"""Util that calls GitHub."""
from __future__ import annotations

import json
from typing import TYPE_CHECKING, Any, Dict, List, Optional

import requests
import tiktoken
from langchain_core.pydantic_v1 import BaseModel, Extra, root_validator

from langchain.utils import get_from_dict_or_env

if TYPE_CHECKING:
    from github.Issue import Issue
    from github.PullRequest import PullRequest


class GitHubAPIWrapper(BaseModel):
    """Wrapper for GitHub API."""

    github: Any  #: :meta private:
    github_repo_instance: Any  #: :meta private:
    github_repository: Optional[str] = None
    github_app_id: Optional[str] = None
    github_app_private_key: Optional[str] = None
    active_branch: Optional[str] = None
    github_base_branch: Optional[str] = None

    class Config:
        """Configuration for this pydantic object."""

        extra = Extra.forbid

    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that api key and python package exists in environment."""
        github_repository = get_from_dict_or_env(
            values, "github_repository", "GITHUB_REPOSITORY"
        )

        github_app_id = get_from_dict_or_env(values, "github_app_id", "GITHUB_APP_ID")

        github_app_private_key = get_from_dict_or_env(
            values, "github_app_private_key", "GITHUB_APP_PRIVATE_KEY"
        )

        try:
            from github import Auth, GithubIntegration

        except ImportError:
            raise ImportError(
                "PyGithub is not installed. "
                "Please install it with `pip install PyGithub`"
            )

        try:
            # interpret the key as a file path
            # fallback to interpreting as the key itself
            with open(github_app_private_key, "r") as f:
                private_key = f.read()
        except Exception:
            private_key = github_app_private_key

        auth = Auth.AppAuth(
            github_app_id,
            private_key,
        )
        gi = GithubIntegration(auth=auth)
        installation = gi.get_installations()[0]

        # create a GitHub instance:
        g = installation.get_github_for_installation()
        repo = g.get_repo(github_repository)

        github_base_branch = get_from_dict_or_env(
            values,
            "github_base_branch",
            "GITHUB_BASE_BRANCH",
            default=repo.default_branch,
        )

        active_branch = get_from_dict_or_env(
            values,
            "active_branch",
            "ACTIVE_BRANCH",
            default=repo.default_branch,
        )

        values["github"] = g
        values["github_repo_instance"] = repo
        values["github_repository"] = github_repository
        values["github_app_id"] = github_app_id
        values["github_app_private_key"] = github_app_private_key
        values["active_branch"] = active_branch
        values["github_base_branch"] = github_base_branch

        return values

    def parse_issues(self, issues: List[Issue]) -> List[dict]:
        """
        Extracts title and number from each Issue and puts them in a dictionary
        Parameters:
            issues(List[Issue]): A list of Github Issue objects
        Returns:
            List[dict]: A dictionary of issue titles and numbers
        """
        parsed = []
        for issue in issues:
            title = issue.title
            number = issue.number
            opened_by = issue.user.login if issue.user else None
            issue_dict = {"title": title, "number": number}
            if opened_by is not None:
                issue_dict["opened_by"] = opened_by
            parsed.append(issue_dict)
        return parsed

    def parse_pull_requests(self, pull_requests: List[PullRequest]) -> List[dict]:
        """
        Extracts title and number from each Issue and puts them in a dictionary
        Parameters:
            issues(List[Issue]): A list of Github Issue objects
        Returns:
            List[dict]: A dictionary of issue titles and numbers
        """
        parsed = []
        for pr in pull_requests:
            parsed.append(
                {
                    "title": pr.title,
                    "number": pr.number,
                    "commits": str(pr.commits),
                    "comments": str(pr.comments),
                }
            )
        return parsed

    def get_issues(self) -> str:
        """
        Fetches all open issues from the repo excluding pull requests

