var path = require('path');
var pull = require("pull-stream");
var marked = require("ssb-marked");
var htime = require("human-time");
var emojis = require("emoji-named-characters");
var cat = require("pull-cat");
var h = require('hyperscript');

var emojiDir = path.join(require.resolve("emoji-named-characters"), "../pngs");

exports.wrapPage = wrapPage;
exports.MdRenderer = MdRenderer;
exports.renderEmoji = renderEmoji;
exports.formatMsgs = formatMsgs;
exports.renderThread = renderThread;
exports.renderAbout = renderAbout;
exports.renderShowAll = renderShowAll;
exports.renderRssItem = renderRssItem;
exports.wrapRss = wrapRss;

function MdRenderer(opts) {
  marked.Renderer.call(this, {});
  this.opts = opts;
}

MdRenderer.prototype = new marked.Renderer();

MdRenderer.prototype.urltransform = function(href) {
  if (!href) return false;
  switch (href[0]) {
    case "#":
      return this.opts.base + "channel/" + href.slice(1);
    case "%":
      return this.opts.msg_base + encodeURIComponent(href);
    case "@":
      href = (this.opts.mentions && this.opts.mentions[href.substr(1)]) || href;
      return this.opts.feed_base + encodeURIComponent(href);
    case "&":
      return this.opts.blob_base + encodeURIComponent(href);
  }
  if (href.indexOf("javascript:") === 0) return false;
  return href;
};

MdRenderer.prototype.image = function(href, title, text) {
  if (text.endsWith(".svg"))
    return h('object',
	     { type: 'image/svg+xml',
	       data: href,
	       alt: text }).outerHTML;
  else
    return h('img',
	     { src: this.opts.img_base + href,
	       alt: text,
	       title: title
	     }).outerHTML;
};

function renderEmoji(emoji) {
  var opts = this.renderer.opts;
  var url = opts.mentions[emoji]
    ? opts.blob_base + encodeURIComponent(opts.mentions[emoji])
    : emoji in emojis && opts.emoji_base + escape(emoji) + '.png';
  return url
	? h('img.ssb-emoji',
	    { src: url,
	      alt: ':' + escape(emoji) + ':',
	      title: ':' + escape(emoji) + ':',
	      height: 16, width: 16
	    }).outerHTML
    : ":" + emoji + ":";
}

function escape(str) {
  return String(str)
    .replace(/&/g, "&")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}

function formatMsgs(id, ext, opts) {
  switch (ext || "html") {
    case "html":
      return pull(renderThread(opts, id, ''), wrapPage(id));
    case "js":
      return pull(renderThread(opts), wrapJSEmbed(opts));
    case "json":
      return wrapJSON();
    case "rss":
      return pull(renderRssItem(opts), wrapRss(id, opts));
    default:
      return null;
  }
}

function wrap(before, after) {
  return function(read) {
    return cat([pull.once(before), read, pull.once(after)]);
  };
}

function callToAction() {
  return h('a.call-to-action',
	   { href: 'https://www.scuttlebutt.nz' },
	   'Join Scuttlebutt now').outerHTML;
}

function toolTipTop() {
  return h('span.top-tip',
	   'You are reading content from ',
	   h('a', { href: 'https://www.scuttlebutt.nz' },
	     'Scuttlebutt')).outerHTML;
}

function renderAbout(opts, about, showAllHTML = "") {
  if (about.publicWebHosting === false) {
    return pull(
      pull.map(renderMsg.bind(this, opts, '')),
      wrap(toolTipTop() + '<main>', '</main>' + callToAction())
    );
  }

  opts.mentions = {};
  var figCaption = h('figcaption');
  figCaption.innerHTML = 'Feed of ' + about.name + '<br>' + marked(String(about.description || ''), opts.marked);
  return pull(
    pull.map(renderMsg.bind(this, opts, '')),
    wrap(toolTipTop() + '<main>' +
	 h('article',
	   h('header',
	     h('figure',
	       h('img',
		 { src: opts.img_base + about.image,
		   style: 'max-height: 200px; max-width: 200px;'
		 }),
	       figCaption)
	    )).outerHTML,
	 showAllHTML + '</main>' + callToAction())
  );
}

