1] : '';
    }
  };
  return publicMethods;
})();

// this function provides a shortcut for managing responses by Accept header
respondWith = function(req, responders) {
  var bestKey = null, accept = req.headers["Accept"];
  if (accept && !req.query.format) {
    var provides = [];
    for (key in responders) {
      if (mimesByKey[key]) {
        provides = provides.concat(mimesByKey[key]);        
      }
    }
    var bestMime = Mimeparse.bestMatch(provides, accept);
    bestKey = keysByMime[bestMime];
  } else {
    bestKey = req.query.format;
  }
  var rFunc = responders[bestKey || responders.fallback || "html"];
  if (rFunc) {      
    var resp = maybeWrapResponse(rFunc());
    resp["headers"] = resp["headers"] || {};
    resp["headers"]["Content-Type"] = bestMime;
    respond(resp);
  } else {
    throw({code:406, body:"Not Acceptable: "+accept});    
  }
};

// whoever registers last wins.
mimesByKey = {};
keysByMime = {};
registerType = function() {
  var mimes = [], key = arguments[0];
  for (var i=1; i < arguments.length; i++) {
    mimes.push(arguments[i]);
  };
  mimesByKey[key] = mimes;
  for (var i=0; i < mimes.length; i++) {
    keysByMime[mimes[i]] = key;
  };
};

// Some default types
// Ported from Ruby on Rails
// Build list of Mime types for HTTP responses
// http://www.iana.org/assignments/media-types/
// http://dev.rubyonrails.org/svn/rails/trunk/actionpack/lib/action_controller/mime_types.rb

registerType("all", "*/*");
registerType("text", "text/plain", "txt");
registerType("html", "text/html");
registerType("xhtml", "application/xhtml+xml", "xhtml");
registerType("xml", "application/xml", "text/xml", "application/x-xml");
// http://www.ietf.org/rfc/rfc4627.txt
registerType("json", "application/json", "text/x-json");
registerType("js", "text/javascript", "application/javascript", "application/x-javascript");
registerType("css", "text/css");
registerType("ics", "text/calendar");
registerType("csv", "text/csv");
registerType("rss", "application/rss+xml");
registerType("atom", "application/atom+xml");
registerType("yaml", "application/x-yaml", "text/yaml");
// just like Rails
registerType("multipart_form", "multipart/form-data");
registerType("url_encoded_form", "application/x-www-form-urlencoded");


var Render = (function() {
  var row_info;
  return {
    showDoc : function(funSrc, doc, req) {
      var formFun = compileFunction(funSrc);
      runRenderFunction(formFun, [doc, req], funSrc);
    },
    listBegin : function(head, req) {
      row_info = { first_key: null, row_number: 0, prev_key: null };
      runRenderFunction(funs[0], [head, null, req, null], funsrc[0]);
    },
    listRow : function(row, req) {
      if (row_info.first_key == null) {
        row_info.first_key = row.key;
      }
      runRenderFunction(funs[0], [null, row, req, row_info], funsrc[0], true);
      row_info.prev_key = row.key;
      row_info.row_number++;
    },
    listTail : function(req) {
      runRenderFunction(funs[0], [null, null, req, row_info], funsrc[0]);
    }
  }
})();

function runRenderFunction(renderFun, args, funSrc, htmlErrors) {
  responseSent = false;
  try {
    var resp = renderFun.apply(null, args);
    if (!responseSent) {
      if (resp) {
        respond(maybeWrapResponse(resp));       
      } else {
        respond({error:"render_error",reason:"undefined response from render function"});
      }      
    }
  } catch(e) {
    var logMessage = "function raised error: "+e.toString();
    log(logMessage);
    // log("stacktrace: "+e.stack);
    var errorMessage = htmlErrors ? htmlRenderError(e, funSrc) : logMessage;
    respond({
      error:"render_error",
      reason:errorMessage});
  }
};

function escapeHTML(string) {
  return string.replace(/&/g, "&amp;")
               .replace(/</g, "&lt;")
               .replace(/>/g, "&gt;");
}

function htmlRenderError(e, funSrc) {
  var msg = ["<html><body><h1>Render Error</h1>",
    "<p>JavaScript function raised error: ",
    e.toString(),
    "</p><h2>Stacktrace:</h2><code><pre>",
    escapeHTML(e.stack),
    "</pre></code><h2>Function source:</h2><code><pre>",
    escapeHTML(funSrc),
    "</pre></code></body></html>"].join('');
  return {body:msg};
};

function maybeWrapResponse(resp) {
  var type = typeof resp;
  if ((type == "string") || (type == "xml")) {
    return {body:resp};
  } else {
    return resp;
  }
};