dotfiles.nix/home-manager/sajenim/features/nvim/config/lua/plugins/coding.lua

return {
  --
  -- LSP Configuration
  --

  {
    'neovim/nvim-lspconfig',
    event = { 'BufReadPost', 'BufNewFile' },
    dependencies = {
      'hrsh7th/nvim-cmp',         -- Autocompletion plugin
      'hrsh7th/cmp-nvim-lsp',     -- LSP source for nvim-cmp
      'saadparwaiz1/cmp_luasnip', -- Snippets source for nvim-cmp
      'L3MON4D3/LuaSnip',         -- Snippets plugin
    },
    config = function ()
      --
      -- Setup language servers.
      --

      local lspconfig = require('lspconfig')

      -- Lua
      lspconfig.lua_ls.setup {
        on_init = function(client)
          local path = client.workspace_folders[1].name
          if not vim.loop.fs_stat(path..'/.luarc.json') and not vim.loop.fs_stat(path..'/.luarc.jsonc') then
            client.config.settings = vim.tbl_deep_extend('force', client.config.settings, {
              Lua = {
                runtime = {
                  -- Tell the language server which version of Lua you're using
                  -- (most likely LuaJIT in the case of Neovim)
                  version = 'LuaJIT'
                },
                -- Make the server aware of Neovim runtime files
                workspace = {
                  checkThirdParty = false,
                  library = {
                    vim.env.VIMRUNTIME
                    -- "${3rd}/luv/library"
                    -- "${3rd}/busted/library",
                  }
                  -- or pull in all of 'runtimepath'. NOTE: this is a lot slower
                  -- library = vim.api.nvim_get_runtime_file("", true)
                }
              }
            })

            client.notify("workspace/didChangeConfiguration", { settings = client.config.settings })
          end
          return true
        end
      }

      -- Haskell
      lspconfig.hls.setup{
        filetypes = { 'haskell', 'lhaskell', 'cabal' },
      }

      -- Nix
      lspconfig.nil_ls.setup{}

      -- C
      lspconfig.clangd.setup{}


      --
      -- Global mappings
      --

      -- See `:help vim.diagnostic.*` for documentation on any of the below functions
      vim.keymap.set('n', '<space>e', vim.diagnostic.open_float)
      vim.keymap.set('n', '[d', vim.diagnostic.goto_prev)
      vim.keymap.set('n', ']d', vim.diagnostic.goto_next)
      vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist)

      -- Use LspAttach autocommand to only map the following keys
      -- after the language server attaches to the current buffer
      vim.api.nvim_create_autocmd('LspAttach', {
        group = vim.api.nvim_create_augroup('UserLspConfig', {}),
        callback = function(ev)
          -- Buffer local mappings.
          -- See `:help vim.lsp.*` for documentation on any of the below functions
          local opts = { buffer = ev.buf }
          vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, opts)
          vim.keymap.set('n', 'gd', vim.lsp.buf.definition, opts)
          vim.keymap.set('n', 'K', vim.lsp.buf.hover, opts)
          vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, opts)
          vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, opts)
          vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, opts)
          vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, opts)
          vim.keymap.set('n', '<space>wl', function()
            print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
          end, opts)
          vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, opts)
          vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, opts)
          vim.keymap.set({ 'n', 'v' }, '<space>ca', vim.lsp.buf.code_action, opts)
          vim.keymap.set('n', 'gr', vim.lsp.buf.references, opts)
          vim.keymap.set('n', '<space>f', function()
            vim.lsp.buf.format { async = true }
          end, opts)
        end,
      })


      --
      -- Autocompletion
      --

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

      -- 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-u>'] = cmp.mapping.scroll_docs(-4), -- Up
          ['<C-d>'] = cmp.mapping.scroll_docs(4), -- Down
          -- C-b (back) C-f (forward) for snippet placeholder navigation.
          ['<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 = {
          { name = 'nvim_lsp' },
          { name = 'luasnip' },
        },
      }
    end
  },
}