Merge remote-tracking branch 'origin/main' into pg/pip_package

CHANGELOG.md

@@ -0,0 +1,6 @@
+## 2023-07-26
+
+### Added
+- New feature for updating the CHANGELOG.md based on the contents of a PR.
+- Added support for this feature for the Github provider.
+- New configuration settings and prompts for the changelog update feature.

README.md

@@ -66,6 +66,7 @@ CodiumAI `PR-Agent` is an open-source tool aiming to help developers review pull
 - [Usage and tools](#usage-and-tools)
 - [Configuration](./CONFIGURATION.md)
 - [How it works](#how-it-works)
+- [Why use PR-Agent](#why-use-pr-agent)
 - [Roadmap](#roadmap)
 - [Similar projects](#similar-projects)
 </div>
@@ -81,6 +82,7 @@ CodiumAI `PR-Agent` is an open-source tool aiming to help developers review pull
 |       | Auto-Description                            |   :white_check_mark:    |  :white_check_mark:      |           |
 |       | Improve Code                                |   :white_check_mark:    |   :white_check_mark:    |           |
 |       | Reflect and Review                          |   :white_check_mark:    |                         |           |
+|       | Update CHANGELOG.md                         |   :white_check_mark:    |                         |           |
 |       |                                             |        |        |           |
 | USAGE | CLI                                         |   :white_check_mark:    |   :white_check_mark:    |   :white_check_mark:       |
 |       | App / webhook                               |   :white_check_mark:    |   :white_check_mark:    |           |
@@ -98,6 +100,7 @@ Examples for invoking the different tools via the CLI:
 - **Improve**:      python cli.py --pr-url=<pr_url>  improve
 - **Ask**:          python cli.py --pr-url=<pr_url>  ask "Write me a poem about this PR"
 - **Reflect**:      python cli.py --pr-url=<pr_url>  reflect
+- **Update changelog**:      python cli.py --pr-url=<pr_url>  update_changelog
 
 "<pr_url>" is the url of the relevant PR (for example: https://github.com/Codium-ai/pr-agent/pull/50).
 
@@ -146,6 +149,19 @@ There are several ways to use PR-Agent:
 
 Check out the [PR Compression strategy](./PR_COMPRESSION.md) page for more details on how we convert a code diff to a manageable LLM prompt
 
+## Why use PR-Agent?
+
+A reasonable question that can be asked is: `"Why use PR-Agent? What make it stand out from existing tools?"`
+
+Here are some of the reasons why:
+
+- We emphasize **real-life practical usage**. Each tool (review, improve, ask, ...) has a single GPT-4 call, no more. We feel that this is critical for realistic team usage - obtaining an answer quickly (~30 seconds) and affordably.
+- Our [PR Compression strategy](./PR_COMPRESSION.md)  is a core ability that enables to effectively tackle both short and long PRs.
+- Our JSON prompting strategy enables to have **modular, customizable tools**. For example, the '/review' tool categories can be controlled via the configuration file. Adding additional categories is easy and accessible.
+- We support **multiple git providers** (GitHub, Gitlab, Bitbucket), and multiple ways to use the tool (CLI, GitHub Action, Docker, ...).
+- We are open-source, and welcome contributions from the community.
+
+
 ## Roadmap
 
 - [ ] Support open-source models, as a replacement for OpenAI models. (Note - a minimal requirement for each open-source model is to have 8k+ context, and good support for generating JSON as an output)

pr_agent/agent/pr_agent.py

@@ -6,6 +6,7 @@ from pr_agent.tools.pr_description import PRDescription
 from pr_agent.tools.pr_information_from_user import PRInformationFromUser
 from pr_agent.tools.pr_questions import PRQuestions
 from pr_agent.tools.pr_reviewer import PRReviewer
+from pr_agent.tools.pr_update_changelog import PRUpdateChangelog
 
 
 class PRAgent:
@@ -26,7 +27,9 @@ class PRAgent:
         elif any(cmd == action for cmd in ["/improve", "/improve_code"]):
             await PRCodeSuggestions(pr_url).suggest()
         elif any(cmd == action for cmd in ["/ask", "/ask_question"]):
-            await PRQuestions(pr_url, args).answer()
+            await PRQuestions(pr_url, args=args).answer()
+        elif any(cmd == action for cmd in ["/update_changelog"]):
+            await PRUpdateChangelog(pr_url, args=args).update_changelog()
         else:
             return False
 

pr_agent/algo/pr_processing.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 import logging
 from typing import Tuple, Union, Callable, List
 
