Source code for orsopy.slddb.comparators

"""
Classes to represent comparisons in SQLite queries.
"""

from abc import ABC, abstractmethod

from .material import Formula




class Comparator(ABC):
    def __init__(self, value, key=None):
        self.key = key
        self.value = value



    @abstractmethod
    def query_string(self):
        """
        Return the SQL query string used when searching.
        Should contain one question mark for each argument that is used.
        """




    @abstractmethod
    def query_args(self):
        """
        Return the arguments used for the query. The number of arguments should
        be equal to the number of question marks returned by query_string.
        """






class GenericComparator(Comparator):
    """
    Comparator used for the generic case. Makes a simple comparison
    based on the type of the argument.
    """



    def query_string(self):
        if type(self.value) in (list, tuple):
            if len(self.value) == 0:
                return ""
            qstr = "("
            qstr += " AND ".join([f"{self.key} LIKE ?" for _ in self.value])
            qstr += ")"
            return qstr
        elif type(self.value) is str:
            return f"{self.key} LIKE ?"
        else:
            return f"{self.key} == ?"




    def query_args(self):
        if type(self.value) in (list, tuple):
            return [f"%%'{vi}'%%" for vi in self.value]
        elif type(self.value) is str:
            return [f"%%{self.value}%%"]
        else:
            return [self.value]






class ExactString(Comparator):
    """
    Perform an exact string comparison.
    """



    def query_string(self):
        return f"{self.key} == ?"




    def query_args(self):
        return [self.value]






class FormulaComparator(Comparator):
    """
    Compare to formula string.
    """



    def query_string(self):
        if type(self.value) is str and self.value.startswith("~"):
            return f"{self.key} LIKE ?"
        else:
            return f"{self.key} == ?"




    def query_args(self):
        if type(self.value) is str and self.value.startswith("~"):
            formula = Formula(self.value[1:])
            return [f"%%{formula}%%"]
        else:
            formula = Formula(self.value)
            return [str(formula)]






class FuzzyFloat(Comparator):
    """
    Compare a float value against a range or +/-10% of given value.
    """



    def query_string(self):
        try:
            float(self.value)
        except ValueError:
            return f"({self.key} >= ? and {self.key} <= ?)"
        else:
            return f"{self.key} == ?"




    def query_args(self):
        svalue = str(self.value)
        if svalue.startswith("~"):
            value = float(svalue[1:])
            return [value * 0.9, value * 1.1]
        elif len(svalue.split("-")) == 2:
            return list(map(float, svalue.split("-")))
        else:
            return [float(self.value)]