local M = {}
local Log = require "core.log"
local utils = require "utils"

local function lsp_highlight_document(client)
  if options.lsp.document_highlight == false then
    return -- we don't need further
  end
  -- Set autocommands conditional on server_capabilities
  if client.resolved_capabilities.document_highlight then
    vim.api.nvim_exec(
      [[
      augroup lsp_document_highlight
        autocmd! * <buffer>
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
      augroup END
    ]],
      false
    )
  end
end

local function add_lsp_buffer_keybindings(bufnr)
  local status_ok, wk = pcall(require, "which-key")
  if not status_ok then
    return
  end

  local keys = {
    ["K"] = { "<cmd>lua vim.lsp.buf.hover()<CR>", "Show hover" },
    ["gd"] = { "<cmd>lua vim.lsp.buf.definition()<CR>", "Goto Definition" },
    ["gD"] = { "<cmd>lua vim.lsp.buf.declaration()<CR>", "Goto declaration" },
    ["gr"] = { "<cmd>lua vim.lsp.buf.references()<CR>", "Goto references" },
    ["gI"] = { "<cmd>lua vim.lsp.buf.implementation()<CR>", "Goto Implementation" },
    ["gs"] = { "<cmd>lua vim.lsp.buf.signature_help()<CR>", "show signature help" },
    ["gp"] = { "<cmd>lua require'lsp.peek'.Peek('definition')<CR>", "Peek definition" },
    ["gl"] = {
      "<cmd>lua require'lsp.handlers'.show_line_diagnostics()<CR>",
      "Show line diagnostics",
    },
  }
  wk.register(keys, { mode = "n", buffer = bufnr })
end

function M.common_capabilities()
  local capabilities = vim.lsp.protocol.make_client_capabilities()
  capabilities.textDocument.completion.completionItem.snippetSupport = true
  capabilities.textDocument.completion.completionItem.resolveSupport = {
    properties = {
      "documentation",
      "detail",
      "additionalTextEdits",
    },
  }

  local status_ok, cmp_nvim_lsp = pcall(require, "cmp_nvim_lsp")
  if status_ok then
    capabilities = cmp_nvim_lsp.update_capabilities(capabilities)
  end

  return capabilities
end

local function select_default_formater(client)
  local client_formatting = client.resolved_capabilities.document_formatting
    or client.resolved_capabilities.document_range_formatting
  if client.name == "null-ls" or not client_formatting then
    return
  end
  Log:debug("Checking for formatter overriding for " .. client.name)
  local client_filetypes = client.config.filetypes or {}
  for _, filetype in ipairs(client_filetypes) do
    if not vim.tbl_isempty(lvim.lang[filetype].formatters) then
      Log:debug("Formatter overriding detected. Disabling formatting capabilities for " .. client.name)
      client.resolved_capabilities.document_formatting = false
      client.resolved_capabilities.document_range_formatting = false
      return
    end
  end
end

function M.common_on_init(client, bufnr)
  if options.lsp.on_init_callback then
    options.lsp.on_init_callback(client, bufnr)
    Log:debug "Called lsp.on_init_callback"
    return
  end
  select_default_formater(client)
end

function M.common_on_attach(client, bufnr)
  if options.lsp.on_attach_callback then
    options.lsp.on_attach_callback(client, bufnr)
    Log:debug "Called lsp.on_attach_callback"
  end
  lsp_highlight_document(client)
  add_lsp_buffer_keybindings(bufnr)
end

local function bootstrap_nlsp(opts)
  opts = opts or {}
  local lsp_settings_status_ok, lsp_settings = pcall(require, "nlspsettings")
  if lsp_settings_status_ok then
    lsp_settings.setup(opts)
  end
end

function M.get_common_opts()
  return {
    on_attach = M.common_on_attach,
    on_init = M.common_on_init,
    capabilities = M.common_capabilities(),
  }
end

function M.setup()
  Log:debug "Setting up LSP support"

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

  for _, sign in ipairs(options.lsp.diagnostics.signs.values) do
    vim.fn.sign_define(
      sign.name,
      { texthl = sign.name, text = sign.text, numhl = sign.name }
    )
  end
  require("lsp.handlers").setup()

  if not utils.is_directory(options.lsp.templates_dir) then
    require("lsp.templates").generate_templates()
  end

  bootstrap_nlsp { config_home = utils.join_paths(get_config_dir(), "lsp-settings") }

  require("lsp.null-ls").setup()

  require("utils").toggle_autoformat()
end

return M