+from github import RateLimitExceededException
+
 from pr_agent.algo import MAX_TOKENS
 from pr_agent.algo.git_patch_processing import convert_to_hunks_with_lines_numbers, extend_patch, handle_patch_deletions
 from pr_agent.algo.language_handler import sort_files_by_main_languages
@@ -19,7 +21,6 @@ OUTPUT_BUFFER_TOKENS_SOFT_THRESHOLD = 1000
 OUTPUT_BUFFER_TOKENS_HARD_THRESHOLD = 600
 PATCH_EXTRA_LINES = 3
 
-
 def get_pr_diff(git_provider: GitProvider, token_handler: TokenHandler, model: str,
                 add_line_numbers_to_hunks: bool = False, disable_extra_lines: bool = False) -> str:
     """
@@ -40,7 +41,11 @@ def get_pr_diff(git_provider: GitProvider, token_handler: TokenHandler, model: s
         global PATCH_EXTRA_LINES
         PATCH_EXTRA_LINES = 0
 
-    diff_files = list(git_provider.get_diff_files())
+    try:
+        diff_files = list(git_provider.get_diff_files())
+    except RateLimitExceededException as e:
+        logging.error(f"Rate limit exceeded for git provider API. original message {e}")
+        raise
 
     # get pr languages
     pr_languages = sort_files_by_main_languages(git_provider.get_languages(), diff_files)

pr_agent/cli.py

@@ -8,6 +8,7 @@ from pr_agent.tools.pr_description import PRDescription
 from pr_agent.tools.pr_information_from_user import PRInformationFromUser
 from pr_agent.tools.pr_questions import PRQuestions
 from pr_agent.tools.pr_reviewer import PRReviewer
+from pr_agent.tools.pr_update_changelog import PRUpdateChangelog
 
 
 def run(args=None):
@@ -27,13 +28,15 @@ ask / ask_question [question] - Ask a question about the PR.
 describe / describe_pr - Modify the PR title and description based on the PR's contents.
 improve / improve_code - Suggest improvements to the code in the PR as pull request comments ready to commit.
 reflect - Ask the PR author questions about the PR.
+update_changelog - Update the changelog based on the PR's contents.
 """)
     parser.add_argument('--pr_url', type=str, help='The URL of the PR to review', required=True)
     parser.add_argument('command', type=str, help='The', choices=['review', 'review_pr',
                                                                   'ask', 'ask_question',
                                                                   'describe', 'describe_pr',
                                                                   'improve', 'improve_code',
-                                                                  'reflect', 'review_after_reflect'],
+                                                                  'reflect', 'review_after_reflect',
+                                                                   'update_changelog'],
                                                                    default='review')
     parser.add_argument('rest', nargs=argparse.REMAINDER, default=[])
     args = parser.parse_args(args)
@@ -49,7 +52,8 @@ reflect - Ask the PR author questions about the PR.
         'review': _handle_review_command,
         'review_pr': _handle_review_command,
         'reflect': _handle_reflect_command,
-        'review_after_reflect': _handle_review_after_reflect_command
+        'review_after_reflect': _handle_review_after_reflect_command,
+        'update_changelog': _handle_update_changelog,
     }
     if command in commands:
         commands[command](args.pr_url, args.rest)
@@ -96,6 +100,10 @@ def _handle_review_after_reflect_command(pr_url: str, rest: list):
     reviewer = PRReviewer(pr_url, cli_mode=True, is_answer=True)
     asyncio.run(reviewer.review())
 
