refactor: Refactor git module into vcs-type agnostic module

lua/diffview/actions.lua

@@ -3,7 +3,7 @@ local lazy = require("diffview.lazy")
 local DiffView = lazy.access("diffview.scene.views.diff.diff_view", "DiffView") ---@type DiffView|LazyModule
 local FileHistoryView = lazy.access("diffview.scene.views.file_history.file_history_view", "FileHistoryView") ---@type FileHistoryView|LazyModule
 local StandardView = lazy.access("diffview.scene.views.standard.standard_view", "StandardView") ---@type StandardView|LazyModule
-local git = lazy.require("diffview.git.utils") ---@module "diffview.git.utils"
+local vcs = lazy.require("diffview.vcs.utils") ---@module "diffview.vcs.utils"
 local lib = lazy.require("diffview.lib") ---@module "diffview.lib"
 local utils = lazy.require("diffview.utils") ---@module "diffview.utils"
 
@@ -166,7 +166,7 @@ function M.next_conflict()
     local curfile = main.file
 
     if main:is_valid() and curfile:is_valid() then
-      local conflicts, _, cur_idx = git.parse_conflicts(
+      local conflicts, _, cur_idx = vcs.parse_conflicts(
         api.nvim_buf_get_lines(curfile.bufnr, 0, -1, false),
         main.id
       )
@@ -197,7 +197,7 @@ function M.prev_conflict()
     local curfile = main.file
 
     if main:is_valid() and curfile:is_valid() then
-      local conflicts, _, cur_idx = git.parse_conflicts(
+      local conflicts, _, cur_idx = vcs.parse_conflicts(
         api.nvim_buf_get_lines(curfile.bufnr, 0, -1, false),
         main.id
       )
@@ -334,7 +334,7 @@ function M.conflict_choose(target)
       local curfile = main.file
 
       if main:is_valid() and curfile:is_valid() then
-        local _, cur = git.parse_conflicts(
+        local _, cur = vcs.parse_conflicts(
           api.nvim_buf_get_lines(curfile.bufnr, 0, -1, false),
           main.id
         )

lua/diffview/api/views/diff/diff_view.lua

@@ -3,10 +3,10 @@ local lazy = require("diffview.lazy")
 local DiffView = lazy.access("diffview.scene.views.diff.diff_view", "DiffView") ---@type DiffView|LazyModule
 local FileEntry = lazy.access("diffview.scene.file_entry", "FileEntry") ---@type FileEntry|LazyModule
 local FilePanel = lazy.access("diffview.scene.views.diff.file_panel", "FilePanel") ---@type FilePanel|LazyModule
-local Rev = lazy.access("diffview.git.rev", "Rev") ---@type Rev|LazyModule
-local RevType = lazy.access("diffview.git.rev", "RevType") ---@type RevType|LazyModule
+local Rev = lazy.access("diffview.vcs.adapters.git.rev", "GitRev") ---@type GitRev|LazyModule
+local RevType = lazy.access("diffview.vcs.rev", "RevType") ---@type RevType|LazyModule
 local async = lazy.require("plenary.async") ---@module "plenary.async"
-local git = lazy.require("diffview.git.utils") ---@module "diffview.git.utils"
+local vcs = lazy.require("diffview.vcs") ---@module "diffview.vcs"
 local logger = lazy.require("diffview.logger") ---@module "diffview.logger"
 local oop = lazy.require("diffview.oop") ---@module "diffview.oop"
 local utils = lazy.require("diffview.utils") ---@module "diffview.utils"
@@ -33,16 +33,19 @@ local CDiffView = oop.create_class("CDiffView", DiffView.__get())
 function CDiffView:init(opt)
   logger.info("[api] Creating a new Custom DiffView.")
   self.valid = false
-  local git_dir = git.git_dir(opt.git_root)
 
-  if not git_dir then
+  local err, adapter = vcs.get_adapter({ top_indicators = { opt.git_root } })
+
+  if err then
     utils.err(
-      ("Failed to find the git dir for the repository: %s")
+      ("Failed to create an adapter for the repository: %s")
       :format(utils.str_quote(opt.git_root))
     )
     return
   end
 
+  ---@cast adapter -?
+
   -- Fix malformed revs
   for _, v in ipairs({ "left", "right" }) do
     local rev = opt[v]
@@ -54,18 +57,13 @@ function CDiffView:init(opt)
   self.fetch_files = opt.update_files
   self.get_file_data = opt.get_file_data
 
-  local git_ctx = {
-    toplevel = opt.git_root,
-    dir = git_dir,
-  }
-
   CDiffView:super().init(self, vim.tbl_extend("force", opt, {
-    git_ctx = git_ctx,
+    adapter = adapter,
     panel = FilePanel(
-      git_ctx,
+      adapter,
       self.files,
       self.path_args,
-      self.rev_arg or git.rev_to_pretty_string(opt.left, opt.right)
+      self.rev_arg or adapter:rev_to_pretty_string(opt.left, opt.right)
     ),
   }))
 
@@ -128,7 +126,7 @@ function CDiffView:create_file_entries(files)
     {
       kind = "staged",
       files = files.staged or {},
-      left = git.head_rev(self.git_ctx.toplevel),
+      left = self.adapter:head_rev(),
       right = Rev(RevType.STAGE, 0),
     },
   }
@@ -139,7 +137,7 @@ function CDiffView:create_file_entries(files)
     for _, file_data in ipairs(v.files) do
       if v.kind == "conflicting" then
         table.insert(entries[v.kind], FileEntry.with_layout(CDiffView.get_default_merge_layout(), {
-          git_ctx = self.git_ctx,
+          adapter = self.adapter,
           path = file_data.path,
           oldpath = file_data.oldpath,
           status = "U",
@@ -148,11 +146,10 @@ function CDiffView:create_file_entries(files)
           rev_main = Rev(RevType.LOCAL),
           rev_theirs = Rev(RevType.STAGE, 3),
           rev_base = Rev(RevType.STAGE, 1),
-          get_data = self.get_file_data,
         }))
       else
         table.insert(entries[v.kind], FileEntry.for_d2(CDiffView.get_default_diff2(), {
-          git_ctx = self.git_ctx,
+          adapter = self.adapter,
           path = file_data.path,
           oldpath = file_data.oldpath,
           status = file_data.status,