local helpers = require('test.functional.helpers')(after_each)
local Screen = require('test.functional.ui.screen')
local NIL = helpers.NIL
local clear, nvim, eq, neq = helpers.clear, helpers.nvim, helpers.eq, helpers.neq
local ok, nvim_async, feed = helpers.ok, helpers.nvim_async, helpers.feed
local os_name = helpers.os_name
local meths = helpers.meths
local funcs = helpers.funcs
local request = helpers.request
local meth_pcall = helpers.meth_pcall
local command = helpers.command

describe('api', function()
  before_each(clear)

  describe('nvim_command', function()
    it('works', function()
      local fname = helpers.tmpname()
      nvim('command', 'new')
      nvim('command', 'edit '..fname)
      nvim('command', 'normal itesting\napi')
      nvim('command', 'w')
      local f = io.open(fname)
      ok(f ~= nil)
      if os_name() == 'windows' then
        eq('testing\r\napi\r\n', f:read('*a'))
      else
        eq('testing\napi\n', f:read('*a'))
      end
      f:close()
      os.remove(fname)
    end)

    it("VimL error: fails (VimL error), does NOT update v:errmsg", function()
      -- Most API methods return generic errors (or no error) if a VimL
      -- expression fails; nvim_command returns the VimL error details.
      local status, rv = pcall(nvim, "command", "bogus_command")
      eq(false, status)                       -- nvim_command() failed.
      eq("E492:", string.match(rv, "E%d*:"))  -- VimL error was returned.
      eq("", nvim("eval", "v:errmsg"))        -- v:errmsg was not updated.
    end)
  end)

  describe('nvim_eval', function()
    it('works', function()
      nvim('command', 'let g:v1 = "a"')
      nvim('command', 'let g:v2 = [1, 2, {"v3": 3}]')
      eq({v1 = 'a', v2 = { 1, 2, { v3 = 3 } } }, nvim('eval', 'g:'))
    end)

    it('handles NULL-initialized strings correctly', function()
      eq(1, nvim('eval',"matcharg(1) == ['', '']"))
      eq({'', ''}, nvim('eval','matcharg(1)'))
    end)

    it('works under deprecated name', function()
      eq(2, request("vim_eval", "1+1"))
    end)

    it("VimL error: fails (generic error), does NOT update v:errmsg", function()
      local status, rv = pcall(nvim, "eval", "bogus expression")
      eq(false, status)                 -- nvim_eval() failed.
      ok(nil ~= string.find(rv, "Failed to evaluate expression"))
      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
    end)
  end)

  describe('nvim_call_function', function()
    it('works', function()
      nvim('call_function', 'setqflist', { { { filename = 'something', lnum = 17 } }, 'r' })
      eq(17, nvim('call_function', 'getqflist', {})[1].lnum)
      eq(17, nvim('call_function', 'eval', {17}))
      eq('foo', nvim('call_function', 'simplify', {'this/./is//redundant/../../../foo'}))
    end)

    it("VimL error: fails (generic error), does NOT update v:errmsg", function()
      local status, rv = pcall(nvim, "call_function", "bogus function", {"arg1"})
      eq(false, status)                 -- nvim_call_function() failed.
      ok(nil ~= string.find(rv, "Error calling function"))
      eq("", nvim("eval", "v:errmsg"))  -- v:errmsg was not updated.
    end)
  end)

  describe('nvim_input', function()
    it("VimL error: does NOT fail, updates v:errmsg", function()
      local status, _ = pcall(nvim, "input", ":call bogus_fn()<CR>")
      local v_errnum = string.match(nvim("eval", "v:errmsg"), "E%d*:")
      eq(true, status)        -- nvim_input() did not fail.
      eq("E117:", v_errnum)   -- v:errmsg was updated.
    end)
  end)

  describe('nvim_strwidth', function()
    it('works', function()
      eq(3, nvim('strwidth', 'abc'))
      -- 6 + (neovim)
      -- 19 * 2 (each japanese character occupies two cells)
      eq(44, nvim('strwidth', 'neovimのデザインかなりまともなのになってる。'))
    end)