+def _handle_update_changelog(pr_url: str, rest: list):
+    print(f"Updating changlog for: {pr_url}")
+    reviewer = PRUpdateChangelog(pr_url, cli_mode=True, args=rest)
+    asyncio.run(reviewer.update_changelog())
 
 if __name__ == '__main__':
     run()

pr_agent/config_loader.py

@@ -19,6 +19,7 @@ settings = Dynaconf(
          "settings/pr_description_prompts.toml",
          "settings/pr_code_suggestions_prompts.toml",
          "settings/pr_information_from_user_prompts.toml",
+         "settings/pr_update_changelog.toml",
          "settings_prod/.secrets.toml"
         ]]
 )

pr_agent/git_providers/git_provider.py

@@ -136,3 +136,4 @@ class IncrementalPR:
         self.commits_range = None
         self.first_new_commit_sha = None
         self.last_seen_commit_sha = None
+

pr_agent/git_providers/github_provider.py

@@ -3,13 +3,15 @@ from datetime import datetime
 from typing import Optional, Tuple
 from urllib.parse import urlparse
 
-from github import AppAuthentication, Github, Auth
+from github import AppAuthentication, Auth, Github, GithubException
+from retry import retry
 
 from pr_agent.config_loader import settings
 
-from .git_provider import FilePatchInfo, GitProvider, IncrementalPR
 from ..algo.language_handler import is_valid_file
 from ..algo.utils import load_large_diff
+from .git_provider import FilePatchInfo, GitProvider, IncrementalPR
+from ..servers.utils import RateLimitExceeded
 
 
 class GithubProvider(GitProvider):
@@ -78,27 +80,34 @@ class GithubProvider(GitProvider):
             return self.file_set.values()
         return self.pr.get_files()
 
+    @retry(exceptions=RateLimitExceeded,
+           tries=settings.github.ratelimit_retries, delay=2, backoff=2, jitter=(1, 3))
     def get_diff_files(self) -> list[FilePatchInfo]:
-        files = self.get_files()
+        try:
-        diff_files = []
+            files = self.get_files()
-        for file in files:
+            diff_files = []
-            if is_valid_file(file.filename):
+            for file in files:
-                new_file_content_str = self._get_pr_file_content(file, self.pr.head.sha)
+                if is_valid_file(file.filename):
-                patch = file.patch
+                    new_file_content_str = self._get_pr_file_content(file, self.pr.head.sha)
-                if self.incremental.is_incremental and self.file_set:
+                    patch = file.patch
-                    original_file_content_str = self._get_pr_file_content(file, self.incremental.last_seen_commit_sha)
+                    if self.incremental.is_incremental and self.file_set:
-                    patch = load_large_diff(file,
+                        original_file_content_str = self._get_pr_file_content(file,
-                                            new_file_content_str,
+                                                                              self.incremental.last_seen_commit_sha)
-                                            original_file_content_str,
+                        patch = load_large_diff(file,
-                                             None)
+                                                new_file_content_str,
-                    self.file_set[file.filename] = patch
+                                                original_file_content_str,
-                else:
+                                                None)
-                    original_file_content_str = self._get_pr_file_content(file, self.pr.base.sha)
+                        self.file_set[file.filename] = patch
+                    else:
+                        original_file_content_str = self._get_pr_file_content(file, self.pr.base.sha)
 
-                diff_files.append(
+                    diff_files.append(
-                    FilePatchInfo(original_file_content_str, new_file_content_str, patch, file.filename))
+                        FilePatchInfo(original_file_content_str, new_file_content_str, patch, file.filename))
-        self.diff_files = diff_files
+            self.diff_files = diff_files
-        return diff_files
+            return diff_files
+        except GithubException.RateLimitExceededException as e:
+            logging.error(f"Rate limit exceeded for GitHub API. Original message: {e}")
+            raise RateLimitExceeded("Rate limit exceeded for GitHub API.") from e
 
     def publish_description(self, pr_title: str, pr_body: str):
         self.pr.edit(title=pr_title, body=pr_body)

pr_agent/git_providers/local_git_provider.py

@@ -30,6 +30,8 @@ class LocalGitProvider(GitProvider):
 
