From 3a67424fec51012b9f9a3faf64a6e8e754056f73 Mon Sep 17 00:00:00 2001
From: johnybx <johnybx@users.noreply.github.com>
Date: Tue, 31 Oct 2023 02:58:53 +0100
Subject: [PATCH] Multiline comment and suggestion (#66)

This MR adds the ability to leave multi-line comments and suggested changes to an MR. The features are only supported for `diffview` because we plan to deprecate `delta` as a reviewer soon.
---
 .editorconfig                    | 119 +++++++++++++++++++
 README.md                        |   7 +-
 cmd/comment.go                   |  73 +++++++++---
 go.mod                           |   2 +-
 go.sum                           |   2 +
 lua/gitlab/actions/comment.lua   | 157 ++++++++++++++++++-------
 lua/gitlab/init.lua              |  40 ++++---
 lua/gitlab/reviewer/delta.lua    | 134 ++++++++++++++-------
 lua/gitlab/reviewer/diffview.lua | 111 +++++++++++++++---
 lua/gitlab/reviewer/init.lua     |  11 +-
 lua/gitlab/utils/init.lua        | 194 +++++++++++++++++++++++++++----
 11 files changed, 689 insertions(+), 161 deletions(-)
 create mode 100644 .editorconfig

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..80df57c
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,119 @@
+# see https://github.com/CppCXY/EmmyLuaCodeStyle
+[*.lua]
+# [basic]
+
+# optional space/tab
+indent_style = space
+# if indent_style is space, this is valid
+indent_size = 2
+# if indent_style is tab, this is valid
+tab_width = 2
+# none/single/double
+quote_style = "double"
+
+continuation_indent = 2
+
+#optional keep/never/always/smart
+trailing_table_separator = keep
+
+# keep/remove/remove_table_only/remove_string_only
+call_arg_parentheses = keep
+
+detect_end_of_line = false
+
+# this will check text end with new line
+insert_final_newline = false
+
+# [space]
+space_around_table_field_list = true
+
+space_before_attribute = true
+
+space_before_function_open_parenthesis = false
+
+space_before_function_call_open_parenthesis = false
+
+space_before_closure_open_parenthesis = false
+
+space_before_function_call_single_arg = true
+
+space_before_open_square_bracket = false
+
+space_inside_function_call_parentheses = false
+
+space_inside_function_param_list_parentheses = false
+
+space_inside_square_brackets = false
+
+# like t[#t+1] = 1
+space_around_table_append_operator = true
+
+ignore_spaces_inside_function_call = false
+
+space_before_inline_comment = 1
+
+# [operator space]
+space_around_math_operator = true
+
+space_after_comma = true
+
+space_after_comma_in_for_statement = true
+
+space_around_concat_operator = true
+
+# [align]
+
+align_call_args = false
+
+align_function_params = true
+
+align_continuous_assign_statement = true
+
+align_continuous_rect_table_field = true
+
+align_if_branch = true
+
+align_array_table = true
+
+# [indent]
+
+never_indent_before_if_condition = false
+
+never_indent_comment_on_if_branch = false
+
+# [line space]
+
+# The following configuration supports four expressions
+# keep  
+# fixed(n)   
+# min(n)
+# max(n)
+# for eg. min(2)
+
+line_space_after_if_statement = keep
+
+line_space_after_do_statement = keep
+
+line_space_after_while_statement = keep
+
+line_space_after_repeat_statement = keep
+
+line_space_after_for_statement = keep
+
+line_space_after_local_or_assign_statement = keep
+
+line_space_after_function_statement = fixed(2)
+
+line_space_after_expression_statement = keep
+
+line_space_after_comment = keep
+
+# [line break]
+break_all_list_when_line_exceed = false
+
+auto_collapse_lines = false
+
+# [preference]
+ignore_space_after_colon = true
+
+remove_call_expression_list_finish_comma = false
diff --git a/README.md b/README.md
index 76d67d0..9c60057 100644
--- a/README.md
+++ b/README.md
@@ -158,13 +158,16 @@ The upper part of the popup contains the title, which can also be edited and sen
 
 ### Reviewing Diffs
 
-The `review` action will open a diff of the changes. You can leave comments using the `create_comment` action.
+The `review` action will open a diff of the changes. You can leave comments using the `create_comment` action or for multiline comments use `create_multiline_comment` in visual mode.
 
 ```lua
 require("gitlab").review()
 require("gitlab").create_comment()
+require("gitlab").create_multiline_comment()
 ```
 
+For suggesting changes you can use `create_comment_suggestion` in visual mode which works similar to `create_multiline_comment` but prefills the comment window with gitlab [suggest changes](https://docs.gitlab.com/ee/user/project/merge_requests/reviews/suggestions.html) code block with prefilled code from visual selection.
+
 The reviewer is Delta by default, but you can configure the plugin to use Diffview instead.
 
 ### Discussions and Notes
@@ -246,6 +249,8 @@ vim.keymap.set("n", "<leader>gls", gitlab.summary)
 vim.keymap.set("n", "<leader>glA", gitlab.approve)
 vim.keymap.set("n", "<leader>glR", gitlab.revoke)
 vim.keymap.set("n", "<leader>glc", gitlab.create_comment)
+vim.keymap.set("v", "<leader>glc", gitlab.create_multiline_comment)
+vim.keymap.set("v", "<leader>glC", gitlab.create_comment_suggestion)
 vim.keymap.set("n", "<leader>gln", gitlab.create_note)
 vim.keymap.set("n", "<leader>gld", gitlab.toggle_discussions)
 vim.keymap.set("n", "<leader>glaa", gitlab.add_assignee)
diff --git a/cmd/comment.go b/cmd/comment.go
index 1908e7b..0c2188f 100644
--- a/cmd/comment.go
+++ b/cmd/comment.go
@@ -1,8 +1,10 @@
 package main
 
 import (
+	"crypto/sha1"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"net/http"
 