        Returns:
            str: A plaintext report containing the number of issues
            and each issue's title and number.
        """
        issues = self.github_repo_instance.get_issues(state="open")
        # Filter out pull requests (part of GH issues object)
        issues = [issue for issue in issues if not issue.pull_request]
        if issues:
            parsed_issues = self.parse_issues(issues)
            parsed_issues_str = (
                "Found " + str(len(parsed_issues)) + " issues:\n" + str(parsed_issues)
            )
            return parsed_issues_str
        else:
            return "No open issues available"

    def list_open_pull_requests(self) -> str:
        """
        Fetches all open PRs from the repo

        Returns:
            str: A plaintext report containing the number of PRs
            and each PR's title and number.
        """
        # issues = self.github_repo_instance.get_issues(state="open")
        pull_requests = self.github_repo_instance.get_pulls(state="open")
        if pull_requests.totalCount > 0:
            parsed_prs = self.parse_pull_requests(pull_requests)
            parsed_prs_str = (
                "Found " + str(len(parsed_prs)) + " pull requests:\n" + str(parsed_prs)
            )
            return parsed_prs_str
        else:
            return "No open pull requests available"

    def list_files_in_main_branch(self) -> str:
        """
        Fetches all files in the main branch of the repo.

        Returns:
            str: A plaintext report containing the paths and names of the files.
        """
        files: List[str] = []
        try:
            contents = self.github_repo_instance.get_contents(
                "", ref=self.github_base_branch
            )
            for content in contents:
                if content.type == "dir":
                    files.extend(self.get_files_from_directory(content.path))
                else:
                    files.append(content.path)

            if files:
                files_str = "\n".join(files)
                return f"Found {len(files)} files in the main branch:\n{files_str}"
            else:
                return "No files found in the main branch"
        except Exception as e:
            return str(e)

    def set_active_branch(self, branch_name: str) -> str:
        """Equivalent to `git checkout branch_name` for this Agent.
        Clones formatting from Github.

        Returns an Error (as a string) if branch doesn't exist.
        """
        curr_branches = [
            branch.name for branch in self.github_repo_instance.get_branches()
        ]
        if branch_name in curr_branches:
            self.active_branch = branch_name
            return f"Switched to branch `{branch_name}`"
        else:
            return (
                f"Error {branch_name} does not exist,"
                f"in repo with current branches: {str(curr_branches)}"
            )

    def list_branches_in_repo(self) -> str:
        """
        Fetches a list of all branches in the repository.

        Returns:
            str: A plaintext report containing the names of the branches.
        """
        try:
            branches = [
                branch.name for branch in self.github_repo_instance.get_branches()
            ]
            if branches:
                branches_str = "\n".join(branches)
                return (
                    f"Found {len(branches)} branches in the repository:"
                    f"\n{branches_str}"
                )
            else:
                return "No branches found in the repository"
        except Exception as e:
            return str(e)

    def create_branch(self, proposed_branch_name: str) -> str:
        """
        Create a new branch, and set it as the active bot branch.
        Equivalent to `git switch -c proposed_branch_name`
        If the proposed branch already exists, we append _v1 then _v2...
        until a unique name is found.

        Returns:
            str: A plaintext success message.
        """
        from github import GithubException

        i = 0
        new_branch_name = proposed_branch_name
        base_branch = self.github_repo_instance.get_branch(
            self.github_repo_instance.default_branch
        )
        for i in range(1000):
            try:
                self.github_repo_instance.create_git_ref(
                    ref=f"refs/heads/{new_branch_name}", sha=base_branch.commit.sha
                )
                self.active_branch = new_branch_name
                return (
                    f"Branch '{new_branch_name}' "
                    "created successfully, and set as current active branch."
                )
            except GithubException as e:
                if e.status == 422 and "Reference already exists" in e.data["message"]:
                    i += 1
                    new_branch_name = f"{proposed_branch_name}_v{i}"
                else:
                    # Handle any other exceptions
                    print(f"Failed to create branch. Error: {e}")
                    raise Exception(
                        "Unable to create branch name from proposed_branch_name: "
                        f"{proposed_branch_name}"
                    )
        return (
            "Unable to create branch. "
            "At least 1000 branches exist with named derived from "
            f"proposed_branch_name: `{proposed_branch_name}`"
        )

    def list_files_in_bot_branch(self) -> str:
        """
        Fetches all files in the active branch of the repo,
        the branch the bot uses to make changes.

