"""
Package for SQL functions wrappers
"""

from __future__ import annotations

from pypika import Field
from pypika.enums import SqlTypes
from pypika.terms import AggregateFunction, Function, LiteralValue, Star
from pypika.utils import builder

__author__ = "Timothy Heys"
__email__ = "theys@kayak.com"


class DistinctOptionFunction(AggregateFunction):
    def __init__(self, name, *args, **kwargs):
        alias = kwargs.get("alias")
        super().__init__(name, *args, alias=alias)
        self._distinct = False

    def get_function_sql(self, **kwargs):
        s = super().get_function_sql(**kwargs)

        n = len(self.name) + 1
        if self._distinct:
            return s[:n] + "DISTINCT " + s[n:]
        return s

    @builder
    def distinct(self):
        self._distinct = True


class Count(DistinctOptionFunction):
    def __init__(self, param: str | Field, alias: str | None = None) -> None:
        is_star = isinstance(param, str) and "*" == param
        super().__init__("COUNT", Star() if is_star else param, alias=alias)


# Arithmetic Functions
class Sum(DistinctOptionFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("SUM", term, alias=alias)


class Avg(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("AVG", term, alias=alias)


class Min(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("MIN", term, alias=alias)


class Max(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("MAX", term, alias=alias)


class Std(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("STD", term, alias=alias)


class StdDev(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("STDDEV", term, alias=alias)


class Abs(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("ABS", term, alias=alias)


class First(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("FIRST", term, alias=alias)


class Last(AggregateFunction):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("LAST", term, alias=alias)


class Sqrt(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("SQRT", term, alias=alias)


class Floor(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("FLOOR", term, alias=alias)


class ApproximatePercentile(AggregateFunction):
    def __init__(self, term, percentile, alias=None):
        super().__init__("APPROXIMATE_PERCENTILE", term, alias=alias)
        self.percentile = float(percentile)

    def get_special_params_sql(self, **kwargs):
        return "USING PARAMETERS percentile={percentile}".format(percentile=self.percentile)


# Type Functions
class Cast(Function):
    def __init__(self, term, as_type, alias=None):
        super().__init__("CAST", term, alias=alias)
        self.as_type = as_type

    def get_special_params_sql(self, **kwargs):
        type_sql = self.as_type.get_sql(**kwargs) if hasattr(self.as_type, "get_sql") else str(self.as_type).upper()
        return "AS {type}".format(type=type_sql)


class Convert(Function):
    def __init__(self, term, encoding, alias=None):
        super().__init__("CONVERT", term, alias=alias)
        self.encoding = encoding

    def get_special_params_sql(self, **kwargs):
        return "USING {type}".format(type=self.encoding.value)


class ToChar(Function):
    def __init__(self, term, as_type, alias=None):
        super().__init__("TO_CHAR", term, as_type, alias=alias)


class Signed(Cast):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__(term, SqlTypes.SIGNED, alias=alias)


class Unsigned(Cast):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__(term, SqlTypes.UNSIGNED, alias=alias)


class Date(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("DATE", term, alias=alias)


class DateDiff(Function):
    def __init__(self, interval, start_date, end_date, alias=None):
        super().__init__("DATEDIFF", interval, start_date, end_date, alias=alias)


class TimeDiff(Function):
    def __init__(self, start_time, end_time, alias=None):
        super().__init__("TIMEDIFF", start_time, end_time, alias=alias)


class DateAdd(Function):
    def __init__(self, date_part, interval, term: str, alias: str | None = None):
        date_part = getattr(date_part, "value", date_part)
        super().__init__("DATE_ADD", LiteralValue(date_part), interval, term, alias=alias)


class ToDate(Function):
    def __init__(self, value, format_mask, alias=None):
        super().__init__("TO_DATE", value, format_mask, alias=alias)


class Timestamp(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("TIMESTAMP", term, alias=alias)


class TimestampAdd(Function):
    def __init__(self, date_part, interval, term: str, alias: str | None = None):
        date_part = getattr(date_part, 'value', date_part)
        super().__init__("TIMESTAMPADD", LiteralValue(date_part), interval, term, alias=alias)


# String Functions
class Ascii(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("ASCII", term, alias=alias)


class NullIf(Function):
    def __init__(self, term, condition, **kwargs):
        super().__init__("NULLIF", term, condition, **kwargs)


class Bin(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("BIN", term, alias=alias)


class Concat(Function):
    def __init__(self, *terms, **kwargs):
        super().__init__("CONCAT", *terms, **kwargs)


class Insert(Function):
    def __init__(self, term, start, stop, subterm, alias=None):
        term, start, stop, subterm = [term for term in [term, start, stop, subterm]]
        super().__init__("INSERT", term, start, stop, subterm, alias=alias)


class Length(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("LENGTH", term, alias=alias)


class Upper(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("UPPER", term, alias=alias)


class Lower(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("LOWER", term, alias=alias)


class Substring(Function):
    def __init__(self, term, start, stop, alias=None):
        super().__init__("SUBSTRING", term, start, stop, alias=alias)


class Reverse(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("REVERSE", term, alias=alias)


class Trim(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("TRIM", term, alias=alias)


class SplitPart(Function):
    def __init__(self, term, delimiter, index, alias=None):
        super().__init__("SPLIT_PART", term, delimiter, index, alias=alias)


class RegexpMatches(Function):
    def __init__(self, term, pattern, modifiers=None, alias=None):
        super().__init__("REGEXP_MATCHES", term, pattern, modifiers, alias=alias)


class RegexpLike(Function):
    def __init__(self, term, pattern, modifiers=None, alias=None):
        super().__init__("REGEXP_LIKE", term, pattern, modifiers, alias=alias)


class Replace(Function):
    def __init__(self, term, find_string, replace_with, alias=None):
        super().__init__("REPLACE", term, find_string, replace_with, alias=alias)


# Date/Time Functions
class Now(Function):
    def __init__(self, alias=None):
        super().__init__("NOW", alias=alias)


class UtcTimestamp(Function):
    def __init__(self, alias=None):
        super().__init__("UTC_TIMESTAMP", alias=alias)


class CurTimestamp(Function):
    def __init__(self, alias=None):
        super().__init__("CURRENT_TIMESTAMP", alias=alias)

    def get_function_sql(self, **kwargs):
        # CURRENT_TIMESTAMP takes no arguments, so the SQL to generate is quite
        # simple.  Note that empty parentheses have been omitted intentionally.
        return "CURRENT_TIMESTAMP"


class CurDate(Function):
    def __init__(self, alias=None):
        super().__init__("CURRENT_DATE", alias=alias)


class CurTime(Function):
    def __init__(self, alias=None):
        super().__init__("CURRENT_TIME", alias=alias)


class Extract(Function):
    def __init__(self, date_part, field, alias=None):
        date_part = getattr(date_part, "value", date_part)
        super().__init__("EXTRACT", LiteralValue(date_part), alias=alias)
        self.field = field

    def get_special_params_sql(self, **kwargs):
        return "FROM {field}".format(field=self.field.get_sql(**kwargs))


# Null Functions
class IsNull(Function):
    def __init__(self, term: str | Field, alias: str | None = None):
        super().__init__("ISNULL", term, alias=alias)


class Coalesce(Function):
    def __init__(self, term, *default_values, **kwargs):
        super().__init__("COALESCE", term, *default_values, **kwargs)


class IfNull(Function):
    def __init__(self, condition, term, **kwargs):
        super().__init__("IFNULL", condition, term, **kwargs)


class NVL(Function):
    def __init__(self, condition, term: str, alias: str | None = None):
        super().__init__("NVL", condition, term, alias=alias)