" Basic editor behavior
set relativenumber
set number
set autoindent
set clipboard+=unnamed  " Use system clipboard
set termguicolors
set cursorline
set ts=4 sw=4
" Lightline already shows the current mode, so hide the default mode text.
set noshowmode
set mouse=a
" Open new splits in the more common IDE-like directions.
set splitright
set splitbelow

" Plugins
call plug#begin()
" File explorer
Plug 'preservim/nerdtree'
" Status line
Plug 'itchyny/lightline.vim'
" Colorschemes
Plug 'gilgigilgil/anderson.vim'
Plug 'sainnhe/sonokai'
" Automatic bracket and quote pairing
Plug 'jiangmiao/auto-pairs'
" Syntax highlighting and structural selection
Plug 'nvim-treesitter/nvim-treesitter', {'do': ':TSUpdate'}
" Commenting helpers
Plug 'numToStr/Comment.nvim'

" Completion and snippet support
Plug 'neovim/nvim-lspconfig'
Plug 'hrsh7th/cmp-nvim-lsp'
Plug 'hrsh7th/cmp-buffer'
Plug 'hrsh7th/cmp-path'
Plug 'hrsh7th/cmp-cmdline'
Plug 'hrsh7th/nvim-cmp'

" Snippet backend used by nvim-cmp
Plug 'hrsh7th/cmp-vsnip'
Plug 'hrsh7th/vim-vsnip'

call plug#end()

let $NVIM_TUI_ENABLE_TRUE_COLOR=1

" NERDTree startup behavior
" - No file argument: open the tree fullscreen.
" - File argument or stdin: open the tree on the side and return focus to the file.
" - If the tree is the last remaining window, quit Neovim.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * call s:RegisterNERDTreeVSplitOverride()
autocmd VimEnter * if argc() == 0 && !exists("s:std_in") | execute 'NERDTree' | only | endif
autocmd VimEnter * if argc() > 0 || exists("s:std_in") | NERDTree | wincmd p | endif
autocmd BufEnter * if tabpagenr('$') == 1 && winnr('$') == 1 && exists('b:NERDTree') && b:NERDTree.isTabTree() | quit | endif

" Close NERDTree after opening a file from it.
let g:NERDTreeQuitOnOpen = 1

" Open a file from NERDTree in a vertical split and close the tree.
function! NERDTreeOpenVSplitAndClose(node) abort
    call a:node.activate({'where': 'v', 'keepopen': 0})
endfunction

" Same behavior as above, but for bookmarked nodes.
function! NERDTreeOpenVSplitBookmarkAndClose(bookmark) abort
    call a:bookmark.activate(b:NERDTree, !a:bookmark.path.isDirectory ? {'where': 'v', 'keepopen': 0} : {})
endfunction

" Override NERDTree's default `s` action once the plugin has been loaded.
function! s:RegisterNERDTreeVSplitOverride() abort
    if !exists('*NERDTreeAddKeyMap')
        return
    endif

    call NERDTreeAddKeyMap({
        \ 'key': 's',
        \ 'scope': 'FileNode',
        \ 'callback': 'NERDTreeOpenVSplitAndClose',
        \ 'quickhelpText': 'open vsplit and close tree',
        \ 'override': 1
        \ })
    call NERDTreeAddKeyMap({
        \ 'key': 's',
        \ 'scope': 'Bookmark',
        \ 'callback': 'NERDTreeOpenVSplitBookmarkAndClose',
        \ 'quickhelpText': 'open vsplit and close tree',
        \ 'override': 1
        \ })
endfunction

" Core NERDTree shortcuts
nnoremap <leader>n :NERDTreeFocus<CR>
nnoremap <C-t> :NERDTreeToggle<CR>
let g:NERDTreeGitStatusWithFlags = 1
" Example icon and color overrides kept here for later use.
"let g:WebDevIconsUnicodeDecorateFolderNodes = 1
"let g:NERDTreeGitStatusNodeColorization = 1
"let g:NERDTreeColorMapCustom = {
    "\ "Staged"    : "#0ee375",
    "\ "Modified"  : "#d9bf91",
    "\ "Renamed"   : "#51C9FC",
    "\ "Untracked" : "#FCE77C",
    "\ "Unmerged"  : "#FC51E6",
    "\ "Dirty"     : "#FFBD61",
    "\ "Clean"     : "#87939A",
    "\ "Ignored"   : "#808080"
    "\ }

let g:NERDTreeIgnore = ['^node_modules$']

" Lightline appearance
let g:lightline = {
      \ 'colorscheme': 'wombat',
      \ }

