feat: diff mode with -d flag (#63)

* refactor: allow smart open to be used as utility fn
* refactor: use dfs / stack instead of queue in smart open

README.md

@@ -12,6 +12,7 @@ Flatten allows you to open files from a neovim terminal buffer in your current n
 - [x] Pipe from terminal into a new Neovim buffer ([demo](https://user-images.githubusercontent.com/38540736/225779817-ed7efea8-9108-4f28-983f-1a889d32826f.mp4))
 - [x] Setting to force blocking from the commandline, regardless of filetype
 - [x] Command passthrough from guest to host
+- [x] Flatten instances from wezterm and kitty tabs/panes based on working directory
 
 ## Plans and Ideas
 
@@ -20,7 +21,6 @@ Ideas:
 - [ ] Multi-screen support
   - [ ] Move buffers between Neovim instances in separate windows
   - [ ] Single cursor between Neovim instances in separate windows
-- [ ] Flatten instances based on working directory
 
 If you have an idea or feature request, open an issue with the `enhancement` tag!
 
@@ -71,6 +71,9 @@ nvim file1 file2
 # force blocking for a file
 nvim --cmd 'let g:flatten_wait=1' file1
 
+# open files in diff mode
+nvim -d file1 file2
+
 # enable blocking for $VISUAL
 # allows edit-exec
 # in your .bashrc, .zshrc, etc.
@@ -93,6 +96,20 @@ nvim +<cmd>
 Flatten comes with the following defaults:
 
 ```lua
+---Types:
+--
+-- Passed to callbacks that handle opening files
+---@alias BufInfo { fname: string, bufnr: buffer }
+--
+-- 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
+--
 {
     callbacks = {
         ---@param argv table a list of all the arguments in the nested session
@@ -103,7 +120,7 @@ Flatten comes with the following defaults:
         pre_open = function() end,
         -- Called after a file is opened
         -- Passed the buf id, win id, and filetype of the new window
-        post_open = function(bufnr, winnr, filetype) end,
+        post_open = function(bufnr, winnr, filetype, is_blocking, is_diff) end,
         -- Called when a file is open in blocking mode, after it's done blocking
         -- (after bufdelete, bufunload, or quitpre for the blocking buffer)
         block_end = function() end,
@@ -125,14 +142,16 @@ Flatten comes with the following defaults:
         -- split          -> open in split
         -- vsplit         -> open in vsplit
         -- smart          -> smart open (avoids special buffers)
-        -- function(new_file_names, argv, stdin_buf_id, guest_cwd) -> bufnr, winnr?
-        -- Only open the files, allowing you to handle window opening yourself.
-        -- The first argument is an array of file names representing the newly opened files.
-        -- The third argument is 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.
+        -- OpenHandler    -> allows you to handle file opening yourself (see Types)
+        --
         open = "current",
+        -- 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)

lua/flatten/core.lua

@@ -26,53 +26,52 @@ end
 
 ---@param focus Flatten.BufInfo
 function M.smart_open(focus)
-  local bufnr = focus.bufnr
-
   local curwin = vim.api.nvim_get_current_win()
-  local available_wins = vim
-    .iter(vim.api.nvim_list_wins())
-    :filter(function(win)
-      if win == curwin then
-        return false
-      end
-      if vim.api.nvim_win_get_config(win).zindex ~= nil then
-        return false
-      end
 
-      local winbuf = vim.api.nvim_win_get_buf(win)
-      return vim.bo[winbuf].buftype == "" and vim.bo[winbuf].buflisted
-    end)
-    :fold({}, function(set, win)
-      set[win] = true
-      return set
-    end)
+  -- set of valid target windows
+  local valid_targets = {}
+  for _, win in ipairs(vim.api.nvim_list_wins()) do
+    local win_buf = vim.api.nvim_win_get_buf(win)
+    if
+      win ~= curwin
+      and vim.api.nvim_win_get_config(win).zindex == nil
+      and vim.bo[win_buf].buftype == ""
+    then
+      valid_targets[win] = true
+    end
+  end
 
   local layout = vim.fn.winlayout()
 
   -- traverse the window tree to find the first available window
-  local queue = { layout }
+  local stack = { layout }
   local win
 
-  while #queue > 0 do
-    local node = table.remove(queue, 1)
+  while #stack > 0 do
+    local node = table.remove(stack)
     if node[1] == "leaf" then
-      if available_wins[node[2]] then
