WIP: migrate persona to agent

lib/agents/tools/github_pull_request_diff.rb

@@ -0,0 +1,155 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  module Agents
+    module Tools
+      class GithubPullRequestDiff < Tool
+        LARGE_OBJECT_THRESHOLD = 30_000
+
+        def self.signature
+          {
+            name: name,
+            description: "Retrieves the diff for a GitHub pull request",
+            parameters: [
+              {
+                name: "repo",
+                description: "The repository name in the format 'owner/repo'",
+                type: "string",
+                required: true,
+              },
+              {
+                name: "pull_id",
+                description: "The ID of the pull request",
+                type: "integer",
+                required: true,
+              },
+            ],
+          }
+        end
+
+        def self.name
+          "github_pull_request_diff"
+        end
+
+        def repo
+          parameters[:repo]
+        end
+
+        def pull_id
+          parameters[:pull_id]
+        end
+
+        def url
+          @url
+        end
+
+        def invoke
+          api_url = "https://api.github.com/repos/#{repo}/pulls/#{pull_id}"
+          @url = "https://github.com/#{repo}/pull/#{pull_id}"
+
+          pr_info = nil
+          diff_body = nil
+          response_code = "unknown error"
+
+          send_http_request(
+            api_url,
+            headers: {
+              "Accept" => "application/json",
+            },
+            authenticate_github: true,
+          ) do |response|
+            response_code = response.code
+            pr_info = JSON.parse(read_response_body(response)) if response_code == "200"
+          end
+
+          if response_code == "200"
+            send_http_request(
+              api_url,
+              headers: {
+                "Accept" => "application/vnd.github.v3.diff",
+              },
+              authenticate_github: true,
+            ) do |response|
+              response_code = response.code
+              diff_body = read_response_body(response)
+            end
+          end
+
+          if response_code == "200" && pr_info && diff_body
+            diff = diff_body
+            diff = self.class.sort_and_shorten_diff(diff)
+            diff = truncate(diff, max_length: 20_000, percent_length: 0.3, llm: llm)
+
+            source_repo = pr_info.dig("head", "repo", "full_name")
+            source_branch = pr_info.dig("head", "ref")
+            source_sha = pr_info.dig("head", "sha")
+
+            {
+              diff: diff,
+              pr_info: {
+                title: pr_info["title"],
+                state: pr_info["state"],
+                source: {
+                  repo: source_repo,
+                  branch: source_branch,
+                  sha: source_sha,
+                  url: "https://github.com/#{source_repo}/tree/#{source_branch}",
+                },
+                target: {
+                  repo: pr_info["base"]["repo"]["full_name"],
+                  branch: pr_info["base"]["ref"],
+                },
+                author: pr_info["user"]["login"],
+                created_at: pr_info["created_at"],
+                updated_at: pr_info["updated_at"],
+              },
+            }
+          else
+            { error: "Failed to retrieve the PR information. Status code: #{response_code}" }
+          end
+        end
+
+        def description_args
+          { repo: repo, pull_id: pull_id, url: url }
+        end
+
+        def self.sort_and_shorten_diff(diff, threshold: LARGE_OBJECT_THRESHOLD)
+          # This regex matches the start of a new file in the diff,
+          # capturing the file paths for later use.
+          file_start_regex = /^diff --git.*/
+
+          prev_start = -1
+          prev_match = nil
+
+          split = []
+
+          diff.scan(file_start_regex) do |match|
+            match_start = $~.offset(0)[0] # Get the start position of this match
+
+            if prev_start != -1
+              full_diff = diff[prev_start...match_start]
+              split << [prev_match, full_diff]
+            end
+
+            prev_match = match
+            prev_start = match_start
+          end
+
+          split << [prev_match, diff[prev_start..-1]] if prev_match
+
+          split.sort! { |x, y| x[1].length <=> y[1].length }
+
+          split
+            .map do |x, y|
+              if y.length < threshold
+                y
+              else
+                "#{x}\nRedacted, Larger than #{threshold} chars"
+              end
+            end
+            .join("\n")
+        end
+      end
+    end
+  end
+end