local fn = vim.fn
local api = vim.api
local executable = function(e)
  return fn.executable(e) > 0
end

local opts_info = vim.api.nvim_get_all_options_info()

local opt = setmetatable(
                {}, {
      __newindex = function(_, key, value)
        vim.o[key] = value
        local scope = opts_info[key].scope
        if scope == 'win' then
          vim.wo[key] = value
        elseif scope == 'buf' then
          vim.bo[key] = value
        end
      end
    }
            )

local function add(value, str, sep)
  sep = sep or ','
  str = str or ''
  value = type(value) == 'table' and table.concat(value, sep) or value
  return str ~= '' and table.concat({ value, str }, sep) or value
end

-- Numbers {{{

vim.o.number = true
vim.o.relativenumber = true

-- }}}

-- Message output on vim actions {{{

vim.o.shortmess = table.concat(
                      {
      't', -- truncate file messages at start
      'A', -- ignore annoying swap file messages
      'o', -- file-read message overwrites previous
      'O', -- file-read message overwrites previous
      'T', -- truncate non-file messages in middle
      'f', -- (file x of x) instead of just (x of x
      'F', -- Don't give file info when editing a file
      's',
      'c',
      'W' -- Dont show [w] or written when writing
    }
                  )

-- }}}

-- Timings {{{

vim.o.updatetime = 1000
vim.o.timeout = true
vim.o.timeoutlen = 500
vim.o.ttimeoutlen = 10

-- }}}

-- Window splitting and buffers {{{

opt.ruler = true
vim.o.hidden = true
vim.o.encoding = 'utf-8'
vim.o.fileencoding = 'utf-8'
vim.o.splitbelow = true
vim.o.splitright = true
vim.o.eadirection = 'hor'
vim.o.t_Co = '256'
-- exclude usetab as we do not want to jump to buffers in already open tabs
-- do not use split or vsplit to ensure we don't open any new windows
vim.o.switchbuf = 'useopen,uselast'
vim.o.fillchars = add {
  'vert:▕', -- alternatives │
  'fold: ',
  'eob: ', -- suppress ~ at EndOfBuffer
  'diff:─', -- alternatives: ⣿ ░
  'msgsep:‾',
  'foldopen:▾',
  'foldsep:│',
  'foldclose:▸'
}

-- }}}

-- Diff {{{

-- Use in vertical diff mode, blank lines to keep sides aligned, Ignore whitespace changes
vim.o.diffopt = add(
                    {
      'vertical',
      'iwhite',
      'hiddenoff',
      'foldcolumn:0',
      'context:4',
      'algorithm:histogram',
      'indent-heuristic'
    }, vim.o.diffopt
                )

-- }}}

-- Format Options {{{

opt.formatoptions = table.concat(
                        {
      '1',
      'q', -- continue comments with gq"
      'c', -- Auto-wrap comments using textwidth
      'r', -- Continue comments when pressing Enter
      'n', -- Recognize numbered lists
      '2', -- Use indent from 2nd line of a paragraph
      't', -- autowrap lines using text width value
      'j', -- remove a comment leader when joining lines.
      -- Only break if the line was not longer than 'textwidth' when the insert
      -- started and only at a white character that has been entered during the
      -- current insert command.
      'lv'
    }
                    )

-- }}}

-- Folds {{{

vim.o.foldtext = 'v:lua.folds()'
vim.o.foldopen = add(vim.o.foldopen, 'search')
vim.o.foldlevel = 99
vim.o.foldlevelstart = 10
opt.foldmethod = 'syntax'

-- }}}

-- Grepprg {{{

-- Use faster grep alternatives if possible
if executable('rg') then
  vim.o.grepprg =
      [[rg --hidden --glob "!.git" --no-heading --smart-case --vimgrep --follow $*]]
  vim.o.grepformat = add('%f:%l:%c:%m', vim.o.grepformat)
elseif executable('ag') then
  vim.o.grepprg = [[ag --nogroup --nocolor --vimgrep]]
  vim.o.grepformat = add('%f:%l:%c:%m', vim.o.grepformat)
end

-- }}}

-- Wild and file globbing stuff in command mode {{{

vim.o.wildcharm = api.nvim_eval([[char2nr("\<C-Z>")]]) -- FIXME: what's the correct way to do this?
vim.o.wildmenu = true
vim.o.wildmode = 'full' -- Shows a menu bar as opposed to an enormous list
vim.o.wildignorecase = true -- Ignore case when completing file names and directories
-- Binary
vim.o.wildignore = add {
  '*.aux,*.out,*.toc',
  '*.o,*.obj,*.dll,*.jar,*.pyc,*.rbc,*.class',
  '*.ai,*.bmp,*.gif,*.ico,*.jpg,*.jpeg,*.png,*.psd,*.webp',
  '*.avi,*.m4a,*.mp3,*.oga,*.ogg,*.wav,*.webm',
  '*.eot,*.otf,*.ttf,*.woff',
  '*.doc,*.pdf',
  '*.zip,*.tar.gz,*.tar.bz2,*.rar,*.tar.xz',
  -- Cache
  '.sass-cache',
  '*/vendor/gems/*,*/vendor/cache/*,*/.bundle/*,*.gem',
  -- Temp/System
  '*.*~,*~ ',
  '*.swp,.lock,.DS_Store,._*,tags.lock'
}
vim.o.wildoptions = 'pum'
vim.o.pumblend = 3 -- Make popup window translucent

