import React, { PropTypes } from 'react';
import ReactDOM from 'react-dom';
import escapeStringRegexp from 'escape-string-regexp';
import srcDoc from 'srcdoc-polyfill';


const startTag = '@fs-';

function getAllScriptOffsets(htmlFile) {
  const offs = [];
  let found = true;
  let lastInd = 0;
  let ind = 0;
  let endFilenameInd = 0;
  let filename = '';
  let lineOffset = 0;
  while (found) {
    ind = htmlFile.indexOf(startTag, lastInd);
    if (ind === -1) {
      found = false;
    } else {
      endFilenameInd = htmlFile.indexOf('.js', ind + startTag.length + 3);
      filename = htmlFile.substring(ind + startTag.length, endFilenameInd);
      lineOffset = htmlFile.substring(0, ind).split('\n').length;
      offs.push([lineOffset, filename]);
      lastInd = ind + 1;
    }
  }
  return offs;
}


function hijackConsoleLogsScript() {
  const s = `<script>
    var iframeWindow = window;
    var originalConsole = iframeWindow.console;
    iframeWindow.console = {};

    var methods = [
      'debug', 'clear', 'error', 'info', 'log', 'warn'
    ];


    function throttle(fn, threshhold, scope) {
      var last, deferTimer;
      return function() {
        var context = scope || this;
        var now = +new Date,
            args = arguments;
        if (last && now < last + threshhold) {
          // hold on to it
          clearTimeout(deferTimer);
          deferTimer = setTimeout(function() {
            last = now;
            fn.apply(context, args);
          }, threshhold);
        } else {
          last = now;
          fn.apply(context, args);
        }
      };
    }

    methods.forEach( function(method) {
      iframeWindow.console[method] = throttle(function() {
        originalConsole[method].apply(originalConsole, arguments);

        var args = Array.from(arguments);
        args = args.map(function(i) {
          // catch objects
          return (typeof i === 'string') ? i : JSON.stringify(i);
        });

        // post message to parent window
        window.parent.postMessage({
          method: method,
          arguments: args,
          source: 'sketch'
        }, '*');
      }, 100);
    });
  </script>`;
  return s;
}

function hijackConsoleErrorsScript(offs) {
  const s = `<script>
    function getScriptOff(line) {
      var offs = ${offs};
      var l = 0;
      var file = '';
      for (var i=0; i<offs.length; i++) {
        var n = offs[i][0];
        if (n < line && n > l) {
          l = n;
          file = offs[i][1];
        }
      }
      return [line - l, file];
    }

    // catch reference errors, via http://stackoverflow.com/a/12747364/2994108
    window.onerror = function (msg, url, lineNumber, columnNo, error) {
        var string = msg.toLowerCase();
        var substring = "script error";
        var data = {};

        if (string.indexOf(substring) !== -1){
          data = 'Script Error: See Browser Console for Detail';
        } else {
          var fileInfo = getScriptOff(lineNumber);
          data = msg + ' (' + fileInfo[1] + ': line ' + fileInfo[0] + ')';
        }
        window.parent.postMessage({
          method: 'error',
          arguments: data,
          source: 'sketch'
        }, '*');
      return false;
    };
  </script>`;
  return s;
}

class PreviewFrame extends React.Component {

  componentDidMount() {
    if (this.props.isPlaying) {
      this.renderFrameContents();
    }

    if (this.props.dispatchConsoleEvent) {
      window.addEventListener('message', (msg) => {
        if (msg.data.source === 'sketch') {
          this.props.dispatchConsoleEvent(msg);
        }
      });
    }
  }

  componentDidUpdate(prevProps) {
    // if sketch starts or stops playing, want to rerender
    if (this.props.isPlaying !== prevProps.isPlaying) {
      this.renderSketch();
      return;
    }

    // if the user explicitly clicks on the play button
    if (this.props.isPlaying && this.props.previewIsRefreshing) {
      this.renderSketch();
      return;
    }

    // small bug - if autorefresh is on, and the usr changes files
    // in the sketch, preview will reload
  }

  componentWillUnmount() {
    ReactDOM.unmountComponentAtNode(ReactDOM.findDOMNode(this).contentDocument.body);
  }

  clearPreview() {
    const doc = ReactDOM.findDOMNode(this);
    doc.srcDoc = '';
  }

  injectLocalFiles() {
    let htmlFile = this.props.htmlFile.content;
    let scriptOffs = [];

    // have to build the array manually because the spread operator is only
    // one level down...

