refactor(git): rewrite diff module around :diffsplit

lua/git/status_view.lua

@@ -176,9 +176,13 @@ local function current_entry(bufnr)
     return s, s.lines[lnum]
 end
 
+---@class ow.Git.StatusView.Pane
+---@field buf integer
+---@field name string?
+
 ---@param r ow.Git.Repo
 ---@param path string
----@return ow.Git.Diff.Side
+---@return ow.Git.StatusView.Pane
 local function head_pane(r, path)
     local rev = Revision.new({ base = "HEAD", path = path })
     return {
@@ -189,7 +193,7 @@ end
 
 ---@param r ow.Git.Repo
 ---@param path string
----@return ow.Git.Diff.Side
+---@return ow.Git.StatusView.Pane
 local function worktree_pane(r, path)
     local buf = vim.fn.bufadd(vim.fs.joinpath(r.worktree, path))
     vim.fn.bufload(buf)
@@ -198,7 +202,7 @@ end
 
 ---@param s ow.Git.StatusView.State
 ---@param path string
----@return ow.Git.Diff.Side
+---@return ow.Git.StatusView.Pane
 local function index_pane(s, path)
     local rev = Revision.new({ stage = 0, path = path })
     return {
@@ -209,7 +213,7 @@ end
 
 ---@param s ow.Git.StatusView.State
 ---@param row ow.Git.Status.Row
----@return ow.Git.Diff.Side?
+---@return ow.Git.StatusView.Pane?
 local function older_pane(s, row)
     local entry = row.entry
     if row.section == "staged" then
@@ -227,7 +231,7 @@ end
 
 ---@param s ow.Git.StatusView.State
 ---@param row ow.Git.Status.Row
----@return ow.Git.Diff.Side?
+---@return ow.Git.StatusView.Pane?
 local function newer_pane(s, row)
     local entry = row.entry
     if row.section == "staged" then
@@ -316,8 +320,7 @@ local function view_row(s, row, focus_left)
 
     if s.placement ~= "sidebar" then
         local pane = right or left
-        ---@cast pane ow.Git.Diff.Side
-        diff.set_diff(status_win, false)
+        ---@cast pane -nil
         vim.cmd.normal({ "m'", bang = true })
         vim.api.nvim_win_set_buf(status_win, pane.buf)
         if pane.name then
@@ -332,11 +335,13 @@ local function view_row(s, row, focus_left)
     end
     close_other_diff_wins(status_win, target)
     vim.api.nvim_win_set_width(status_win, WINDOW_WIDTH)
-    diff.set_diff(target, false)
+    vim.api.nvim_win_call(target, function()
+        vim.cmd.diffoff()
+    end)
 
     if not (left and right) then
         local side = right or left
-        ---@cast side ow.Git.Diff.Side
+        ---@cast side ow.Git.StatusView.Pane
         vim.api.nvim_win_set_buf(target, side.buf)
         if side.name then
             util.set_buf_name(side.buf, side.name)
@@ -344,15 +349,23 @@ local function view_row(s, row, focus_left)
         vim.api.nvim_set_current_win(focus_left and target or status_win)
         return
     end
-    ---@cast left ow.Git.Diff.Side
-    ---@cast right ow.Git.Diff.Side
+    ---@cast left ow.Git.StatusView.Pane
+    ---@cast right ow.Git.StatusView.Pane
 
-    local left_win = vsplit_at(target, "left")
-    local combined = vim.api.nvim_win_get_width(left_win)
-        + vim.api.nvim_win_get_width(target)
-    vim.api.nvim_win_set_width(left_win, math.floor(combined / 2))
+    vim.api.nvim_win_set_buf(target, right.buf)
+    if right.name then
+        util.set_buf_name(right.buf, right.name)
+    end
 
-    diff.update_pair(left_win, target, { left = left, right = right })
+    local older = left.name or vim.api.nvim_buf_get_name(left.buf)
+    local left_win
+    vim.api.nvim_win_call(target, function()
+        diff.split({
+            target = older,
+            mods = { vertical = true },
+        })
+        left_win = vim.api.nvim_get_current_win()
+    end)
     vim.api.nvim_set_current_win(focus_left and left_win or status_win)
 end