-- To test tui/input.c, this module spawns `nvim` inside :terminal and sends
-- bytes via jobsend().  Note: the functional/helpers.lua test-session methods
-- operate on the _host_ session, _not_ the child session.
local helpers = require('test.functional.helpers')(nil)
local Screen = require('test.functional.ui.screen')
local testprg = helpers.testprg
local exec_lua = helpers.exec_lua
local api = helpers.api
local nvim_prog = helpers.nvim_prog

local function feed_data(data)
  if type(data) == 'table' then
    data = table.concat(data, '\n')
  end
  exec_lua('vim.api.nvim_chan_send(vim.b.terminal_job_id, ...)', data)
end

local function feed_termcode(data)
  feed_data('\027' .. data)
end

local function make_lua_executor(session)
  return function(code, ...)
    local status, rv = session:request('nvim_exec_lua', code, { ... })
    if not status then
      session:stop()
      error(rv[2])
    end
    return rv
  end
end

-- some helpers for controlling the terminal. the codes were taken from
-- infocmp xterm-256color which is less what libvterm understands
-- civis/cnorm
local function hide_cursor()
  feed_termcode('[?25l')
end
local function show_cursor()
  feed_termcode('[?25h')
end
-- smcup/rmcup
local function enter_altscreen()
  feed_termcode('[?1049h')
end
local function exit_altscreen()
  feed_termcode('[?1049l')
end
-- character attributes
local function set_fg(num)
  feed_termcode('[38;5;' .. num .. 'm')
end
local function set_bg(num)
  feed_termcode('[48;5;' .. num .. 'm')
end
local function set_bold()
  feed_termcode('[1m')
end
local function set_italic()
  feed_termcode('[3m')
end
local function set_underline()
  feed_termcode('[4m')
end
local function set_underdouble()
  feed_termcode('[4:2m')
end
local function set_undercurl()
  feed_termcode('[4:3m')
end
local function set_strikethrough()
  feed_termcode('[9m')
end
local function clear_attrs()
  feed_termcode('[0;10m')
end
-- mouse
local function enable_mouse()
  feed_termcode('[?1002h')
end
local function disable_mouse()
  feed_termcode('[?1002l')
end

local default_command = { testprg('tty-test') }

local function screen_setup(extra_rows, command, cols, env, screen_opts)
  extra_rows = extra_rows and extra_rows or 0
  command = command and command or default_command
  cols = cols and cols or 50

  api.nvim_command('highlight TermCursor cterm=reverse')
  api.nvim_command('highlight TermCursorNC ctermbg=11')

  local screen = Screen.new(cols, 7 + extra_rows)
  screen:set_default_attr_ids({
    [1] = { reverse = true }, -- focused cursor
    [2] = { background = 11 }, -- unfocused cursor
    [3] = { bold = true },
    [4] = { foreground = 12 }, -- NonText in :terminal session
    [5] = { bold = true, reverse = true },
    [6] = { foreground = 81 }, -- SpecialKey in :terminal session
    [7] = { foreground = 130 }, -- LineNr in host session
    [8] = { foreground = 15, background = 1 }, -- ErrorMsg in :terminal session
    [9] = { foreground = 4 },
    [10] = { foreground = 121 }, -- MoreMsg in :terminal session
    [11] = { foreground = 11 }, -- LineNr in :terminal session
    [12] = { underline = true },
    [13] = { underline = true, reverse = true },
    [14] = { underline = true, reverse = true, bold = true },
    [15] = { underline = true, foreground = 12 },
    [16] = { background = 248, foreground = 0 }, -- Visual in :terminal session
  })

  screen:attach(screen_opts or { rgb = false })

  api.nvim_command('enew')
  api.nvim_call_function('termopen', { command, env and { env = env } or nil })
  api.nvim_input('<CR>')
  local vim_errmsg = api.nvim_eval('v:errmsg')
  if vim_errmsg and '' ~= vim_errmsg then
    error(vim_errmsg)
  end

  api.nvim_command('setlocal scrollback=10')
  api.nvim_command('startinsert')
  api.nvim_input('<Ignore>') -- Add input to separate two RPC requests

  -- tty-test puts the terminal into raw mode and echoes input. Tests work by
  -- feeding termcodes to control the display and asserting by screen:expect.
  if command == default_command and screen_opts == nil then
    -- Wait for "tty ready" to be printed before each test or the terminal may
    -- still be in canonical mode (will echo characters for example).
    local empty_line = (' '):rep(cols)
    local expected = {
      'tty ready' .. (' '):rep(cols - 9),
      '{1: }' .. (' '):rep(cols - 1),
      empty_line,
      empty_line,
      empty_line,
      empty_line,
    }
    for _ = 1, extra_rows do
      table.insert(expected, empty_line)
    end

    table.insert(expected, '{3:-- TERMINAL --}' .. ((' '):rep(cols - 14)))
    screen:expect(table.concat(expected, '|\n') .. '|')
  else
    -- This eval also acts as a poke_eventloop().
    if 0 == api.nvim_eval("exists('b:terminal_job_id')") then
      error('terminal job failed to start')
    end
  end
  return screen
end

local function setup_child_nvim(args, opts)
  opts = opts or {}
  local argv = { nvim_prog, unpack(args) }

  local env = opts.env or {}
  if not env.VIMRUNTIME then
    env.VIMRUNTIME = os.getenv('VIMRUNTIME')
  end

  return screen_setup(0, argv, opts.cols, env)
end

return {
  feed_data = feed_data,
  feed_termcode = feed_termcode,
  make_lua_executor = make_lua_executor,
  hide_cursor = hide_cursor,
  show_cursor = show_cursor,
  enter_altscreen = enter_altscreen,
  exit_altscreen = exit_altscreen,
  set_fg = set_fg,
  set_bg = set_bg,
  set_bold = set_bold,
  set_italic = set_italic,
  set_underline = set_underline,
  set_underdouble = set_underdouble,
  set_undercurl = set_undercurl,
  set_strikethrough = set_strikethrough,
  clear_attrs = clear_attrs,
  enable_mouse = enable_mouse,
  disable_mouse = disable_mouse,
  screen_setup = screen_setup,
  setup_child_nvim = setup_child_nvim,
}