local config = {}

local _errors
local _warnings
local _hints
local _info
local icons

local diagnostics = require('lsp-status/diagnostics')
local messages = require('lsp-status/messaging').messages
local aliases = {pyls_ms = 'MPLS'}

local function make_statusline_component(diagnostics_key)
  return function(bufh)
    bufh = bufh or vim.api.nvim_get_current_buf()
    local icon = icons[diagnostics_key] .. config.indicator_separator
    local _diagnostics = diagnostics(bufh)[diagnostics_key]
    if _diagnostics > 0 then return (icon or '') .. diagnostics(bufh)[diagnostics_key] end
  end
end

local function init(_, _config)
  config = vim.tbl_extend('force', config, _config)

  icons = {
    errors = config.indicator_errors,
    warnings = config.indicator_warnings,
    hints = config.indicator_hint,
    info = config.indicator_info
  }

  _errors = make_statusline_component('errors')
  _warnings = make_statusline_component('warnings')
  _hints = make_statusline_component('hints')
  _info = make_statusline_component('info')
end

local function get_lsp_progress()
  local buf_messages = messages()
  local msgs = {}

  for _, msg in ipairs(buf_messages) do
    local name = aliases[msg.name] or msg.name
    local client_name = '[' .. name .. ']'
    local contents
    if msg.progress then
      contents = msg.title
      if msg.message then contents = contents .. ' ' .. msg.message end

      -- this percentage format string escapes a percent sign once to show a percentage and one more
      -- time to prevent errors in vim statusline's because of it's treatment of % chars
      if msg.percentage then contents = contents .. string.format(" (%.0f%%%%)", msg.percentage) end

      if msg.spinner then
        contents = config.spinner_frames[(msg.spinner % #config.spinner_frames) + 1] .. ' ' ..
          contents
      end
    elseif msg.status then
      contents = msg.content
      if config.show_filename and msg.uri then
        local filename = vim.uri_to_fname(msg.uri)
        filename = vim.fn.fnamemodify(filename, ':~:.')
        local space = math.min(60, math.floor(0.6 * vim.fn.winwidth(0)))
        if #filename > space then filename = vim.fn.pathshorten(filename) end

        contents = '(' .. filename .. ') ' .. contents
      end
    else
      contents = msg.content
    end

    table.insert(msgs, client_name .. ' ' .. contents)
  end
  return table.concat(msgs, config.component_separator)
end

local function get_lsp_statusline(bufnr)
  bufnr = bufnr or 0
  if vim.tbl_count(vim.lsp.buf_get_clients(bufnr)) == 0 then return '' end
  local buf_diagnostics = config.diagnostics and diagnostics(bufnr) or nil
  local only_hint = true
  local some_diagnostics = false
  local status_parts = {}
  if buf_diagnostics then
    if buf_diagnostics.errors and buf_diagnostics.errors > 0 then
      table.insert(status_parts,
                   config.indicator_errors .. config.indicator_separator .. buf_diagnostics.errors)
      only_hint = false
      some_diagnostics = true
    end

    if buf_diagnostics.warnings and buf_diagnostics.warnings > 0 then
      table.insert(status_parts, config.indicator_warnings .. config.indicator_separator ..
                     buf_diagnostics.warnings)
      only_hint = false
      some_diagnostics = true
    end

    if buf_diagnostics.info and buf_diagnostics.info > 0 then
      table.insert(status_parts,
                   config.indicator_info .. config.indicator_separator .. buf_diagnostics.info)
      only_hint = false
      some_diagnostics = true
    end

    if buf_diagnostics.hints and buf_diagnostics.hints > 0 then
      table.insert(status_parts,
                   config.indicator_hint .. config.indicator_separator .. buf_diagnostics.hints)
      some_diagnostics = true
    end
  end

  local msgs = get_lsp_progress()

  local base_status = vim.trim(table.concat(status_parts, config.component_separator) .. ' ' .. msgs)
  local symbol = config.status_symbol .. ((some_diagnostics and only_hint) and '' or ' ')
  if config.current_function then
    local current_function = vim.b.lsp_current_function
    if current_function and current_function ~= '' then
      symbol = symbol .. '(' .. current_function .. ')' .. config.component_separator
    end
  end

  if base_status ~= '' then return symbol .. base_status .. ' ' end
  if not config.diagnostics then return symbol end
  return symbol .. config.indicator_ok .. ' '
end

local function get_component_functions()
  return {errors = _errors, warnings = _warnings, hints = _hints, info = _info}
end

local M = {
  _init = init,
  status = get_lsp_statusline,
  progress = get_lsp_progress,
  _get_component_functions = get_component_functions,
}

return M