@@ -12,14 +14,29 @@ import (
 const mrVersionsUrl = "%s/api/v4/projects/%s/merge_requests/%d/versions"
 
 type PostCommentRequest struct {
-	Comment        string `json:"comment"`
-	FileName       string `json:"file_name"`
-	NewLine        int    `json:"new_line"`
-	OldLine        int    `json:"old_line"`
-	HeadCommitSHA  string `json:"head_commit_sha"`
-	BaseCommitSHA  string `json:"base_commit_sha"`
-	StartCommitSHA string `json:"start_commit_sha"`
-	Type           string `json:"type"`
+	Comment        string     `json:"comment"`
+	FileName       string     `json:"file_name"`
+	NewLine        *int       `json:"new_line,omitempty"`
+	OldLine        *int       `json:"old_line,omitempty"`
+	HeadCommitSHA  string     `json:"head_commit_sha"`
+	BaseCommitSHA  string     `json:"base_commit_sha"`
+	StartCommitSHA string     `json:"start_commit_sha"`
+	Type           string     `json:"type"`
+	LineRange      *LineRange `json:"line_range,omitempty"`
+}
+
+// LineRange represents the range of a note.
+type LineRange struct {
+	StartRange *LinePosition `json:"start"`
+	EndRange   *LinePosition `json:"end"`
+}
+
+// LinePosition represents a position in a line range.
+// unlike gitlab struct this does not contain LineCode with sha1 of filename
+type LinePosition struct {
+	Type    string `json:"type"`
+	OldLine int    `json:"old_line"`
+	NewLine int    `json:"new_line"`
 }
 
 type DeleteCommentRequest struct {
@@ -115,16 +132,42 @@ func PostComment(w http.ResponseWriter, r *http.Request) {
 	/* If we are leaving a comment on a line, leave position. Otherwise,
 	we are leaving a note (unlinked comment) */
 	if postCommentRequest.FileName != "" {
-		opt.Position = &gitlab.NotePosition{
-			PositionType: "text",
-			StartSHA:     postCommentRequest.StartCommitSHA,
-			HeadSHA:      postCommentRequest.HeadCommitSHA,
-			BaseSHA:      postCommentRequest.BaseCommitSHA,
-			NewPath:      postCommentRequest.FileName,
-			OldPath:      postCommentRequest.FileName,
+		opt.Position = &gitlab.PositionOptions{
+			PositionType: &postCommentRequest.Type,
+			StartSHA:     &postCommentRequest.StartCommitSHA,
+			HeadSHA:      &postCommentRequest.HeadCommitSHA,
+			BaseSHA:      &postCommentRequest.BaseCommitSHA,
+			NewPath:      &postCommentRequest.FileName,
+			OldPath:      &postCommentRequest.FileName,
 			NewLine:      postCommentRequest.NewLine,
 			OldLine:      postCommentRequest.OldLine,
 		}
+
+		if postCommentRequest.LineRange != nil {
+			var format = "%x_%d_%d"
+			var start_filename_sha1 = fmt.Sprintf(
+				format,
+				sha1.Sum([]byte(postCommentRequest.FileName)),
+				postCommentRequest.LineRange.StartRange.OldLine,
+				postCommentRequest.LineRange.StartRange.NewLine,
+			)
+			var end_filename_sha1 = fmt.Sprintf(
+				format,
+				sha1.Sum([]byte(postCommentRequest.FileName)),
+				postCommentRequest.LineRange.EndRange.OldLine,
+				postCommentRequest.LineRange.EndRange.NewLine,
+			)
+			opt.Position.LineRange = &gitlab.LineRangeOptions{
+				Start: &gitlab.LinePositionOptions{
+					Type:     &postCommentRequest.LineRange.StartRange.Type,
+					LineCode: &start_filename_sha1,
+				},
+				End: &gitlab.LinePositionOptions{
+					Type:     &postCommentRequest.LineRange.EndRange.Type,
+					LineCode: &end_filename_sha1,
+				},
+			}
+		}
 	}
 
 	discussion, _, err := c.git.Discussions.CreateMergeRequestDiscussion(c.projectId, c.mergeId, &opt)
diff --git a/go.mod b/go.mod
index 1305ae8..57f8fe2 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,7 @@ module gitlab.com/harrisoncramer/gitlab.nvim
 
 go 1.19
 
-require github.com/xanzy/go-gitlab v0.83.0
+require github.com/xanzy/go-gitlab v0.93.2
 
 require (
 	github.com/golang/protobuf v1.5.3 // indirect
diff --git a/go.sum b/go.sum
index bc150bb..1bd7d24 100644
--- a/go.sum
+++ b/go.sum
@@ -21,6 +21,8 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/xanzy/go-gitlab v0.83.0 h1:37p0MpTPNbsTMKX/JnmJtY8Ch1sFiJzVF342+RvZEGw=
 github.com/xanzy/go-gitlab v0.83.0/go.mod h1:5ryv+MnpZStBH8I/77HuQBsMbBGANtVpLWC15qOjWAw=
+github.com/xanzy/go-gitlab v0.93.2 h1:kNNf3BYNYn/Zkig0B89fma12l36VLcYSGu7OnaRlRDg=
+github.com/xanzy/go-gitlab v0.93.2/go.mod h1:5ryv+MnpZStBH8I/77HuQBsMbBGANtVpLWC15qOjWAw=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.8.0 h1:Zrh2ngAOFYneWTAIAPethzeaQLuHwhuBkuV6ZiRnUaQ=
diff --git a/lua/gitlab/actions/comment.lua b/lua/gitlab/actions/comment.lua
index 660e5f6..2254926 100644
--- a/lua/gitlab/actions/comment.lua
+++ b/lua/gitlab/actions/comment.lua
@@ -1,35 +1,126 @@
 -- This module is responsible for creating new comments
 -- in the reviewer's buffer. The reviewer will pass back
 -- to this module the data required to make the API calls
-local Popup              = require("nui.popup")
-local state              = require("gitlab.state")
-local job                = require("gitlab.job")
-local u                  = require("gitlab.utils")
-local discussions        = require("gitlab.actions.discussions")
-local miscellaneous      = require("gitlab.actions.miscellaneous")
-local reviewer           = require("gitlab.reviewer")
-local M                  = {}
+local Popup = require("nui.popup")
+local state = require("gitlab.state")
+local job = require("gitlab.job")
+local u = require("gitlab.utils")
+local discussions = require("gitlab.actions.discussions")
+local miscellaneous = require("gitlab.actions.miscellaneous")
+local reviewer = require("gitlab.reviewer")
+local M = {}
 
