1 files changed, 324 insertions, 0 deletions
diff --git a/redis/commands/search/querystring.py b/redis/commands/search/querystring.py
new file mode 100644
index 0000000..f5f59b7
--- /dev/null
+++ b/redis/commands/search/querystring.py
@@ -0,0 +1,324 @@
+from six import string_types, integer_types
+
+
+def tags(*t):
+    """
+    Indicate that the values should be matched to a tag field
+
+    ### Parameters
+
+    - **t**: Tags to search for
+    """
+    if not t:
+        raise ValueError("At least one tag must be specified")
+    return TagValue(*t)
+
+
+def between(a, b, inclusive_min=True, inclusive_max=True):
+    """
+    Indicate that value is a numeric range
+    """
+    return RangeValue(a, b, inclusive_min=inclusive_min,
+                      inclusive_max=inclusive_max)
+
+
+def equal(n):
+    """
+    Match a numeric value
+    """
+    return between(n, n)
+
+
+def lt(n):
+    """
+    Match any value less than n
+    """
+    return between(None, n, inclusive_max=False)
+
+
+def le(n):
+    """
+    Match any value less or equal to n
+    """
+    return between(None, n, inclusive_max=True)
+
+
+def gt(n):
+    """
+    Match any value greater than n
+    """
+    return between(n, None, inclusive_min=False)
+
+
+def ge(n):
+    """
+    Match any value greater or equal to n
+    """
+    return between(n, None, inclusive_min=True)
+
+
+def geo(lat, lon, radius, unit="km"):
+    """
+    Indicate that value is a geo region
+    """
+    return GeoValue(lat, lon, radius, unit)
+
+
+class Value(object):
+    @property
+    def combinable(self):
+        """
+        Whether this type of value may be combined with other values
+        for the same field. This makes the filter potentially more efficient
+        """
+        return False
+
+    @staticmethod
+    def make_value(v):
+        """
+        Convert an object to a value, if it is not a value already
+        """
+        if isinstance(v, Value):
+            return v
+        return ScalarValue(v)
+
+    def to_string(self):
+        raise NotImplementedError()
+
+    def __str__(self):
+        return self.to_string()
+
+
+class RangeValue(Value):
+    combinable = False
+
+    def __init__(self, a, b, inclusive_min=False, inclusive_max=False):
+        if a is None:
+            a = "-inf"
+        if b is None:
+            b = "inf"
+        self.range = [str(a), str(b)]
+        self.inclusive_min = inclusive_min
+        self.inclusive_max = inclusive_max
+
+    def to_string(self):
+        return "[{1}{0[0]} {2}{0[1]}]".format(
+            self.range,
+            "(" if not self.inclusive_min else "",
+            "(" if not self.inclusive_max else "",
+        )
+
+
+class ScalarValue(Value):
+    combinable = True
+
+    def __init__(self, v):
+        self.v = str(v)
+
+    def to_string(self):
+        return self.v
+
+
+class TagValue(Value):
+    combinable = False
+
+    def __init__(self, *tags):
+        self.tags = tags
+
+    def to_string(self):
+        return "{" + " | ".join(str(t) for t in self.tags) + "}"
+
+
+class GeoValue(Value):
+    def __init__(self, lon, lat, radius, unit="km"):
+        self.lon = lon
+        self.lat = lat
+        self.radius = radius
+        self.unit = unit
+
+
+class Node(object):
+    def __init__(self, *children, **kwparams):
+        """
+        Create a node
+
+        ### Parameters
+
+        - **children**: One or more sub-conditions. These can be additional
+            `intersect`, `disjunct`, `union`, `optional`, or any other `Node`
+            type.
+
+            The semantics of multiple conditions are dependent on the type of
+            query. For an `intersection` node, this amounts to a logical AND,
+            for a `union` node, this amounts to a logical `OR`.