     def __init__(self, target_branch_name, incremental=False):
         self.repo_path = _find_repository_root()
+        if self.repo_path is None:
+            raise ValueError('Could not find repository root')
         self.repo = Repo(self.repo_path)
         self.head_branch_name = self.repo.head.ref.name
         self.target_branch_name = target_branch_name
@@ -167,7 +169,7 @@ class LocalGitProvider(GitProvider):
         """
         Substitutes the branch-name as the PR-mimic title.
         """
-        return self.target_branch_name
+        return self.head_branch_name
 
     def get_issue_comments(self):
         raise NotImplementedError('Getting issue comments is not implemented for the local git provider')

pr_agent/servers/utils.py

@@ -21,3 +21,7 @@ def verify_signature(payload_body, secret_token, signature_header):
     if not hmac.compare_digest(expected_signature, signature_header):
         raise HTTPException(status_code=403, detail="Request signatures didn't match!")
 
+
+class RateLimitExceeded(Exception):
+    """Raised when the git provider API rate limit has been exceeded."""
+    pass

pr_agent/settings/configuration.toml

@@ -1,6 +1,6 @@
 [config]
 model="gpt-4"
-fallback-models=["gpt-3.5-turbo-16k", "gpt-3.5-turbo"]
+fallback_models=["gpt-3.5-turbo-16k"]
 git_provider="github"
 publish_output=true
 publish_output_progress=true
@@ -24,9 +24,13 @@ publish_description_as_comment=false
 [pr_code_suggestions]
 num_code_suggestions=4
 
+[pr_update_changelog]
+push_changelog_changes=false
+
 [github]
 # The type of deployment to create. Valid values are 'app' or 'user'.
 deployment_type = "user"
+ratelimit_retries = 5
 
 [gitlab]
 # URL to the gitlab service

pr_agent/settings/pr_update_changelog.toml

@@ -0,0 +1,34 @@
+[pr_update_changelog_prompt]
+system="""You are a language model called CodiumAI-PR-Changlog-summarizer.
+Your task is to update the CHANGELOG.md file of the project, to shortly summarize important changes introduced in this PR (the '+' lines).
+- The output should match the existing CHANGELOG.md format, style and conventions, so it will look like a natural part of the file. For example, if previous changes were summarized in a single line, you should do the same.
+- Don't repeat previous changes. Generate only new content, that is not already in the CHANGELOG.md file.
+- Be general, and avoid specific details, files, etc. The output should be minimal, no more than 3-4 short lines. Ignore non-relevant subsections.
+"""
+
+user="""PR Info:
+Title: '{{title}}'
+Branch: '{{branch}}'
+Description: '{{description}}'
+{%- if language %}
+Main language: {{language}}
+{%- endif %}
+
+
+The PR Diff:
+```
+{{diff}}
+```
+
+Current date:
+```
+{{today}}
+```
+
+The current CHANGELOG.md:
+```
+{{ changelog_file_str }}
+```
+
+Response:
+"""

pr_agent/tools/pr_reviewer.py

@@ -2,6 +2,7 @@ import copy
 import json
 import logging
 from collections import OrderedDict
+from typing import Tuple, List
 
 from jinja2 import Environment, StrictUndefined
 
@@ -16,7 +17,19 @@ from pr_agent.servers.help import actions_help_text, bot_help_text
 
 
 class PRReviewer:
-    def __init__(self, pr_url: str, cli_mode=False, is_answer: bool = False, args=None):
+    """
+    The PRReviewer class is responsible for reviewing a pull request and generating feedback using an AI model.
+    """
+    def __init__(self, pr_url: str, cli_mode: bool = False, is_answer: bool = False, args: list = None):
+        """
+        Initialize the PRReviewer object with the necessary attributes and objects to review a pull request.
+
+        Args:
+            pr_url (str): The URL of the pull request to be reviewed.
+            cli_mode (bool, optional): Indicates whether the review is being done in command-line interface mode. Defaults to False.
+            is_answer (bool, optional): Indicates whether the review is being done in answer mode. Defaults to False.
+            args (list, optional): List of arguments passed to the PRReviewer class. Defaults to None.
+        """
         self.parse_args(args)
 
