-- Copyright (c) 2020-2021 hoob3rt
-- MIT license, see LICENSE for more details.
local highlight = require('lualine.highlight')
local utils = require('lualine.utils.utils')

local Diagnostics = require('lualine.component'):new()

-- LuaFormatter off
Diagnostics.default_colors = {
  error = '#e32636',
  warn  = '#ffdf00',
  info  = '#ffffff',
}
-- LuaFormatter on

-- Initializer
Diagnostics.new = function(self, options, child)
  local new_diagnostics = self._parent:new(options, child or Diagnostics)
  local default_symbols = new_diagnostics.options.icons_enabled and {
    error = ' ', -- xf659
    warn = ' ', -- xf529
    info = ' ' -- xf7fc
  } or {error = 'E:', warn = 'W:', info = 'I:'}
  new_diagnostics.symbols = vim.tbl_extend('force', default_symbols,
                                           new_diagnostics.options.symbols or {})
  if new_diagnostics.options.sources == nil then
    print('no sources for diagnostics configured')
    return ''
  end
  if new_diagnostics.options.sections == nil then
    new_diagnostics.options.sections = {'error', 'warn', 'info'}
  end
  if new_diagnostics.options.colored == nil then
    new_diagnostics.options.colored = true
  end
  -- apply colors
  if not new_diagnostics.options.color_error then
    new_diagnostics.options.color_error =
        utils.extract_highlight_colors('LspDiagnosticsDefaultError', 'fg') or
            utils.extract_highlight_colors('DiffDelete', 'fg') or
            Diagnostics.default_colors.error
  end
  if not new_diagnostics.options.color_warn then
    new_diagnostics.options.color_warn =
        utils.extract_highlight_colors('LspDiagnosticsDefaultWarning', 'fg') or
            utils.extract_highlight_colors('DiffText', 'fg') or
            Diagnostics.default_colors.warn
  end
  if not new_diagnostics.options.color_info then
    new_diagnostics.options.color_info =
        utils.extract_highlight_colors('LspDiagnosticsDefaultInformation', 'fg') or
            utils.extract_highlight_colors('Normal', 'fg') or
            Diagnostics.default_colors.info
  end

  if new_diagnostics.options.colored then
    new_diagnostics.highlight_groups = {
      error = highlight.create_component_highlight_group(
          {fg = new_diagnostics.options.color_error}, 'diagnostics_error',
          new_diagnostics.options),
      warn = highlight.create_component_highlight_group(
          {fg = new_diagnostics.options.color_warn}, 'diagnostics_warn',
          new_diagnostics.options),
      info = highlight.create_component_highlight_group(
          {fg = new_diagnostics.options.color_info}, 'diagnostics_info',
          new_diagnostics.options)
    }
  end

  return new_diagnostics
end

Diagnostics.update_status = function(self)
  local error_count, warning_count, info_count = 0, 0, 0
  local diagnostic_data = self.get_diagnostics(self.options.sources)
  for _, data in pairs(diagnostic_data) do
    error_count = error_count + data.error
    warning_count = warning_count + data.warn
    info_count = info_count + data.info
  end
  local result = {}
  local data = {error = error_count, warn = warning_count, info = info_count}
  if self.options.colored then
    local colors = {}
    for name, hl in pairs(self.highlight_groups) do
      colors[name] = highlight.component_format_highlight(hl)
    end
    for _, section in ipairs(self.options.sections) do
      if data[section] ~= nil and data[section] > 0 then
        table.insert(result,
                     colors[section] .. self.symbols[section] .. data[section])
      end
    end
  else
    for _, section in ipairs(self.options.sections) do
      if data[section] ~= nil and data[section] > 0 then
        table.insert(result, self.symbols[section] .. data[section])
      end
    end
  end
  if result[1] ~= nil then
    return table.concat(result, ' ')
  else
    return ''
  end
end

Diagnostics.diagnostic_sources = {
  nvim_lsp = function()
    local error_count = vim.lsp.diagnostic.get_count(0, 'Error')
    local warning_count = vim.lsp.diagnostic.get_count(0, 'Warning')
    local info_count = vim.lsp.diagnostic.get_count(0, 'Information') +
                           vim.lsp.diagnostic.get_count(0, 'Hint')
    return error_count, warning_count, info_count
  end,
  coc = function()
    local data = vim.b.coc_diagnostic_info
    if data then
      return data.error, data.warning, data.information
    else
      return 0, 0, 0
    end
  end,
  ale = function()
    local ok, data = pcall(vim.fn['ale#statusline#Count'], vim.fn.bufnr())
    if ok then
      return data.error, data.warning, data.info
    else
      return 0, 0, 0
    end
  end
}

Diagnostics.get_diagnostics = function(sources)
  local result = {}
  for index, source in ipairs(sources) do
    local error_count, warning_count, info_count =
        Diagnostics.diagnostic_sources[source]()
    result[index] = {
      error = error_count,
      warn = warning_count,
      info = info_count
    }
  end
  return result
end

return Diagnostics