    htmlFile = hijackConsoleLogsScript() + htmlFile;
    const mediaFiles = this.props.files.filter(file => file.url);

    const jsFiles = [];
    this.props.jsFiles.forEach(jsFile => {
      const newJSFile = { ...jsFile };
      let jsFileStrings = newJSFile.content.match(/(['"])((\\\1|.)*?)\1/gm);
      const jsFileRegex = /^('|")(?!(http:\/\/|https:\/\/)).*\.(png|jpg|jpeg|gif|bmp|mp3|wav|aiff|ogg|json)('|")$/i;
      jsFileStrings = jsFileStrings || [];
      jsFileStrings.forEach(jsFileString => {
        if (jsFileString.match(jsFileRegex)) {
          const filePath = jsFileString.substr(1, jsFileString.length - 2);
          const filePathArray = filePath.split('/');
          const fileName = filePathArray[filePathArray.length - 1];
          mediaFiles.forEach(file => {
            if (file.name === fileName) {
              newJSFile.content = newJSFile.content.replace(filePath, file.blobURL); // eslint-disable-line
            }
          });
        }
      });
      jsFiles.push(newJSFile);
    });

    jsFiles.forEach(jsFile => {
      const fileName = escapeStringRegexp(jsFile.name);
      const fileRegex = new RegExp(`<script.*?src=('|")((\.\/)|\/)?${fileName}('|").*?>([\s\S]*?)<\/script>`, 'gmi');
      const replacementString = `<script data-tag="${startTag}${jsFile.name}">\n${jsFile.content}\n</script>`;
      htmlFile = htmlFile.replace(fileRegex, replacementString);
    });

    this.props.cssFiles.forEach(cssFile => {
      const fileName = escapeStringRegexp(cssFile.name);
      const fileRegex = new RegExp(`<link.*?href=('|")((\.\/)|\/)?${fileName}('|").*?>`, 'gmi');
      htmlFile = htmlFile.replace(fileRegex, `<style>\n${cssFile.content}\n</style>`);
    });

    if (this.props.textOutput || this.props.isTextOutputPlaying) {
      const htmlHead = htmlFile.match(/(?:<head.*?>)([\s\S]*?)(?:<\/head>)/gmi);
      const headRegex = new RegExp('head', 'i');
      let htmlHeadContents = htmlHead[0].split(headRegex)[1];
      htmlHeadContents = htmlHeadContents.slice(1, htmlHeadContents.length - 2);
      htmlHeadContents += '<script src="/loadData.js"></script>\n';
      htmlHeadContents += '<script src="/interceptor-functions.js"></script>\n';
      htmlHeadContents += '<script src="/intercept-p5.js"></script>\n';
      htmlHeadContents += '<script type="text/javascript" src="/ntc.min.js"></script>';
      htmlFile = htmlFile.replace(/(?:<head.*?>)([\s\S]*?)(?:<\/head>)/gmi, `<head>\n${htmlHeadContents}\n</head>`);
    }

    scriptOffs = getAllScriptOffsets(htmlFile);
    htmlFile += hijackConsoleErrorsScript(JSON.stringify(scriptOffs));


    return htmlFile;
  }

  renderSketch() {
    const doc = ReactDOM.findDOMNode(this);
    if (this.props.isPlaying && !this.props.infiniteLoop) {
      srcDoc.set(doc, this.injectLocalFiles());
      this.props.endSketchRefresh();
    } else {
      doc.srcdoc = '';
      srcDoc.set(doc, '  ');
    }
  }

  renderFrameContents() {
    const doc = ReactDOM.findDOMNode(this).contentDocument;
    if (doc.readyState === 'complete') {
      this.renderSketch();
    } else {
      setTimeout(this.renderFrameContents, 0);
    }
  }

  render() {
    return (
      <iframe
        className="preview-frame"
        aria-label="sketch output"
        role="main"
        tabIndex="0"
        frameBorder="0"
        title="sketch output"
        sandbox="allow-scripts allow-pointer-lock allow-same-origin allow-popups allow-modals allow-forms"
      />
    );
  }
}

PreviewFrame.propTypes = {
  isPlaying: PropTypes.bool.isRequired,
  isTextOutputPlaying: PropTypes.bool.isRequired,
  textOutput: PropTypes.bool.isRequired,
  head: PropTypes.object.isRequired,
  content: PropTypes.string,
  htmlFile: PropTypes.shape({
    content: PropTypes.string.isRequired
  }),
  jsFiles: PropTypes.array.isRequired,
  cssFiles: PropTypes.array.isRequired,
  files: PropTypes.array.isRequired,
  dispatchConsoleEvent: PropTypes.func,
  children: PropTypes.element,
  infiniteLoop: PropTypes.bool.isRequired,
  resetInfiniteLoops: PropTypes.func.isRequired,
  autorefresh: PropTypes.bool.isRequired,
  endSketchRefresh: PropTypes.func.isRequired,
  previewIsRefreshing: PropTypes.bool.isRequired,
};

export default PreviewFrame;