-- Add additional capabilities supported by nvim-cmp
local capabilities = require('cmp_nvim_lsp').default_capabilities()

local lspconfig = require('lspconfig')

-- Enable some language servers with the additional completion capabilities offered by nvim-cmp
local servers = { 'clangd', 'rust_analyzer', 'pyright', 'tsserver' }
for _, lsp in ipairs(servers) do
  lspconfig[lsp].setup {
    -- on_attach = my_custom_on_attach,
    capabilities = capabilities,
  }
end

-- luasnip setup
local luasnip = require 'luasnip'

-- nvim-cmp setup
local cmp = require 'cmp'
cmp.setup {
  snippet = {
    expand = function(args)
      luasnip.lsp_expand(args.body)
    end,
  },
  mapping = cmp.mapping.preset.insert({
    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<CR>'] = cmp.mapping.confirm {
      behavior = cmp.ConfirmBehavior.Replace,
      select = true,
    },
    ['<Tab>'] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_next_item()
      elseif luasnip.expand_or_jumpable() then
        luasnip.expand_or_jump()
      else
        fallback()
      end
    end, { 'i', 's' }),
    ['<S-Tab>'] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_prev_item()
      elseif luasnip.jumpable(-1) then
        luasnip.jump(-1)
      else
        fallback()
      end
    end, { 'i', 's' }),
  }),
  sources = cmp.config.sources({
    { name = 'nvim_lsp' },
    { name = 'luasnip' },
  }),
  window = { 
    completion = cmp.config.window.bordered(),
    documentation = cmp.config.window.bordered()
  },
  formatting = {
    fields = { "abbr", "menu", "kind" },
    format = function(entry, item)
        -- Define menu shorthand for different completion sources.
        local menu_icon = {
            nvim_lsp = "LSP",
            nvim_lua = "LUA",
            luasnip  = "SNP",
            buffer   = "BUFF",
            path     = "PATH",
        }
        -- Set the menu "icon" to the shorthand for each completion source.
        item.menu = menu_icon[entry.source.name]

        -- Set the fixed width of the completion menu to 60 characters.
        -- fixed_width = 20

        -- Set 'fixed_width' to false if not provided.
        fixed_width = fixed_width or false

        -- Get the completion entry text shown in the completion window.
        local content = item.abbr

        -- Set the fixed completion window width.
        if fixed_width then
            vim.o.pumwidth = fixed_width
        end

        -- Get the width of the current window.
        local win_width = vim.api.nvim_win_get_width(0)

        -- Set the max content width based on either: 'fixed_width'
        -- or a percentage of the window width, in this case 20%.
        -- We subtract 10 from 'fixed_width' to leave room for 'kind' fields.
        local max_content_width = fixed_width and fixed_width - 10 or math.floor(win_width * 0.2)

        -- Truncate the completion entry text if it's longer than the
        -- max content width. We subtract 3 from the max content width
        -- to account for the "..." that will be appended to it.
        if #content > max_content_width then
            item.abbr = vim.fn.strcharpart(content, 0, max_content_width - 3) .. "..."
        else
            item.abbr = content .. (" "):rep(max_content_width - #content)
        end
        return item
    end,
},
}