" Colorscheme configuration
let g:sonokai_style = 'shusia'
let g:sonokai_better_performance = 1
colorscheme sonokai

lua << EOF
-- Treesitter config: prefer the older `configs` entrypoint, but fall back to
-- the newer top-level module for the version currently installed locally.
local ok, ts = pcall(require, 'nvim-treesitter.configs')
if not ok then
  ok, ts = pcall(require, 'nvim-treesitter')
end

if ok then
  ts.setup {
    -- Parsers to install automatically.
    ensure_installed = { "c", "cpp", "python", "lua", "vim", "go", "html", "css", "javascript", "ocaml" },

    -- Install all maintained parsers instead.
    -- ensure_installed = "all",

    -- Treesitter-powered syntax highlighting.
    highlight = {
      enable = true,
      additional_vim_regex_highlighting = false,
    },

    -- Treesitter indentation where supported.
    indent = {
      enable = true
    },

    -- Grow and shrink selections by syntax node instead of by raw text.
    incremental_selection = {
      enable = true,
      keymaps = {
        init_selection = "gnn",
        node_incremental = "grn",
        scope_incremental = "grc",
        node_decremental = "grm",
      },
    }
  }
else
  -- Keep startup working even if Treesitter is installed incorrectly.
  vim.notify('nvim-treesitter is installed but could not be loaded', vim.log.levels.WARN)
end

-- Enable default comment mappings like gcc and gc.
require('Comment').setup()
EOF


lua <<EOF
  -- Completion setup
  local cmp = require'cmp'

  cmp.setup({
    snippet = {
      -- nvim-cmp needs a snippet expansion function, and this config uses vsnip.
      expand = function(args)
        vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
        -- require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
        -- require('snippy').expand_snippet(args.body) -- For `snippy` users.
        -- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
        -- vim.snippet.expand(args.body) -- For native neovim snippets (Neovim v0.10+)

        -- For `mini.snippets` users:
        -- local insert = MiniSnippets.config.expand.insert or MiniSnippets.default_insert
        -- insert({ body = args.body }) -- Insert at cursor
        -- cmp.resubscribe({ "TextChangedI", "TextChangedP" })
        -- require("cmp.config").set_onetime({ sources = {} })
      end,
    },
    window = {
      -- completion = cmp.config.window.bordered(),
      -- documentation = cmp.config.window.bordered(),
    },
    mapping = cmp.mapping.preset.insert({
      ['<C-b>'] = cmp.mapping.scroll_docs(-4),
      ['<C-f>'] = cmp.mapping.scroll_docs(4),
      ['<C-Space>'] = cmp.mapping.complete(),
      ['<C-e>'] = cmp.mapping.abort(),
      -- Use Tab to confirm the current completion item, otherwise keep normal Tab behavior.
      ['<Tab>'] = cmp.mapping(function(fallback)
        if cmp.visible() then
          cmp.confirm({ select = true })
        else
          fallback()
        end
      end, { 'i', 's' }),
    }),
    sources = cmp.config.sources({
      { name = 'nvim_lsp' },
      { name = 'vsnip' }, -- For vsnip users.
      -- { name = 'luasnip' }, -- For luasnip users.
      -- { name = 'ultisnips' }, -- For ultisnips users.
      -- { name = 'snippy' }, -- For snippy users.
    }, {
      { name = 'buffer' },
    })
  })

  -- Example git completion setup left commented out for future use.
  --[[ cmp.setup.filetype('gitcommit', {
    sources = cmp.config.sources({
      { name = 'git' },
    }, {
      { name = 'buffer' },
    })
 })
 require("cmp_git").setup() ]]--

  -- Use buffer completion while searching with `/` or `?`.
  cmp.setup.cmdline({ '/', '?' }, {
    mapping = cmp.mapping.preset.cmdline(),
    sources = {
      { name = 'buffer' }
    }
  })

  -- Use path and command completion for `:`.
  cmp.setup.cmdline(':', {
    mapping = cmp.mapping.preset.cmdline(),
    sources = cmp.config.sources({
      { name = 'path' }
    }, {
      { name = 'cmdline' }
    }),
    matching = { disallow_symbol_nonprefix_matching = false }
  })

  -- Placeholder LSP wiring kept here because cmp-nvim-lsp is installed.
  local capabilities = require('cmp_nvim_lsp').default_capabilities()
  -- Replace <YOUR_LSP_SERVER> with each lsp server you've enabled.
  vim.lsp.config('<YOUR_LSP_SERVER>', {
    capabilities = capabilities
  })
  vim.lsp.enable('<YOUR_LSP_SERVER>')
EOF