imgcache2.lua

module("modules/imgcache2/imgcache2")

function parse_message(bot, msg)
  local i,j,chan,s = string.find(msg, ":.-!.- PRIVMSG (.-) :(.+)")
  if not (i == nil) then

    function db_connect()
      local luasql = require("luasql.sqlite3")
      local env = luasql.sqlite3()
      local conn = env:connect("imgcache2.sqlite")

      -- create table if needed
      assert(conn:execute([[CREATE TABLE IF NOT EXISTS cachedimages (
        orgurl VARCHAR(256) PRIMARY KEY,
        cachedfile VARCHAR(256)
      )
      ]]))

      return env, conn

    end

    function db_close(env, conn)
      conn:close()
      env:close()
    end
    
    function get_image(url, block_hosts)

      local socket = require("socket")

      -- get host and path
      local socketurl = require("socket.url")
      local parsedurl = socketurl.parse(url)
      local host = parsedurl.host
      local path = parsedurl.path
      
      -- check if host is blocked
      for k,v in pairs(block_hosts) do
        local i,j,t = string.find(host, v)
        if (i) then
          return nil
        end
      end

      -- connect somewhere
      local c = socket.try(socket.connect(host, 80))
      c:settimeout(10)
      local try = socket.newtry(function() print("connection failed"); c:close() end)
      try(c:send("GET " .. tostring(path) .. " HTTP/1.1\r\nHost: " .. tostring(host) .. "\r\nReferer: " .. tostring(url) .. "\r\n\r\n"))


      local content = ""
      local answer = ""
      local get_mode = "*l"
      local recv_type = "header"
      local content_length = nil
      local content_type = "png"
      repeat
        answer = try(c:receive(get_mode))
        if (not answer) then
          break
        end

        --print(recv_type .. ": " .. tostring(answer))

        -- recieving content
        if (recv_type == "content") then
          content = answer
          if (get_mode ~= "*l") then
            break
          end
        else
        -- recieving header

          -- Redirected?
          local i,j,l = string.find(answer, "Location: (.*)")
          if (i) then
            --print("Redirected to: " .. tostring(l))
            content = get_image(l, block_hosts)
            break
          end

          -- Is this an image?
          local i,j,t = string.find(answer, "Content%-Type: (.*)")
          if (i) then
            local i,j,t = string.find(t, "image/(.*)")
            if (not i) then
              print("Not an image!")
              return nil
            else
              print("Image type: " .. tostring(t))
              if (t == "jpeg") then
                content_type = "jpg"
              else
                content_type = t
              end
            end
          end
        end

        -- see if the header has ended
        if (answer == "") then
          if (content_length) then
            get_mode = content_length
          end
          recv_type = "content"
        end

        -- find content length
        local i,j,l = string.find(answer, "Content%-Length: (.*)")
        if (i) then
          content_length = tonumber(l)
          if (content_length) <= 0 then
            print("get_content Error: Invalid content length.")
            return nil
          end
        end
      until (not answer)

      c:close()

      return content, content_type
    end
    
    -- settings aoeu
    local output_dir = "/home/sweetfish/www.md5/cache"
    local output_url = "http://cache.md5.se/"
    local block_hosts = {"md5%.se"}

    -- see if we have a url in this message
    local i,j,url = string.find(s, "([%S]+://[%S]+)")
    if not (i == nil) then
      -- see if this is an image
      
      -- connect db
      local env, conn = db_connect()

      -- see if url allready has been cached
      local cursor = assert(conn:execute("SELECT * FROM cachedimages WHERE orgurl = '" .. tostring(url) .. "'"))
      row = {}
      if not cursor:fetch(row) then
        
        -- a 'new' url, check if image / get content
        local content, content_type = get_image(url, block_hosts)
        if (content) then
          
          -- image found, save to disk
          local new_filename = tostring(os.time()) .. "-" .. tostring(math.random(1000,9999)) .. "." .. tostring(content_type)
          local tmpfile = io.open(tostring(output_dir) .. "/" .. tostring(new_filename), "w+")
          tmpfile:write(content)
          tmpfile:close()
          
          -- and store in database
          assert(conn:execute("INSERT INTO cachedimages VALUES('" .. url .. "', '" .. tostring(new_filename) .. "')"))
        end

      end
      cursor:close()

      -- close db
      db_close(env, conn)
      

      
    end
    
    -- see if last message was a title-trigger
    local i,j,sender,chan,url = string.find(msg, ":(.-)!.- PRIVMSG (.-) :" .. tostring(bot.config.triggerprefix) .. "cache (.+)")
    if not (i == nil) then

      if not (string.sub(chan, 1, 1) == "#") then
        chan = sender
      end
      
      -- connect db
      local env, conn = db_connect()
      
      -- get cache filename
      local cursor = assert(conn:execute("SELECT * FROM cachedimages WHERE orgurl = '" .. tostring(url) .. "'"))
      row = {}
      if cursor:fetch(row) then
        --print("cache: " .. tostring(row[2]))
        bot:say(chan, output_url .. tostring(row[2]))
      else
        bot:say(chan, "No cache for that url.")
      end
      cursor:close()
      
      -- close db
      db_close(env, conn)
      
    end
    
  end

end