        Returns:
            str: A plaintext list containing the the filepaths in the branch.
        """
        files: List[str] = []
        try:
            contents = self.github_repo_instance.get_contents(
                "", ref=self.active_branch
            )
            for content in contents:
                if content.type == "dir":
                    files.extend(self.get_files_from_directory(content.path))
                else:
                    files.append(content.path)

            if files:
                files_str = "\n".join(files)
                return (
                    f"Found {len(files)} files in branch `{self.active_branch}`:\n"
                    f"{files_str}"
                )
            else:
                return f"No files found in branch: `{self.active_branch}`"
        except Exception as e:
            return f"Error: {e}"

    def get_files_from_directory(self, directory_path: str) -> str:
        """
        Recursively fetches files from a directory in the repo.

        Parameters:
            directory_path (str): Path to the directory

        Returns:
            str: List of file paths, or an error message.
        """
        from github import GithubException

        files: List[str] = []
        try:
            contents = self.github_repo_instance.get_contents(
                directory_path, ref=self.active_branch
            )
        except GithubException as e:
            return f"Error: status code {e.status}, {e.message}"

        for content in contents:
            if content.type == "dir":
                files.extend(self.get_files_from_directory(content.path))
            else:
                files.append(content.path)
        return str(files)

    def get_issue(self, issue_number: int) -> Dict[str, Any]:
        """
        Fetches a specific issue and its first 10 comments
        Parameters:
            issue_number(int): The number for the github issue
        Returns:
            dict: A dictionary containing the issue's title,
            body, comments as a string, and the username of the user
            who opened the issue
        """
        issue = self.github_repo_instance.get_issue(number=issue_number)
        page = 0
        comments: List[dict] = []
        while len(comments) <= 10:
            comments_page = issue.get_comments().get_page(page)
            if len(comments_page) == 0:
                break
            for comment in comments_page:
                comments.append({"body": comment.body, "user": comment.user.login})
            page += 1

        opened_by = None
        if issue.user and issue.user.login:
            opened_by = issue.user.login

        return {
            "number": issue_number,
            "title": issue.title,
            "body": issue.body,
            "comments": str(comments),
            "opened_by": str(opened_by),
        }

    def list_pull_request_files(self, pr_number: int) -> List[Dict[str, Any]]:
        """Fetches the full text of all files in a PR. Truncates after first 3k tokens.
        # TODO: Enhancement to summarize files with ctags if they're getting long.

        Args:
            pr_number(int): The number of the pull request on Github

        Returns:
            dict: A dictionary containing the issue's title,
            body, and comments as a string
        """
        MAX_TOKENS_FOR_FILES = 3_000
        pr_files = []
        pr = self.github_repo_instance.get_pull(number=int(pr_number))
        total_tokens = 0
        page = 0
        while True:  # or while (total_tokens + tiktoken()) < MAX_TOKENS_FOR_FILES:
            files_page = pr.get_files().get_page(page)
            if len(files_page) == 0:
                break
            for file in files_page:
                try:
                    file_metadata_response = requests.get(file.contents_url)
                    if file_metadata_response.status_code == 200:
                        download_url = json.loads(file_metadata_response.text)[
                            "download_url"
                        ]
                    else:
                        print(f"Failed to download file: {file.contents_url}, skipping")
                        continue

                    file_content_response = requests.get(download_url)
                    if file_content_response.status_code == 200:
                        # Save the content as a UTF-8 string
                        file_content = file_content_response.text
                    else:
                        print(
                            "Failed downloading file content "
                            f"(Error {file_content_response.status_code}). Skipping"
                        )
                        continue

                    file_tokens = len(
                        tiktoken.get_encoding("cl100k_base").encode(
                            file_content + file.filename + "file_name file_contents"
                        )
                    )
                    if (total_tokens + file_tokens) < MAX_TOKENS_FOR_FILES:
                        pr_files.append(
                            {
                                "filename": file.filename,
                                "contents": file_content,
                                "additions": file.additions,
                                "deletions": file.deletions,
                            }
                        )
                        total_tokens += file_tokens
                except Exception as e:
                    print(f"Error when reading files from a PR on github. {e}")
            page += 1
        return pr_files

    def get_pull_request(self, pr_number: int) -> Dict[str, Any]:
        """
        Fetches a specific pull request and its first 10 comments,
        limited by max_tokens.

