BREAKING CHANGE: Delta Pager + Large Refactor (#43)

BREAKING CHANGE: This MR addresses an underlying issue with the original implementation in regards to detecting line numbers for comments. 

As such, this is a major breaking change. The setup function signature has changed, please review the `README.md` for the new arguments. The delta pager has also been added as a dependency: https://github.com/dandavison/delta

There will be future work to implement a native solution for parsing changes and line numbers.

lua/gitlab/actions/comment.lua

@@ -0,0 +1,64 @@
+-- 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 reviewer           = require("gitlab.reviewer")
+local M                  = {}
+
+local comment_popup      = Popup(u.create_popup_state("Comment", "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()
+  comment_popup:mount()
+  state.set_popup_keymaps(comment_popup, M.confirm_create_comment)
+end
+
+-- This function (settings.popup.perform_action) will send the comment to the Go server
+M.confirm_create_comment = function(text)
+  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)
+    return
+  end
+
+  local revision = state.MR_REVISIONS[1]
+  local jsonTable = {
+    comment = text,
+    file_name = file_name,
+    old_line = line_numbers.old_line,
+    new_line = line_numbers.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"
+  }
+
+  local json = vim.json.encode(jsonTable)
+
+  job.run_job("/comment", "POST", json, function(data)
+    vim.notify("Comment created")
+    discussions.refresh_tree()
+  end)
+end
+
+return M