# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: MIT-0

import re
import datetime
import util.faker_config as config
from util.fake_tokens import FakeTokens


class LinePattern:
    """Parse a pattern to generate a line inside the logs."""

    patterns = config.patterns

    def __init__(self, pattern=None, date_pattern=None, file_format="elf", fake_tokens=None):
        self.pattern = self.get_default_format(pattern, file_format)
        self.date_pattern = "%d/%b/%Y:%H:%M:%S" if date_pattern is None else date_pattern
        self._sleep = None
        self.fake_tokens = FakeTokens(date=(datetime.datetime.now() - datetime.timedelta(hours=0)
                                            + datetime.timedelta(minutes=config.preview_time)))\
            if fake_tokens is None else fake_tokens
        self.dispatcher = self.fake_tokens.get_tokens(self.date_pattern)
        self.tokens = []

        tokens_regex = re.compile("%([0-9a-zA-Z\-]{1,})")
        self.line = tokens_regex.sub(self.match_token, self.pattern)

    def get_default_format(self, pattern=None, file_format="elf"):
        """Return a correct pattern (custom or relative a standard file format)."""
        if pattern is not None:
            return pattern

        if any(file_format in s for s in ["apache", "elf", "lighttpd", "ncsa", "nginx"]):
            file_format = "elf"
        elif any(file_format in s for s in ["clf"]):
            file_format = "clf"

        return self.patterns[file_format]

    @property
    def sleep(self):
        """Getter to retrieve 'sleep' attribute."""
        return self._sleep

    @sleep.setter
    def sleep(self, sleep):
        """Setter to update fake_tokens configuration."""
        self._sleep = sleep
        self.fake_tokens.sleep = sleep

    def match_token(self, match):
        """Register token."""
        key = match.group(1)

        if key not in self.dispatcher:
            raise KeyError("Unsupported key '%{}'".format(key))

        self.tokens.append(self.dispatcher[key])
        return "{}"

    def __iter__(self):
        return iter(self.tokens)

    def create_line(self):
        """Format a line according to the pattern."""
        values = []
        for get_token in self:
            values.append(get_token())

        return self.line.format(*values)