-local comment_popup      = Popup(u.create_popup_state("Comment", "40%", "60%"))
-local note_popup         = Popup(u.create_popup_state("Note", "40%", "60%"))
+local comment_popup = Popup(u.create_popup_state("Comment", "40%", "60%"))
+local note_popup = Popup(u.create_popup_state("Note", "40%", "60%"))
 
--- This function will open a comment popup in order to create a comment on the changed/updated line in the current MR
-M.create_comment         = function()
+-- This function will open a comment popup in order to create a comment on the changed/updated
+-- line in the current MR
+M.create_comment = function()
   comment_popup:mount()
   state.set_popup_keymaps(comment_popup, function(text)
     M.confirm_create_comment(text)
   end, miscellaneous.attach_file)
 end
 
-M.create_note            = function()
-  note_popup:mount()
-  state.set_popup_keymaps(note_popup, function(text)
-    M.confirm_create_comment(text, true)
+---Create multiline comment for the last selection.
+M.create_multiline_comment = function()
+  if not u.check_visual_mode() then
+    return
+  end
+  local start_line, end_line = u.get_visual_selection_boundaries()
+  comment_popup:mount()
+  state.set_popup_keymaps(comment_popup, function(text)
+    M.confirm_create_comment(text, { start_line = start_line, end_line = end_line })
   end, miscellaneous.attach_file)
 end
 
--- This function (settings.popup.perform_action) will send the comment to the Go server
-M.confirm_create_comment = function(text, unlinked)
+---Create comment prepopulated with gitlab suggestion
+---https://docs.gitlab.com/ee/user/project/merge_requests/reviews/suggestions.html
+M.create_comment_suggestion = function()
+  if not u.check_visual_mode() then
+    return
+  end
+  local start_line, end_line = u.get_visual_selection_boundaries()
+  local current_line = vim.api.nvim_win_get_cursor(0)[1]
+  local range = end_line - start_line
+  local backticks = "```"
+  local selected_lines = reviewer.get_lines(start_line, end_line)
+
+  if selected_lines == nil then
+    -- TODO: remove when delta is supported
+    return
+  end
+
+  for line in ipairs(selected_lines) do
+    if string.match(line, "^```$") then
+      backticks = "````"
+      break
+    end
+  end
+
+  local suggestion_start
+  if start_line == current_line then
+    suggestion_start = backticks .. "suggestion:-0+" .. range
+  elseif end_line == current_line then
+    suggestion_start = backticks .. "suggestion:-" .. range .. "+0"
+  else
+    -- This should never happen afaik
+    vim.notify("Unexpected suggestion position", vim.log.levels.ERROR)
+    return
+  end
+  suggestion_start = suggestion_start
+  local suggestion_lines = {}
+  table.insert(suggestion_lines, suggestion_start)
+  vim.list_extend(suggestion_lines, selected_lines)
+  table.insert(suggestion_lines, backticks)
+
+  comment_popup:mount()
+  vim.api.nvim_buf_set_lines(comment_popup.bufnr, 0, 0, false, suggestion_lines)
+  state.set_popup_keymaps(comment_popup, function(text)
+    if range > 0 then
+      M.confirm_create_comment(text, { start_line = start_line, end_line = end_line })
+    else
+      M.confirm_create_comment(text, nil)
+    end
+  end, miscellaneous.attach_file)
+end
+
+M.create_note = function()
+  note_popup:mount()
+  state.set_popup_keymaps(note_popup, function(text)
+    M.confirm_create_comment(text, nil, true)
+  end, miscellaneous.attach_file)
+end
+
+---@class LineRange
+---@field start_line integer
+---@field end_line integer
+
+---@class ReviewerLineInfo
+---@field old_line integer
+---@field new_line integer
+---@field type string either "new" or "old"
+
+---@class ReviewerRangeInfo
+---@field start ReviewerLineInfo
+---@field end ReviewerLineInfo
+
+---@class ReviewerInfo
+---@field file_name string
+---@field old_line integer | nil
+---@field new_line integer | nil
+---@field range_info ReviewerRangeInfo
+
+---This function (settings.popup.perform_action) will send the comment to the Go server
+---@param text string comment text
+---@param range LineRange | nil range of visuel selection or nil
+---@param unlinked boolean | nil if true, the comment is not linked to a line
+M.confirm_create_comment = function(text, range, unlinked)
+  if text == nil then
+    vim.notify("Reviewer did not provide text of change", vim.log.levels.ERROR)
+    return
+  end
+
   if unlinked then
     local body = { comment = text }
     job.run_job("/comment", "POST", body, function(data)
@@ -39,38 +130,22 @@ M.confirm_create_comment = function(text, unlinked)
     return
   end
 
-  local file_name, line_numbers, error = reviewer.get_location()
-
-  if error then
-    vim.notify(error, vim.log.levels.ERROR)
-    return
-  end
-
-  if file_name == nil then
-    vim.notify("Reviewer did not provide file name", vim.log.levels.ERROR)
-    return
-  end
-
-  if line_numbers == nil then
-    vim.notify("Reviewer did not provide line numbers of change", vim.log.levels.ERROR)
-    return
-  end
-
-  if text == nil then
-    vim.notify("Reviewer did not provide text of change", vim.log.levels.ERROR)
+  local reviewer_info = reviewer.get_location(range)
+  if not reviewer_info then
     return
   end
 
   local revision = state.MR_REVISIONS[1]
   local body = {
     comment = text,
-    file_name = file_name,
-    old_line = line_numbers.old_line,
-    new_line = line_numbers.new_line,
+    file_name = reviewer_info.file_name,
+    old_line = reviewer_info.old_line,
+    new_line = reviewer_info.new_line,
     base_commit_sha = revision.base_commit_sha,
     start_commit_sha = revision.start_commit_sha,
     head_commit_sha = revision.head_commit_sha,
-    type = "modification"
+    type = "text",
+    line_range = reviewer_info.range_info,
   }
 
