# tools/log_tool.py
from .base_tool import BaseTool
import logging
import os
from datetime import datetime, timedelta

class LogTool(BaseTool):
    # Default log format string that _get_log_contents expects for time-based filtering.
    # Making it a class variable so it's visible and could be overridden by a subclass if needed,
    # though the parser is still hardcoded in this version.
    EXPECTED_LOG_TIMESTAMP_FORMAT = '%Y-%m-%d %H:%M:%S,%f'

    def __init__(self, log_file_path=None, logger=None):
        self.configured_log_file_path = log_file_path if log_file_path else 'logs/output.log'
        self.logger = logger if logger else logging.getLogger(__name__)
        if not self.logger.handlers:
            self.logger.addHandler(logging.NullHandler())
        self.logger.info(f"LogTool initialized. Log file path: {self.configured_log_file_path}")

    def clear(self):
        # No specific state to clear for LogTool in this version.
        self.logger.debug("LogTool clear called, no action taken.")
        pass

    def get_functions(self):
        return [
            {
                "type": "function",
                "function": {
                    "name": "get_log_contents",
                    "description": "Get the contents of the log file. If line_count is not provided, it attempts to return logs from the last 24 hours based on timestamp.",
                    "parameters": {
                        "type": "object",
                        "properties": {
                            "line_count": {
                                "type": "integer",
                                "description": "Number of lines from the end of the log file to retrieve. If omitted, logs from last 24 hours are returned."
                            }
                        },
                        "required": [] # line_count is optional
                    }
                }
            }
        ]

    def execute(self, function_name, **kwargs):
        self.logger.info(f"Executing LogTool function: {function_name} with args: {kwargs}")
        if function_name == "get_log_contents":
            # kwargs.get("line_count") will be None if not provided, which is handled by _get_log_contents
            return self._get_log_contents(line_count=kwargs.get("line_count"))
        else:
            error_message = f"Unknown function: {function_name}"
            self.logger.error(error_message)
            return error_message

    def _get_log_contents(self, line_count=None): # Default line_count is None to trigger 24h logic if not specified
        self.logger.info(f"Attempting to get log contents from: {self.configured_log_file_path}. Line count: {line_count if line_count is not None else 'Last 24 hours'}")
        
        if not os.path.exists(self.configured_log_file_path):
            error_message = f"Log file does not exist at path: {self.configured_log_file_path}"
            self.logger.error(error_message)
            return error_message

        try:
            with open(self.configured_log_file_path, 'r', encoding='utf-8') as log_file:
                log_lines = log_file.readlines()
            self.logger.debug(f"Read {len(log_lines)} total lines from log file.")

            if line_count is not None:
                # Ensure line_count is positive if specified, otherwise could lead to unexpected slicing
                if not isinstance(line_count, int) or line_count <= 0:
                    self.logger.warning(f"Invalid line_count '{line_count}' provided, defaulting to fetch last 150 lines.")
                    line_count = 150 # Default to a sensible number if invalid value provided
                log_lines = log_lines[-line_count:]
                self.logger.info(f"Returning last {len(log_lines)} lines based on line_count: {line_count}")
            else:
                # Default to last 24 hours if line_count is explicitly None or not provided
                self.logger.info(f"Filtering logs for the last 24 hours. Expected timestamp format: {self.EXPECTED_LOG_TIMESTAMP_FORMAT}")
                now = datetime.now()
                twenty_four_hours_ago = now - timedelta(days=1)
                
                filtered_lines = []
                for line in log_lines:
                    try:
                        # Attempt to parse timestamp from the beginning of the line
                        timestamp_str = line.split(' - ', 1)[0]
                        log_time = datetime.strptime(timestamp_str, self.EXPECTED_LOG_TIMESTAMP_FORMAT)
                        if log_time > twenty_four_hours_ago:
                            filtered_lines.append(line)
                    except (ValueError, IndexError) as e:
                        # This means the line doesn't start with a parsable timestamp in the expected format.
                        # Depending on requirements, these lines might be skipped or included.
                        # For strict 24-hour filtering, we skip them.
                        self.logger.debug(f"Skipping line due to timestamp parse error ('{e}') or format mismatch: {line.strip()[:100]}...")
                log_lines = filtered_lines
                self.logger.info(f"Returning {len(log_lines)} lines from the last 24 hours.")

            return "".join(log_lines)
        except Exception as e:
            error_message = f"An error occurred while reading the log file '{self.configured_log_file_path}': {e}"
            self.logger.error(error_message, exc_info=True)
            return error_message