         self.git_provider = get_git_provider()(pr_url, incremental=self.incremental)
@@ -25,13 +38,15 @@ class PRReviewer:
         )
         self.pr_url = pr_url
         self.is_answer = is_answer
+
         if self.is_answer and not self.git_provider.is_supported("get_issue_comments"):
             raise Exception(f"Answer mode is not supported for {settings.config.git_provider} for now")
-        answer_str, question_str = self._get_user_answers()
         self.ai_handler = AiHandler()
         self.patches_diff = None
         self.prediction = None
         self.cli_mode = cli_mode
+
+        answer_str, question_str = self._get_user_answers()
         self.vars = {
             "title": self.git_provider.pr.title,
             "branch": self.git_provider.get_pr_branch(),
@@ -43,16 +58,27 @@ class PRReviewer:
             "require_security": settings.pr_reviewer.require_security_review,
             "require_focused": settings.pr_reviewer.require_focused_review,
             'num_code_suggestions': settings.pr_reviewer.num_code_suggestions,
-            #
             'question_str': question_str,
             'answer_str': answer_str,
         }
-        self.token_handler = TokenHandler(self.git_provider.pr,
-                                          self.vars,
-                                          settings.pr_review_prompt.system,
-                                          settings.pr_review_prompt.user)
 
-    def parse_args(self, args):
+        self.token_handler = TokenHandler(
+            self.git_provider.pr,
+            self.vars,
+            settings.pr_review_prompt.system,
+            settings.pr_review_prompt.user
+        )
+
+    def parse_args(self, args: List[str]) -> None:
+        """
+        Parse the arguments passed to the PRReviewer class and set the 'incremental' attribute accordingly.
+
+        Args:
+            args: A list of arguments passed to the PRReviewer class.
+
+        Returns:
+            None
+        """
         is_incremental = False
         if args and len(args) >= 1:
             arg = args[0]
@@ -60,60 +86,93 @@ class PRReviewer:
                 is_incremental = True
         self.incremental = IncrementalPR(is_incremental)
 
-    async def review(self):
+    async def review(self) -> None:
+        """
+        Review the pull request and generate feedback.
+        """
         logging.info('Reviewing PR...')
+    
         if settings.config.publish_output:
             self.git_provider.publish_comment("Preparing review...", is_temporary=True)
+    
         await retry_with_fallback_models(self._prepare_prediction)
+    
         logging.info('Preparing PR review...')
         pr_comment = self._prepare_pr_review()
+    
         if settings.config.publish_output:
             logging.info('Pushing PR review...')
             self.git_provider.publish_comment(pr_comment)
             self.git_provider.remove_initial_comment()
+        
             if settings.pr_reviewer.inline_code_comments:
                 logging.info('Pushing inline code comments...')
                 self._publish_inline_code_comments()
-        return ""
 
-    async def _prepare_prediction(self, model: str):
+    async def _prepare_prediction(self, model: str) -> None:
+        """
+        Prepare the AI prediction for the pull request review.
+
+        Args:
+            model: A string representing the AI model to be used for the prediction.
+
+        Returns:
+            None
+        """
         logging.info('Getting PR diff...')
         self.patches_diff = get_pr_diff(self.git_provider, self.token_handler, model)
         logging.info('Getting AI prediction...')
         self.prediction = await self._get_prediction(model)
 
-    async def _get_prediction(self, model: str):
+    async def _get_prediction(self, model: str) -> str:
+        """
+        Generate an AI prediction for the pull request review.
+
+        Args:
+            model: A string representing the AI model to be used for the prediction.
+
+        Returns:
+            A string representing the AI prediction for the pull request review.
+        """
         variables = copy.deepcopy(self.vars)
         variables["diff"] = self.patches_diff  # update diff
+
         environment = Environment(undefined=StrictUndefined)
         system_prompt = environment.from_string(settings.pr_review_prompt.system).render(variables)
         user_prompt = environment.from_string(settings.pr_review_prompt.user).render(variables)
+
         if settings.config.verbosity_level >= 2:
             logging.info(f"\nSystem prompt:\n{system_prompt}")
             logging.info(f"\nUser prompt:\n{user_prompt}")
-        response, finish_reason = await self.ai_handler.chat_completion(model=model, temperature=0.2,
+
-                                                                        system=system_prompt, user=user_prompt)
+        response, finish_reason = await self.ai_handler.chat_completion(
+            model=model,
+            temperature=0.2,
+            system=system_prompt,
+            user=user_prompt
+        )
 