   job.run_job("/comment", "POST", body, function(data)
diff --git a/lua/gitlab/init.lua b/lua/gitlab/init.lua
index 39d1b83..39c89e4 100644
--- a/lua/gitlab/init.lua
+++ b/lua/gitlab/init.lua
@@ -25,25 +25,27 @@ return {
     u.has_reviewer(args.reviewer or "delta")
   end,
   -- Global Actions 🌎
-  summary            = async.sequence({ info }, summary.summary),
-  approve            = async.sequence({ info }, approvals.approve),
-  revoke             = async.sequence({ info }, approvals.revoke),
-  add_reviewer       = async.sequence({ info, project_members }, assignees_and_reviewers.add_reviewer),
-  delete_reviewer    = async.sequence({ info, project_members }, assignees_and_reviewers.delete_reviewer),
-  add_assignee       = async.sequence({ info, project_members }, assignees_and_reviewers.add_assignee),
-  delete_assignee    = async.sequence({ info, project_members }, assignees_and_reviewers.delete_assignee),
-  create_comment     = async.sequence({ info, revisions }, comment.create_comment),
-  create_note        = async.sequence({ info }, comment.create_note),
-  review             = async.sequence({ u.merge(info, { refresh = true }) }, function() reviewer.open() end),
-  pipeline           = async.sequence({ info }, pipeline.open),
+  summary                   = async.sequence({ info }, summary.summary),
+  approve                   = async.sequence({ info }, approvals.approve),
+  revoke                    = async.sequence({ info }, approvals.revoke),
+  add_reviewer              = async.sequence({ info, project_members }, assignees_and_reviewers.add_reviewer),
+  delete_reviewer           = async.sequence({ info, project_members }, assignees_and_reviewers.delete_reviewer),
+  add_assignee              = async.sequence({ info, project_members }, assignees_and_reviewers.add_assignee),
+  delete_assignee           = async.sequence({ info, project_members }, assignees_and_reviewers.delete_assignee),
+  create_comment            = async.sequence({ info, revisions }, comment.create_comment),
+  create_multiline_comment  = async.sequence({ info, revisions }, comment.create_multiline_comment),
+  create_comment_suggestion = async.sequence({ info, revisions }, comment.create_comment_suggestion),
+  create_note               = async.sequence({ info }, comment.create_note),
+  review                    = async.sequence({ u.merge(info, { refresh = true }) }, function() reviewer.open() end),
+  pipeline                  = async.sequence({ info }, pipeline.open),
   -- Discussion Tree Actions 🌴
-  toggle_discussions = async.sequence({ info }, discussions.toggle),
-  edit_comment       = async.sequence({ info }, discussions.edit_comment),
-  delete_comment     = async.sequence({ info }, discussions.delete_comment),
-  toggle_resolved    = async.sequence({ info }, discussions.toggle_resolved),
-  reply              = async.sequence({ info }, discussions.reply),
+  toggle_discussions        = async.sequence({ info }, discussions.toggle),
+  edit_comment              = async.sequence({ info }, discussions.edit_comment),
+  delete_comment            = async.sequence({ info }, discussions.delete_comment),
+  toggle_resolved           = async.sequence({ info }, discussions.toggle_resolved),
+  reply                     = async.sequence({ info }, discussions.reply),
   -- Other functions 🤷
-  state              = state,
-  print_settings     = state.print_settings,
-  open_in_browser    = async.sequence({ info }, miscellaneous.open_in_browser),
+  state                     = state,
+  print_settings            = state.print_settings,
+  open_in_browser           = async.sequence({ info }, miscellaneous.open_in_browser),
 }
diff --git a/lua/gitlab/reviewer/delta.lua b/lua/gitlab/reviewer/delta.lua
index 2295acb..64f82c6 100644
--- a/lua/gitlab/reviewer/delta.lua
+++ b/lua/gitlab/reviewer/delta.lua
@@ -1,16 +1,16 @@
 -- This Module contains all of the code specific to the Delta reviewer.
-local state                   = require("gitlab.state")
-local u                       = require("gitlab.utils")
+local state = require("gitlab.state")
+local u = require("gitlab.utils")
 
-local M                       = {
-  bufnr = nil
+local M = {
+  bufnr = nil,
 }
 
 -- Public Functions
 -- These functions are exposed externally and are used
 -- when the reviewer is consumed by other code. They must follow the specification
 -- outlined in the reviewer/init.lua file
-M.open                        = function()
+M.open = function()
   local current_buf = vim.api.nvim_get_current_buf()
   if current_buf == state.discussion_buf then
     vim.api.nvim_command("wincmd w")
@@ -23,20 +23,22 @@ M.open                        = function()
   end
 
   local term_command_template =
-  "GIT_PAGER='delta --hunk-header-style omit --line-numbers --paging never --file-added-label %s --file-removed-label %s --file-modified-label %s' git diff %s...HEAD"
+    "GIT_PAGER='delta --hunk-header-style omit --line-numbers --paging never --file-added-label %s --file-removed-label %s --file-modified-label %s' git diff %s...HEAD"
 
-  local term_command = string.format(term_command_template,
+  local term_command = string.format(
+    term_command_template,
     state.settings.review_pane.delta.added_file,
     state.settings.review_pane.delta.removed_file,
     state.settings.review_pane.delta.modified_file,
-    state.INFO.target_branch)
+    state.INFO.target_branch
+  )
 
   vim.fn.termopen(term_command) -- Calls delta and sends the output to the currently blank buffer
   M.bufnr = vim.api.nvim_get_current_buf()
   M.winnr = vim.api.nvim_get_current_win()
 end
 
-M.jump                        = function(file_name, new_line, old_line)
+M.jump = function(file_name, new_line, old_line)
   local linnr, error = M.get_jump_location(file_name, new_line, old_line)
   if error ~= nil then
     vim.notify(error, vim.log.levels.ERROR)
@@ -47,25 +49,47 @@ M.jump                        = function(file_name, new_line, old_line)
   u.jump_to_buffer(M.bufnr, linnr)
 end
 
