vim.opt.ignorecase = true -- search case insensitive
vim.opt.smartcase = true -- search matters if capital letter
vim.opt.inccommand = "split" -- "for incsearch while sub
vim.g.mapleader = ","

vim.opt.ruler = true        -- cursor position all the time
vim.opt.autowrite = true    -- save before commands

-- softtabs, 2 spaces
vim.opt.tabstop = 2
vim.opt.shiftwidth = 2
vim.opt.shiftround = true
vim.optexpandtab = true

-- listchars (show tabs and trailing whitespace)
vim.opt.list = true
vim.opt.listchars.tab = "»·"
vim.opt.listchars.trail= "·"
vim.opt.listchars.nbsp = "·"

-- width and height indications
vim.opt.textwidth = 80
vim.opt.colorcolumn = "+1"
vim.opt.number = true
vim.opt.numberwidth = 5

-- textwidth but don't wrap
vim.opt.formatoptions:remove { "t" }

-- telescope setup
local tbuiltin = require('telescope.builtin')
vim.keymap.set('n', '<leader>fg', tbuiltin.live_grep, {})
vim.keymap.set('n', '<leader>ff', tbuiltin.find_files, {})
vim.keymap.set('n', '<leader>fo', tbuiltin.oldfiles, {})
vim.keymap.set('n', '<leader>fb', tbuiltin.buffers, {})
vim.keymap.set('n', '<leader>fh', tbuiltin.help_tags, {})
vim.keymap.set('n', '<leader>fs', tbuiltin.spell_suggest, {})

-- Mason (tool manager) setup
-- we want rust-analyzer and codelldb
require("mason").setup({
  ui = {
    icons = {
      package_installed = "✔️",
      package_pending = "🔄",
      package_uninstalled = "🌐"
    }
  }
})
require("mason-lspconfig").setup()

-- General LSP settings
-- from https://rsdlt.github.io/posts/rust-nvim-ide-guide-walkthrough-development-debug/
local sign = function(opts)
  vim.fn.sign_define(opts.name, {
    texthl = opts.name,
    text = opts.text,
    numhl = ''
  })
end

sign({name = 'DiagnosticSignError', text = '🛑'})
sign({name = 'DiagnosticSignWarn', text = '⚠️'})
sign({name = 'DiagnosticSignHint', text = '💭'})
sign({name = 'DiagnosticSignInfo', text = '🗒️'})

vim.diagnostic.config({
    virtual_text = false,
    signs = true,
    update_in_insert = true,
    underline = true,
    severity_sort = false,
    float = {
        border = 'rounded',
        source = 'always',
        header = '',
        prefix = '',
    },
})

vim.cmd([[
set signcolumn=yes
autocmd CursorHold * lua vim.diagnostic.open_float(nil, { focusable = false })
]])

-- Rust tools for Rust-specific LSP
local rt = require("rust-tools")
rt.setup({
  server = {
    on_attach = function(_, bufnr)
      -- ctrl + space for hover actions
      vim.keymap.set("n", "<C-space>", rt.hover_actions.hover_actions, { buffer = bufnr })
      -- ,a for code actions
      vim.keymap.set("n", "<Leader>a", rt.code_action_group.code_action_group, { buffer = bufnr })
    end,
  }
})

-- set up treesitter
require('nvim-treesitter.configs').setup {
  auto_install = false,
  ident = { enable = true }, 
  rainbow = {
    enable = true,
    extended_mode = true,
    max_file_lines = nil,
  }
}

-- completion setup
local cmp = require 'cmp'
cmp.setup({
  -- Enable LSP snippets
  snippet = {
    expand = function(args)
        vim.fn["vsnip#anonymous"](args.body)
    end,
  },
  mapping = {
    ['<C-p>'] = cmp.mapping.select_prev_item(),
    ['<C-n>'] = cmp.mapping.select_next_item(),
    -- Add tab support
    ['<S-Tab>'] = cmp.mapping.select_prev_item(),
    ['<Tab>'] = cmp.mapping.select_next_item(),
    ['<C-S-f>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.close(),
    ['<CR>'] = cmp.mapping.confirm({
      behavior = cmp.ConfirmBehavior.Insert,
      select = true,
    })
  },
  -- Installed sources:
  sources = {
    { name = 'path' },                              -- file paths
    { name = 'nvim_lsp', keyword_length = 3 },      -- from language server
    { name = 'nvim_lsp_signature_help'},            -- display function signatures with current parameter emphasized
    { name = 'nvim_lua', keyword_length = 2},       -- complete neovim's Lua runtime API such vim.lsp.*
    { name = 'buffer', keyword_length = 2 },        -- source current buffer
    { name = 'vsnip', keyword_length = 2 },         -- nvim-cmp source for vim-vsnip 
    { name = 'calc'},                               -- source for math calculation
  },
  window = {
      completion = cmp.config.window.bordered(),
      documentation = cmp.config.window.bordered(),
  },
  formatting = {
      fields = {'menu', 'abbr', 'kind'},
      format = function(entry, item)
          local menu_icon ={
              nvim_lsp = 'λ',
              vsnip = '⋗',
              buffer = 'Ω',
              path = '🖫',
          }
          item.menu = menu_icon[entry.source.name]
          return item
      end,
  },
})

-- set terminal title
function _G.current_tab()
  local curr_buf = vim.fn.bufnr()
  local total = 0
  local curr_tab

  for i = 1, vim.fn.tabpagenr('$') do
    total = total + 1
    for _, bufnr in ipairs(vim.fn.tabpagebuflist(i)) do
      if bufnr == curr_buf then
        curr_tab = i
      end
    end
  end

  return string.format('(%d of %d)', curr_tab, total)
end

vim.opt.title = true
vim.opt.titlestring = [[%f %h%m%r%w - %{v:progname} %{luaeval('current_tab()')}]]

-- vimsense (rich presence) options
vim.g.vimsense_small_text = "NeoVim"
vim.g.vimsense_small_image = "neovim"
vim.g.vimsense_editing_details = "Editing: {}"
vim.g.vimsense_editing_state = "Working on: {}"
vim.g.vimsense_file_explorer_text = "In file manager"
vim.g.vimsense_file_explorer_details = "Looking for files"