local M = {
  "hrsh7th/nvim-cmp",
  dependencies = {
    "andersevenrud/cmp-tmux",
    "hrsh7th/cmp-nvim-lsp",
    "hrsh7th/cmp-buffer",
    "hrsh7th/cmp-path",
    "hrsh7th/cmp-cmdline",
    "hrsh7th/cmp-nvim-lsp-signature-help",
    "L3MON4D3/LuaSnip",
    "onsails/lspkind-nvim",
    "saadparwaiz1/cmp_luasnip",
  },
  event = "InsertEnter",
}

function M.config()
  local cmp = require("cmp")
  local luasnip = require("luasnip")

  local has_words_before = function()
    local line, col = unpack(vim.api.nvim_win_get_cursor(0))
    return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
  end

  cmp.setup({
    formatting = {
      format = require("lspkind").cmp_format({
        with_text = true,
        menu = {
          buffer = "[Buffer]",
          tmux = "[Tmux]",
          luasnip = "[LuaSnip]",
          nvim_lsp = "[LSP]",
          nvim_lua = "[Lua]",
          path = "[Path]",
        },
      }),
    },

    window = {
      completion = cmp.config.window.bordered({
        winhighlight = "Normal:PMenu,FloatBorder:PMenuBorder,CursorLine:PMenuSel,Search:None",
      }),
      documentation = cmp.config.window.bordered({
        winhighlight = "Normal:PMenu,FloatBorder:PMenu,CursorLine:PMenuSel,Search:None",
      }),
    },

    snippet = {
      expand = function(args)
        luasnip.lsp_expand(args.body)
      end,
    },

    mapping = {
      ["<Up>"] = cmp.mapping(cmp.mapping.select_prev_item(), { "i", "c" }),
      ["<Down>"] = cmp.mapping(cmp.mapping.select_next_item(), { "i", "c" }),
      ["<C-p>"] = cmp.mapping(cmp.mapping.select_prev_item(), { "i", "c" }),
      ["<C-n>"] = cmp.mapping(cmp.mapping.select_next_item(), { "i", "c" }),
      ["<C-d>"] = cmp.mapping.scroll_docs(-4),
      ["<C-u>"] = cmp.mapping.scroll_docs(4),
      ["<C-e>"] = cmp.mapping({
        i = cmp.mapping.abort(),
        c = cmp.mapping.close(),
      }),
      ["<CR>"] = cmp.mapping(cmp.mapping.confirm({ select = false }), { "i", "c" }),
      ["<C-y>"] = cmp.mapping(cmp.mapping.confirm({ select = false }), { "i", "c" }),
      ["<C-Space>"] = cmp.mapping(cmp.mapping.complete(), { "i", "c" }),
      ["<Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
          cmp.select_next_item()
        elseif luasnip.expand_or_locally_jumpable() then
          luasnip.expand_or_jump()
        elseif has_words_before() then
          cmp.complete()
        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 = "buffer", priority = 1 },
      { name = "luasnip", priority = 4 },
      { name = "copilot", group_index = 5 },
      {
        name = "tmux",
        priority = 2,
        option = {
          all_panes = true,
          trigger_characters = {},
        },
      },
      { name = "nvim_lsp", priority = 3 },
      { name = "nvim_lsp_signature_help", priority = 4 },
    }),
  })
end

return M