-- ===== CONFIG =====
local CENTRAL_ID   = nil          -- set with :cid <id>
local PROTO_CMD    = "central_cmd"  -- protocol for sending commands to central
local TIMEOUT_S    = 2
-- ==================

-- open wireless modem
rednet.close()
for _,s in ipairs(rs.getSides()) do if peripheral.getType(s)=="modem" then rednet.open(s) end end
assert(rednet.isOpen(), "No wireless modem. Use an Advanced Wireless Pocket Computer.")

-- ui state
local W,H = term.getSize()
local log = {}
local input = ""
local cursor = 1
local running = true

local function push(msg)
  log[#log+1] = msg
  if #log > 100 then table.remove(log,1) end
end

local function redraw()
  term.setBackgroundColor(colors.black)
  term.setTextColor(colors.white)
  term.clear()
  W,H = term.getSize()
  -- header
  term.setCursorPos(1,1)
  term.setTextColor(colors.yellow)
  local hdr = ("central:%s  proto:%s"):format(CENTRAL_ID and tostring(CENTRAL_ID) or "none", PROTO_CMD)
  term.write(hdr)
  -- log
  term.setTextColor(colors.white)
  local maxLines = math.max(0, H-3)
  local start = math.max(1, #log - maxLines + 1)
  local y = 2
  for i=start,#log do
    term.setCursorPos(1,y)
    term.write(("%-"..W.."s"):format(tostring(log[i]):sub(1,W)))
    y=y+1
  end
  -- input line
  term.setCursorPos(1,H)
  term.setBackgroundColor(colors.blue)
  term.setTextColor(colors.white)
  term.write((":%s"):format(input))
  term.setBackgroundColor(colors.black)
  term.setCursorPos(2+cursor, H)
end

local function send_line(line)
  if not CENTRAL_ID then push("ERR: set central id with :cid <id>"); return end
  local ok = rednet.send(CENTRAL_ID, {type="cmd", line=line}, PROTO_CMD)
  if not ok then push("ERR: rednet.send failed") else push("> "..line) end
end

local function ping()
  if not CENTRAL_ID then push("ERR: no central id") return end
  rednet.send(CENTRAL_ID, {type="ping"}, PROTO_CMD)
  local id,msg,proto = rednet.receive(PROTO_CMD, TIMEOUT_S)
  if id==CENTRAL_ID and type(msg)=="table" and msg.type=="pong" then
    push("pong:"..(msg.note or "ok"))
  else
    push("no pong")
  end
end

local function help()
  push("Commands:")
  push(":cid <id>         set central computer ID")
  push(":ping             test connection")
  push(":proto <name>     set protocol (default central_cmd)")
  push(":send <text>      send raw line")
  push(":help             show this help")
  push("Shortcuts (mapped to central commands):")
  push(" cam yaw <deg> | cam pitch <deg> | cam dist <n>")
  push(" track on|off | highlight x y z [r] | clear highlights")
  push(" center x y z   | tid <id> | tfind")
  push(" fwd/back/up/down <n> | left/right | halt | goto x y z")
end

local function parse_local(cmdline)
  local args = {}
  for w in tostring(cmdline):gmatch("%S+") do args[#args+1]=w end
  if #args==0 then return end
  local c = args[1]:lower()

  if c=="cid" and args[2] then CENTRAL_ID = tonumber(args[2]); push("central id="..tostring(CENTRAL_ID)); return
  elseif c=="ping" then ping(); return
  elseif c=="proto" and args[2] then PROTO_CMD = args[2]; push("proto="..PROTO_CMD); return
  elseif c=="send" then table.remove(args,1); send_line(table.concat(args, " ")); return
  elseif c=="help" or c=="?" then help(); return end

  -- otherwise treat whole line as central command
  send_line(table.concat(args, " "))
end

-- receive loop (acks or server help)
local function net_loop()
  while running do
    local id,msg,proto = rednet.receive(PROTO_CMD, 0.2)
    if id and type(msg)=="table" then
      if msg.type=="ack" then push("ack:"..tostring(msg.note or msg.line or "ok"))
      elseif msg.type=="err" then push("err:"..tostring(msg.note or ""))
      elseif msg.type=="info" then push(tostring(msg.text or ""))
      elseif msg.type=="pong" then push("pong")
      end
    end
  end
end

-- input loop
local function input_loop()
  redraw()
  while running do
    local e = {os.pullEvent()}
    if e[1]=="char" then
      input = input .. e[2]
      cursor = #input
      redraw()
    elseif e[1]=="key" then
      local k=e[2]
      if k==keys.enter then
        local line = input
        input=""; cursor=0
        redraw()
        parse_local(line)
        redraw()
      elseif k==keys.backspace then
        input = input:sub(1, math.max(0,#input-1))
        cursor = #input
        redraw()
      elseif k==keys.q then
        running=false
      end
    elseif e[1]=="term_resize" then
      redraw()
    end
  end
end

parallel.waitForAny(net_loop, input_loop)
term.setBackgroundColor(colors.black); term.setTextColor(colors.white); term.clear()
print("Console closed.")