-M.get_location                = function()
-  if M.bufnr == nil then return nil, nil, "Delta reviewer must be initialized first" end
+---Get the location of a line within the delta buffer. If range is specified, then also the location
+---of the lines in range.
+---@param range LineRange | nil Line range to get location for
+---@return ReviewerInfo | nil nil is returned only if error was encountered
+M.get_location = function(range)
+  if M.bufnr == nil then
+    vim.notify("Delta reviewer must be initialized first", vim.log.levels.ERROR)
+    return
+  end
+
+  if range then
+    vim.notify("Multiline comments are not yet supported for delta reviewer", vim.log.levels.ERROR)
+    return
+  end
 
   local bufnr = vim.api.nvim_get_current_buf()
-  if bufnr ~= M.bufnr then return nil, nil, "Line location can only be determined within reviewer window" end
+  if bufnr ~= M.bufnr then
+    vim.notify("Line location can only be determined within reviewer window")
+    return
+  end
 
   local line_num = u.get_current_line_number()
   local file_name = M.get_file_from_review_buffer(u.get_current_line_number())
 
-  local range, error = M.get_review_buffer_range(file_name)
+  local review_range, error = M.get_review_buffer_range(file_name)
 
-  if error ~= nil then return nil, nil, error end
-  if range == nil then return nil, nil, "Review buffer range could not be identified" end
+  if error ~= nil then
+    vim.notify(error, vim.log.levels.ERROR)
+    return
+  end
+
+  if review_range == nil then
+    vim.notify("Review buffer range could not be identified", vim.log.levels.ERROR)
+    return
+  end
 
   -- In case the comment is left on a line without change information, we
   -- iterate backward until we find it within the range of the changes
   local current_line_changes = nil
   local num = line_num
-  while range ~= nil and num >= range[1] and current_line_changes == nil do
+  while review_range ~= nil and num >= review_range[1] and current_line_changes == nil do
     local content = u.get_line_content(M.bufnr, num)
     local change_nums = M.get_change_nums(content)
     current_line_changes = change_nums
@@ -73,12 +97,13 @@ M.get_location                = function()
   end
 
   if current_line_changes == nil then
-    return nil, nil, "Could not find current line change information"
+    vim.notify("Could not find current line change information", vim.log.levels.ERROR)
+    return
   end
 
   local new_line_num = line_num + 1
   local next_line_changes = nil
-  while range ~= nil and new_line_num <= range[2] and next_line_changes == nil do
+  while review_range ~= nil and new_line_num <= review_range[2] and next_line_changes == nil do
     local content = u.get_line_content(M.bufnr, new_line_num)
     local change_nums = M.get_change_nums(content)
     next_line_changes = change_nums
@@ -86,41 +111,53 @@ M.get_location                = function()
   end
 
   if next_line_changes == nil then
-    return nil, nil, "Could not find next line change information"
+    vim.notify("Could not find next line change information", vim.log.levels.ERROR)
+    return
   end
 
+  local result = { file_name = file_name }
   -- This is actually a modified line if these conditions are met
-  if (current_line_changes.old_line and not current_line_changes.new_line and not next_line_changes.old_line and next_line_changes.new_line) then
-    do
-      current_line_changes = {
-        old_line = current_line_changes.old,
-        new_line = next_line_changes.new_line
-      }
-    end
+  if
+    current_line_changes.old_line
+    and not current_line_changes.new_line
+    and not next_line_changes.old_line
+    and next_line_changes.new_line
+  then
+    result.old_line = current_line_changes.old
+    result.new_line = next_line_changes.new_line
+  else
+    vim.notify("Could not determine line location", vim.log.levels.ERROR)
+    return
   end
 
-  return file_name, current_line_changes
+  return result
 end
 
 -- Helper Functions 🤝
 -- These functions are not exported and should be private
 -- to the delta reviewer, they are used to support the public functions
-M.get_jump_location           = function(file_name, new_line, old_line)
+M.get_jump_location = function(file_name, new_line, old_line)
   local range, error = M.get_review_buffer_range(file_name)
-  if error ~= nil then return nil, error end
-  if range == nil then return nil, "Review buffer range could not be identified" end
+  if error ~= nil then
+    return nil, error
+  end
+  if range == nil then
+    return nil, "Review buffer range could not be identified"
+  end
 
   local linnr = nil
 
   local lines = M.get_review_buffer_lines(range)
   for _, line in ipairs(lines) do
     local line_data = M.get_change_nums(line.line_content)
-    if old_line == line_data.old_line and new_line == line_data.new_line then
+    if line_data and old_line == line_data.old_line and new_line == line_data.new_line then
       linnr = line.line_number
       break
     end
   end
-  if linnr == nil then return nil, "Could not find matching line" end
+  if linnr == nil then
+    return nil, "Could not find matching line"
+  end
   return linnr, nil
 end
 
@@ -134,32 +171,39 @@ M.get_file_from_review_buffer = function(linenr)
   end
 end
 
-M.get_change_nums             = function(line)
+M.get_change_nums = function(line)
   local data, _ = line:match("(.-)" .. "│" .. "(.*)")
   local line_data = {}
-  if data == nil then return nil end
+  if data == nil then
+    return nil
+  end
 
-  if data ~= nil then
+  if data ~= nil and data ~= "" then
     local old_line = u.trim(u.get_first_chunk(data, "[^" .. "⋮" .. "]+"))
     local new_line = u.trim(u.get_last_chunk(data, "[^" .. "⋮" .. "]+"))
     line_data.new_line = tonumber(new_line)
     line_data.old_line = tonumber(old_line)
   end
 