function renderThread(opts, id, showAllHTML = "") {
  return pull(
    pull.map(renderMsg.bind(this, opts, id)),
    wrap(toolTipTop() + '<main>', 
	 showAllHTML + '</main>' + callToAction())
  );
}

function renderRssItem(opts) {
  return pull(
    pull.map(renderRss.bind(this, opts))
  );
}

function wrapPage(id) {
  return wrap(
    "<!doctype html><html><head>" +
      "<meta charset=utf-8>" +
      "<title>" +
      id + " | ssb-viewer" +
      "</title>" +
      '<meta name=viewport content="width=device-width,initial-scale=1">' +
      styles +
      "</head><body>",
    "</body></html>"
  );
}

function wrapRss(id, opts) {
  return wrap(
    '<?xml version="1.0" encoding="UTF-8" ?>' +
    '<rss version="2.0">' +
      '<channel>' +
        '<title>' + id + ' | ssb-viewer</title>',

      '</channel>'+
    '</rss>'
  );
}

var styles = `
  <style>
    html { background-color: #f1f3f5; }
    body {
      color: #212529;
      font-family: "Helvetica Neue", "Calibri Light", Roboto, sans-serif;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      letter-spacing: 0.02em;
      padding-top: 30px;
      padding-bottom: 50px;
    }
    a { color: #364fc7; }

    .top-tip, .top-tip a {
      color: #868e96;
    }
    .top-tip {
      text-align: center;
      display: block;
      margin-bottom: 10px;
      font-size: 14px;
    }
    main { margin: 0 auto; max-width: 40rem; }
    main article:first-child { border-radius: 3px 3px 0 0; }
    main article:last-child { border-radius: 0 0 3px 3px; }
    article {
      background-color: white;
      padding: 20px;
      box-shadow: 0 1px 3px #949494;
      position: relative;
    }
    .top-right { position: absolute; top: 20px; right: 20px; }
    article > header { margin-bottom: 20px; }
    article > header > figure {
      margin: 0; display: flex;
    }
    article > header > figure > img {
      border-radius: 2px; margin-right: 10px;
    }
    article > header > figure > figcaption {
      display: flex; flex-direction: column;
    }
    .ssb-avatar-name { font-size: 1.2em; font-weight: bold; }
    time a { color: #868e96; }
    .ssb-avatar-name, time a {
      text-decoration: none;
    }
    .ssb-avatar-name:hover, time:hover a {
      text-decoration: underline;
    }
    section p { line-height: 1.45em; }
    section p img {
      max-width: 100%;
      max-height: 50vh;
      margin: 0 auto;
    }
    .status {
      font-style: italic;
    }

    code {
      display: inline;
      padding: 2px 5px;
      font-weight: 600;
      background-color: #e9ecef;
      border-radius: 3px;
      color: #495057;
    }
    blockquote {
      padding-left: 1.2em;
      margin: 0;
      color: #868e96;
      border-left: 5px solid #ced4da;
    }
    pre {
      background-color: #212529;
      color: #ced4da;
      font-weight: bold;
      padding: 5px;
      border-radius: 3px;
      position: relative;
    }
    pre::before {
      content: "METADATA";
      position: absolute;
      top: -7px;
      left: 0px;
      background-color: #212529;
      padding: 2px 4px 0;
      border-radius: 2px;
      font-family: "Helvetica Neue", "Calibri Light", Roboto, sans-serif;
      font-size: 9px;
    }
    .call-to-action {
      display: block;
      margin: 0 auto;
      width: 13em;
      text-align: center;
      text-decoration: none;
      margin-top: 20px;
      margin-bottom: 60px;
      background-color: #5c7cfa;
      padding: 15px 0;
      color: #edf2ff;
      border-radius: 3px;
      border-bottom: 3px solid #3b5bdb;
    }
    .call-to-action:hover {
      background-color: #748ffc;
      border-bottom: 3px solid #4c6ef5;
    }
  </style>
`;