+      if valid_targets[node[2]] then
         win = node[2]
         break
       end
     else
-      for _, child in ipairs(node[2]) do
-        table.insert(queue, child)
+      for i = #node[2], 1, -1 do
+        table.insert(stack, node[2][i])
       end
     end
   end
 
+  -- allows using this function as a utility to get a window to open something in
+  if not focus then
+    return win
+  end
+
   if win then
-    vim.api.nvim_win_set_buf(win, bufnr)
+    vim.api.nvim_win_set_buf(win, focus.bufnr)
     vim.api.nvim_set_current_win(win)
   else
     vim.cmd("split")
-    vim.api.nvim_win_set_buf(0, bufnr)
+    vim.api.nvim_win_set_buf(0, focus.bufnr)
   end
 end
 
@@ -175,8 +174,50 @@ M.edit_files = function(opts)
   local winnr
   local bufnr
 
-  -- Open window
-  if type(open) == "function" then
+  local is_diff = vim.tbl_contains(argv, "-d")
+
+  if is_diff then
+    local diff_open = config.window.diff
+    if type(diff_open) == "function" then
+      winnr, bufnr = config.window.diff(files, argv, stdin_buf, guest_cwd)
+    else
+      winnr = M.smart_open()
+      vim.api.nvim_set_current_win(winnr)
+
+      if stdin_buf then
+        files = vim.list_extend({ stdin_buf }, files)
+      end
+      local tab = false
+      local vert = false
+
+      if diff_open == "tab_split" or diff_open == "tab_vsplit" then
+        tab = true
+      end
+      if diff_open == "vsplit" or diff_open == "tab_vsplit" then
+        vert = true
+      end
+
+      for i, file in ipairs(files) do
+        if i == 1 then
+          if tab then
+            vim.cmd.tabedit(file.fname)
+          else
+            vim.api.nvim_set_current_buf(file.bufnr)
+          end
+        else
+          if vert then
+            vim.cmd.vsplit(file.fname)
+          else
+            vim.cmd.split(file.fname)
+          end
+        end
+        vim.cmd.diffthis()
+      end
+    end
+
+    winnr = winnr or vim.api.nvim_get_current_win()
+    bufnr = bufnr or vim.api.nvim_get_current_buf()
+  elseif type(open) == "function" then
     bufnr, winnr = open(files, argv, stdin_buf, guest_cwd)
     if winnr == nil and bufnr ~= nil then
       winnr = vim.fn.bufwinid(bufnr)
@@ -225,7 +266,7 @@ M.edit_files = function(opts)
     end
   end
 
-  callbacks.post_open(bufnr, winnr, ft, block)
+  callbacks.post_open(bufnr, winnr, ft, block, is_diff)
 
   if block then
     M.augroup = vim.api.nvim_create_augroup("flatten_notify", { clear = true })

lua/flatten/guest.lua

@@ -108,7 +108,7 @@ M.init = function(host_pipe)
         return result
       end
       files = filter_map(vim.api.nvim_list_bufs(), function(buffer)
-        if not vim.api.nvim_buf_is_loaded(buffer) then
+        if not vim.api.nvim_buf_is_valid(buffer) then
           return
         end
         local buftype = vim.api.nvim_buf_get_option(buffer, "buftype")

lua/flatten/init.lua

@@ -81,6 +81,9 @@ function M.is_guest()
   return is_guest
 end
 
+---@alias Flatten.BufInfo { fname: string, bufnr: buffer }
+---@alias Flatten.OpenHandler fun(files: Flatten.BufInfo[], argv: string[], stdin_buf: Flatten.BufInfo, guest_cwd: string):window, buffer
+
 -- selene: allow(unused_variable)
 M.config = {
   callbacks = {
@@ -100,7 +103,8 @@ M.config = {
     ---@param winnr window
     ---@param filetype string
     ---@param is_blocking boolean
-    post_open = function(bufnr, winnr, filetype, is_blocking) end,
+    ---@param is_diff boolean
+    post_open = function(bufnr, winnr, filetype, is_blocking, is_diff) end,
     ---Called when a nested session is done waiting for the host.
     ---@param filetype string
     block_end = function(filetype) end,
@@ -111,9 +115,10 @@ M.config = {
     gitrebase = true,
   },
   window = {
-    ---@alias Flatten.BufInfo { fname: string, bufnr: buffer }
-    ---@type "current" | "alternate" | "split" | "vsplit" | "tab" | "smart" | fun(files: Flatten.BufInfo[], arv: string[], stdin_buf: Flatten.BufInfo, guest_cwd: string):window, buffer
+    ---@type "current" | "alternate" | "split" | "vsplit" | "tab" | "smart" | Flatten.OpenHandler
     open = "current",
+    ---@type "split" | "vsplit" | "tab_split" | "tab_vsplit" | Flatten.OpenHandler
+    diff = "tab_vsplit",
     ---@type "first" | "last"
     focus = "first",
   },