#!/usr/bin/env lua


--___________--
--> GLOBALS <--
---------------

filepath = os.getenv('HOME') .. '/.notes/'
Note = {}
Note.__index = Note
setmetatable(Note, {__call = function(cls, ...) return cls:new() end})
Note.editor = os.getenv('VISUAL') or os.getenv('EDITOR') or 'vim'
current_notes = {}
term_width = 80

--______________--
--> Main Calls <--
------------------

function mainloop()
  term_width = get_term_width()
  local key = string.lower(getch())
  io.write('\27[100D\27[1A\27[K')
  if key == 'q' then os.exit(0)
  elseif key == 'a' then add_note()
  elseif key == 'l' then list_notes()
  elseif key == 'v' then get_note_id('view',view_note)
  elseif key == 'd' then get_note_id('delete', delete_note)
  elseif key == 'e' then get_note_id('edit', edit_note)
  end
end

function add_note()
  local note = Note()
  if note then
    io.write('Save note (y/n)? ')
    local subkey = string.lower(getch())
    if subkey ~= 'y' then
      return list_notes()
    end
    local s, e = note:save_local()
    if s then
      table.insert(current_notes, note)
      list_notes()
    else
      print(e)
    end
  else
    list_notes()
  end
end

function view_note(num)
  clear()
  display_header()

  print('Title    : \27[3m' ..current_notes[num].title .. '\27[m')
  print('Note id  : ' .. tostring(num))
  print('Priority : ' .. current_notes[num].priority .. '\n\n')
  local wrapped_content = wrap_text(current_notes[num].content, term_width)
  print(wrapped_content)
  display_footer()
end

function edit_note(num)
  -- TODO
  -- add a check for save and revert if check fails
  local content = current_notes[num].content
  current_notes[num]:edit_content()
  current_notes[num]:save_local()
  list_notes()
end

function delete_note(num)
  local s = '\nAre you sure you want to delete note %q (y/n)? '
  s = string.format(s, current_notes[num].title)
  s = wrap_text(s, term_width)
  io.write(s)
  res = string.lower(getch())
  if not res or res ~= 'y' then return list_notes() end
  local d = os.execute('rm ' .. filepath .. current_notes[num].time .. '.no')
  table.remove(current_notes, num)
  list_notes()
end

function order_notes()
  -- pass
end

function show_help()
  -- pass
end

function list_notes()
  term_width = get_term_width()
  clear()
  display_header()
  if #current_notes < 1 then
    print('\n\n' .. string.rep(' ', 24) .. 'You have not taken any notes yet\n\n')
  else
    for i, note in ipairs(current_notes) do
      -- TODO add priority to the list view, maybe sort?
      print(string.format('%4d) %-' .. tostring(term_width - 19) .. 's %s', i, note.title ,os.date('%d %b %Y', note.time)))
    end
  end
  display_footer()
end

function get_note_id(action, fn)
  local num
  while true do
    io.write(string.format('\nWhich note would you like to %s? ', action))
    num = tonumber(io.read())
    if num and num > 0 and num <= #current_notes then break
    elseif num then print('Entry must be a valid note id')
    else return list_notes() end
  end
  return fn(num)
end


--___________--
--> HELPERS <--
---------------

function retrieve_from_remote()
  --
end

function push_to_remote()
  --
end

function get_notes()
  local dir = io.popen('ls ' .. filepath)
  while true do
    local fname = dir:read()
    if not fname then break end
    local n = Note:create(fname)
    if n then table.insert(current_notes, n) end
  end
end

function display_header()
  local pencil = [[


             ,----,---,---------------------------------------.
             |    |||||______________________________________/  `.
             |    |||||    _  .                              |    >
             :____;|_|;___|_|_|_______________________________\.`
    ]]
  if term_width > 68 then
    print(pencil)
  end
  print('\n' .. string.rep('*', term_width / 2 - 3) .. ' jott ' .. string.rep('*', term_width / 2 - 3) .. '\n\n' )
end

function display_footer()
  local bar = '--- (L)ist, (V)iew, (A)dd, (E)dit, (D)elete ' .. string.rep('-', term_width - 64) .. ' (H)elp, (Q)uit --> '
  local shortbar = string.rep('-', term_width - 20) .. ' (H)elp, (Q)uit --> '
  local bar_to_use = term_width >= 70 and bar or shortbar
  print('\n')
  print(bar_to_use)
end

function clear()
  io.write(string.char(27) .. '[1;1H ' .. string.char(27) .. '[0J')
end


