local luv = vim.loop
local api = vim.api

local lib = require'nvim-tree.lib'
local colors = require'nvim-tree.colors'
local renderer = require'nvim-tree.renderer'
local view = require'nvim-tree.view'
local utils = require'nvim-tree.utils'
local change_dir = require'nvim-tree.actions.change-dir'

local _config = {}

local M = {}

function M.focus()
  M.open()
  view.focus();
end

---@deprecated
M.on_keypress = require'nvim-tree.actions'.on_keypress

function M.toggle(find_file)
  if view.is_visible() then
    view.close()
  else
    M.open()
    if TreeExplorer and (_config.update_focused_file.enable or find_file) then
      M.find_file(false)
    end
  end
end

function M.open(cwd)
  cwd = cwd ~= "" and cwd or nil
  if not view.is_visible() then
    lib.open(cwd)
  end
end

function M.tab_change()
  vim.schedule(function()
    if not view.is_visible() and view.is_visible({ any_tabpage = true }) then
      local bufname = vim.api.nvim_buf_get_name(0)
      if bufname:match("Neogit") ~= nil or bufname:match("--graph") ~= nil then
        return
      end
      view.open({ focus_tree = false })
    end
  end)
end

local function find_existing_windows()
  return vim.tbl_filter(
    function(win)
      local buf = api.nvim_win_get_buf(win)
      return api.nvim_buf_get_name(buf):match("NvimTree") ~= nil
    end,
    api.nvim_list_wins()
  )
end

function M.on_enter(netrw_disabled)
  local bufnr = api.nvim_get_current_buf()
  local bufname = api.nvim_buf_get_name(bufnr)
  local buftype = api.nvim_buf_get_option(bufnr, 'filetype')
  local ft_ignore = _config.ignore_ft_on_setup

  local stats = luv.fs_stat(bufname)
  local is_dir = stats and stats.type == 'directory'
  local cwd
  if is_dir then
    cwd = vim.fn.expand(bufname)
    -- INFO: could potentially conflict with rooter plugins
    vim.cmd("noautocmd cd "..cwd)
  end

  local lines = not is_dir and api.nvim_buf_get_lines(bufnr, 0, -1, false) or {}
  local buf_has_content = #lines > 1 or (#lines == 1 and lines[1] ~= "")

  local buf_is_dir = is_dir and netrw_disabled
  local buf_is_empty = bufname == "" and not buf_has_content
  local should_be_preserved = vim.tbl_contains(ft_ignore, buftype)
  local should_open = _config.open_on_setup and not should_be_preserved and (buf_is_dir or buf_is_empty)
  local should_hijack = _config.hijack_directories.enable and _config.hijack_directories.auto_open and is_dir and not should_be_preserved

  -- Session that left a NvimTree Buffer opened, reopen with it
  local existing_tree_wins = find_existing_windows()
  if existing_tree_wins[1] then
    api.nvim_set_current_win(existing_tree_wins[1])
  end

  if should_open or should_hijack or existing_tree_wins[1] ~= nil then
    lib.init(true, cwd)
  end
  M.initialized = true
end

local function is_file_readable(fname)
  local stat = luv.fs_stat(fname)
  return stat and stat.type == "file" and luv.fs_access(fname, 'R')
end

local function update_base_dir_with_filepath(filepath, bufnr)
  local ft = api.nvim_buf_get_option(bufnr, 'filetype') or ""
  for _, value in pairs(_config.update_focused_file.ignore_list) do
    if utils.str_find(filepath, value) or utils.str_find(ft, value) then
      return
    end
  end

  if not vim.startswith(filepath, TreeExplorer.cwd) then
    change_dir.fn(vim.fn.fnamemodify(filepath, ':p:h'))
  end
end

function M.find_file(with_open)
  if not with_open and not TreeExplorer then return end

  local bufname = vim.fn.bufname()
  local bufnr = api.nvim_get_current_buf()
  local filepath = vim.fn.fnamemodify(bufname, ':p')
  if not is_file_readable(filepath) then
    return
  end

  if with_open then
    M.open()
  end

  if _config.update_focused_file.update_cwd then
    update_base_dir_with_filepath(filepath, bufnr)
  end
  require"nvim-tree.actions.find-file".fn(filepath)
end

M.resize = view.resize

function M.on_leave()
  vim.defer_fn(function()
    if not view.is_visible() then
      return
    end

    local windows = api.nvim_list_wins()
    local curtab = api.nvim_get_current_tabpage()
    local wins_in_tabpage = vim.tbl_filter(function(w)
      return api.nvim_win_get_tabpage(w) == curtab
    end, windows)
    if #windows == 1 then
      api.nvim_command(':silent qa!')
    elseif #wins_in_tabpage == 1 then
      api.nvim_command(':tabclose')
    end
  end, 50)
end

function M.open_on_directory()
  local should_proceed = M.initialized and (_config.hijack_directories.auto_open or view.is_visible())
  if not should_proceed then
    return
  end

  local buf = api.nvim_get_current_buf()
  local bufname = api.nvim_buf_get_name(buf)
  if vim.fn.isdirectory(bufname) ~= 1 then
    return
  end

  change_dir.force_dirchange(bufname, true)
end

function M.reset_highlight()
  colors.setup()
  renderer.render_hl(view.get_bufnr())
end

local prev_line
function M.place_cursor_on_node()
  local l = vim.api.nvim_win_get_cursor(0)[1]
  if l == prev_line then
    return
  end
  prev_line = l

  local node = lib.get_node_at_cursor()
  if not node or node.name == ".." then
    return
  end

