fix(ui): prevent duplicate windows

[disrupted]

fix #144
not entirely sure if this approach aligns with best-practices
at least I am no longer seeing the issue on my end

[sudo-tee]

I played a little bit wit it.
It seems to work when resizingf but it does not fix the root cause.

I am still able to duplicate the input window if I wun :tabdo wincmd = when focused in the input.

I will play a little bit with this to see if there is a better solution

[sudo-tee]

How about a more generic approach with a utility for fix a buf to a window, it's like the opposite of winfixbuf.

I came up with the following based on your reconcile_windows

--- Prevents a buffer from appearing in multiple windows (opposite of 'winfixbuf')
---
--- This module solves the problem where buffers can appear in multiple windows
--- despite having 'winfixbuf' set. The 'winfixbuf' option prevents a window from
--- changing buffers, but doesn't prevent a buffer from appearing in multiple windows.
---
local M = {}
local buff_to_win_map = {}
local global_autocmd_setup = false

local function close_duplicates(buf, get_win)
  local intended = get_win()
  if not intended then
    return
  end

  local wins = vim.fn.win_findbuf(buf)
  if #wins <= 1 then
    return
  end

  for _, win in ipairs(wins) do
    if win ~= intended and vim.api.nvim_win_is_valid(win) then
      vim.schedule(function()
        pcall(vim.api.nvim_win_close, win, true)
      end)
    end
  end
end

local function setup()
  if global_autocmd_setup then
    return
  end
  global_autocmd_setup = true

  vim.api.nvim_create_autocmd('WinNew', {
    callback = function()
      vim.schedule(function()
        for buf, get_win in pairs(buff_to_win_map) do
          if vim.api.nvim_buf_is_valid(buf) then
            close_duplicates(buf, get_win)
          else
            buff_to_win_map[buf] = nil
          end
        end
      end)
    end,
  })
end

--- Protect a buffer from appearing in multiple windows
---@param buf integer Buffer number
---@param get_intended_window fun(): integer? Function returning intended window ID
function M.fix_to_win(buf, get_intended_window)
  setup()

  buff_to_win_map[buf] = get_intended_window
  vim.api.nvim_create_autocmd('BufWinEnter', {
    buffer = buf,
    callback = function()
      close_duplicates(buf, get_intended_window)
    end,
  })
end

return M

And it could be used like so on a buffer after creation

  local buffixwin = require('opencode.ui.buf_fix_win')
  buffixwin.fix_to_win(input_buf, function()
    local state = require('opencode.state')
    return state.windows and state.windows.input_win
  end)

In my quick tests it covers,

resizing, tabdo wincmd=, vsplit and split from messing the layout.

[disrupted]

great, clearly this is a much more robust solution! feel free to open a PR to supersede mine.

overall I haven't fully understand why this issue occurs in the first place. it feels like we're doing something fundamentally wrong that makes these workarounds necessary. but I am happy about any pragmatic solution at this point. we can always refine it later once we identify the root cause of this problem

[sudo-tee]

great, clearly this is a much more robust solution! feel free to open a PR to supersede mine.

overall I haven't fully understand why this issue occurs in the first place. it feels like we're doing something fundamentally wrong that makes these workarounds necessary. but I am happy about any pragmatic solution at this point. we can always refine it later once we identify the root cause of this problem

I have tested other similar plugins and most of them have similar issues . you can split , duplicate windows. I think it's more of an issue related to fixed window layout, some plugins like https://github.com/stevearc/stickybuf.nvim uses a similar approach.

I will create a PR to use my fix

Thanks

[sudo-tee]

Closing this one in favor of
#238

Which was inspired by the work on this branch