rebulk.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Entry point functions and classes for Rebulk
"""
from logging import getLogger

from .builder import Builder
from .match import Matches
from .processors import ConflictSolver, PrivateRemover
from .rules import Rules
from .utils import extend_safe

log = getLogger(__name__).log


class Rebulk(Builder):
    r"""
    Regular expression, string and function based patterns are declared in a ``Rebulk`` object. It use a fluent API to
    chain ``string``, ``regex``, and ``functional`` methods to define various patterns types.

    .. code-block:: python

        >>> from rebulk import Rebulk
        >>> bulk = Rebulk().string('brown').regex(r'qu\w+').functional(lambda s: (20, 25))

    When ``Rebulk`` object is fully configured, you can call ``matches`` method with an input string to retrieve all
    ``Match`` objects found by registered pattern.

    .. code-block:: python

        >>> bulk.matches("The quick brown fox jumps over the lazy dog")
        [<brown:(10, 15)>, <quick:(4, 9)>, <jumps:(20, 25)>]

    If multiple ``Match`` objects are found at the same position, only the longer one is kept.

    .. code-block:: python

        >>> bulk = Rebulk().string('lakers').string('la')
        >>> bulk.matches("the lakers are from la")
        [<lakers:(4, 10)>, <la:(20, 22)>]
    """

    # pylint:disable=protected-access

    def __init__(self, disabled=lambda context: False, default_rules=True):
        """
        Creates a new Rebulk object.
        :param disabled: if True, this pattern is disabled. Can also be a function(context).
        :type disabled: bool|function
        :param default_rules: use default rules
        :type default_rules:
        :return:
        :rtype:
        """
        super().__init__()
        if not callable(disabled):
            self.disabled = lambda context: disabled
        else:
            self.disabled = disabled
        self._patterns = []
        self._rules = Rules()
        if default_rules:
            self.rules(ConflictSolver, PrivateRemover)
        self._rebulks = []

    def pattern(self, *pattern):
        """
        Add patterns objects

        :param pattern:
        :type pattern: rebulk.pattern.Pattern
        :return: self
        :rtype: Rebulk
        """
        self._patterns.extend(pattern)
        return self

    def rules(self, *rules):
        """
        Add rules as a module, class or instance.
        :param rules:
        :type rules: list[Rule]
        :return:
        """
        self._rules.load(*rules)
        return self

    def rebulk(self, *rebulks):
        """
        Add a children rebulk object
        :param rebulks:
        :type rebulks: Rebulk
        :return:
        """
        self._rebulks.extend(rebulks)
        return self

    def matches(self, string, context=None):
        """
        Search for all matches with current configuration against input_string
        :param string: string to search into
        :type string: str
        :param context: context to use
        :type context: dict
        :return: A custom list of matches
        :rtype: Matches
        """
        matches = Matches(input_string=string)
        if context is None:
            context = {}

        self._matches_patterns(matches, context)

        self._execute_rules(matches, context)

        return matches

    def effective_rules(self, context=None):
        """
        Get effective rules for this rebulk object and its children.
        :param context:
        :type context:
        :return:
        :rtype:
        """
        rules = Rules()
        rules.extend(self._rules)
        for rebulk in self._rebulks:
            if not rebulk.disabled(context):
                extend_safe(rules, rebulk._rules)
        return rules

    def _execute_rules(self, matches, context):
        """
        Execute rules for this rebulk and children.
        :param matches:
        :type matches:
        :param context:
        :type context:
        :return:
        :rtype:
        """
        if not self.disabled(context):
            rules = self.effective_rules(context)
            rules.execute_all_rules(matches, context)

    def effective_patterns(self, context=None):
        """
        Get effective patterns for this rebulk object and its children.
        :param context:
        :type context:
        :return:
        :rtype:
        """
        patterns = list(self._patterns)
        for rebulk in self._rebulks:
            if not rebulk.disabled(context):
                extend_safe(patterns, rebulk._patterns)
        return patterns

    def _matches_patterns(self, matches, context):
        """
        Search for all matches with current paterns agains input_string
        :param matches: matches list
        :type matches: Matches
        :param context: context to use
        :type context: dict
        :return:
        :rtype:
        """
        if not self.disabled(context):
            patterns = self.effective_patterns(context)
            for pattern in patterns:
                if not pattern.disabled(context):
                    pattern_matches = pattern.matches(matches.input_string, context)
                    if pattern_matches:
                        log(pattern.log_level, "Pattern has %s match(es). (%s)", len(pattern_matches), pattern)
                    else:
                        pass
                        # log(pattern.log_level, "Pattern doesn't match. (%s)" % (pattern,))
                    for match in pattern_matches:
                        if match.marker:
                            log(pattern.log_level, "Marker found. (%s)", match)
                            matches.markers.append(match)
                        else:
                            log(pattern.log_level, "Match found. (%s)", match)
                            matches.append(match)
                else:
                    log(pattern.log_level, "Pattern is disabled. (%s)", pattern)