local hexchat = hexchat
hexchat.register("rot13", "3.0.1", "rot13")

local rot13 = {}

for i = string.byte('a'), string.byte('m') do
  local a, b = string.char(i), string.char(i+13)
  local A, B = a:upper(), b:upper()
  rot13[a] = b
  rot13[b] = a
  rot13[A] = B
  rot13[B] = A
end

local function do_rot13(arg, arg_eol)
  if not arg[3] then
    hexchat.print("Usage: /" .. arg[1] .. " <reason> <content>")
    return hexchat.EAT_ALL
  end
  hexchat.command("say " .. arg[2] .. "\x01CW1 " .. arg_eol[3]:gsub("[A-Za-z]", rot13) .. "\x01")
  return hexchat.EAT_ALL
end

hexchat.hook_command("cw-rot13", do_rot13)

local function startswith(str1, str2)
  return str1:sub(1, #str2) == str2
end

local function parsecw(msg)
  local hidden = {}
  msg = msg:gsub("()(\1([^\1]*)\1)()", function(start, ctcp, contents, finish)
      if startswith(contents, "CW1 ") then
        local cw = contents:sub(5)
        hidden[#hidden + 1] = cw:gsub("[A-Za-z]", rot13)
        return " [Hidden Text " .. #hidden .. "] "
      end
      return ctcp
    end)
  return msg, hidden
end

local invert_notice = false
local last_notice = false

local tunpack = unpack or table.unpack

local skip = false
local function mkparse(event, pos)
  return function(word, attributes)
    if skip then return end
    if event:find("Notice$") then
        if invert_notice then
            word[pos] = '\1'.. word[pos]
            if last_notice then
                word[pos] = word[pos] .. '\1'
            end
        end
    end
    invert_notice = false
    local old_msg = word[pos]
    local hidden
    word[pos], hidden = parsecw(word[pos])
    if word[pos] ~= old_msg then
      skip = true
      hexchat.emit_print_attrs(attributes, event, tunpack(word))
      for i, v in ipairs(hidden) do
        hexchat.print("\00326*\tHidden Text " .. i .. "\3 > \8"..v.."\8 < (Copy and paste to expand)")
      end
      skip = false
      return hexchat.EAT_ALL
    end
  end
end

local function hookparse(event, pos)
  return hexchat.hook_print_attrs(event, mkparse(event, pos))
end

do
  (function(f,...)return f(f,...) end)(function(f, a, b, ...)
      if a then 
        hookparse(a, b)
        return f(f, ...)
      end
    end,
    "Channel Message", 2,
    "Channel Msg Hilight", 2,
    "Channel Notice", 3,
    "Private Message", 2,
    "Private Message to Dialog", 2,
    "Notice", 2,
    "Your Message", 2,
    "Notice Send", 2,
    "Message Send", 2,
    nil)
end

-- from here on: 3.0.1 bugfix

-- TODO maybe move these to a separate plugin. (or integrate them in hexchat)

local function tooct(n)
    return string.format("%o", n)
end

local function on_privmsg(word, word_eol, attrs)
    -- fix up some PRIVMSGs, pass them on to our handlers above
    local i_at = 0
    for i,v in ipairs(word) do
        if v == "PRIVMSG" then
            i_at = i + 2
            break
        end
    end
    if i_at == 0 then return end
    if word_eol[i_at]:sub(1, 2):find(":[-+]") and tooct(hexchat.props["flags"]):find("[4-7].$") then -- bleh
        word_eol[i_at] = ":" .. word_eol[i_at]:sub(3)
    end
    if word_eol[i_at]:sub(1, 6) == ":\1CW1 " then
        if not word_eol[i_at]:find("\1", 7, true) == #word_eol[i_at] then
            return hexchat.EAT_NONE -- let hexchat handle it normally
        end
        local target = word[i_at - 1]
        local source
        if word[1]:sub(1,1) ~= "@" then
            source = word[1]
        else
            source = word[2]
        end
        source = source:match("^:([^!]+)!") -- this seems easy, right?
        local context = hexchat.find_context(hexchat.get_info("server"), target)
        if context then
            local old_ctx = hexchat.get_context()
            local serv_id = hexchat.props["id"]
            -- sanity check
            if hexchat.set_context(context) and hexchat.props["id"] == serv_id then
                if hexchat.props["type"] == 2 then
                    local prefix = ""
                    for user in hexchat.iterate("users") do
                        if user.nick == source then
                            prefix = user.prefix
                        end
                    end
                    -- TODO fix highlights
                    hexchat.emit_print_attrs(attrs, "Channel Message", source, word_eol[i_at]:sub(2), prefix)
                    return hexchat.EAT_HEXCHAT
                elseif hexchat.props["type"] == 3 then
                    hexchat.emit_print_attrs(attrs, "Private Message to Dialog", source, word_eol[i_at]:sub(2))
                    return hexchat.EAT_HEXCHAT
                end
            end
            -- assume it's a query, because usually you only get channel messages if you're in the channel
            if not hexchat.set_context(old_ctx) then return end -- how did we get this far without segfaulting?
        end
        if hexchat.prefs["gui_autoopen_dialog"] then
            hexchat.command("query -nofocus " .. target)
            local context = hexchat.find_context(hexchat.get_info("server"), target)
            if context then
                local old_ctx = hexchat.get_context()
                local serv_id = hexchat.props["id"]
                -- sanity check
                if hexchat.set_context(context) and hexchat.props["id"] == serv_id then
                    -- meh, go hardmode on this (this shouldn't happen unless find_context returns the server context for some reason)
                    if hexchat.props["type"] ~= 3 then
                        local found = false
                        for chan in hexchat.iterate("channels") do
                            if chan.id == serv_id and chan.type == 3 and chan.channel == source then
                                found = true
                                hexchat.set_context(chan.context)
                            end
                        end
                        -- still not found? ragequit!
                        if not found then return hexchat.EAT_HEXCHAT end
                    end
                    hexchat.emit_print_attrs(attrs, "Private Message to Dialog", source, word_eol[i_at]:sub(2))
                end
            end
            return hexchat.EAT_HEXCHAT
        end
        hexchat.emit_print_attrs(attrs, "Private Message", source, word_eol[i_at]:sub(2))
        return hexchat.EAT_HEXCHAT
    end
end

local function on_notice(word, word_eol, attrs) -- this one is much simpler
    local i_at = 0
    for i,v in ipairs(word) do
        if v == "NOTICE" then
            i_at = i + 2
            break
        end
    end
    if i_at == 0 then return end
    if word_eol[i_at]:sub(1, 2):find(":[-+]") and tooct(hexchat.props["flags"]):find("[4-7].$") then -- bleh
        word_eol[i_at] = ":" .. word_eol[i_at]:sub(3)
    end
    if word_eol[i_at]:sub(1, 6) == ":\1CW1 " then
        -- workaround
        invert_notice = true
        last_notice = word_eol[i_at]:sub(-1,-1) == "\1"
        -- then just let hexchat handle it
    end
end


hexchat.hook_server_attrs("PRIVMSG", on_privmsg)

hexchat.hook_server_attrs("NOTICE", on_notice)

hexchat.print("rot13 loaded") -- this was in 3.0.0 too