cyclop/tools/repo_index_tool.py

from .base_tool import BaseTool
import os
import requests
import base64
import logging
import fnmatch
from typing import List, Dict, Any, Optional

class RepoIndexTool(BaseTool):
    """
    Lightweight repository index and discovery helper using the GitHub Contents API.

    Functions provided:
      - get_repo_tree(path="", ref="main", max_depth=3, include_files=True, include_dirs=True)
      - find_files(pattern, path="", ref="main", max_results=50)
      - get_file_head(path, ref="main", max_bytes=4096)
    """

    def __init__(self, session: Optional[requests.Session] = None, token: Optional[str] = None,
                 repo: Optional[str] = None, base_url: Optional[str] = None, logger: Optional[logging.Logger] = None):
        self.base_url = base_url if base_url else "https://api.github.com"
        self._token = token if token else os.environ.get("GITHUB_TOKEN")
        self._repo = repo if repo else os.environ.get("GITHUB_REPOSITORY")

        if not self._token:
            raise ValueError("GitHub token must be provided either as an argument or via GITHUB_TOKEN env var.")
        if not self._repo:
            raise ValueError("GitHub repository (e.g., 'owner/repo') must be provided either as an argument or via GITHUB_REPOSITORY env var.")

        if session:
            self.session = session
        else:
            self.session = requests.Session()
            self.session.headers.update({
                "Authorization": f"token {self._token}",
                "Accept": "application/vnd.github.v3+json"
            })

        self.logger = logger if logger else logging.getLogger(__name__)
        if not self.logger.handlers:
            self.logger.addHandler(logging.NullHandler())

    def clear(self):
        # No state to clear for this tool currently
        self.logger.debug("RepoIndexTool.clear called; no state to reset.")

    def get_functions(self):
        return [
            {
                "type": "function",
                "function": {
                    "name": "get_repo_tree",
                    "description": "List repository paths under a directory with depth control via the Contents API.",
                    "parameters": {
                        "type": "object",
                        "properties": {
                            "path": {"type": "string", "description": "Path to start from (directory or file). Use '' or '.' for repo root.", "default": ""},
                            "ref": {"type": "string", "description": "Branch, tag, or commit SHA to query.", "default": "main"},
                            "max_depth": {"type": "integer", "description": "Maximum directory depth to recurse (0 = only the provided path).", "default": 3},
                            "include_files": {"type": "boolean", "description": "Include file entries in results.", "default": True},
                            "include_dirs": {"type": "boolean", "description": "Include directory entries in results.", "default": True}
                        },
                        "required": []
                    }
                },
                "_tags": ["read"]
            },
            {
                "type": "function",
                "function": {
                    "name": "find_files",
                    "description": "Find files matching a glob pattern starting under a path.",
                    "parameters": {
                        "type": "object",
                        "properties": {
                            "pattern": {"type": "string", "description": "Glob pattern (e.g., **/*.py, *.md) applied to full repository path."},
                            "path": {"type": "string", "description": "Directory to start search from.", "default": ""},
                            "ref": {"type": "string", "description": "Branch, tag, or commit SHA to query.", "default": "main"},
                            "max_results": {"type": "integer", "description": "Maximum number of results to return.", "default": 50}
                        },
                        "required": ["pattern"]
                    }
                },
                "_tags": ["read"]
            },
            {
                "type": "function",
                "function": {
                    "name": "get_file_head",
                    "description": "Return the first N bytes of a file (decoded as text) for a quick preview.",
                    "parameters": {
                        "type": "object",
                        "properties": {
                            "path": {"type": "string", "description": "Path to the file in the repository."},
                            "ref": {"type": "string", "description": "Branch, tag, or commit SHA to query.", "default": "main"},
                            "max_bytes": {"type": "integer", "description": "Maximum number of bytes from the beginning of the file to return.", "default": 4096}
                        },
                        "required": ["path"]
                    }
                },
                "_tags": ["read"]
            }
        ]

    def execute(self, function_name, **kwargs):
        self.logger.info(f"Executing RepoIndexTool function: {function_name} with args: {kwargs}")
        method_name = f"_{function_name}"
        if hasattr(self, method_name) and callable(getattr(self, method_name)):
            try:
                return getattr(self, method_name)(**kwargs)
            except Exception as e:
                self.logger.error(f"Error executing {function_name}: {e}", exc_info=True)
                return f"Error during {function_name} execution: {str(e)}"
        else:
            msg = f"Unknown function: {function_name}"
            self.logger.error(msg)
            return msg

