local serial = require "serialization"
local event = require "event"
local rpc = require "rpc"
local _, unicode = pcall(require, "unicode")

local cfg = {}
local status = ""
local bboard
local ssub = (unicode or {}).sub or string.sub

local function loadConfig()
 local f = io.open("/etc/bbs.cfg","rb")
 if not f then return false end
 cfg = serial.unserialize(f:read("*a"))
 f:close()
 return true
end
local function saveConfig()
 local f = io.open("/etc/bbs.cfg","wb")
 if not f then return false end
 f:write(serial.serialize(cfg))
 f:close()
 return true
end

-- figure out terminal geometry

local function getCursor()
 io.write("\27[6n")
 local b = ""
 repeat
  b = b .. io.read(1)
 until b:match("\27%[%d+;%d+R")
 local y,x = b:match("\27%[(%d+);(%d+)R")
 return tonumber(x), tonumber(y)
end
io.write("\27[999;999H")
local mx, my = getCursor()
print(mx, my)

local function setStatus(str)
 local ox, oy = getCursor()
 status = str
 io.write(string.format("\27[%d;1H\27[0m\27[7m\27[2K%s\27[0m\27[%i;%iH", my, status, oy, ox))
end

local function menu(items, state)
 local state = state or {1,1}
 local i, si = state[1], state[2]
 while true do
  if si > i - 3 then
   si = math.max(1, i-5)
  elseif i > (si+my) - 6 then
   si = math.min(i - (my-3) + 5, #items - (my - 3))
  end
  i = math.max(1,math.min(#items, i))
  print(string.format("\27[H\27[0m\27[7m\27[2K%s\27[0m", items.header or ""))
  for j = si, (si+my)-3 do
   print((i==j and "\27[7m" or "\27[0m") .. "\27[2K" .. (items[j] or ""):sub(1,mx))
  end
  setStatus(status)
  local _,_,ch,co = event.pull(60,"key_down")
  ch=string.char(ch or 0)
  if co == 208 then -- down
   i = i + 1
  elseif co == 200 then -- up
   i = i - 1
  elseif co == 201 then -- pgdn
   i = i - (my - 2)
  elseif co == 209 then -- pgdn
   i = i + my - 2
  else
   return i, ch, co, {i, si}
  end
 end
end

local function popup(str,title)
 local len = (unicode or {}).len or string.len
 if title then
  title=string.format("[%s]",title or "")
 else
  title = ""
 end
 local width, height, content = 0, 0, {}
 for line in str:gmatch("[^\n]*") do
  height = height + 1
  width = math.max(width,len(line))
  content[#content+1] = line
 end
 if width < 1 or height < 1 then return false end
 local startx,starty = ((mx//2)-(width//2))-2, ((my//2)-(height//2))-2
 io.write(string.format("\27[%d;%dH╒═%s%s╕",starty,startx,title,("═"):rep((width+1)-len(title))))
 for k,v in pairs(content) do
  io.write(string.format("\27[%d;%dH│ %s%s │",starty+k,startx,v,(" "):rep(width-len(v))))
 end
 io.write(string.format("\27[%d;%dH┕%s┙",starty+1+#content,startx,("━"):rep(width+2)))
end

local function query(str, default)
 local rv
 io.write(string.format(str, default or "no default"))
 repeat
  rv = io.read()
  rv = #rv > 0 and rv or default or ""
 until #rv > 0
 return rv
end

local function help()
 popup([[
[↑][↓] Move 1 entry
[PgUp][PgDn] Move 1 page
[Enter] Select item

[c] Compose new post
[r] Reply to post
[t] Thread view

[q] Exit

Press any key to continue...]],"Usage")
 event.pull("key_down")
end

local function compose(board, post)
 local post = post or {}
 io.write("\27[2J\27[H")
 post.author = cfg.handle
 post.subject = query("Subject [%s]? ", post.subject)
 fn = os.tmpname()
 os.execute(string.format("edit '%s'",fn))
 f = io.open(fn, "rb")
 if f then
  post.content = f:read("*a")
  f:close()
  os.execute(string.format("rm '%s'", fn))
  print("Posting...")
  bboard.post(board,post)
 else
  print("Post empty, cancelled.")
 end
end

local function viewPost(board,id)
 io.write("\27[2J\27[H")
 post = bboard.getPost(board, id)
 fn = os.tmpname()
 f = io.open(fn, "wb")
 f:write(string.format("Author: %s\nSubject: %s\n", post.author, post.subject))
 f:write(post.content)
 f:close()
 os.execute(string.format("less '%s'", fn))
 os.execute(string.format("rm '%s'", fn))
end

local function threadView(board,id)
 local run = true
 local i, ch, co, st
 local list = bboard.getThread(board, id)
 while run do
  local vl = {header=string.format("%4s %15s %s", "ID", "Author", "Subject")}
  status = string.format("[%s] Thread: %s - %i items", cfg.handle, list[1].subject, #list)
  for k,v in pairs(list) do
   vl[k] = string.format("%4d %15s %s", v.id, v.author:sub(1,15), v.subject):sub(1,mx)
  end
  i, ch, co, st = menu(vl, st)
  if ch == "q" then -- quit
   run = false
  elseif co == 28 then -- enter, view
   viewPost(board, list[i].id)
  elseif ch == "r" then -- reply
   local prev = list[i]
   compose(board, {replyTo=prev.id, subject="Re:"..prev.subject})
   list = bboard.list(board)
  elseif ch == "h" or ch == "?" then
   help()
  end
 end
end

local function boardView(name)
 local run = true
 local i, ch, co, st, fn, f, post
 local list = bboard.list(name)
 while run do
  status = string.format("[%s] %s/%s - %i items", cfg.handle, cfg.server, name, #list)
  local vl = {header=string.format("%4s %15s %s", "ID", "Author", "Subject")}
  for k,v in pairs(list) do
   vl[k] = string.format("%4d %15s %s", v.id, v.author:sub(1,15), v.subject):sub(1,mx)
  end
  i, ch, co, st = menu(vl, st)
  if ch == "q" then -- quit
   run = false
  elseif co == 28 then -- enter, view
   viewPost(name, list[i].id)
  elseif ch == "c" then -- compose
   compose(name)
   list = bboard.list(name)
  elseif ch == "r" then -- reply
   local prev = list[i]
   compose(name, {replyTo=prev.id, subject="Re:"..prev.subject})
   list = bboard.list(name)
  elseif ch == "t" then -- thread view
   threadView(name,list[i].id)
  elseif ch == "h" or ch == "?" then
   help()
  end
 end
end

io.write("\27[2J\27[H")
setStatus("Loading config")
loadConfig()
setStatus("Basic setup...")
cfg.server = query("Server [%s]?", cfg.server)
cfg.handle = query("Username? [%s]?", cfg.handle)
setStatus("Saving config")
saveConfig()

setStatus("Connecting...")
bboard = rpc.proxy(cfg.server, "bbs_")

local run = true
local i, ch, co, st
while run do
 local list = bboard.boards()
 setStatus(string.format("Connected to %s - %i boards",cfg.server,#list))
 list.header = "Choose a board..."
 i, ch, co, st = menu(list, st)
 if ch == "q" then
  run = false
 elseif co == 28 then
  boardView(list[i])
 elseif ch == "h" or ch == "?" then
  help()
 end
end