local lfs = require('lfs')
local helpers = require('test.functional.helpers')(after_each)

local assert_log = helpers.assert_log
local assert_nolog = helpers.assert_nolog
local clear = helpers.clear
local command = helpers.command
local eq = helpers.eq
local neq = helpers.neq
local ok = helpers.ok
local feed = helpers.feed
local funcs = helpers.funcs
local nvim_prog = helpers.nvim_prog
local request = helpers.request
local retry = helpers.retry
local rmdir = helpers.rmdir
local matches = helpers.matches
local mkdir = helpers.mkdir
local sleep = helpers.sleep
local read_file = helpers.read_file
local tmpname = helpers.tmpname
local trim = helpers.trim
local currentdir = helpers.funcs.getcwd
local iswin = helpers.iswin
local assert_alive = helpers.assert_alive
local expect_exit = helpers.expect_exit
local write_file = helpers.write_file
local Screen = require('test.functional.ui.screen')
local feed_command = helpers.feed_command
local isCI = helpers.isCI
local skip = helpers.skip

describe('fileio', function()
  before_each(function()
  end)
  after_each(function()
    expect_exit(command, ':qall!')
    os.remove('Xtest_startup_shada')
    os.remove('Xtest_startup_file1')
    os.remove('Xtest_startup_file1~')
    os.remove('Xtest_startup_file2')
    os.remove('Xtest_тест.md')
    os.remove('Xtest-u8-int-max')
    os.remove('Xtest-overwrite-forced')
    rmdir('Xtest_startup_swapdir')
    rmdir('Xtest_backupdir')
  end)

  it('fsync() codepaths #8304', function()
    clear({ args={ '-i', 'Xtest_startup_shada',
                   '--cmd', 'set directory=Xtest_startup_swapdir' } })

    -- These cases ALWAYS force fsync (regardless of 'fsync' option):

    -- 1. Idle (CursorHold) with modified buffers (+ 'swapfile').
    command('write Xtest_startup_file1')
    feed('ifoo<esc>h')
    command('write')
    eq(0, request('nvim__stats').fsync)   -- 'nofsync' is the default.
    command('set swapfile')
    command('set updatetime=1')
    feed('izub<esc>h')                    -- File is 'modified'.
    sleep(3)                              -- Allow 'updatetime' to expire.
    retry(3, nil, function()
      eq(1, request('nvim__stats').fsync)
    end)
    command('set updatetime=9999')

    -- 2. Exit caused by deadly signal (+ 'swapfile').
    local j = funcs.jobstart({ nvim_prog, '-u', 'NONE', '-i',
                               'Xtest_startup_shada', '--headless',
                               '-c', 'set swapfile',
                               '-c', 'write Xtest_startup_file2',
                               '-c', 'put =localtime()', })
    sleep(10)         -- Let Nvim start.
    funcs.jobstop(j)  -- Send deadly signal.

    -- 3. SIGPWR signal.
    -- ??

    -- 4. Explicit :preserve command.
    command('preserve')
    eq(2, request('nvim__stats').fsync)

    -- 5. Enable 'fsync' option, write file.
    command('set fsync')
    feed('ibaz<esc>h')
    command('write')
    eq(4, request('nvim__stats').fsync)
  end)

  it('backup #9709', function()
    skip(isCI('cirrus'))
    clear({ args={ '-i', 'Xtest_startup_shada',
                   '--cmd', 'set directory=Xtest_startup_swapdir' } })

    command('write Xtest_startup_file1')
    feed('ifoo<esc>')
    command('set backup')
    command('set backupcopy=yes')
    command('write')
    feed('Abar<esc>')
    command('write')

    local foobar_contents = trim(read_file('Xtest_startup_file1'))
    local bar_contents = trim(read_file('Xtest_startup_file1~'))

    eq('foobar', foobar_contents);
    eq('foo', bar_contents);
  end)

  it('backup with full path #11214', function()
    skip(isCI('cirrus'))
    clear()
    mkdir('Xtest_backupdir')
    command('set backup')
    command('set backupdir=Xtest_backupdir//')
    command('write Xtest_startup_file1')
    feed('ifoo<esc>')
    command('write')
    feed('Abar<esc>')
    command('write')

