#!/usr/bin/env lua

local version = 'v0.6.0'
local socket = require("socket")
local urlparser = require("socket.url")
local separator = '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -\n'
local valid_types = {'0', '1', 'i'}
session = { history={ loc=0, items={} }, current_links = {}, favorites={} }
local save_file_location = string.format('%s/.stubbfaves', assert(os.getenv('HOME'), 'Unable to get home directory'))


function string.split(str, sep)
  assert(str and sep, 'sting.split requires both an input string and a field separator string')
  local start = 1
  local t = {}
  while true do
    local out
    local point = string.find(str, sep, start)
    if point == start then
      out = ''
    elseif not point then
      out = string.sub(str, start)
    else
      out = string.sub(str, start, point - 1)
    end
    table.insert(t, out)
    start = point and point + 1 or nil
    if not start then
      break
    end
  end
  return t
end


function table.out(t)
  for i, v in ipairs(t) do
    print(string.format('%q', v))
  end
end


table.has = function(t, item)
  for i, v in pairs(t) do
    if v == item then
      return true
    end
  end

  return false
end


table.truncate = function(t, i)
  while t[i] do
    table.remove(t, i)
  end
end


--based on:
--https://stackoverflow.com/questions/9013290/lua-socket-client/9014261#9014261
function request_gopher(host, port, query)
  local tcp = assert(socket.tcp())
  local response = {}

  tcp:settimeout(4, 't')
  local connection = tcp:connect(host, port);
  local request
  if connection then
    request = tcp:send(query.."\n");
  end

  if request then
    while true do
      local s, status, partial = tcp:receive()
      if status == "closed" then break end
      if s ~= '.' then
        table.insert(response, (s or partial))
      end
    end
    tcp:close()
  elseif connection then
    response[1] = 'iConnection error. Bad request.'
    tcp:close()
  else
    response[1] = 'iConnection error. Bad host.'
  end

  return response
end


function display_gophermap_row(row)
  local val = string.split(row, '\t')
  local gophertype = string.sub(val[1], 1, 1)
  local text = string.sub(val[1], 2)
  local spacer = '              '
  if gophertype == 'i' then
    print(spacer..text)
  elseif table.has(valid_types, gophertype) then
    local leader = gophertype == '0' and 'TXT' or 'MAP'
    local url = string.format('%s:%s/%s%s', val[3] or '', val[4] or '', gophertype, val[2] or '/')
    table.insert(session.current_links, url)
    local linknum = string.format('(%d)', #session.current_links)
    print(string.format(' %s %5s    %s', leader, linknum, text))
  end
end


function getch()
  -- taken from: http://lua.2524044.n2.nabble.com/How-to-get-one-keystroke-without-hitting-Enter-td5858614.html
  os.execute("stty cbreak </dev/tty >/dev/tty 2>&1")
  local key = io.read(1)
  os.execute("stty -cbreak </dev/tty >/dev/tty 2>&1");
  print('\27[1D ')
  return(key);
end


function mainloop()
  print('\n')
  while true do
    local bar = string.format('\27[7m  o--[ S t u b b ]-->    (H)elp, (Q)uit      %d/%d  \27[0m', session.history.loc, #session.history.items)
    print(bar)
    -- print('\27[7m (G)o to url, (B)ack, (V)isit link, (Q)uit \27[0m')
    local key = string.lower(getch())
    if key == 'q' then
      save_favorites()
      os.exit(0)
    elseif key == 'h' then
      print_help()
    elseif key == 'b' then
      back()
    elseif key == 'f' then
      forward()
    elseif key == 'a' then
      add_favorite()
    elseif key == 'l' then
      show_favorites()
    elseif key == 'u' then
      update_favorite()
    elseif key == 'd' then
      remove_favorite()
    elseif key == 's' then
      save_file()
    elseif key == 'r' then
      refresh()
    elseif key == 'g' then
      io.write('Enter gopher url > ')
      local url = io.read()
      if url ~= '0' and url ~= '' then
        go_to_url(url, true)
      else
        print('\n')
      end
    elseif key == 'v' then
      visit_link()
    end
  end
end


function refresh()
  if session.history.loc > 0 then
    go_to_url(session.history.items[session.history.loc])
  end
end


function add_favorite()
  if #session.history.items == 0 then return false end
  local title
  repeat
    io.write('Enter title for bookmark (! to cancel): ')
    title = io.read()
  until title
  if title == '!' then return print('Cancelled') end
  table.insert(session.favorites,{display = title, link = session.history.items[session.history.loc]})
  print('Bookmark added')
  save_favorites()
end


function update_favorite()
  local title
  io.write('Enter the bookmark id (! to cancel) > ')
  local favid = io.read()
  if favid == '!' then return print('Cancelled') end
  local id = tonumber(favid) or tonumber(string.sub(favid,2))
  if id then
    local item = session.favorites[id]
    if item then
      print(string.format('Old title: %s', item.display))
      while not title or title == '' do
        io.write('Enter new title (! to cancel) > ')
        title = io.read()
        if title == '!' then return print('Cancelled') end
      end
      item.display = title
      print('Bookmark has been updated')
      save_favorites()
    else
      print('Invalid bookmark id')
    end
  else
    print('Invalid bookmark id')
  end
end


