local api = vim.api
local fn = vim.fn

local queries = require'nvim-treesitter.query'
local info = require'nvim-treesitter.info'

local health_start = vim.fn["health#report_start"]
local health_ok = vim.fn['health#report_ok']
local health_error = vim.fn['health#report_error']

local M = {}

local function install_health()
  health_start('Installation')
  if fn.executable('git') == 0 then
    health_error('`git` executable not found.', {
      'Install it with your package manager.',
      'Check that your `$PATH` is set correctly.'
    })
  else
    health_ok('`git` executable found.')
  end

  if fn.executable('cc') == 0 then
    health_error('`cc` executable not found.', {
      'Check that either gcc or clang is in your $PATH'
    })
  else
    health_ok('`cc` executable found.')
  end
end

local function query_status(lang, query_group)
  local ok, found_query = pcall(queries.get_query, lang, query_group)
  if not ok then
    return "x"
  elseif not found_query then
    return "."
  else
    return "✓"
  end
end

function M.checkhealth()
  -- Installation dependency checks
  install_health()
  health_start("Parser/Features H L F I")
  -- Parser installation checks
  for _, parser_name in pairs(info.installed_parsers()) do
    local installed = #api.nvim_get_runtime_file('parser/'..parser_name..'.so', false)

    -- Only print informations about installed parsers
    if installed >= 1 then
      local multiple_parsers = installed > 1 and "*" or ""
      local out = "  - "..parser_name..multiple_parsers..string.rep(" ", 15 - (#parser_name + #multiple_parsers))
      for _, query_group in pairs(queries.built_in_query_groups) do
        out = out..query_status(parser_name, query_group).." "
      end
      print(out)
    end
  end
  print([[ Legend: H[ighlight], L[ocals], F[olds], I[ndents]
         *) multiple parsers found, only one will be used
         x) errors found in the query, try to run :TSUpdate {lang}]])
end

return M