function wrapJSON() {
  var first = true;
  return pull(pull.map(JSON.stringify), join(","), wrap("[", "]"));
}

function wrapJSEmbed(opts) {
  return pull(
    wrap('<link rel=stylesheet href="' + opts.base + 'static/base.css">', ""),
    pull.map(docWrite),
    opts.base_token && rewriteBase(new RegExp(opts.base_token, "g"))
  );
}

function rewriteBase(token) {
  // detect the origin of the script and rewrite the js/html to use it
  return pull(
    replace(token, '" + SSB_VIEWER_ORIGIN + "/'),
    wrap(
      "var SSB_VIEWER_ORIGIN = (function () {" +
        'var scripts = document.getElementsByTagName("script")\n' +
        "var script = scripts[scripts.length-1]\n" +
        "if (!script) return location.origin\n" +
        'return script.src.replace(/\\/%.*$/, "")\n' +
        "}())\n",
      ""
    )
  );
}

function join(delim) {
  var first = true;
  return pull.map(function(val) {
    if (!first) return delim + String(val);
    first = false;
    return val;
  });
}

function replace(re, rep) {
  return pull.map(function(val) {
    return String(val).replace(re, rep);
  });
}

function docWrite(str) {
  return "document.write(" + JSON.stringify(str) + ")\n";
}

function renderMsg(opts, id, msg) {
  if (opts.renderPrivate == false && typeof(msg.value.content) == 'string') return ''
  if (msg.author.publicWebHosting === false) return h('article', 'User has chosen not to be hosted publicly').outerHTML;
  var c = msg.value.content || {};
  var name = encodeURIComponent(msg.key);
  return h('article#' + name,
	   h('header',
	     h('figure',
	       h('img', { alt: '',
			  src: opts.img_base + msg.author.image,
			  height: 50, width: 50 }),
	       h('figcaption',
		 h('a.ssb-avatar-name',
		   { href: opts.base + escape(msg.value.author) },
		   msg.author.name),
		 msgTimestamp(msg, opts.base + name)))),
	   render(opts, id, c)).outerHTML;
}

function renderRss(opts, msg) {
  var c = msg.value.content || {};
  var name = encodeURIComponent(msg.key);

  let content = h('div', render(opts, c)).innerHTML;

  if (!content) {
    return null;
  }

  return (
    '<item>' +
      '<title>' + escape(c.type || 'private') + '</title>' +
      '<author>' + escape(msg.author.name) + '</author>' +
      '<description><![CDATA[' + content + ']]></description>' +
      '<link>' + opts.base + escape(name) + '</link>' +
      '<pubDate>' + new Date(msg.value.timestamp).toUTCString() + '</pubDate>' +
      '<guid>' + msg.key + '</guid>' +
    '</item>'
  );
}

function msgTimestamp(msg, link) {
  var date = new Date(msg.value.timestamp);
  var isoStr = date.toISOString();
  return h('time.ssb-timestamp',
	   { datetime: isoStr },
	   h('a',
	     { href: link,
	       title: isoStr },
	     formatDate(date)));
}