  local line = api.nvim_get_current_line()
  local cursor = api.nvim_win_get_cursor(0)
  local idx = vim.fn.stridx(line, node.name)

  if idx >= 0 then
    api.nvim_win_set_cursor(0, {cursor[1], idx})
  end
end

local function manage_netrw(disable_netrw, hijack_netrw)
  if hijack_netrw then
    vim.cmd "silent! autocmd! FileExplorer *"
  end
  if disable_netrw then
    vim.g.loaded_netrw = 1
    vim.g.loaded_netrwPlugin = 1
  end
end

local function setup_vim_commands()
  vim.cmd [[
    command! -nargs=? -complete=dir NvimTreeOpen lua require'nvim-tree'.open("<args>")
    command! NvimTreeClose lua require'nvim-tree.view'.close()
    command! NvimTreeToggle lua require'nvim-tree'.toggle(false)
    command! NvimTreeFocus lua require'nvim-tree'.focus()
    command! NvimTreeRefresh lua require'nvim-tree.actions.reloaders'.reload_explorer()
    command! NvimTreeClipboard lua require'nvim-tree.actions.copy-paste'.print_clipboard()
    command! NvimTreeFindFile lua require'nvim-tree'.find_file(true)
    command! NvimTreeFindFileToggle lua require'nvim-tree'.toggle(true)
    command! -nargs=1 NvimTreeResize lua require'nvim-tree'.resize(<args>)
  ]]
end

function M.change_dir(name)
  change_dir.fn(name)

  if _config.update_focused_file.enable then
    M.find_file(false)
  end
end

local function setup_autocommands(opts)
  vim.cmd "augroup NvimTree"

  -- reset highlights when colorscheme is changed
  vim.cmd "au ColorScheme * lua require'nvim-tree'.reset_highlight()"
  if opts.auto_reload_on_write then
    vim.cmd "au BufWritePost * lua require'nvim-tree.actions.reloaders'.reload_explorer()"
  end
  vim.cmd "au User FugitiveChanged,NeogitStatusRefreshed lua require'nvim-tree.actions.reloaders'.reload_git()"

  if opts.auto_close then
    vim.cmd "au WinClosed * lua require'nvim-tree'.on_leave()"
  end
  if opts.open_on_tab then
    vim.cmd "au TabEnter * lua require'nvim-tree'.tab_change()"
  end
  if opts.hijack_cursor then
    vim.cmd "au CursorMoved NvimTree lua require'nvim-tree'.place_cursor_on_node()"
  end
  if opts.update_cwd then
    vim.cmd "au DirChanged * lua require'nvim-tree'.change_dir(vim.loop.cwd())"
  end
  if opts.update_focused_file.enable then
    vim.cmd "au BufEnter * lua require'nvim-tree'.find_file(false)"
  end

  if not opts.actions.open_file.quit_on_open then
    vim.cmd "au BufWipeout NvimTree lua require'nvim-tree.view'._prevent_buffer_override()"
  end

  if opts.hijack_directories.enable then
    vim.cmd "au BufEnter,BufNewFile * lua require'nvim-tree'.open_on_directory()"
  end

  vim.cmd "augroup end"
end

local DEFAULT_OPTS = {
  disable_netrw        = true,
  hijack_netrw         = true,
  open_on_setup        = false,
  open_on_tab          = false,
  hijack_directories   = {
    enable = true,
    auto_open = true,
  },
  auto_close           = false,
  auto_reload_on_write = true,
  hijack_cursor        = false,
  update_cwd           = false,
  hide_root_folder     = false,
  update_focused_file  = {
    enable = false,
    update_cwd = false,
    ignore_list = {}
  },
  ignore_ft_on_setup = {},
  system_open = {
    cmd  = nil,
    args = {}
  },
  diagnostics = {
    enable = false,
    show_on_dirs = false,
    icons = {
      hint = "",
      info = "",
      warning = "",
      error = "",
    }
  },
  filters = {
    dotfiles = false,
    custom_filter = {},
    exclude = {}
  },
  git = {
    enable = true,
    ignore = true,
    timeout = 400,
  },
  actions = {
    change_dir = {
      global = vim.g.nvim_tree_change_dir_global == 1,
    },
    open_file = {
      quit_on_open = vim.g.nvim_tree_quit_on_open == 1,
    }
  }
}

local function merge_options(conf)
  if conf and conf.update_to_buf_dir then
    conf.hijack_directories = conf.update_to_buf_dir
    conf.update_to_buf_dir = nil
  end
  return vim.tbl_deep_extend('force', DEFAULT_OPTS, conf or {})
end

function M.setup(conf)
  local opts = merge_options(conf)
  local netrw_disabled = opts.disable_netrw or opts.hijack_netrw

  _config.update_focused_file = opts.update_focused_file
  _config.open_on_setup = opts.open_on_setup
  _config.ignore_ft_on_setup = opts.ignore_ft_on_setup
  _config.hijack_directories = opts.hijack_directories
  _config.hijack_directories.enable = _config.hijack_directories.enable and netrw_disabled

  manage_netrw(opts.disable_netrw, opts.hijack_netrw)

  require'nvim-tree.actions'.setup(opts)
  require'nvim-tree.colors'.setup()
  require'nvim-tree.diagnostics'.setup(opts)
  require'nvim-tree.explorer'.setup(opts)
  require'nvim-tree.git'.setup(opts)
  require'nvim-tree.view'.setup(opts)

  setup_vim_commands()
  setup_autocommands(opts)

  vim.schedule(function()
    M.on_enter(netrw_disabled)
  end)
end

return M