    # Private implementations

    def _get_repo_tree(self, path: str = "", ref: str = "main", max_depth: int = 3,
                        include_files: bool = True, include_dirs: bool = True):
        start_path = path.strip("/")
        if start_path in (".",):
            start_path = ""
        self.logger.info(f"Building repo tree from path='{start_path or '/'}', ref='{ref}', max_depth={max_depth}")
        results: List[Dict[str, Any]] = []
        try:
            self._collect_entries(start_path, ref, depth=max_depth, include_files=include_files, include_dirs=include_dirs, out=results)
            # Sort results for stability: directories first, then files, lexicographically by path
            results.sort(key=lambda e: (0 if e.get('type') == 'dir' else 1, e.get('path', '')))
            return results
        except requests.HTTPError as e:
            return f"HTTP error while listing '{start_path or '/'}' at '{ref}': {e.response.status_code} - {e.response.text if e.response is not None else e}"
        except Exception as e:
            return f"Error while building repo tree from '{start_path or '/'}' at '{ref}': {str(e)}"

    def _collect_entries(self, path: str, ref: str, depth: int, include_files: bool, include_dirs: bool, out: List[Dict[str, Any]]):
        # Stop condition: when depth < 0, we do nothing; when depth == 0, we only include the node itself (if file/dir allowed)
        url = f"{self.base_url}/repos/{self._repo}/contents/{path}" if path else f"{self.base_url}/repos/{self._repo}/contents"
        params = {"ref": ref}
        self.logger.debug(f"Listing '{path or '/'}' with depth={depth}")
        resp = self.session.get(url, params=params)
        if resp.status_code == 404:
            self.logger.warning(f"Path not found: '{path or '/'}' at ref '{ref}'")
            return
        resp.raise_for_status()
        data = resp.json()

        if isinstance(data, dict) and data.get('type') == 'file':
            if include_files:
                out.append(self._entry_from_item(data))
            return

        # If it's a directory (list of items)
        if not isinstance(data, list):
            # Unexpected payload
            self.logger.debug(f"Unexpected payload for path '{path}': {type(data)}")
            return

        # Add the directory itself if requested
        if include_dirs:
            out.append({
                "name": os.path.basename(path) if path else "/",
                "path": data[0]["path"].rsplit('/', 1)[0] if data else path,  # derive path; if empty dir, fallback to path
                "type": "dir"
            })

        if depth <= 0:
            return

        for item in data:
            item_type = item.get('type')
            if item_type == 'file':
                if include_files:
                    out.append(self._entry_from_item(item))
            elif item_type == 'dir':
                if depth > 0:
                    # Recurse into subdir
                    self._collect_entries(item.get('path', ''), ref, depth=depth - 1,
                                          include_files=include_files, include_dirs=include_dirs, out=out)
            else:
                # symlink, submodule, etc. We include a minimal record.
                out.append({"name": item.get('name'), "path": item.get('path'), "type": item_type or 'unknown'})

    def _entry_from_item(self, item: Dict[str, Any]) -> Dict[str, Any]:
        return {
            "name": item.get('name'),
            "path": item.get('path'),
            "type": item.get('type'),
            "size": item.get('size'),
            "sha": item.get('sha')
        }

    def _find_files(self, pattern: str, path: str = "", ref: str = "main", max_results: int = 50):
        # Build a limited-depth tree; for search, default to a moderate depth to avoid huge traversals.
        # Here we use a depth of 10 to allow most repos; adjust if needed via path segmentation.
        self.logger.info(f"Finding files matching pattern='{pattern}' under '{path or '/'}' at ref '{ref}' (max_results={max_results})")
        tree = self._get_repo_tree(path=path, ref=ref, max_depth=10, include_files=True, include_dirs=False)
        if isinstance(tree, str):
            return tree  # error string
        matches = []
        for entry in tree:
            p = entry.get('path', '')
            if entry.get('type') == 'file' and fnmatch.fnmatch(p, pattern):
                matches.append(entry)
                if len(matches) >= max_results:
                    break
        return matches

    def _get_file_head(self, path: str, ref: str = "main", max_bytes: int = 4096):
        self.logger.info(f"Fetching head of file '{path}' at ref '{ref}', up to {max_bytes} bytes")
        url = f"{self.base_url}/repos/{self._repo}/contents/{path}"
        resp = self.session.get(url, params={"ref": ref})
        if resp.status_code == 404:
            return f"Error: File '{path}' not found at ref '{ref}'."
        if resp.status_code != 200:
            return f"Error reading file '{path}' at ref '{ref}': {resp.status_code} - {resp.text}"
        data = resp.json()
        if data.get('type') != 'file':
            return f"Error: Path '{path}' is not a file."
        try:
            content_b64 = data.get('content', '')
            decoded = base64.b64decode(content_b64).decode('utf-8', errors='replace')
            return decoded[:max_bytes]
        except Exception as e:
            return f"Error decoding content for '{path}': {str(e)}"