function remove_favorite()
  io.write('Enter the bookmark id (! to cancel) > ')
  local favid = io.read()
  if favid == '!' then return print('Cancelled') end
  local id = tonumber(favid) or tonumber(string.sub(favid,2))
  if id then
    local item = session.favorites[id]
    if item then
      table.remove(session.favorites, id)
      print('Bookmark has been removed')
      save_favorites()
    else
      print('Invalid bookmark id')
    end
  else
    print('Invalid bookmark id')
  end
end


function visit_link()
  local linkid
  local favorite
  repeat
    favorite = false
    io.write('Enter link id (! to cancel) > ')
    local inp = io.read()
    if inp == '!' then return print('Cancelled') end
    linkid = tonumber(inp)
    if not linkid and string.sub(inp, 1, 1) == 'f' then
      linkid = tonumber(string.sub(inp, 2))
      favorite = true
    end
  until linkid
  local linkurl
  if favorite then
    selection = session.favorites[linkid]
    if selection then
      linkurl = session.favorites[linkid].link
    else
      return print('Invalid bookmark id')
    end
  else
    linkurl = session.current_links[linkid]
  end
  if linkurl then
    table.truncate(session.history.items, session.history.loc + 1)
    go_to_url(linkurl, true)
  else
    local out = string.format('Link id %d does not exist...', linkid)
    print_gopher_error(out)
  end
end

function back()
  if session.history.loc > 1 and #session.history.items > 1 then
    session.history.loc = session.history.loc - 1
    go_to_url(session.history.items[session.history.loc])
  end
end


function forward()
  if session.history.loc < #session.history.items then
    session.history.loc = session.history.loc + 1
    go_to_url(session.history.items[session.history.loc])
  end
end

function print_help()
  print(separator)
  print('\nStubb  ' .. version)
  local helpstring = [[

    Stubb is a text based gopher client that only displays and supports gophertypes:
    0 (text)  and  1 (gopher map).  The application is named for the character Stubb
    from Moby Dick known for his imaginative patter and good humor.

    Commands:

      <Navigation>
        (B)ack
        (F)orward
        (G)o to url
        (R)eload current address
        (V)iew link/bookmark

      <Bookmarks>
        (A)dd bookmark
        (D)elete bookmark
        (L)ist bookmarks
        (U)pdate bookmark title

      <System>
        (H)elp
        (Q)uit Stubb
        (S)ave file to disk
    ]]
  print(helpstring)
end


function print_gopher_error(text)
  print(separator)
  print(text)
end


function save_file()
  if not session.filedata then return print('No file available. Save canceled.') end
  local homedir = assert(os.getenv('HOME'), 'Unable to find home directory')
  io.write('Enter the filename to save as (! to cancel): ' .. homedir .. '/')
  local filename = io.read()
  if filename == '!' or filename == '' then
    return print('Cancelled')
  elseif string.match(filename, '^[%.%w_-]+$') then
    local filepath = homedir .. '/' .. filename
    local f = io.open(filepath, 'w+')
    f:write(table.concat(session.filedata,'\n'))
    f:close()
    print(string.format('File saved as: %s', filepath))
  else
    print('Invalid filename')
  end
end


function go_to_url(u, add2history)
  url = parse_url(u)
  if not url.host or url.scheme ~= 'gopher' then
    print(separator)
    print('             I n v a l i d   u r l')
  elseif table.has(valid_types, url.gophertype) then
    session.filedata = request_gopher(url.host, url.port, url.path)
    print(separator)
    handle_response(session.filedata, url.gophertype)
    local o = url.scheme .. '://' .. url.host .. ':' .. url.port .. '/' .. url.gophertype .. url.path
    print('\n\n')
    print(o)
    if add2history then
      table.truncate(session.history.items, session.history.loc + 1)
      table.insert(session.history.items, o)
      session.history.loc = session.history.loc + 1
    end
  end
end


function handle_response(res_table, gtype)
  if gtype == '0' or gtype == 0 then
    local o = table.concat(res_table, '\n')
    print(o)
  else
    session.current_links = {}
    for i, v in ipairs(res_table) do
      display_gophermap_row(v)
    end
  end
end


-- Modified version of socket.url.parse
-- Sets up defaults and adds parsing of gophertype
function parse_url(u)
  if not string.find(u, '://', 1, true) then
    u = 'gopher://'..u
  end

  local default = {port=70, scheme='gopher'}
  local parsed = urlparser.parse(u, default)
  if not parsed.path then
    parsed.path = '/'
  end
  if string.find(parsed.path, '^/[%d%a]') then
    parsed.gophertype = string.sub(parsed.path, 2, 2)
    parsed.path = string.sub(parsed.path, 3) or '/'
  elseif string.sub(parsed.path, -1) == '/' then
    parsed.gophertype = '1'
  else
    parsed.gophertype = '0'
  end

  return parsed
end


function show_favorites()
  print(separator)
  print('\n >---B O O K M A R K S--->\n\n')
  for i, v in ipairs(session.favorites) do
    print(string.format(' (f%d)  %s', i, v.display))
  end
  print('\n' .. separator)
end


function save_favorites()
  local file = io.open(save_file_location, 'w+')
  file:write("session.favorites = {\n")
  for _,v in ipairs(session.favorites) do
    file:write(string.format("  {[%q] = %q, [%q] = %q},\n", 'display', v.display, 'link', v.link))
  end
  file:write("}\n")
  file:close()
end


function file_exists(name)
  local f=io.open(name,"r")
  if f~=nil then io.close(f) return true else return false end
end




-- run the program
if file_exists(save_file_location) then
  dofile(save_file_location)
end
mainloop()
-- end of program