local M = {}

local sidebar_filetypes = {
  ['neo-tree'] = true,
  ['snacks_layout_box'] = true,
  ['snacks_terminal'] = true,
  ['toggleterm'] = true,
  ['opencode'] = true,
}

function M.is_main_window(win)
  if not win or not vim.api.nvim_win_is_valid(win) then return false end

  local buf = vim.api.nvim_win_get_buf(win)
  local ft = vim.bo[buf].filetype
  local bt = vim.bo[buf].buftype
  return not sidebar_filetypes[ft] and bt == ''
end

function M.focus_main_window()
  for _, win in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
    if M.is_main_window(win) then
      vim.api.nvim_set_current_win(win)
      return true
    end
  end

  return false
end

local function find_window_by_filetype(filetype)
  for _, win in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
    local buf = vim.api.nvim_win_get_buf(win)
    if vim.bo[buf].filetype == filetype then return win end
  end

  return nil
end

local function is_opencode_window(win)
  if not win or not vim.api.nvim_win_is_valid(win) then return false end

  local buf = vim.api.nvim_win_get_buf(win)
  local ft = vim.bo[buf].filetype
  if ft == 'opencode' then return true end

  local bt = vim.bo[buf].buftype
  if bt ~= 'terminal' then return false end

  if ft ~= '' and ft ~= 'snacks_terminal' and ft ~= 'toggleterm' then return false end

  local buf_name = string.lower(vim.api.nvim_buf_get_name(buf))
  return buf_name:find('opencode', 1, true) ~= nil
end

local function find_opencode_window()
  for _, win in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
    if is_opencode_window(win) then return win end
  end

  return nil
end

function M.capture_focus()
  local current_win = vim.api.nvim_get_current_win()
  if not M.is_main_window(current_win) then return nil end

  local buf = vim.api.nvim_win_get_buf(current_win)
  local buf_name = vim.api.nvim_buf_get_name(buf)
  if buf_name == '' then return nil end

  return {
    buf_name = buf_name,
  }
end

function M.restore_focus(focus)
  if type(focus) ~= 'table' then return M.focus_main_window() end

  local target_buf_name = focus.buf_name
  if type(target_buf_name) ~= 'string' or target_buf_name == '' then return M.focus_main_window() end

  for _, win in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
    if M.is_main_window(win) then
      local buf = vim.api.nvim_win_get_buf(win)
      if vim.api.nvim_buf_get_name(buf) == target_buf_name then
        vim.api.nvim_set_current_win(win)
        return true
      end
    end
  end

  return M.focus_main_window()
end

local function ensure_neotree_window()
  local neotree_win = find_window_by_filetype 'neo-tree'
  if neotree_win then return neotree_win end

  pcall(
    function()
      require('neo-tree.command').execute {
        action = 'show',
        source = 'filesystem',
        position = 'left',
        reveal = true,
      }
    end
  )

  return find_window_by_filetype 'neo-tree'
end

local function ensure_opencode_window()
  local opencode_win = find_opencode_window()
  if opencode_win then return opencode_win end

  pcall(function() require('opencode').toggle() end)

  vim.wait(1000, function() return find_opencode_window() ~= nil end, 50)
  return find_opencode_window()
end

function M.reset_ide_layout(opts)
  opts = opts or {}

  local neotree_win = ensure_neotree_window()
  local opencode_win = ensure_opencode_window()

  local total_columns = vim.o.columns
  local left_width = math.max(20, math.floor(total_columns * 0.10))
  local right_width = math.max(40, math.floor(total_columns * 0.25))
  local min_main_width = 40

  if left_width + right_width + min_main_width > total_columns then
    local available_sidebar_width = math.max(total_columns - min_main_width, 0)
    left_width = math.floor(available_sidebar_width * (10 / 35))
    right_width = available_sidebar_width - left_width
  end

  if neotree_win and vim.api.nvim_win_is_valid(neotree_win) then vim.api.nvim_win_set_width(neotree_win, left_width) end
  if opencode_win and vim.api.nvim_win_is_valid(opencode_win) then vim.api.nvim_win_set_width(opencode_win, right_width) end

  if opts.focus_main ~= false then M.focus_main_window() end
end

return M