function formatDate(date) {
  return htime(date);
}

function render(opts, id, c) {
  var base = opts.base;
  if (!c) return
  if (c.type === "post") {
    var channel = c.channel
	? h('div.top-right',
	    h('a',
	      { href: base + 'channel/' + c.channel },
	      '#' + c.channel))
	: "";
    return [channel, renderPost(opts, id, c)];
  } else if (c.type == "vote" && c.vote.expression == "Dig") {
    var channel = c.channel
	? [' in ',
	   h('a',
	     { href: base + 'channel/' + c.channel },
	     '#' + c.channel)]
	: "";
    var linkedText = "this";
    if (typeof c.vote.linkedText != "undefined")
	linkedText = c.vote.linkedText.substring(0, 75);
    return h('span.status',
	     ['Liked ',
	      h('a', { href: base + c.vote.link }, linkedText),
	      channel]);
  } else if (c.type == "vote") {
    var linkedText = "this";
    if (typeof c.vote.linkedText != "undefined")
      linkedText = c.vote.linkedText.substring(0, 75);
      return h('span.status',
	       ['Voted ',
		h('a', { href: base + c.vote.link }, linkedText)]);
  } else if (c.type == "contact" && c.following) {
    var name = c.contact;
    if (typeof c.contactAbout != "undefined")
	name = c.contactAbout.name;
    return h('span.status',
	     ['Followed ',
	      h('a', { href: base + c.contact }, name)]);
  } else if (c.type == "contact" && !c.following) {
    var name = c.contact;
    if (typeof c.contactAbout != "undefined")
	name = c.contactAbout.name;
    return h('span.status',
	     ['Unfollowed ',
	      h('a', { href: base + c.contact }, name)]);
  } else if (typeof c == "string") {
    return h('span.status', 'Wrote something private')
  } else if (c.type == "chess_move") {
    return h('span.status', 'Moved a chess piece')
  } else if (c.type == "chess_invite") {
    return h('span.status', 'Started a chess game')
  }
  else if (c.type == "about") {
    return [h('span.status', 'Changed something in about'),
 	    renderDefault(c)];
  }
  else if (c.type == "issue") {
    return [h('span.status',
	     "Created a git issue" +
	      (c.repoName != undefined ? " in repo " + c.repoName : ""),
	      renderPost(opts, id, c))];
  }
  else if (c.type == "git-repo") {
    return h('span.status',
	     "Created a git repo " + c.name);
  }
  else if (c.type == "git-update") {
    var s = h('span.status');
    s.innerHTML = "Did a git update " +
	  (c.repoName != undefined ? " in repo " + c.repoName : "") +
	  '<br>' +
	  (c.commits != undefined ?
	   c.commits.map(com => { return "-" +com.title; }).join('<br>') : "");
    return s;
  }
  else if (c.type == "ssb-dns") {
    return [h('span.status', 'Updated DNS'), renderDefault(c)];
  }
  else if (c.type == "pub") {
    return h('span.status', 'Connected to the pub ' + c.address.host);
  }
  else if (c.type == "npm-packages") {
    return [h('span.status', 'Pushed npm packages')];
  }
  else if (c.type == "channel" && c.subscribed)
    return h('span.status',
	     'Subscribed to channel ',
	     h('a',
	       { href: base + 'channel/' + c.channel },
	       '#' + c.channel));
  else if (c.type == "channel" && !c.subscribed)
    return h('span.status',
	     'Unsubscribed from channel ',
	     h('a',
	       { href: base + 'channel/' + c.channel },
	       '#' + c.channel))
  else return renderDefault(c);
}

function renderPost(opts, id, c) {
  opts.mentions = {};
  if (Array.isArray(c.mentions)) {
      c.mentions.forEach(function (link) {
	  if (link && link.name && link.link)
	      opts.mentions[link.name] = link.link;
      });
  }
  var s = h('section');
  var content = '';
  if (c.root && c.root != id)
      content += 'Re: ' + h('a',
			    { href: '/' + encodeURIComponent(c.root) },
			    c.root.substring(0, 10)).outerHTML + '<br>';
  s.innerHTML = content + marked(String(c.text), opts.marked);
  return s;
}

function renderDefault(c) {
  return h('pre', JSON.stringify(c, 0, 2));
}

function renderShowAll(showAll, url) {
  if (showAll)
    return '';
  else
    return '<br>' + h('a', { href : url + '?showAll' }, 'Show whole feed').outerHTML;
}