-- }}}

-- Display {{{

opt.conceallevel = 2
opt.breakindentopt = 'sbr'
opt.linebreak = true -- lines wrap at words rather than random characters
opt.synmaxcol = 1024 -- don't syntax highlight long lines
opt.signcolumn = 'yes:2'
opt.colorcolumn = '+1' -- Set the colour column to highlight one column after the 'textwidth'
vim.o.cmdheight = 2 -- Set command line height to two lines
vim.o.showbreak = [[↪ ]] -- Options include -> '…', '↳ ', '→','↪ '
vim.g.vimsyn_embed = 'lPr' -- allow embedded syntax highlighting for lua,python and ruby

-- }}}

-- List chars {{{

vim.o.list = true -- invisible chars
vim.o.listchars = add {
  'eol: ',
  'tab:│ ',
  'extends:›', -- Alternatives: … »
  'precedes:‹', -- Alternatives: … «
  'trail:•' -- BULLET (U+2022, UTF-8: E2 80 A2)
}

-- }}}

-- Indentation {{{

opt.wrap = true
opt.wrapmargin = 2
opt.softtabstop = 2
opt.textwidth = 80
opt.shiftwidth = 2
opt.expandtab = true
opt.smarttab = true
opt.autoindent = true
opt.smartindent = true
opt.breakindent = true
vim.o.shiftround = true

vim.o.joinspaces = false
vim.o.gdefault = true
vim.o.pumheight = 15
vim.o.confirm = true -- make vim prompt me to save before doing destructive things
vim.o.completeopt = add { 'menuone', 'noinsert', 'noselect' }
vim.o.hlsearch = true
vim.o.autowriteall = true -- automatically :write before running commands and changing files
vim.o.clipboard = 'unnamedplus'
vim.o.lazyredraw = true
vim.o.laststatus = 2
vim.o.showtabline = 2
vim.o.cursorline = true
vim.o.ttyfast = true
vim.o.belloff = 'all'
vim.o.termguicolors = true
vim.o.background = 'dark'
vim.o.showmode = false
vim.o.showcmd = false
vim.o.backup = false
vim.o.writebackup = false
vim.o.visualbell = true
vim.o.errorbells = false

-- }}}

-- Emoji {{{1

-- emoji is true by default but makes (n)vim treat all emoji as double width
-- which breaks rendering so we turn this off.
-- CREDIT: https://www.youtube.com/watch?v=F91VWOelFNE
vim.o.emoji = false

-- }}}

-- Title {{{

vim.o.titlestring = ' ❐ %t %r %m'
vim.o.titleold = '%{fnamemodify(getcwd(), ":t")}'
vim.o.title = true
vim.o.titlelen = 70

-- }}}

-- Utilities {{{

vim.o.showmode = false
vim.o.sessionoptions = add {
  'globals',
  'buffers',
  'curdir',
  'tabpages',
  'help',
  'winpos'
}
vim.o.viewoptions = add { 'cursor', 'folds', 'slash', 'unix' } -- save/restore just these (with `:{mk,load}view`)
vim.o.virtualedit = 'block' -- allow cursor to move where there is no text in visual block mode
vim.o.dictionary = '/usr/share/dict/words'
vim.o.inccommand = 'split'
-- This is from the help docs, it enables mode shapes, "Cursor" highlight, and blinking
vim.o.guicursor = table.concat(
                      {
      [[n-v-c:block,i-ci-ve:ver25,r-cr:hor20,o:hor50]],
      [[a:blinkwait700-blinkoff400-blinkon250-Cursor/lCursor]],
      [[sm:block-blinkwait175-blinkoff150-blinkon175]]
    }, ','
                  )
vim.o.autoread = true
vim.o.mat = 2
vim.o.history = 1000
vim.o.swapfile = false
vim.o.backspace = add { 'indent', 'eol', 'start' }
vim.o.path = table.concat({ '**' })
vim.o.tags = table.concat({ './tags', 'tags:$HOME' })

-- }}}

-- BACKUP AND SWAPS {{{

vim.o.swapfile = false
vim.o.backup = false
vim.o.writebackup = false
if fn.isdirectory(vim.o.undodir) == 0 then
  fn.mkdir(vim.o.undodir, 'p')
end
opt.undofile = true

-- }}}

-- Match and search {{{

vim.o.showmatch = true
vim.o.magic = true
vim.o.ignorecase = true
vim.o.smartcase = true
vim.o.incsearch = true
vim.o.wrapscan = true -- Searches wrap around the end of the file
vim.o.scrolloff = 9
vim.o.sidescrolloff = 10
vim.o.sidescroll = 1

-- }}}

-- Spelling {{{

vim.o.spellsuggest = add(12, vim.o.spellsuggest)
vim.o.spelloptions = 'camel'
vim.o.spellcapcheck = '' -- don't check for capital letters at start of sentence
vim.o.fileformats = 'unix,mac,dos'
vim.o.complete = add('kspell', vim.o.complete)

-- }}}

-- Mouse {{{

vim.o.mouse = 'a'
vim.o.mousefocus = true
-- FIXME - these don't work in lua
-- vim.o.mousehide = true -- Raise issue on Neovim as this errors

-- }}}

-- these only read ".vim" files {{{

vim.o.secure = true -- Disable autocmd etc for project local vimrc files.
vim.o.exrc = true -- Allow project local vimrc files example .nvimrc see :h exrc

-- }}}

-- Git editor {{{

if executable('nvr') then
  vim.env.GIT_EDITOR = 'nvr -cc split --remote-wait +\'set bufhidden=wipe\''
  vim.env.EDITOR = 'nvr -cc split --remote-wait +\'set bufhidden=wipe\''
end

-- }}}

-- vim:foldmethod=marker