    -- Backup filename = fullpath, separators replaced with "%".
    local backup_file_name = string.gsub(currentdir()..'/Xtest_startup_file1',
      iswin() and '[:/\\]' or '/', '%%') .. '~'
    local foo_contents = trim(read_file('Xtest_backupdir/'..backup_file_name))
    local foobar_contents = trim(read_file('Xtest_startup_file1'))

    eq('foobar', foobar_contents);
    eq('foo', foo_contents);
  end)

  it('backup symlinked files #11349', function()
    skip(isCI('cirrus'))
    clear()

    local initial_content = 'foo'
    local link_file_name = 'Xtest_startup_file2'
    local backup_file_name = link_file_name .. '~'

    write_file('Xtest_startup_file1', initial_content, false)
    lfs.link('Xtest_startup_file1', link_file_name, true)
    command('set backup')
    command('set backupcopy=yes')
    command('edit ' .. link_file_name)
    feed('Abar<esc>')
    command('write')

    local backup_raw = read_file(backup_file_name)
    neq(nil, backup_raw, "Expected backup file " .. backup_file_name .. "to exist but did not")
    eq(initial_content, trim(backup_raw), 'Expected backup to contain original contents')
  end)


  it('backup symlinked files in first avialable backupdir #11349', function()
    skip(isCI('cirrus'))
    clear()

    local initial_content = 'foo'
    local backup_dir = 'Xtest_backupdir'
    local sep = helpers.get_pathsep()
    local link_file_name = 'Xtest_startup_file2'
    local backup_file_name = backup_dir .. sep .. link_file_name .. '~'

    write_file('Xtest_startup_file1', initial_content, false)
    lfs.link('Xtest_startup_file1', link_file_name, true)
    mkdir(backup_dir)
    command('set backup')
    command('set backupcopy=yes')
    command('set backupdir=.__this_does_not_exist__,' .. backup_dir)
    command('edit ' .. link_file_name)
    feed('Abar<esc>')
    command('write')

    local backup_raw = read_file(backup_file_name)
    neq(nil, backup_raw, "Expected backup file " .. backup_file_name .. " to exist but did not")
    eq(initial_content, trim(backup_raw), 'Expected backup to contain original contents')
  end)

  it('readfile() on multibyte filename #10586', function()
    clear()
    local text = {
      'line1',
      '  ...line2...  ',
      '',
      'line3!',
      'тест yay тест.',
      '',
    }
    local fname = 'Xtest_тест.md'
    funcs.writefile(text, fname, 's')
    table.insert(text, '')
    eq(text, funcs.readfile(fname, 'b'))
  end)
  it('read invalid u8 over INT_MAX doesn\'t segfault', function()
    clear()
    command('call writefile(0zFFFFFFFF, "Xtest-u8-int-max")')
    -- This should not segfault
    command('edit ++enc=utf32 Xtest-u8-int-max')
    assert_alive()
  end)

  it(':w! does not show "file has been changed" warning', function()
    clear()
    write_file("Xtest-overwrite-forced", 'foobar')
    command('set nofixendofline')
    local screen = Screen.new(40,4)
    screen:set_default_attr_ids({
      [1] = {bold = true, foreground = Screen.colors.Blue1},
      [2] = {foreground = Screen.colors.Grey100, background = Screen.colors.Red},
      [3] = {bold = true, foreground = Screen.colors.SeaGreen4}
    })
    screen:attach()
    command("set shortmess-=F")

    command("e Xtest-overwrite-forced")
    screen:expect([[
      ^foobar                                  |
      {1:~                                       }|
      {1:~                                       }|
      "Xtest-overwrite-forced" [noeol] 1L, 6B |
    ]])