-  if line_data.new_line == nil and line_data.old_line == nil then return nil end
+  if line_data.new_line == nil and line_data.old_line == nil then
+    return nil
+  end
 
   return line_data
 end
 
-
 M.get_review_buffer_range = function(file_name)
-  if M.bufnr == nil then return nil, "Delta reviewer must be initialized first" end
+  if M.bufnr == nil then
+    return nil, "Delta reviewer must be initialized first"
+  end
   local lines = vim.api.nvim_buf_get_lines(M.bufnr, 0, -1, false)
   local start = nil
   local stop = nil
 
   for i, line in ipairs(lines) do
-    if start ~= nil and stop ~= nil then return { start, stop } end
+    if start ~= nil and stop ~= nil then
+      return { start, stop }
+    end
     if M.starts_with_file_symbol(line) then
       -- Check if the file name matches the node name
       local delta_file_name = u.get_last_chunk(line)
@@ -173,7 +217,9 @@ M.get_review_buffer_range = function(file_name)
 
   -- We've reached the end of the file, set "stop" in case we already found start
   stop = #lines
-  if start ~= nil and stop ~= nil then return { start, stop } end
+  if start ~= nil and stop ~= nil then
+    return { start, stop }
+  end
 end
 
 M.starts_with_file_symbol = function(line)
@@ -200,4 +246,12 @@ M.get_review_buffer_lines = function(review_buffer_range)
   return lines
 end
 
+---Return content between start_line and end_line
+---@param start_line integer
+---@param end_line integer
+---@return string[] | nil
+M.get_lines = function(start_line, end_line)
+  vim.notify("Getting lines in delta is not supported yet", vim.log.levels.ERROR)
+  return nil
+end
 return M
diff --git a/lua/gitlab/reviewer/diffview.lua b/lua/gitlab/reviewer/diffview.lua
index c50b3e3..f53d0ee 100644
--- a/lua/gitlab/reviewer/diffview.lua
+++ b/lua/gitlab/reviewer/diffview.lua
@@ -1,22 +1,23 @@
 -- This Module contains all of the code specific to the Diffview reviewer.
-local state           = require("gitlab.state")
+local u = require("gitlab.utils")
+local state = require("gitlab.state")
 local async_ok, async = pcall(require, "diffview.async")
 
-local M               = {
+local M = {
   bufnr = nil,
-  tabnr = nil
+  tabnr = nil,
 }
 
 -- Public Functions
 -- These functions are exposed externally and are used
 -- when the reviewer is consumed by other code. They must follow the specification
 -- outlined in the reviewer/init.lua file
-M.open                = function()
+M.open = function()
   vim.api.nvim_command(string.format("DiffviewOpen %s", state.INFO.target_branch))
   M.tabnr = vim.api.nvim_get_current_tabpage()
 end
 
-M.jump                = function(file_name, new_line, old_line)
+M.jump = function(file_name, new_line, old_line)
   if M.tabnr == nil then
     vim.notify("Can't jump to Diffvew. Is it open?", vim.log.levels.ERROR)
     return
@@ -49,12 +50,25 @@ M.jump                = function(file_name, new_line, old_line)
   end
 end
 
-M.get_location        = function()
-  if M.tabnr == nil then return nil, nil, "Diffview reviewer must be initialized first" end
+---Get the location of a line within the diffview. If range is specified, then also the location
+---of the lines in range.
+---@param range LineRange | nil Line range to get location for
+---@return ReviewerInfo | nil nil is returned only if error was encountered
+M.get_location = function(range)
+  if M.tabnr == nil then
+    vim.notify("Diffview reviewer must be initialized first")
+    return
+  end
   local bufnr = vim.api.nvim_get_current_buf()
+  local current_line = vim.api.nvim_win_get_cursor(0)[1]
+
   -- check if we are in the diffview tab
   local tabnr = vim.api.nvim_get_current_tabpage()
-  if tabnr ~= M.tabnr then return nil, nil, "Line location can only be determined within reviewer window" end
+  if tabnr ~= M.tabnr then
+    vim.notify("Line location can only be determined within reviewer window")
+    return
+  end
+
   -- check if we are in the diffview buffer
   local view = require("diffview.lib").get_current_view()
   if view == nil then
@@ -62,18 +76,81 @@ M.get_location        = function()
     return
   end
   local layout = view.cur_layout
-  local file_name = nil
-  local current_line_changes = nil
+  local result = {}
+  local type
+  local is_new
   if layout.a.file.bufnr == bufnr then
-    file_name = layout.a.file.path
-    current_line_changes = { new_line = nil, old_line = vim.api.nvim_win_get_cursor(0)[1] }
-    return file_name, current_line_changes
+    result.file_name = layout.a.file.path
+    result.old_line = current_line
+    type = "old"
+    is_new = false
   elseif layout.b.file.bufnr == bufnr then
-    file_name = layout.b.file.path
-    current_line_changes = { new_line = vim.api.nvim_win_get_cursor(0)[1], old_line = nil }
-    return file_name, current_line_changes
+    result.file_name = layout.b.file.path
+    result.new_line = current_line
+    type = "new"
+    is_new = true
+  else
+    vim.notify("Line location can only be determined within reviewer window")
+    return
   end
-  return nil, nil, "Line location can only be determined within reviewer window"
+
+  local hunks = u.parse_hunk_headers(result.file_name, state.INFO.target_branch)
+  if hunks == nil then
+    vim.notify("Could not parse hunks", vim.log.levels.ERROR)
+    return
+  end
+
+  local current_line_info
+  if is_new then
+    current_line_info = u.get_lines_from_hunks(hunks, result.new_line, is_new)
+  else
+    current_line_info = u.get_lines_from_hunks(hunks, result.old_line, is_new)
+  end
+
+  -- If single line comment is outside of changed lines then we need to specify both new line and old line
+  -- otherwise the API returns error.
+  -- https://docs.gitlab.com/ee/api/discussions.html#create-a-new-thread-in-the-merge-request-diff
+  if not current_line_info.in_hunk then
+    result.old_line = current_line_info.old_line
+    result.new_line = current_line_info.new_line
+  end
+
+  if range == nil then
+    return result
+  end
+
+  result.range_info = { start = {}, ["end"] = {} }
+  if current_line == range.start_line then
+    result.range_info.start.old_line = current_line_info.old_line
+    result.range_info.start.new_line = current_line_info.new_line
+    result.range_info.start.type = type
+  else
+    local start_line_info = u.get_lines_from_hunks(hunks, range.start_line, is_new)
+    result.range_info.start.old_line = start_line_info.old_line
+    result.range_info.start.new_line = start_line_info.new_line
+    result.range_info.start.type = type
+  end
+
+  if current_line == range.end_line then
+    result.range_info["end"].old_line = current_line_info.old_line
+    result.range_info["end"].new_line = current_line_info.new_line
+    result.range_info["end"].type = type
+  else
+    local end_line_info = u.get_lines_from_hunks(hunks, range.end_line, is_new)
+    result.range_info["end"].old_line = end_line_info.old_line
+    result.range_info["end"].new_line = end_line_info.new_line
+    result.range_info["end"].type = type
+  end
+
+  return result
+end
+
+---Return content between start_line and end_line
+---@param start_line integer
+---@param end_line integer
+---@return string[]
+M.get_lines = function(start_line, end_line)
+  return vim.api.nvim_buf_get_lines(0, start_line - 1, end_line, false)
 end
 
