" Set completeopt to have a better completion experience
" :help completeopt
" menuone: popup even when there's only one match
" noinsert: Do not insert text until a selection is made
" noselect: Do not select, force user to select one from the menu
set completeopt=menuone,noinsert,noselect

" Avoid showing extra messages when using completion
set shortmess+=c

" Configure LSP through rust-tools.nvim plugin.
" rust-tools will configure and enable certain LSP features for us.
" See https://github.com/simrat39/rust-tools.nvim#configuration
lua <<EOF
local nvim_lsp = require'lspconfig'

local opts = {
    tools = { -- rust-tools options
        autoSetHints = true,
        hover_with_actions = true,
        inlay_hints = {
            show_parameter_hints = false,
            parameter_hints_prefix = "",
            other_hints_prefix = "",
        },
    },

    -- all the opts to send to nvim-lspconfig
    -- these override the defaults set by rust-tools.nvim
    -- see https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#rust_analyzer
    server = {
        -- on_attach is a callback called when the language server attachs to the buffer
        -- on_attach = on_attach,
        settings = {
            -- to enable rust-analyzer settings visit:
            -- https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/generated_config.adoc
            ["rust-analyzer"] = {
                -- enable clippy on save
                checkOnSave = {
                    command = "clippy"
                },
            }
        }
    },
}

require('rust-tools').setup(opts)
EOF

" Setup Completion
" See https://github.com/hrsh7th/nvim-cmp#basic-configuration
lua <<EOF
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-d>'] = 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 = 'nvim_lsp' },
    { name = 'vsnip' },
    { name = 'path' },
    { name = 'buffer' },
  },
})
EOF

" Code navigation shortcuts
nnoremap <silent> <c-]> <cmd>lua vim.lsp.buf.definition()<CR>
nnoremap <silent> K     <cmd>lua vim.lsp.buf.hover()<CR>
nnoremap <silent> gD    <cmd>lua vim.lsp.buf.implementation()<CR>
nnoremap <silent> <c-k> <cmd>lua vim.lsp.buf.signature_help()<CR>
nnoremap <silent> 1gD   <cmd>lua vim.lsp.buf.type_definition()<CR>
nnoremap <silent> gr    <cmd>lua vim.lsp.buf.references()<CR>
nnoremap <silent> g0    <cmd>lua vim.lsp.buf.document_symbol()<CR>
nnoremap <silent> gW    <cmd>lua vim.lsp.buf.workspace_symbol()<CR>
nnoremap <silent> gd    <cmd>lua vim.lsp.buf.definition()<CR>

nnoremap <silent> ga    <cmd>lua vim.lsp.buf.code_action()<CR>

" Goto previous/next diagnostic warning/error
nnoremap <silent> g[ <cmd>lua vim.diagnostic.goto_prev()<CR>
nnoremap <silent> g] <cmd>lua vim.diagnostic.goto_next()<CR>