         return response
 
     def _prepare_pr_review(self) -> str:
+        """
+        Prepare the PR review by processing the AI prediction and generating a markdown-formatted text that summarizes the feedback.
+        """
         review = self.prediction.strip()
+    
         try:
             data = json.loads(review)
         except json.decoder.JSONDecodeError:
             data = try_fix_json(review)
 
-        # reordering for nicer display
+        # Move 'Security concerns' key to 'PR Analysis' section for better display
-        if 'PR Feedback' in data:
+        if 'PR Feedback' in data and 'Security concerns' in data['PR Feedback']:
-            if 'Security concerns' in data['PR Feedback']:
+            val = data['PR Feedback']['Security concerns']
-                val = data['PR Feedback']['Security concerns']
+            del data['PR Feedback']['Security concerns']
-                del data['PR Feedback']['Security concerns']
+            data['PR Analysis']['Security concerns'] = val
-                data['PR Analysis']['Security concerns'] = val
 
-        if settings.config.git_provider != 'bitbucket' and \
+        # Filter out code suggestions that can be submitted as inline comments
-                settings.pr_reviewer.inline_code_comments and \
+        if settings.config.git_provider != 'bitbucket' and settings.pr_reviewer.inline_code_comments and 'Code suggestions' in data['PR Feedback']:
-                'Code suggestions' in data['PR Feedback']:
-            # keeping only code suggestions that can't be submitted as inline comments
             data['PR Feedback']['Code suggestions'] = [
                 d for d in data['PR Feedback']['Code suggestions']
                 if any(key not in d for key in ('relevant file', 'relevant line in file', 'suggestion content'))
@@ -121,8 +180,8 @@ class PRReviewer:
             if not data['PR Feedback']['Code suggestions']:
                 del data['PR Feedback']['Code suggestions']
 
+        # Add incremental review section
         if self.incremental.is_incremental:
-            # Rename title when incremental review - Add to the beginning of the dict
             last_commit_url = f"{self.git_provider.get_pr_url()}/commits/{self.git_provider.incremental.first_new_commit_sha}"
             data = OrderedDict(data)
             data.update({'Incremental PR Review': {
@@ -132,6 +191,7 @@ class PRReviewer:
         markdown_text = convert_to_markdown(data)
         user = self.git_provider.get_user_id()
 
+        # Add help text if not in CLI mode
         if not self.cli_mode:
             markdown_text += "\n### How to use\n"
             if user and '[bot]' not in user:
@@ -139,11 +199,16 @@ class PRReviewer:
             else:
                 markdown_text += actions_help_text
 
+        # Log markdown response if verbosity level is high
         if settings.config.verbosity_level >= 2:
             logging.info(f"Markdown response:\n{markdown_text}")
+    
         return markdown_text
 
-    def _publish_inline_code_comments(self):
+    def _publish_inline_code_comments(self) -> None:
+        """
+        Publishes inline comments on a pull request with code suggestions generated by the AI model.
+        """
         if settings.pr_reviewer.num_code_suggestions == 0:
             return
 
@@ -153,11 +218,11 @@ class PRReviewer:
         except json.decoder.JSONDecodeError:
             data = try_fix_json(review)
 
-        comments = []
+        comments: List[str] = []
-        for d in data['PR Feedback']['Code suggestions']:
+        for suggestion in data.get('PR Feedback', {}).get('Code suggestions', []):
-            relevant_file = d.get('relevant file', '').strip()
+            relevant_file = suggestion.get('relevant file', '').strip()
-            relevant_line_in_file = d.get('relevant line in file', '').strip()
+            relevant_line_in_file = suggestion.get('relevant line in file', '').strip()
-            content = d.get('suggestion content', '')
+            content = suggestion.get('suggestion content', '')
             if not relevant_file or not relevant_line_in_file or not content:
                 logging.info("Skipping inline comment with missing file/line/content")
                 continue
@@ -172,15 +237,26 @@ class PRReviewer:
         if comments:
             self.git_provider.publish_inline_comments(comments)
 
