#!/usr/bin/env lua
local sitelib = require "sitelib"
local fs = require "lfs"
local tags = {}

if not fs.attributes(sitelib.outpath.."/tag") then
 fs.mkdir(sitelib.outpath.."/tag")
end

local mdfiles = {}
local dqueue = {sitelib.srcpath}
for k,path in pairs(dqueue) do
 for file in fs.dir(path) do
  if file:sub(1,1) ~= "." then
   local attr = fs.attributes(path.."/"..file)
   if attr.mode == "directory" then
    dqueue[#dqueue+1] = path.."/"..file
   elseif file:sub(-3) == ".md" then
    mdfiles[#mdfiles+1] = path.."/"..file
   end
  end
 end
end

for k,infile in pairs(mdfiles) do
 local f = io.open(infile,"rb")
 local c = f:read("*a")
 f:close()
 local page = sitelib.parsepage(c)
 if page.tags then
   print((infile:sub(sitelib.srcpath:len()+1)):sub(1,-4)..".html")
  for w in page.tags:gmatch("%S+") do
   tags[w] = tags[w] or {}
   table.insert(tags[w],{(infile:sub(sitelib.srcpath:len()+1)):sub(1,-4)..".html",page.title})
  end
 end
end

local haslabel = {}
print("graph blog {")
for tag,v in pairs(tags) do
 for l,m in pairs(v) do
  if not haslabel[m[1]:match("(%d+).html")] then
   print(m[1]:match("(%d+).html").." [label=\""..m[2]:gsub("\"","").."\"];")
   haslabel[m[1]:match("(%d+).html")] = true
  end
  print(tag:gsub("-","").." -- "..m[1]:match("(%d+).html")..";")
 end
end
print("}")