    -- Get current unix time.
    local cur_unix_time = os.time(os.date("!*t"))
    local future_time = cur_unix_time + 999999
    -- Set the file's access/update time to be
    -- greater than the time at which it was created.
    local uv = require("luv")
    uv.fs_utime('Xtest-overwrite-forced', future_time, future_time)
    -- use async feed_command because nvim basically hangs on the prompt
    feed_command("w")
    screen:expect([[
      {2:WARNING: The file has been changed since}|
      {2: reading it!!!}                          |
      {3:Do you really want to write to it (y/n)^?}|
                                              |
    ]])

    feed("n")
    feed("<cr>")
    screen:expect([[
      ^foobar                                  |
      {1:~                                       }|
      {1:~                                       }|
                                              |
    ]])
    -- Use a screen test because the warning does not set v:errmsg.
    command("w!")
    screen:expect([[
      ^foobar                                  |
      {1:~                                       }|
      {1:~                                       }|
      <erwrite-forced" [noeol] 1L, 6B written |
    ]])
  end)
end)

describe('tmpdir', function()
  local tmproot_pat = [=[.*[/\\]nvim%.[^/\\]+]=]
  local testlog = 'Xtest_tmpdir_log'
  local faketmp

  before_each(function()
    -- Fake /tmp dir so that we can mess it up.
    faketmp = tmpname()
    os.remove(faketmp)
    mkdir(faketmp)
  end)

  after_each(function()
    expect_exit(command, ':qall!')
    os.remove(testlog)
  end)

  it('failure modes', function()
    clear({ env={ NVIM_LOG_FILE=testlog, TMPDIR=faketmp, } })
    assert_nolog('tempdir is not a directory', testlog)
    assert_nolog('tempdir has invalid permissions', testlog)

    -- Tempfiles typically look like: "…/nvim.<user>/xxx/0".
    --  - "…/nvim.<user>/xxx/" is the per-process tmpdir, not shared with other Nvims.
    --  - "…/nvim.<user>/" is the tmpdir root, shared by all Nvims (normally).
    local tmproot = (funcs.tempname()):match(tmproot_pat)
    ok(tmproot:len() > 4, 'tmproot like "nvim.foo"', tmproot)

    -- Test how Nvim handles invalid tmpdir root (by hostile users or accidents).
    --
    -- "…/nvim.<user>/" is not a directory:
    expect_exit(command, ':qall!')
    rmdir(tmproot)
    write_file(tmproot, '')  -- Not a directory, vim_mktempdir() should skip it.
    clear({ env={ NVIM_LOG_FILE=testlog, TMPDIR=faketmp, } })
    matches(tmproot_pat, funcs.stdpath('run'))  -- Tickle vim_mktempdir().
    -- Assert that broken tmpdir root was handled.
    retry(nil, 1000, function()
      assert_log('tempdir root not a directory', testlog, 100)
    end)

    -- "…/nvim.<user>/" has wrong permissions:
    skip(iswin(), 'TODO(justinmk): need setfperm/getfperm on Windows. #8244')
    os.remove(testlog)
    os.remove(tmproot)
    mkdir(tmproot)
    funcs.setfperm(tmproot, 'rwxr--r--')  -- Invalid permissions, vim_mktempdir() should skip it.
    clear({ env={ NVIM_LOG_FILE=testlog, TMPDIR=faketmp, } })
    matches(tmproot_pat, funcs.stdpath('run'))  -- Tickle vim_mktempdir().
    -- Assert that broken tmpdir root was handled.
    retry(nil, 1000, function()
      assert_log('tempdir root has invalid permissions', testlog, 100)
    end)
  end)

  it('too long', function()
    local bigname = ('%s/%s'):format(faketmp, ('x'):rep(666))
    mkdir(bigname)
    clear({ env={ NVIM_LOG_FILE=testlog, TMPDIR=bigname, } })
    matches(tmproot_pat, funcs.stdpath('run'))  -- Tickle vim_mktempdir().
    local len = (funcs.tempname()):len()
    ok(len > 4 and len < 256, '4 < len < 256', tostring(len))
  end)
end)