-    def _get_user_answers(self):
+    def _get_user_answers(self) -> Tuple[str, str]:
-        answer_str = question_str = ""
+        """
+        Retrieves the question and answer strings from the discussion messages related to a pull request.
+
+        Returns:
+            A tuple containing the question and answer strings.
+        """
+        question_str = ""
+        answer_str = ""
+
         if self.is_answer:
             discussion_messages = self.git_provider.get_issue_comments()
-            for message in discussion_messages.reversed:
+
+            for message in reversed(discussion_messages):
                 if "Questions to better understand the PR:" in message.body:
                     question_str = message.body
                 elif '/answer' in message.body:
                     answer_str = message.body
+
                 if answer_str and question_str:
                     break
+
         return question_str, answer_str

pr_agent/tools/pr_update_changelog.py

@@ -0,0 +1,171 @@
+import copy
+import logging
+from datetime import date
+from time import sleep
+from typing import Tuple
+
+from jinja2 import Environment, StrictUndefined
+
+from pr_agent.algo.ai_handler import AiHandler
+from pr_agent.algo.pr_processing import get_pr_diff, retry_with_fallback_models
+from pr_agent.algo.token_handler import TokenHandler
+from pr_agent.config_loader import settings
+from pr_agent.git_providers import get_git_provider, GithubProvider
+from pr_agent.git_providers.git_provider import get_main_pr_language
+
+CHANGELOG_LINES = 50
+
+
+class PRUpdateChangelog:
+    def __init__(self, pr_url: str, cli_mode=False, args=None):
+
+        self.git_provider = get_git_provider()(pr_url)
+        self.main_language = get_main_pr_language(
+            self.git_provider.get_languages(), self.git_provider.get_files()
+        )
+        self.commit_changelog = self._parse_args(args, settings)
+        self._get_changlog_file()  # self.changelog_file_str
+        self.ai_handler = AiHandler()
+        self.patches_diff = None
+        self.prediction = None
+        self.cli_mode = cli_mode
+        self.vars = {
+            "title": self.git_provider.pr.title,
+            "branch": self.git_provider.get_pr_branch(),
+            "description": self.git_provider.get_pr_description(),
+            "language": self.main_language,
+            "diff": "",  # empty diff for initial calculation
+            "changelog_file_str": self.changelog_file_str,
+            "today": date.today(),
+        }
+        self.token_handler = TokenHandler(self.git_provider.pr,
+                                          self.vars,
+                                          settings.pr_update_changelog_prompt.system,
+                                          settings.pr_update_changelog_prompt.user)
+
+    async def update_changelog(self):
+        assert type(self.git_provider) == GithubProvider, "Currently only Github is supported"
+
+        logging.info('Updating the changelog...')
+        if settings.config.publish_output:
+            self.git_provider.publish_comment("Preparing changelog updates...", is_temporary=True)
+        await retry_with_fallback_models(self._prepare_prediction)
+        logging.info('Preparing PR changelog updates...')
+        new_file_content, answer = self._prepare_changelog_update()
+        if settings.config.publish_output:
+            self.git_provider.remove_initial_comment()
+            logging.info('Publishing changelog updates...')
+            if self.commit_changelog:
+                logging.info('Pushing PR changelog updates to repo...')
+                self._push_changelog_update(new_file_content, answer)
+            else:
+                logging.info('Publishing PR changelog as comment...')
+                self.git_provider.publish_comment(f"**Changelog updates:**\n\n{answer}")
+
+    async def _prepare_prediction(self, model: str):
+        logging.info('Getting PR diff...')
+        self.patches_diff = get_pr_diff(self.git_provider, self.token_handler, model)
+        logging.info('Getting AI prediction...')
+        self.prediction = await self._get_prediction(model)
+
+    async def _get_prediction(self, model: str):
+        variables = copy.deepcopy(self.vars)
+        variables["diff"] = self.patches_diff  # update diff
+        environment = Environment(undefined=StrictUndefined)