    it('cannot handle NULs', function()
      eq(0, nvim('strwidth', '\0abc'))
    end)
  end)

  describe('nvim_get_current_line, nvim_set_current_line', function()
    it('works', function()
      eq('', nvim('get_current_line'))
      nvim('set_current_line', 'abc')
      eq('abc', nvim('get_current_line'))
    end)
  end)

  describe('nvim_get_var, nvim_set_var, nvim_del_var', function()
    it('works', function()
      nvim('set_var', 'lua', {1, 2, {['3'] = 1}})
      eq({1, 2, {['3'] = 1}}, nvim('get_var', 'lua'))
      eq({1, 2, {['3'] = 1}}, nvim('eval', 'g:lua'))
      eq(1, funcs.exists('g:lua'))
      meths.del_var('lua')
      eq(0, funcs.exists('g:lua'))
      eq({false, 'Key "lua" doesn\'t exist'}, meth_pcall(meths.del_var, 'lua'))
      meths.set_var('lua', 1)
      command('lockvar lua')
      eq({false, 'Key is locked: lua'}, meth_pcall(meths.del_var, 'lua'))
      eq({false, 'Key is locked: lua'}, meth_pcall(meths.set_var, 'lua', 1))
    end)

    it('vim_set_var returns the old value', function()
      local val1 = {1, 2, {['3'] = 1}}
      local val2 = {4, 7}
      eq(NIL, request('vim_set_var', 'lua', val1))
      eq(val1, request('vim_set_var', 'lua', val2))
    end)

    it('vim_del_var returns the old value', function()
      local val1 = {1, 2, {['3'] = 1}}
      local val2 = {4, 7}
      eq(NIL,  request('vim_set_var', 'lua', val1))
      eq(val1, request('vim_set_var', 'lua', val2))
      eq(val2, request('vim_del_var', 'lua'))
    end)

    it('truncates values with NULs in them', function()
      nvim('set_var', 'xxx', 'ab\0cd')
      eq('ab', nvim('get_var', 'xxx'))
    end)
  end)

  describe('nvim_get_option, nvim_set_option', function()
    it('works', function()
      ok(nvim('get_option', 'equalalways'))
      nvim('set_option', 'equalalways', false)
      ok(not nvim('get_option', 'equalalways'))
    end)
  end)

  describe('nvim_{get,set}_current_buf, nvim_list_bufs', function()
    it('works', function()
      eq(1, #nvim('list_bufs'))
      eq(nvim('list_bufs')[1], nvim('get_current_buf'))
      nvim('command', 'new')
      eq(2, #nvim('list_bufs'))
      eq(nvim('list_bufs')[2], nvim('get_current_buf'))
      nvim('set_current_buf', nvim('list_bufs')[1])
      eq(nvim('list_bufs')[1], nvim('get_current_buf'))
    end)
  end)

  describe('nvim_{get,set}_current_win, nvim_list_wins', function()
    it('works', function()
      eq(1, #nvim('list_wins'))
      eq(nvim('list_wins')[1], nvim('get_current_win'))
      nvim('command', 'vsplit')
      nvim('command', 'split')
      eq(3, #nvim('list_wins'))
      eq(nvim('list_wins')[1], nvim('get_current_win'))
      nvim('set_current_win', nvim('list_wins')[2])
      eq(nvim('list_wins')[2], nvim('get_current_win'))
    end)
  end)

  describe('nvim_{get,set}_current_tabpage, nvim_list_tabpages', function()
    it('works', function()
      eq(1, #nvim('list_tabpages'))
      eq(nvim('list_tabpages')[1], nvim('get_current_tabpage'))
      nvim('command', 'tabnew')
      eq(2, #nvim('list_tabpages'))
      eq(2, #nvim('list_wins'))
      eq(nvim('list_wins')[2], nvim('get_current_win'))
      eq(nvim('list_tabpages')[2], nvim('get_current_tabpage'))
      nvim('set_current_win', nvim('list_wins')[1])
      -- Switching window also switches tabpages if necessary
      eq(nvim('list_tabpages')[1], nvim('get_current_tabpage'))
      eq(nvim('list_wins')[1], nvim('get_current_win'))
      nvim('set_current_tabpage', nvim('list_tabpages')[2])
      eq(nvim('list_tabpages')[2], nvim('get_current_tabpage'))
      eq(nvim('list_wins')[2], nvim('get_current_win'))
    end)
  end)

