export default function(dom, data) {
  let css = `
    dt-cite {
      color: hsla(206, 90%, 20%, 0.7);
    }
    dt-cite .citation-number {
      cursor: default;
      white-space: nowrap;
      font-family: -apple-system, BlinkMacSystemFont, "Roboto", Helvetica, sans-serif;
      font-size: 75%;
      color: hsla(206, 90%, 20%, 0.7);
      display: inline-block;
      line-height: 1.1em;
      text-align: center;
      position: relative;
      top: -2px;
      margin: 0 2px;
    }
    figcaption dt-cite .citation-number {
      font-size: 11px;
      font-weight: normal;
      top: -2px;
      line-height: 1em;
    }
  `;

  let style = dom.createElement("style");
  style.textContent = css;
  dom.querySelector("body").appendChild(style);

  let citations = data.citations;
  /*if (data.citations) {
    citations = Object.keys(data.citations).map(c => data.citations[c]);
    citations.sort((a, b) => {
      return a.author.localeCompare(b.author);
    });
  }*/

  var citeTags = [].slice.apply(dom.querySelectorAll("dt-cite"));
  citeTags.forEach((el,n) => {
    var key = el.getAttribute("key");
    if (key) {
      var keys = key.split(",");
      var cite_string = inline_cite_short(keys);
      var cite_hover_str = "";
      keys.map((key,n) => {
        if (n>0) cite_hover_str += "<br><br>";
        cite_hover_str += hover_cite(data.bibliography[key]);
      });
      cite_hover_str = cite_hover_str.replace(/"/g, "&#39;")
      var orig_string = el.innerHTML;
      if (orig_string != "") orig_string += " ";
      el.innerHTML = `<span id="citation-${n}" data-hover="${cite_hover_str}">${orig_string}<span class="citation-number">${cite_string}</span></span>`;
    }
  });

  let bibEl = dom.querySelector("dt-bibliography");
  if (bibEl) {
    let ol = dom.createElement("ol");
    citations.forEach(key => {
      let el = dom.createElement("li");
      el.innerHTML = bibliography_cite(data.bibliography[key]);
      ol.appendChild(el);
    })
    bibEl.appendChild(ol);
  }

  function inline_cite_short(keys){
    function cite_string(key){
      if (key in data.bibliography){
        var n = data.citations.indexOf(key)+1;
        return ""+n;
      } else {
        return "?";
      }
    }
    return "["+keys.map(cite_string).join(", ")+"]";
  }

  function inline_cite_long(keys){
    function cite_string(key){
      if (key in data.bibliography){
        var ent = data.bibliography[key];
        var names = ent.author.split(" and ");
        names = names.map(name => name.split(",")[0].trim())
        var year = ent.year;
        if (names.length == 1) return names[0] + ", " + year;
        if (names.length == 2) return names[0] + " & " + names[1] + ", " + year;
        if (names.length  > 2) return names[0] + ", et al., " + year;
      } else {
        return "?";
      }
    }
    return keys.map(cite_string).join(", ");
  }

  function author_string(ent, template, sep, finalSep){
    var names = ent.author.split(" and ");
    let name_strings = names.map(name => {
      name = name.trim();
      if (name.indexOf(",") != -1){
        var last = name.split(",")[0].trim();
        var firsts = name.split(",")[1];
      } else {
        var last = name.split(" ").slice(-1)[0].trim();
        var firsts = name.split(" ").slice(0,-1).join(" ");
      }
      var initials = "";
      if (firsts != undefined) {
        initials = firsts.trim().split(" ").map(s => s.trim()[0]);
        initials = initials.join(".")+".";
      }
      return template.replace("${F}", firsts)
                     .replace("${L}", last)
                     .replace("${I}", initials);
    });
    if (names.length > 1) {
      var str = name_strings.slice(0, names.length-1).join(sep);
      str += (finalSep || sep) + name_strings[names.length-1];
      return str;
    } else {
      return name_strings[0];
    }
  }

  function venue_string(ent) {
    var cite = (ent.journal || ent.booktitle || "")
    if ("volume" in ent){
      var issue = ent.issue || ent.number;
      issue = (issue != undefined)? "("+issue+")" : "";
      cite += ", Vol " + ent.volume + issue;
    }
    if ("pages" in ent){
      cite += ", pp. " + ent.pages
    }
    if (cite != "") cite += ". "
    if ("publisher" in ent){
      cite += ent.publisher;
      if (cite[cite.length-1] != ".") cite += ".";
    }
    return cite;
  }

  function link_string(ent){
    if ("url" in ent){
      var url = ent.url;
      var arxiv_match = (/arxiv\.org\/abs\/([0-9\.]*)/).exec(url);
      if (arxiv_match != null){
        url = `http://arxiv.org/pdf/${arxiv_match[1]}.pdf`;
      }

      if (url.slice(-4) == ".pdf"){
        var label = "PDF";
      } else if (url.slice(-5) == ".html") {
        var label = "HTML";
      }
      return ` &ensp;<a href="${url}">[${label||"link"}]</a>`;
    }/* else if ("doi" in ent){
      return ` &ensp;<a href="https://doi.org/${ent.doi}" >[DOI]</a>`;
    }*/ else {
      return "";
    }
  }
  function doi_string(ent, new_line){
    if ("doi" in ent) {
      return `${new_line?"<br>":""} <a href="https://doi.org/${ent.doi}" style="text-decoration:inherit;">DOI: ${ent.doi}</a>`;
    } else {
      return "";
    }
  }

  function bibliography_cite(ent, fancy){
    if (ent){
      var cite =  "<b>" + ent.title + "</b> "
      cite += link_string(ent) + "<br>";
      cite += author_string(ent, "${L}, ${I}", ", ", " and ");
      if (ent.year || ent.date){
        cite += ", " + (ent.year || ent.date) + ". "
      } else {
        cite += ". "
      }
      cite += venue_string(ent);
      cite += doi_string(ent);
      return cite
      /*var cite =  author_string(ent, "${L}, ${I}", ", ", " and ");
      if (ent.year || ent.date){
        cite += ", " + (ent.year || ent.date) + ". "
      } else {
        cite += ". "
      }
      cite += "<b>" + ent.title + "</b>. ";
      cite += venue_string(ent);
      cite += doi_string(ent);
      cite += link_string(ent);
      return cite*/
    } else {
      return "?";
    }
  }

  function hover_cite(ent){
    if (ent){
      var cite = "";
      cite += "<b>" + ent.title + "</b>";
      cite += link_string(ent);
      cite += "<br>"

      var a_str = author_string(ent, "${I} ${L}", ", ") + ".";
      var v_str = venue_string(ent).trim() + " " + ent.year + ". " + doi_string(ent, true);

      if ((a_str+v_str).length < Math.min(40, ent.title.length)) {
        cite += a_str + " " + v_str;
      } else {
        cite += a_str + "<br>" + v_str;
      }
      return cite;
    } else {
      return "?";
    }
  }


  //https://scholar.google.com/scholar?q=allintitle%3ADocument+author%3Aolah
  function get_GS_URL(ent){
    if (ent){
      var names = ent.author.split(" and ");
      names = names.map(name => name.split(",")[0].trim())
      var title = ent.title.split(" ")//.replace(/[,:]/, "")
      var url = "http://search.labs.crossref.org/dois?"//""https://scholar.google.com/scholar?"
      url += uris({q: names.join(" ") + " " + title.join(" ")})
    }

  }
}