--
-- html.lua -- irccd HTML writer
--
-- Copyright (c) 2013-2018 David Demelier <markand@malikania.fr>
--
-- Permission to use, copy, modify, and/or distribute this software for any
-- purpose with or without fee is hereby granted, provided that the above
-- copyright notice and this permission notice appear in all copies.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--

local function escape(s, in_attribute)
  return s:gsub("[<>&\"']",
    function(x)
      if x == '<' then
        return '&lt;'
      elseif x == '>' then
        return '&gt;'
      elseif x == '&' then
        return '&amp;'
      elseif x == '"' then
        return '&quot;'
      elseif x == "'" then
        return '&#39;'
      else
        return x
      end
    end)
end

local function attributes(attr)
  local attr_table = {}
  for x,y in pairs(attr) do
    if y and y ~= "" then
      table.insert(attr_table, ' ' .. x .. '="' .. escape(y,true) .. '"')
    end
  end
  return table.concat(attr_table)
end

local function html_align(align)
  if align == 'AlignLeft' then
    return 'left'
  elseif align == 'AlignRight' then
    return 'right'
  elseif align == 'AlignCenter' then
    return 'center'
  else
    return 'left'
  end
end

local notes = {}

function Blocksep()
  return "\n\n"
end

function Doc(body, metadata, variables)

  for k, v in pairs(metadata) do
    print(k .. " = " .. tostring(v))
  end



  local buffer = {}
  local function add(s)
    table.insert(buffer, s)
  end
  add(body)
  if #notes > 0 then
    add('<ol class="footnotes">')
    for _,note in pairs(notes) do
      add(note)
    end
    add('</ol>')
  end
  return table.concat(buffer,'\n') .. '\n'
end

function Str(s)
  return escape(s)
end

function Space()
  return " "
end

function SoftBreak()
  return "\n"
end

function LineBreak()
  return "<br/>"
end

function Emph(s)
  return "<em>" .. s .. "</em>"
end

function Strong(s)
  return "<strong>" .. s .. "</strong>"
end

function Subscript(s)
  return "<sub>" .. s .. "</sub>"
end

function Superscript(s)
  return "<sup>" .. s .. "</sup>"
end

function SmallCaps(s)
  return '<span style="font-variant: small-caps;">' .. s .. '</span>'
end

function Strikeout(s)
  return '<del>' .. s .. '</del>'
end

function Link(s, src, tit, attr)
  return "<a href='" .. escape(src,true) .. "' title='" ..
         escape(tit,true) .. "'>" .. s .. "</a>"
end

function Image(s, src, tit, attr)
  return "<img src='" .. escape(src,true) .. "' title='" ..
         escape(tit,true) .. "'/>"
end

function Code(s, attr)
  return "<code" .. attributes(attr) .. ">" .. escape(s) .. "</code>"
end

function InlineMath(s)
  return "\\(" .. escape(s) .. "\\)"
end

function DisplayMath(s)
  return "\\[" .. escape(s) .. "\\]"
end

function Note(s)
  local num = #notes + 1
  -- insert the back reference right before the final closing tag.
  s = string.gsub(s,
          '(.*)</', '%1 <a href="#fnref' .. num ..  '">&#8617;</a></')
  -- add a list item with the note to the note table.
  table.insert(notes, '<li id="fn' .. num .. '">' .. s .. '</li>')
  -- return the footnote reference, linked to the note.
  return '<a id="fnref' .. num .. '" href="#fn' .. num ..
            '"><sup>' .. num .. '</sup></a>'
end

function Span(s, attr)
  return "<span" .. attributes(attr) .. ">" .. s .. "</span>"
end

function RawInline(format, str)
  if format == "html" then
    return str
  else
    return ''
  end
end

function Cite(s, cs)
  local ids = {}
  for _,cit in ipairs(cs) do
    table.insert(ids, cit.citationId)
  end
  return "<span class=\"cite\" data-citation-ids=\"" .. table.concat(ids, ",") ..
    "\">" .. s .. "</span>"
end

function Plain(s)
  return s
end

function Para(s)
  return "<p>" .. s .. "</p>"
end

function Header(lev, s, attr)
  return "<h" .. lev .. attributes(attr) ..  ">" .. s .. "</h" .. lev .. ">"
end

function BlockQuote(s)
  return "<blockquote>\n" .. s .. "\n</blockquote>"
end

function HorizontalRule()
  return "<hr/>"
end

function LineBlock(ls)
  return '<div style="white-space: pre-line;">' .. table.concat(ls, '\n') ..
         '</div>'
end

function CodeBlock(s, attr)
  return "<pre><code" .. attributes(attr) .. ">" .. escape(s) ..
         "</code></pre>"
end

function BulletList(items)
  local buffer = {}
  for _, item in pairs(items) do
    table.insert(buffer, "<li>" .. item .. "</li>")
  end
  return "<ul>\n" .. table.concat(buffer, "\n") .. "\n</ul>"
end

function OrderedList(items)
  local buffer = {}
  for _, item in pairs(items) do
    table.insert(buffer, "<li>" .. item .. "</li>")
  end
  return "<ol>\n" .. table.concat(buffer, "\n") .. "\n</ol>"
end

-- Revisit association list STackValue instance.
function DefinitionList(items)
  local buffer = {}
  for _,item in pairs(items) do
    for k, v in pairs(item) do
      table.insert(buffer,"<dt>" .. k .. "</dt>\n<dd>" ..
                        table.concat(v,"</dd>\n<dd>") .. "</dd>")
    end
  end
  return "<dl>\n" .. table.concat(buffer, "\n") .. "\n</dl>"
end

function CaptionedImage(src, tit, caption, attr)
   return '<div class="figure">\n<img src="' .. escape(src,true) ..
      '" title="' .. escape(tit,true) .. '"/>\n' ..
      '<p class="caption">' .. caption .. '</p>\n</div>'
end

function Table(caption, aligns, widths, headers, rows)
  local buffer = {}
  local function add(s)
    table.insert(buffer, s)
  end
  add("<table>")
  if caption ~= "" then
    add("<caption>" .. caption .. "</caption>")
  end
  if widths and widths[1] ~= 0 then
    for _, w in pairs(widths) do
      add('<col width="' .. string.format("%d%%", w * 100) .. '" />')
    end
  end
  local header_row = {}
  local empty_header = true
  for i, h in pairs(headers) do
    local align = html_align(aligns[i])
    table.insert(header_row,'<th align="' .. align .. '">' .. h .. '</th>')
    empty_header = empty_header and h == ""
  end
  if empty_header then
    head = ""
  else
    add('<tr class="header">')
    for _,h in pairs(header_row) do
      add(h)
    end
    add('</tr>')
  end
  local class = "even"
  for _, row in pairs(rows) do
    class = (class == "even" and "odd") or "even"
    add('<tr class="' .. class .. '">')
    for i,c in pairs(row) do
      add('<td align="' .. html_align(aligns[i]) .. '">' .. c .. '</td>')
    end
    add('</tr>')
  end
  add('</table')
  return table.concat(buffer,'\n')
end

function RawBlock(format, str)
  if format == "html" then
    return str
  else
    return ''
  end
end

function Div(s, attr)
  return "<div" .. attributes(attr) .. ">\n" .. s .. "</div>"
end

local meta = {}

function meta.__index(_, key)
    io.stderr:write(string.format("WARNING: Undefined function '%s'\n",key))

    return function ()
        return ""
    end
end

setmetatable(_G, meta)