+
+        - **kwparams**: key-value parameters. Each key is the name of a field,
+            and the value should be a field value. This can be one of the
+            following:
+
+            - Simple string (for text field matches)
+            - value returned by one of the helper functions
+            - list of either a string or a value
+
+
+        ### Examples
+
+        Field `num` should be between 1 and 10
+        ```
+        intersect(num=between(1, 10)
+        ```
+
+        Name can either be `bob` or `john`
+
+        ```
+        union(name=("bob", "john"))
+        ```
+
+        Don't select countries in Israel, Japan, or US
+
+        ```
+        disjunct_union(country=("il", "jp", "us"))
+        ```
+        """
+
+        self.params = []
+
+        kvparams = {}
+        for k, v in kwparams.items():
+            curvals = kvparams.setdefault(k, [])
+            if isinstance(v, (string_types, integer_types, float)):
+                curvals.append(Value.make_value(v))
+            elif isinstance(v, Value):
+                curvals.append(v)
+            else:
+                curvals.extend(Value.make_value(subv) for subv in v)
+
+        self.params += [Node.to_node(p) for p in children]
+
+        for k, v in kvparams.items():
+            self.params.extend(self.join_fields(k, v))
+
+    def join_fields(self, key, vals):
+        if len(vals) == 1:
+            return [BaseNode("@{}:{}".format(key, vals[0].to_string()))]
+        if not vals[0].combinable:
+            return [BaseNode("@{}:{}".format(key,
+                                             v.to_string())) for v in vals]
+        s = BaseNode(
+            "@{}:({})".format(key,
+                              self.JOINSTR.join(v.to_string() for v in vals))
+        )
+        return [s]
+
+    @classmethod
+    def to_node(cls, obj):  # noqa
+        if isinstance(obj, Node):
+            return obj
+        return BaseNode(obj)
+
+    @property
+    def JOINSTR(self):
+        raise NotImplementedError()
+
+    def to_string(self, with_parens=None):
+        with_parens = self._should_use_paren(with_parens)
+        pre, post = ("(", ")") if with_parens else ("", "")
+        return "{}{}{}".format(
+            pre, self.JOINSTR.join(n.to_string() for n in self.params), post
+        )
+
+    def _should_use_paren(self, optval):
+        if optval is not None:
+            return optval
+        return len(self.params) > 1
+
+    def __str__(self):
+        return self.to_string()
+
+
+class BaseNode(Node):
+    def __init__(self, s):
+        super(BaseNode, self).__init__()
+        self.s = str(s)
+
+    def to_string(self, with_parens=None):
+        return self.s
+
+
+class IntersectNode(Node):
+    """
+    Create an intersection node. All children need to be satisfied in order for
+    this node to evaluate as true
+    """
+
+    JOINSTR = " "
+
+
+class UnionNode(Node):
+    """
+    Create a union node. Any of the children need to be satisfied in order for
+    this node to evaluate as true
+    """
+
+    JOINSTR = "|"
+
+
+class DisjunctNode(IntersectNode):
+    """
+    Create a disjunct node. In order for this node to be true, all of its
+    children must evaluate to false
+    """
+
+    def to_string(self, with_parens=None):
+        with_parens = self._should_use_paren(with_parens)
+        ret = super(DisjunctNode, self).to_string(with_parens=False)
+        if with_parens:
+            return "(-" + ret + ")"
+        else:
+            return "-" + ret
+
+
+class DistjunctUnion(DisjunctNode):
+    """
+    This node is true if *all* of its children are false. This is equivalent to
+    ```
+    disjunct(union(...))
+    ```
+    """
+
+    JOINSTR = "|"
+
+
+class OptionalNode(IntersectNode):
+    """
+    Create an optional node. If this nodes evaluates to true, then the document
+    will be rated higher in score/rank.
+    """
+
+    def to_string(self, with_parens=None):
+        with_parens = self._should_use_paren(with_parens)
+        ret = super(OptionalNode, self).to_string(with_parens=False)
+        if with_parens:
+            return "(~" + ret + ")"
+        else:
+            return "~" + ret
+
+
+def intersect(*args, **kwargs):
+    return IntersectNode(*args, **kwargs)
+
+
+def union(*args, **kwargs):
+    return UnionNode(*args, **kwargs)
+
+
+def disjunct(*args, **kwargs):
+    return DisjunctNode(*args, **kwargs)
+
+
+def disjunct_union(*args, **kwargs):
+    return DistjunctUnion(*args, **kwargs)
+
+
+def querystring(*args, **kwargs):
+    return intersect(*args, **kwargs).to_string()