-- nixos-config - My current NixOS configuration
--
-- Copyright (C) 2025 Benedikt Peetz <benedikt.peetz@b-peetz.de>
-- SPDX-License-Identifier: GPL-3.0-or-later
--
-- This file is part of my nixos-config.
--
-- You should have received a copy of the License along with this program.
-- If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.

local flatten = require("flatten")

---Types:
--
-- Passed to callbacks that handle opening files
---@alias BufInfo { fname: string, bufnr: buffer }
--
-- Needed aliases
---@alias buffer integer: Buffer id
---@alias window integer: Window id
--
-- The first argument is a list of BufInfo tables representing the newly opened files.
-- The third argument is a single BufInfo table, only provided when a buffer is created from stdin.
--
-- IMPORTANT: For `block_for` to work, you need to return a buffer number OR a buffer number and a window number.
--            The `winnr` return value is not required, `vim.fn.bufwinid(bufnr)` is used if it is not provided.
--            The `filetype` of this buffer will determine whether block should happen or not.
--
---@alias OpenHandler fun(files: BufInfo[], argv: string[], stdin_buf: BufInfo, guest_cwd: string):window, buffer
--
require("flatten").setup({
  hooks = {
    ---Called to determine if a nested session should wait for the host to close the file.
    ---param argv: a list of all the arguments in the nested session
    ---@type fun(argv: table): boolean
    should_block = flatten.hooks.should_block;

    ---If this returns true, the nested session will be opened.
    ---If false, default behavior is used, and
    ---config.nest_if_no_args is respected.
    ---@type fun(host: channel):boolean
    should_nest = flatten.hooks.should_nest;

    ---Called before a nested session is opened.
    pre_open = flatten.hooks.pre_open;

    ---Called after a nested session is opened.
    ---@param bufnr buffer
    ---@param winnr window
    ---@param filetype string
    ---@param is_blocking boolean
    ---@param is_diff boolean
    post_open = flatten.hooks.post_open;

    ---Called when a nested session is done waiting for the host.
    ---@param filetype string
    block_end = flatten.hooks.block_end;

    no_files = flatten.hooks.no_files;
    guest_data = flatten.hooks.guest_data;

    -- Override this function to use a different socket to connect to the host
    -- On the host side this can return nil or the socket address.
    -- On the guest side this should return the socket address
    -- or a non-zero channel id from `sockconnect`
    -- flatten.nvim will detect if the address refers to this instance of nvim, to determine if this is a host or a guest
    pipe_path = flatten.hooks.pipe_path;
  };

  -- <String, Bool> dictionary of filetypes that should be blocking
  block_for = {
    gitcommit = true;
    gitrebase = true;
  };

  -- Command passthrough
  disable_cmd_passthrough = false;

  -- Allow a nested session to open if Neovim is opened without arguments
  nest_if_no_args = false;
  nest_if_cmds = false;

  -- Window options
  window = {
    -- Options:
    -- current        -> open in current window (default)
    -- alternate      -> open in alternate window (recommended)
    -- tab            -> open in new tab
    -- split          -> open in split
    -- vsplit         -> open in vsplit
    -- smart          -> smart open (avoids special buffers)
    -- OpenHandler    -> allows you to handle file opening yourself (see Types)
    --
    -- TODO: Open gitcommit filetypes in the current buffer, everything else in a new tab <2023-08-29>
    open = "split";

    -- Options:
    -- vsplit         -> opens files in diff vsplits
    -- split          -> opens files in diff splits
    -- tab_vsplit     -> creates a new tabpage, and opens diff vsplits
    -- tab_split      -> creates a new tabpage, and opens diff splits
    -- OpenHandler    -> allows you to handle file opening yourself (see Types)
    diff = "tab_vsplit";

    -- Affects which file gets focused when opening multiple at once
    -- Options:
    -- "first"        -> open first file of new files (default)
    -- "last"         -> open last file of new files
    focus = "first";
  };

  -- The `default_pipe_path` will treat the first nvim instance within a single kitty/wezterm session as the host
  -- You can configure this behaviour using the following:
  integrations = {
    kitty = false;   -- Flatten all instance in the current Kitty session
    wezterm = false; -- Flatten all instance in the current Wezterm session
  };
})