local lspconfig_ok, lspconfig = pcall(require, "lspconfig")
if not lspconfig_ok then
    return
end

local language_servers = {
    gopls = {},
    -- grammarly = {},
    -- marksman = {},
    jsonls = {},
    tsserver = {},
    sumneko_lua = {
        settings = {
            Lua = {
                runtime = {
                    -- Tell the language server which version of Lua you're using (most likely LuaJIT in the case of Neovim)
                    version = 'LuaJIT',
                },
                diagnostics = {
                    -- Get the language server to recognize the `vim` global
                    globals = { 'vim' },
                },
                workspace = {
                    -- Make the server aware of Neovim runtime files
                    library = vim.api.nvim_get_runtime_file("", true),
                },
                -- Do not send telemetry data containing a randomized but unique identifier
                telemetry = {
                    enable = false,
                },
            },
        },
    }
}

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
    -- Enable completion triggered by <c-x><c-o>
    vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

    -- Mappings.
    -- See `:help vim.lsp.*` for documentation on any of the below functions
    local bufopts = { noremap = true, silent = true, buffer = bufnr }
    vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
    vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
    vim.keymap.set('n', 'od', vim.lsp.buf.hover, bufopts)
    vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
    vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
    vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
    vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
    vim.keymap.set('n', '<space>wl', function()
        print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
    end, bufopts)
    vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
    vim.keymap.set('n', '<leader>rn', vim.lsp.buf.rename, bufopts)
    vim.keymap.set('n', '<leader>ca', vim.lsp.buf.code_action, bufopts)
    vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
    vim.keymap.set('n', '<leader>fd', vim.lsp.buf.formatting, bufopts)
end

local capabilities = vim.lsp.protocol.make_client_capabilities()


local cmp_status_ok, cmp = pcall(require, "cmp")
if cmp_status_ok then
    local cmp_nvim_lsp_status_ok, cmp_nvim_lsp = pcall(require, "cmp_nvim_lsp")
    if cmp_nvim_lsp_status_ok then
        capabilities = cmp_nvim_lsp.update_capabilities(capabilities)
    end
end

for langsvr, settings in pairs(language_servers) do
    settings["on_attach"] = on_attach
    settings["capabilities"] = capabilities
    lspconfig[langsvr].setup(settings)
end

if not cmp_status_ok then
    return
end

local luasnip_status_ok, luasnip = pcall(require, "luasnip")

cmp.setup {
    snippet = {
        expand = function(args)
            if luasnip_status_ok then
                luasnip.lsp_expand(args.body)
            end
        end,
    },
    mapping = cmp.mapping.preset.insert({
        ['<C-d>'] = cmp.mapping.scroll_docs(-4),
        ['<C-f>'] = cmp.mapping.scroll_docs(4),
        ['<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_status_ok and 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_status_ok and luasnip.jumpable(-1) then
                luasnip.jump(-1)
            else
                fallback()
            end
        end, { 'i', 's' }),
    }),
    sources = {
        { name = 'nvim_lsp' },
        { name = 'luasnip' },
        { name = 'buffer' },
        { name = 'path' },
    },
}

local null_ls_ok, null_ls = pcall(require, "null_ls")
if not null_ls_ok then
    return
end

null_ls.setup({
    sources = {
        null_ls.builtins.formatting.stylua,
        null_ls.builtins.diagnostics.eslint,
        null_ls.builtins.completion.spell,
        null_ls.builtins.formatting.goimports,
        null_ls.builtins.formatting.gofumpt,
    },
})