  describe('nvim_replace_termcodes', function()
    it('escapes K_SPECIAL as K_SPECIAL KS_SPECIAL KE_FILLER', function()
      eq('\128\254X', helpers.nvim('replace_termcodes', '\128', true, true, true))
    end)

    it('leaves non-K_SPECIAL string unchanged', function()
      eq('abc', helpers.nvim('replace_termcodes', 'abc', true, true, true))
    end)

    it('converts <expressions>', function()
      eq('\\', helpers.nvim('replace_termcodes', '<Leader>', true, true, true))
    end)

    it('converts <LeftMouse> to K_SPECIAL KS_EXTRA KE_LEFTMOUSE', function()
      -- K_SPECIAL KS_EXTRA KE_LEFTMOUSE
      -- 0x80      0xfd     0x2c
      -- 128       253      44
      eq('\128\253\44', helpers.nvim('replace_termcodes',
                                     '<LeftMouse>', true, true, true))
    end)
  end)

  describe('nvim_feedkeys', function()
    it('CSI escaping', function()
      local function on_setup()
        -- notice the special char(…) \xe2\80\xa6
        nvim('feedkeys', ':let x1="…"\n', '', true)

        -- Both replace_termcodes and feedkeys escape \x80
        local inp = helpers.nvim('replace_termcodes', ':let x2="…"<CR>', true, true, true)
        nvim('feedkeys', inp, '', true)

        -- Disabling CSI escaping in feedkeys
        inp = helpers.nvim('replace_termcodes', ':let x3="…"<CR>', true, true, true)
        nvim('feedkeys', inp, '', false)

        helpers.stop()
      end

      -- spin the loop a bit
      helpers.run(nil, nil, on_setup)

      eq(nvim('get_var', 'x1'), '…')
      -- Because of the double escaping this is neq
      neq(nvim('get_var', 'x2'), '…')
      eq(nvim('get_var', 'x3'), '…')
    end)
  end)

  describe('nvim_err_write', function()
    local screen

    before_each(function()
      clear()
      screen = Screen.new(40, 8)
      screen:attach()
      screen:set_default_attr_ids({
        [0] = {bold=true, foreground=Screen.colors.Blue},
        [1] = {foreground = Screen.colors.White, background = Screen.colors.Red},
        [2] = {bold = true, foreground = Screen.colors.SeaGreen}
      })
    end)

    it('can show one line', function()
      nvim_async('err_write', 'has bork\n')
      screen:expect([[
        ^                                        |
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {1:has bork}                                |
      ]])
    end)

    it('shows return prompt when more than &cmdheight lines', function()
      nvim_async('err_write', 'something happened\nvery bad\n')
      screen:expect([[
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {1:something happened}                      |
        {1:very bad}                                |
        {2:Press ENTER or type command to continue}^ |
      ]])
    end)

    it('shows return prompt after all lines are shown', function()
      nvim_async('err_write', 'FAILURE\nERROR\nEXCEPTION\nTRACEBACK\n')
      screen:expect([[
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {1:FAILURE}                                 |
        {1:ERROR}                                   |
        {1:EXCEPTION}                               |
        {1:TRACEBACK}                               |
        {2:Press ENTER or type command to continue}^ |
      ]])
    end)

    it('handles multiple calls', function()
      -- without linebreak text is joined to one line
      nvim_async('err_write', 'very ')
      nvim_async('err_write', 'fail\n')
      screen:expect([[
        ^                                        |
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {1:very fail}                               |
      ]])
      helpers.wait()