        Parameters:
            pr_number(int): The number for the Github pull
            max_tokens(int): The maximum number of tokens in the response
        Returns:
            dict: A dictionary containing the pull's title, body,
            and comments as a string
        """
        max_tokens = 2_000
        pull = self.github_repo_instance.get_pull(number=pr_number)
        total_tokens = 0

        def get_tokens(text: str) -> int:
            return len(tiktoken.get_encoding("cl100k_base").encode(text))

        def add_to_dict(data_dict: Dict[str, Any], key: str, value: str) -> None:
            nonlocal total_tokens  # Declare total_tokens as nonlocal
            tokens = get_tokens(value)
            if total_tokens + tokens <= max_tokens:
                data_dict[key] = value
                total_tokens += tokens  # Now this will modify the outer variable

        response_dict: Dict[str, str] = {}
        add_to_dict(response_dict, "title", pull.title)
        add_to_dict(response_dict, "number", str(pr_number))
        add_to_dict(response_dict, "body", pull.body)

        comments: List[str] = []
        page = 0
        while len(comments) <= 10:
            comments_page = pull.get_issue_comments().get_page(page)
            if len(comments_page) == 0:
                break
            for comment in comments_page:
                comment_str = str({"body": comment.body, "user": comment.user.login})
                if total_tokens + get_tokens(comment_str) > max_tokens:
                    break
                comments.append(comment_str)
                total_tokens += get_tokens(comment_str)
            page += 1
        add_to_dict(response_dict, "comments", str(comments))

        commits: List[str] = []
        page = 0
        while len(commits) <= 10:
            commits_page = pull.get_commits().get_page(page)
            if len(commits_page) == 0:
                break
            for commit in commits_page:
                commit_str = str({"message": commit.commit.message})
                if total_tokens + get_tokens(commit_str) > max_tokens:
                    break
                commits.append(commit_str)
                total_tokens += get_tokens(commit_str)
            page += 1
        add_to_dict(response_dict, "commits", str(commits))
        return response_dict

    def create_pull_request(self, pr_query: str) -> str:
        """
        Makes a pull request from the bot's branch to the base branch
        Parameters:
            pr_query(str): a string which contains the PR title
            and the PR body. The title is the first line
            in the string, and the body are the rest of the string.
            For example, "Updated README\nmade changes to add info"
        Returns:
            str: A success or failure message
        """
        if self.github_base_branch == self.active_branch:
            return """Cannot make a pull request because 
            commits are already in the main or master branch."""
        else:
            try:
                title = pr_query.split("\n")[0]
                body = pr_query[len(title) + 2 :]
                pr = self.github_repo_instance.create_pull(
                    title=title,
                    body=body,
                    head=self.active_branch,
                    base=self.github_base_branch,
                )
                return f"Successfully created PR number {pr.number}"
            except Exception as e:
                return "Unable to make pull request due to error:\n" + str(e)

    def comment_on_issue(self, comment_query: str) -> str:
        """
        Adds a comment to a github issue
        Parameters:
            comment_query(str): a string which contains the issue number,
            two newlines, and the comment.
            for example: "1\n\nWorking on it now"
            adds the comment "working on it now" to issue 1
        Returns:
            str: A success or failure message
        """
        issue_number = int(comment_query.split("\n\n")[0])
        comment = comment_query[len(str(issue_number)) + 2 :]
        try:
            issue = self.github_repo_instance.get_issue(number=issue_number)
            issue.create_comment(comment)
            return "Commented on issue " + str(issue_number)
        except Exception as e:
            return "Unable to make comment due to error:\n" + str(e)