 return M
diff --git a/lua/gitlab/reviewer/init.lua b/lua/gitlab/reviewer/init.lua
index f4c0932..1cced8d 100644
--- a/lua/gitlab/reviewer/init.lua
+++ b/lua/gitlab/reviewer/init.lua
@@ -10,7 +10,7 @@ local M = {
 
 local reviewer_map = {
   delta = delta,
-  diffview = diffview
+  diffview = diffview,
 }
 
 M.init = function()
@@ -31,9 +31,12 @@ M.init = function()
   --   • {interval}  The old_line of the change
 
   M.get_location = reviewer.get_location
-  -- Returns the current location (based on cursor) from the reviewer window in format:
-  -- file_name, {new_line, old_line}, error
+  -- Parameters:
+  --   • {range}  LineRange if function was triggered from visual selection
+  -- Returns the current location (based on cursor) from the reviewer window as ReviewerInfo class
+
+  M.get_lines = reviewer.get_lines
+  -- Returns the content of the file in the current location in the reviewer window
 end
 
-
 return M
diff --git a/lua/gitlab/utils/init.lua b/lua/gitlab/utils/init.lua
index 5f36d87..4e68bde 100644
--- a/lua/gitlab/utils/init.lua
+++ b/lua/gitlab/utils/init.lua
@@ -1,7 +1,8 @@
+local Job = require("plenary.job")
 local M = {}
 
 M.get_current_line_number = function()
-  return vim.api.nvim_call_function('line', { '.' })
+  return vim.api.nvim_call_function("line", { "." })
 end
 
 M.has_reviewer = function(reviewer)
@@ -62,13 +63,13 @@ M.format_date = function(date_string)
     day = date_table.day,
     hour = date_table.hour,
     min = date_table.min,
-    sec = date_table.sec
+    sec = date_table.sec,
   })
 
   local time_diff = current_date - date
 
   local function pluralize(num, word)
-    return num .. string.format(" %s", word) .. (num > 1 and "s" or '') .. " ago"
+    return num .. string.format(" %s", word) .. (num > 1 and "s" or "") .. " ago"
   end
 
   if time_diff < 60 then
@@ -86,7 +87,9 @@ M.format_date = function(date_string)
 end
 
 M.jump_to_file = function(filename, line_number)
-  if line_number == nil then line_number = 1 end
+  if line_number == nil then
+    line_number = 1
+  end
   local bufnr = vim.fn.bufnr(filename)
   if bufnr ~= -1 then
     M.jump_to_buffer(bufnr, line_number)
@@ -106,7 +109,7 @@ end
 M.create_popup_state = function(title, width, height)
   return {
     buf_options = {
-      filetype = 'markdown'
+      filetype = "markdown",
     },
     relative = "editor",
     enter = true,
@@ -114,7 +117,7 @@ M.create_popup_state = function(title, width, height)
     border = {
       style = "rounded",
       text = {
-        top = title
+        top = title,
       },
     },
     position = "50%",
@@ -142,7 +145,7 @@ M.join = function(tbl, separator)
 
   -- Remove the trailing separator
   if separator ~= "" then
-    result = result:sub(1, - #separator - 1)
+    result = result:sub(1, -#separator - 1)
   end
 
   return result
@@ -169,16 +172,16 @@ M.read_file = function(file_path)
 end
 
 M.current_file_path = function()
-  local path = debug.getinfo(1, 'S').source:sub(2)
-  return vim.fn.fnamemodify(path, ':p')
+  local path = debug.getinfo(1, "S").source:sub(2)
+  return vim.fn.fnamemodify(path, ":p")
 end
 
 local random = math.random
 M.uuid = function()
-  local template = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'
-  return string.gsub(template, '[xy]', function(c)
-    local v = (c == 'x') and random(0, 0xf) or random(8, 0xb)
-    return string.format('%x', v)
+  local template = "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"
+  return string.gsub(template, "[xy]", function(c)
+    local v = (c == "x") and random(0, 0xf) or random(8, 0xb)
+    return string.format("%x", v)
   end)
 end
 
@@ -192,7 +195,9 @@ end
 
 M.table_size = function(t)
   local count = 0
-  for _ in pairs(t) do count = count + 1 end
+  for _ in pairs(t) do
+    count = count + 1
+  end
   return count
 end
 
@@ -247,11 +252,7 @@ end
 
 M.get_line_content = function(bufnr, start)
   local current_buffer = vim.api.nvim_get_current_buf()
-  local lines = vim.api.nvim_buf_get_lines(
-    bufnr ~= nil and bufnr or current_buffer,
-    start - 1,
-    start,
-    false)
+  local lines = vim.api.nvim_buf_get_lines(bufnr ~= nil and bufnr or current_buffer, start - 1, start, false)
 
   for _, line in ipairs(lines) do
     return line
@@ -267,8 +268,8 @@ M.get_win_from_buf = function(bufnr)
 end
 