      -- shows up to &cmdheight lines
      nvim_async('err_write', 'more fail\ntoo fail\n')
      screen:expect([[
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {0:~                                       }|
        {1:more fail}                               |
        {1:too fail}                                |
        {2:Press ENTER or type command to continue}^ |
      ]])
      feed('<cr>')  -- exit the press ENTER screen
    end)
  end)

  describe('nvim_call_atomic', function()
    it('works', function()
      meths.buf_set_lines(0, 0, -1, true, {'first'})
      local req = {
        {'nvim_get_current_line', {}},
        {'nvim_set_current_line', {'second'}},
      }
      eq({{'first', NIL}, NIL}, meths.call_atomic(req))
      eq({'second'}, meths.buf_get_lines(0, 0, -1, true))
    end)

    it('allows multiple return values', function()
      local req = {
        {'nvim_set_var', {'avar', true}},
        {'nvim_set_var', {'bvar', 'string'}},
        {'nvim_get_var', {'avar'}},
        {'nvim_get_var', {'bvar'}},
      }
      eq({{NIL, NIL, true, 'string'}, NIL}, meths.call_atomic(req))
    end)

    it('is aborted by errors in call', function()
      local error_types = meths.get_api_info()[2].error_types
      local req = {
        {'nvim_set_var', {'one', 1}},
        {'nvim_buf_set_lines', {}},
        {'nvim_set_var', {'two', 2}},
      }
      eq({{NIL}, {1, error_types.Exception.id,
                  'Wrong number of arguments: expecting 5 but got 0'}},
         meths.call_atomic(req))
      eq(1, meths.get_var('one'))
      eq(false, pcall(meths.get_var, 'two'))

      -- still returns all previous successful calls
      req = {
        {'nvim_set_var', {'avar', 5}},
        {'nvim_set_var', {'bvar', 'string'}},
        {'nvim_get_var', {'avar'}},
        {'nvim_buf_get_lines', {0, 10, 20, true}},
        {'nvim_get_var', {'bvar'}},
      }
      eq({{NIL, NIL, 5}, {3, error_types.Validation.id, 'Index out of bounds'}},
        meths.call_atomic(req))

      req = {
        {'i_am_not_a_method', {'xx'}},
        {'nvim_set_var', {'avar', 10}},
      }
      eq({{}, {0, error_types.Exception.id, 'Invalid method name'}},
         meths.call_atomic(req))
      eq(5, meths.get_var('avar'))
    end)

    it('throws error on malformated arguments', function()
      local req = {
        {'nvim_set_var', {'avar', 1}},
        {'nvim_set_var'},
        {'nvim_set_var', {'avar', 2}},
      }
      local status, err = pcall(meths.call_atomic, req)
      eq(false, status)
      ok(err:match(' All items in calls array must be arrays of size 2') ~= nil)
      -- call before was done, but not after
      eq(1, meths.get_var('avar'))

      req = {
        { 'nvim_set_var', { 'bvar', { 2, 3 } } },
        12,
      }
      status, err = pcall(meths.call_atomic, req)
      eq(false, status)
      ok(err:match('All items in calls array must be arrays') ~= nil)
      eq({2,3}, meths.get_var('bvar'))

      req = {
        {'nvim_set_current_line', 'little line'},
        {'nvim_set_var', {'avar', 3}},
      }
      status, err = pcall(meths.call_atomic, req)
      eq(false, status)
      ok(err:match('args must be Array') ~= nil)
      -- call before was done, but not after
      eq(1, meths.get_var('avar'))
      eq({''}, meths.buf_get_lines(0, 0, -1, true))
    end)
  end)

  it('can throw exceptions', function()
    local status, err = pcall(nvim, 'get_option', 'invalid-option')
    eq(false, status)
    ok(err:match('Invalid option name') ~= nil)
  end)

  it("doesn't leak memory on incorrect argument types", function()
    local status, err = pcall(nvim, 'set_current_dir',{'not', 'a', 'dir'})
    eq(false, status)
    ok(err:match(': Wrong type for argument 1, expecting String') ~= nil)
  end)

end)