    def create_file(self, file_query: str) -> str:
        """
        Creates a new file on the Github repo
        Parameters:
            file_query(str): a string which contains the file path
            and the file contents. The file path is the first line
            in the string, and the contents are the rest of the string.
            For example, "hello_world.md\n# Hello World!"
        Returns:
            str: A success or failure message
        """
        if self.active_branch == self.github_base_branch:
            return (
                "You're attempting to commit to the directly to the"
                f"{self.github_base_branch} branch, which is protected. "
                "Please create a new branch and try again."
            )

        file_path = file_query.split("\n")[0]
        file_contents = file_query[len(file_path) + 2 :]

        try:
            try:
                file = self.github_repo_instance.get_contents(
                    file_path, ref=self.active_branch
                )
                if file:
                    return (
                        f"File already exists at `{file_path}` "
                        f"on branch `{self.active_branch}`. You must use "
                        "`update_file` to modify it."
                    )
            except Exception:
                # expected behavior, file shouldn't exist yet
                pass

            self.github_repo_instance.create_file(
                path=file_path,
                message="Create " + file_path,
                content=file_contents,
                branch=self.active_branch,
            )
            return "Created file " + file_path
        except Exception as e:
            return "Unable to make file due to error:\n" + str(e)

    def read_file(self, file_path: str) -> str:
        """
        Read a file from this agent's branch, defined by self.active_branch,
        which supports PR branches.
        Parameters:
            file_path(str): the file path
        Returns:
            str: The file decoded as a string, or an error message if not found
        """
        try:
            file = self.github_repo_instance.get_contents(
                file_path, ref=self.active_branch
            )
            return file.decoded_content.decode("utf-8")
        except Exception as e:
            return (
                f"File not found `{file_path}` on branch"
                f"`{self.active_branch}`. Error: {str(e)}"
            )

    def update_file(self, file_query: str) -> str:
        """
        Updates a file with new content.
        Parameters:
            file_query(str): Contains the file path and the file contents.
                The old file contents is wrapped in OLD <<<< and >>>> OLD
                The new file contents is wrapped in NEW <<<< and >>>> NEW
                For example:
                /test/hello.txt
                OLD <<<<
                Hello Earth!
                >>>> OLD
                NEW <<<<
                Hello Mars!
                >>>> NEW
        Returns:
            A success or failure message
        """
        if self.active_branch == self.github_base_branch:
            return (
                "You're attempting to commit to the directly"
                f"to the {self.github_base_branch} branch, which is protected. "
                "Please create a new branch and try again."
            )
        try:
            file_path: str = file_query.split("\n")[0]
            old_file_contents = (
                file_query.split("OLD <<<<")[1].split(">>>> OLD")[0].strip()
            )
            new_file_contents = (
                file_query.split("NEW <<<<")[1].split(">>>> NEW")[0].strip()
            )

            file_content = self.read_file(file_path)
            updated_file_content = file_content.replace(
                old_file_contents, new_file_contents
            )

            if file_content == updated_file_content:
                return (
                    "File content was not updated because old content was not found."
                    "It may be helpful to use the read_file action to get "
                    "the current file contents."
                )

            self.github_repo_instance.update_file(
                path=file_path,
                message="Update " + str(file_path),
                content=updated_file_content,
                branch=self.active_branch,
                sha=self.github_repo_instance.get_contents(
                    file_path, ref=self.active_branch
                ).sha,
            )
            return "Updated file " + str(file_path)
        except Exception as e:
            return "Unable to update file due to error:\n" + str(e)

    def delete_file(self, file_path: str) -> str:
        """
        Deletes a file from the repo
        Parameters:
            file_path(str): Where the file is
        Returns:
            str: Success or failure message
        """
        if self.active_branch == self.github_base_branch:
            return (
                "You're attempting to commit to the directly"
                f"to the {self.github_base_branch} branch, which is protected. "
                "Please create a new branch and try again."
            )
        try:
            self.github_repo_instance.delete_file(
                path=file_path,
                message="Delete " + file_path,
                branch=self.active_branch,
                sha=self.github_repo_instance.get_contents(
                    file_path, ref=self.active_branch
                ).sha,
            )
            return "Deleted file " + file_path
        except Exception as e:
            return "Unable to delete file due to error:\n" + str(e)

    def search_issues_and_prs(self, query: str) -> str:
        """
        Searches issues and pull requests in the repository.

