-- Echoing of LSP diagnostics in the commandline.

local M = {}

-- Location information about the last message printed. The format is

-- `(did print, buffer number, line number)`.

local last_echo = { false, -1, -1 }

-- The timer used for displaying a diagnostic in the commandline.

local echo_timer = nil

-- The timer after which to display a diagnostic in the commandline.

local echo_timeout = 250

-- The highlight group to use for warning messages.

local warning_hlgroup = 'WarningMsg'

-- The highlight group to use for error messages.

local error_hlgroup = 'ErrorMsg'

-- If the first diagnostic line has fewer than this many characters, also add

-- the second line to it.

local short_line_limit = 20

-- Shows the current line's diagnostics in a floating window.

function M.show_line_diagnostics()

  vim

    .lsp

    .diagnostic

    .show_line_diagnostics({ severity_limit = 'Warning' }, vim.fn.bufnr(''))

end

-- Prints the first diagnostic for the current line.

function M.echo_diagnostic()

  if echo_timer then

    echo_timer:stop()

  end

  echo_timer = vim.defer_fn(

    function()

      local line = vim.fn.line('.') - 1

      local bufnr = vim.api.nvim_win_get_buf(0)

      if last_echo[1] and last_echo[2] == bufnr and last_echo[3] == line then

        return

      end

      local diags = vim

        .lsp

        .diagnostic

        .get_line_diagnostics(bufnf, line, { severity_limit = 'Warning' })

      if #diags == 0 then

        -- If we previously echo'd a message, clear it out by echoing an empty

        -- message.

        if last_echo[1] then

          last_echo = { false, -1, -1 }

          vim.api.nvim_command('echo ""')

        end

        return

      end

      last_echo = { true, bufnr, line }

      local diag = diags[1]

      local width = vim.api.nvim_get_option('columns') - 15

      local lines = vim.split(diag.message, "\n")

      local message = lines[1]

      local trimmed = false

      if #lines > 1 and #message <= short_line_limit then

        message = message .. ' ' .. lines[2]

      end

      if width > 0 and #message >= width then

        message = message:sub(1, width) .. '...'

      end

      local kind = 'warning'

      local hlgroup = warning_hlgroup

      if diag.severity == vim.lsp.protocol.DiagnosticSeverity.Error then

        kind = 'error'

        hlgroup = error_hlgroup

      end

      local chunks = {

        { kind .. ': ', hlgroup },

        { message }

      }

      vim.api.nvim_echo(chunks, false, {})

    end,

    echo_timeout

  )

end

return M