local component = require "component"
local event = require "event"
local f = component.list("openprinter")()
local printer = f and component.proxy(f)
local _, unicode = pcall(require, "unicode")
local _, printwidth = pcall(require, "printwidth")
local tA = {...}

local buffer = {}
local cx, cy = 1, 1
local vx, vy = 1, 1
local lcx, lcy = 1, 1
local mx, my = 80, 25
local w, f = pcall(require, "mtmenu")
if w then
 mx, my = t.getScreenSize()
else
 mx, my = require("term").getViewport()
end

local mw = printer and printer.maxWidth() or 164
local width = (printwidth or {}).width or printer.width

if #tA < 1 then
 print("Usage: wip <filename>")
 os.exit()
end

local f = io.open(tA[1], "rb")
if f then
 for line in f:lines() do
  buffer[#buffer+1] = line
 end
else
 buffer[1] = ""
end

local function save(fn)
 fn=fn or tA[1]
 local f = io.open(fn, "wb")
 if f then
  for k,v in ipairs(buffer) do
   f:write(v.."\n")
  end
  f:close()
 end
end

local function fwrite(...)
 return io.write(string.format(...))
end

local function printerFormat(s)
 s=s:gsub("^##","§n")
 s=s:gsub("^#","§l§n")
 s=s:gsub("%*(.-)%*","§o%1§r")
 s=s:gsub("$DATE",os.date("%Y-%m-%d"))
 return s
end

local function getOF(s, start)
 start=start or 1
 local f, o = "", ""
 for i = start, #s do
  if width(printerFormat(s:sub(1,i))) >= mw then
   f, o = s:sub(1,i-1), s:sub(i)
   return f, o, i
  end
 end
 return s:sub(start), "", 80
end

local function findLastPageBreak(n)
 for i = n, 1, -1 do
  if (buffer[i] or ""):sub(1,1) == "&" then
   return i
  end
 end
 return 0
end
local function displayLine(n)
 for i = n, 1, -1 do
  if (buffer[i] or ""):sub(1,1) == "&" then
   return (n - i)%21
  end
 end
 return n%21
end
local function displayPage(n)
 local r,l = 0, 0
 for i,v in ipairs(buffer) do
  if v:sub(1,1) == "&" or i > l+20 then
   r, l = r + 1, i
  end
  if i == n then break end
 end
 return r
end

local function draw(full)
 cx, cy = math.max(1, math.min(cx, #(buffer[cy] or "")+1)), math.max(1, math.min(cy, #buffer))
 local dx=mx-4
 while cy > (vy + my - (my/4)) do vy = vy + math.ceil(my/3) end
 while cy < (vy + (my/4)) do vy = vy - math.ceil(my/3) end
 while cx > (vx + dx - (dx/4)) do vx = vx + math.ceil(dx/3) end
 while cx < (vx + (dx/4)) do vx = vx - math.ceil(dx/3) end
 vx, vy=math.max(1, vx), math.max(1,vy)
 local start, finish = math.max(1,cy-1), math.min(cy+1, #buffer)
 if cy ~= lcy or full then start, finish = vy, vy + (my-2) end
 local tcx, tcy = cx - vx + 5, cy - vy + 1
 for i = start, finish do
  local ti = i - vy + 1
  local line = buffer[i] or ""
  local fit, overflow, ofi = getOF(line, vx)
  fit=fit:sub(vx)
  local lc = line:sub(1,1) == "#" and 32 or line:sub(1,1) == "&" and 7 or 0
  fwrite("\27[%i;1H\27[36m%3i \27[%im%s\27[31m%s\27[0m%s", ti, displayLine(i), lc, fit:gsub("%*(.-)%*","\27[7m*%1*\27[0m"), overflow:sub(1,mx-#fit-4), (" "):rep(mx-#fit-#overflow-4))
 end
 if cy ~= lcy or cx ~= lcx or full then
  local lst = string.format("🗑^W 🖬^S 🖨^P 🗎%s",tA[1])
  local rst = string.format("🗐%i/%i%+4i,%-3i", displayPage(cy),displayPage(#buffer), cx, cy)
  fwrite("\27[%i;1H%s%"..tostring(mx-unicode.wlen(lst)).."s",my,lst,rst)
 end
 local cc = buffer[cy]:sub(cx, cx)
 cc = #cc > 0 and cc or " "
 fwrite("\27[%i;%iH\27[7m%s\27[0m",tcy, tcx,cc)
 lcx, lcy = cx, cy
end

io.write("\27[2J\27[H")
draw(true)
local frd = false
while true do
 draw(frd)
 frd=false
 local tE = {event.pull()}
 if tE[1] == "key_down" then
  ch, co = tE[3], tE[4]
  if ch == 23 and co == 17 then
   break
  elseif co == 200 then -- up
   cy = cy - 1
  elseif co == 208 then -- down
   cy = cy + 1
  elseif co == 203 then -- left
   cx = cx - 1
  elseif co == 205 then -- right
   cx = cx + 1
  elseif ch > 31 and ch < 127 then -- insert character
   buffer[cy] = buffer[cy]:sub(1,cx-1) .. string.char(ch) .. buffer[cy]:sub(cx)
   cx = cx + 1
  elseif ch == 8 and co == 14 then -- backspace
   if cx == 1 and cy > 1 then
    cx = #buffer[cy-1]+1
    buffer[cy-1] = buffer[cy-1] .. table.remove(buffer, cy)
    cy = cy - 1
    frd = true
   else
    buffer[cy] = buffer[cy]:sub(1,cx-2) .. buffer[cy]:sub(cx)
    cx = cx - 1
   end
  elseif ch == 127 and co == 211 then -- delete
   if cx == #buffer[cy]+1 then
    buffer[cy] = buffer[cy] .. (table.remove(buffer,cy+1) or "")
    frd = true
   else
    buffer[cy] = buffer[cy]:sub(1,cx-1) .. buffer[cy]:sub(cx+1)
    end
  elseif ch == 13 and co == 28 then -- enter
   table.insert(buffer, cy+1, buffer[cy]:sub(cx))
   buffer[cy] = buffer[cy]:sub(1,cx-1)
   cx,cy=1,cy+1
   frd = true
  elseif co == 199 then -- home
   cx = 1
  elseif co == 207 then -- end
   cx = #buffer[cy] + 1
  elseif co == 201 then -- pgup
   cy = cy - (my-1)
  elseif co == 209 then -- pgdn
   cy = cy + (my-1)
  elseif ch == 19 and co == 31 then -- ^s, save
   save()
  elseif ch == 16 and co == 25 then -- ^p, print
   local tn = os.tmpname()
   save(tn)
   io.write("\27[2J\27[H")
   os.execute(string.format("wipprint '%s'", tn))
   require("filesystem").remove(tn)
   frd = true
  end
 elseif tE[1] == "touch" then
  local tx, ty = tE[3], tE[4]
  cx, cy = vx + tx - 5, vy + ty - 1
  frd = true
 end
end
io.write("\27[2J\27[H")