 M.switch_can_edit_buf = function(buf, bool)
-  vim.api.nvim_buf_set_option(buf, 'modifiable', bool)
-  vim.api.nvim_buf_set_option(buf, "readonly", not bool)
+  vim.api.nvim_set_option_value("modifiable", bool, { buf = buf })
+  vim.api.nvim_set_option_value("readonly", not bool, { buf = buf })
 end
 
 M.list_files_in_folder = function(folder_path)
@@ -278,12 +279,14 @@ M.list_files_in_folder = function(folder_path)
 
   local folder_ok, folder = pcall(vim.fn.readdir, folder_path)
 
-  if not folder_ok then return nil end
+  if not folder_ok then
+    return nil
+  end
 
   local files = {}
   if folder ~= nil then
     for _, file in ipairs(folder) do
-      local file_path = folder_path .. (M.is_windows() and "\\" or '/') .. file
+      local file_path = folder_path .. (M.is_windows() and "\\" or "/") .. file
       local timestamp = vim.fn.getftime(file_path)
       table.insert(files, { name = file, timestamp = timestamp })
     end
@@ -310,4 +313,149 @@ M.reverse = function(list)
   return rev
 end
 
+---@class Hunk
+---@field old_line integer
+---@field old_range integer
+---@field new_line integer
+---@field new_range integer
+
+---Parse git diff hunks.
+---@param file_path string Path to file.
+---@param base_branch string Git base branch of merge request.
+---@return Hunk[] list of hunks.
+M.parse_hunk_headers = function(file_path, base_branch)
+  local hunks = {}
+
+  local diff_job = Job:new({
+    command = "git",
+    args = { "diff", "--minimal", "--unified=0", "--no-color", base_branch, "--", file_path },
+    on_exit = function(j, return_code)
+      if return_code == 0 then
+        for _, line in ipairs(j:result()) do
+          if line:sub(1, 2) == "@@" then
+            -- match:
+            --  @@ -23 +23 @@ ...
+            --  @@ -23,0 +23 @@ ...
+            --  @@ -41,0 +42,4 @@ ...
+            local old_start, old_range, new_start, new_range = line:match("@@+ %-(%d+),?(%d*) %+(%d+),?(%d*) @@+")
+
+            table.insert(hunks, {
+              old_line = tonumber(old_start),
+              old_range = tonumber(old_range) or 0,
+              new_line = tonumber(new_start),
+              new_range = tonumber(new_range) or 0,
+            })
+          end
+        end
+      else
+        vim.notify("Failed to get git diff: " .. j:stderr(), vim.log.levels.WARN)
+      end
+    end,
+  })
+
+  diff_job:sync()
+
+  return hunks
+end
+
+---@class LineDiffInfo
+---@field old_line integer
+---@field new_line integer
+---@field in_hunk boolean
+
+---Search git diff hunks to find old and new line number corresponding to target line.
+---This function does not check if target line is outside of boundaries of file.
+---@param hunks Hunk[] git diff parsed hunks.
+---@param target_line integer line number to search for - based on is_new paramter the search is
+---either in new lines or old lines of hunks.
+---@param is_new boolean whether to search for new line or old line
+---@return LineDiffInfo
+M.get_lines_from_hunks = function(hunks, target_line, is_new)
+  if #hunks == 0 then
+    -- If there are zero hunks, return target_line for both old and new lines
+    return { old_line = target_line, new_line = target_line, in_hunk = false }
+  end
+  local current_new_line = 0
+  local current_old_line = 0
+  if is_new then
+    for _, hunk in ipairs(hunks) do
+      -- target line is before current hunk
+      if target_line < hunk.new_line then
+        return {
+          old_line = current_old_line + (target_line - current_new_line),
+          new_line = target_line,
+          in_hunk = false,
+        }
+      -- target line is within the current hunk
+      elseif hunk.new_line <= target_line and target_line <= (hunk.new_line + hunk.new_range) then
+        -- this is interesting magic of gitlab calculation
+        return {
+          old_line = hunk.old_line + hunk.old_range + 1,
+          new_line = target_line,
+          in_hunk = true,
+        }
+      -- target line is after the current hunk
+      else
+        current_new_line = hunk.new_line + hunk.new_range
+        current_old_line = hunk.old_line + hunk.old_range
+      end
+    end
+    -- target line is after last hunk
+    return {
+      old_line = current_old_line + (target_line - current_new_line),
+      new_line = target_line,
+      in_hunk = false,
+    }
+  else
+    for _, hunk in ipairs(hunks) do
+      -- target line is before current hunk
+      if target_line < hunk.old_line then
+        return {
+          old_line = target_line,
+          new_line = current_new_line + (target_line - current_old_line),
+          in_hunk = false,
+        }
+      -- target line is within the current hunk
+      elseif hunk.old_line <= target_line and target_line <= (hunk.old_line + hunk.old_range) then
+        return {
+          old_line = target_line,
+          new_line = hunk.new_line,
+          in_hunk = true,
+        }
+      -- target line is after the current hunk
+      else
+        current_new_line = hunk.new_line + hunk.new_range
+        current_old_line = hunk.old_line + hunk.old_range
+      end
+    end
+    -- target line is after last hunk
+    return {
+      old_line = current_old_line + (target_line - current_new_line),
+      new_line = target_line,
+      in_hunk = false,
+    }
+  end
+end
+
+---Check if current mode is visual mode
+---@return boolean true if current mode is visual mode
+M.check_visual_mode = function()
+  local mode = vim.api.nvim_get_mode().mode
+  if mode ~= "v" and mode ~= "V" then
+    vim.notify("Code suggestions are only available in visual mode", vim.log.levels.WARN)
+    return false
+  end
+  return true
+end
+
+---Return start line and end line of visual selection.
+---Exists visual mode in order to access marks "<" , ">"
+---@return integer,integer start line and end line
+M.get_visual_selection_boundaries = function()
+  vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Esc>", false, true, true), "nx", false)
+  local start_line = vim.api.nvim_buf_get_mark(0, "<")[1]
+  local end_line = vim.api.nvim_buf_get_mark(0, ">")[1]
+  return start_line, end_line
+end
+
 return M