+        system_prompt = environment.from_string(settings.pr_update_changelog_prompt.system).render(variables)
+        user_prompt = environment.from_string(settings.pr_update_changelog_prompt.user).render(variables)
+        if settings.config.verbosity_level >= 2:
+            logging.info(f"\nSystem prompt:\n{system_prompt}")
+            logging.info(f"\nUser prompt:\n{user_prompt}")
+        response, finish_reason = await self.ai_handler.chat_completion(model=model, temperature=0.2,
+                                                                        system=system_prompt, user=user_prompt)
+
+        return response
+
+    def _prepare_changelog_update(self) -> Tuple[str, str]:
+        answer = self.prediction.strip().strip("```").strip()
+        if hasattr(self, "changelog_file"):
+            existing_content = self.changelog_file.decoded_content.decode()
+        else:
+            existing_content = ""
+        if existing_content:
+            new_file_content = answer + "\n\n" + self.changelog_file.decoded_content.decode()
+        else:
+            new_file_content = answer
+
+        if not self.commit_changelog:
+            answer += "\n\n\n>to commit the new content to the CHANGELOG.md file, please type:" \
+                      "\n>'/update_changelog -commit'\n"
+
+        if settings.config.verbosity_level >= 2:
+            logging.info(f"answer:\n{answer}")
+
+        return new_file_content, answer
+
+    def _push_changelog_update(self, new_file_content, answer):
+        self.git_provider.repo_obj.update_file(path=self.changelog_file.path,
+                                               message="Update CHANGELOG.md",
+                                               content=new_file_content,
+                                               sha=self.changelog_file.sha,
+                                               branch=self.git_provider.get_pr_branch())
+        d = dict(body="CHANGELOG.md update",
+                 path=self.changelog_file.path,
+                 line=max(2, len(answer.splitlines())),
+                 start_line=1)
+
+        sleep(5)  # wait for the file to be updated
+        last_commit_id = list(self.git_provider.pr.get_commits())[-1]
+        try:
+            self.git_provider.pr.create_review(commit=last_commit_id, comments=[d])
+        except:
+            # we can't create a review for some reason, let's just publish a comment
+            self.git_provider.publish_comment(f"**Changelog updates:**\n\n{answer}")
+
+
+    def _get_default_changelog(self):
+        example_changelog = \
+"""
+Example:
+## <current_date>
+
+### Added
+...
+### Changed
+...
+### Fixed
+...
+"""
+        return example_changelog
+
+    def _parse_args(self, args, setting):
+        commit_changelog = False
+        if args and len(args) >= 1:
+            try:
+                if args[0] == "-commit":
+                    commit_changelog = True
+            except:
+                pass
+        else:
+            commit_changelog = setting.pr_update_changelog.push_changelog_changes
+
+        return commit_changelog
+
+    def _get_changlog_file(self):
+        try:
+            self.changelog_file = self.git_provider.repo_obj.get_contents("CHANGELOG.md",
+                                                                          ref=self.git_provider.get_pr_branch())
+            changelog_file_lines = self.changelog_file.decoded_content.decode().splitlines()
+            changelog_file_lines = changelog_file_lines[:CHANGELOG_LINES]
+            self.changelog_file_str = "\n".join(changelog_file_lines)
+        except:
+            self.changelog_file_str = ""
+            if self.commit_changelog:
+                logging.info("No CHANGELOG.md file found in the repository. Creating one...")
+                changelog_file = self.git_provider.repo_obj.create_file(path="CHANGELOG.md",
+                                                                             message='add CHANGELOG.md',
+                                                                             content="",
+                                                                             branch=self.git_provider.get_pr_branch())
+                self.changelog_file = changelog_file['content']
+
+        if not self.changelog_file_str:
+            self.changelog_file_str = self._get_default_changelog()