        Parameters:
            query(str): The search query

        Returns:
            str: A string containing the first 5 issues and pull requests
        """
        search_result = self.github.search_issues(query, repo=self.github_repository)
        max_items = min(5, len(search_result))
        results = [f"Top {max_items} results:"]
        for issue in search_result[:max_items]:
            results.append(
                f"Title: {issue.title}, Number: {issue.number}, State: {issue.state}"
            )
        return "\n".join(results)

    def search_code(self, query: str) -> str:
        """
        Searches code in the repository.
        # Todo: limit total tokens returned...

        Parameters:
            query(str): The search query

        Returns:
            str: A string containing, at most, the top 5 search results
        """
        search_result = self.github.search_code(
            query=query, repo=self.github_repository
        )
        if search_result.totalCount == 0:
            return "0 results found."
        max_results = min(5, search_result.totalCount)
        results = [f"Showing top {max_results} of {search_result.totalCount} results:"]
        count = 0
        for code in search_result:
            if count >= max_results:
                break
            # Get the file content using the PyGithub get_contents method
            file_content = self.github_repo_instance.get_contents(
                code.path, ref=self.active_branch
            ).decoded_content.decode()
            results.append(
                f"Filepath: `{code.path}`\nFile contents: "
                f"{file_content}\n<END OF FILE>"
            )
            count += 1
        return "\n".join(results)

    def create_review_request(self, reviewer_username: str) -> str:
        """
        Creates a review request on *THE* open pull request
        that matches the current active_branch.

        Parameters:
            reviewer_username(str): The username of the person who is being requested

        Returns:
            str: A message confirming the creation of the review request
        """
        pull_requests = self.github_repo_instance.get_pulls(
            state="open", sort="created"
        )
        # find PR against active_branch
        pr = next(
            (pr for pr in pull_requests if pr.head.ref == self.active_branch), None
        )
        if pr is None:
            return (
                "No open pull request found for the "
                f"current branch `{self.active_branch}`"
            )

        try:
            pr.create_review_request(reviewers=[reviewer_username])
            return (
                f"Review request created for user {reviewer_username} "
                f"on PR #{pr.number}"
            )
        except Exception as e:
            return f"Failed to create a review request with error {e}"

    def run(self, mode: str, query: str) -> str:
        if mode == "get_issue":
            return json.dumps(self.get_issue(int(query)))
        elif mode == "get_pull_request":
            return json.dumps(self.get_pull_request(int(query)))
        elif mode == "list_pull_request_files":
            return json.dumps(self.list_pull_request_files(int(query)))
        elif mode == "get_issues":
            return self.get_issues()
        elif mode == "comment_on_issue":
            return self.comment_on_issue(query)
        elif mode == "create_file":
            return self.create_file(query)
        elif mode == "create_pull_request":
            return self.create_pull_request(query)
        elif mode == "read_file":
            return self.read_file(query)
        elif mode == "update_file":
            return self.update_file(query)
        elif mode == "delete_file":
            return self.delete_file(query)
        elif mode == "list_open_pull_requests":
            return self.list_open_pull_requests()
        elif mode == "list_files_in_main_branch":
            return self.list_files_in_main_branch()
        elif mode == "list_files_in_bot_branch":
            return self.list_files_in_bot_branch()
        elif mode == "list_branches_in_repo":
            return self.list_branches_in_repo()
        elif mode == "set_active_branch":
            return self.set_active_branch(query)
        elif mode == "create_branch":
            return self.create_branch(query)
        elif mode == "get_files_from_directory":
            return self.get_files_from_directory(query)
        elif mode == "search_issues_and_prs":
            return self.search_issues_and_prs(query)
        elif mode == "search_code":
            return self.search_code(query)
        elif mode == "create_review_request":
            return self.create_review_request(query)
        else:
            raise ValueError("Invalid mode" + mode)