--______________--
--> NOTE CLASS <--
------------------

function Note:create(name)
  self = setmetatable({}, Note)
  local fd
  if name then
    fd, err = self.parse_file(name)
    if not fd then return false end
  else
    fd = {}
  end

  self.title = fd.title or ''
  self.content = fd.content or ''
  self.priority = fd.priority or ''
  self.time = tonumber(fd.time) or os.time()
  return self
end

function Note:set_title()
  self.title = ''
  while true do
    io.write('Title : ')
    self.title = io.read()
    if #self.title > 60 then
      print('Titles must be between 1 and 60 characters')
    else
      break
    end
  end
end

function Note:set_priority()
  self.priority = nil
  while not self.priority do
    io.write('Priority (1-10): ')
    self.priority = tonumber(io.read())
    if not self.priority then
      print('Priority must be between 1 and 10...')
    end
  end
end

function Note:set_content()
  local filename = os.tmpname()
  os.execute(self.editor .. " " .. filename)
  if not file_exists(filename) then
    return false
  end
  local file = io.open(filename, 'r')
  local buffer
  file:seek('set')
  buffer = file:read('*a')
  file:close()
  local s, e = os.remove(filename)
  if not s then
    return false
  end
  self.content = buffer
end

function Note:edit_content()
  local actual_fn = filepath .. tostring(self.time) .. '.no'
  if not file_exists(actual_fn) then
    return false
  end
  local temp_fn = os.tmpname()
  local file = io.open(temp_fn, 'w')
  file:seek('set')
  file:write(self.content)
  file:close()
  os.execute(self.editor .. " " .. temp_fn)
  file = io.open(temp_fn, 'r')
  file:seek('set')
  local buffer = file:read('*a')
  file:close()
  self.content = buffer
  local s = os.remove(temp_fn)
  if not s then
    return false
  end
  return true
end

function Note.check_priority(num)
  local num = tonumber(num)
  if num and num > 0 and num < 11 then
    return num
  end

  return false
end

function Note:new()
  local n = self.create()
  if not n then return nil, 'There was an error adding your note :(' end
  n:set_title()
  if n.title == '' then return false end
  n:set_priority()
  n:set_content()
  return n
end

function Note:save_local()
  local filename = filepath .. tostring(self.time) .. '.no'
  local f = assert(io.open(filename, 'w'))
  if not f then
    return nil, 'Could not open file: ' .. filename
  end
  local data = 'title|%s\ntime|%d\npriority|%s\n.\n%s'
  local out = string.format(data, self.title, self.time, self.priority, self.content)
  f:write(out)
  f:flush()
  f:close()
  return true
end

function Note.parse_file(fname)
  local fpath = filepath .. fname
  local file = io.open(fpath, 'r')
  local out = {}
  local content = false
  local c_out = {}
  if not file then
    return nil, 'Error opening file ' .. filepath
  end
  for line in file:lines() do
    if line == '.' then
      content = true
    elseif not content then
      local s = string.split(line, '|')
      out[s[1]] = s[2]
    else
      table.insert(c_out, line)
    end
  end
  out['content'] = table.concat(c_out,'\n')

  return out
end


--_____________--
--> UTILITIES <--
-----------------

function build_path()
  os.execute('mkdir ' .. filepath .. ' 2>/dev/null')
  --os.execute('mkdir ' .. filepath .. 'content/' .. ' 2>/dev/null')
  --os.execute('mkdir ' .. filepath .. 'meta/' .. ' 2>/dev/null')
end

function get_term_width()
  local pop = io.popen('tput cols')
  local cols = tonumber(pop:read())
  pop:close()
  return (cols and cols < 80) and cols or 80
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 string.sub(key,1,1);
-- end

function getch()
  os.execute("stty cbreak -echo")
  local key = io.read(1)
  if string.byte(key) == 27 then
    io.read(2)
  end
  os.execute("stty -cbreak echo");
  print('\27[1D ')
  return key
end

function wrap_text(str,len)
  local lines = string.split(str, '\n')
  local out = {}
  for i, line in ipairs(lines) do
    if #line <= len then
      table.insert(out,line)
    else
      local words = string.split(line, ' ')
      local subout = ''
      for i, word in ipairs(words) do
        if #subout + #word <= len then
          local spc = #subout > 0 and ' ' or ''
          subout = subout .. spc .. word
          if i == #words then
            table.insert(out, subout)
          end
        else
          table.insert(out, subout)
          subout = word
        end
      end
    end
  end
  return table.concat(out, '\n')
end

function string.trim(str)
  local pattern = '^%s*([%w%p ]-)%s*$'
  return string.match(s, pattern)
end

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 file_exists(fn)
  local file = io.open(fn, 'r')
  if file ~= nil  then
    file:close()
    return true
  end

  return false
end


--________--
--> INIT <--
------------

function init()
  term_width = get_term_width()
  build_path()
  get_notes()
  list_notes()
  while true do
    mainloop()
  end
end

init()