"""This module defines specific functions for MariaDB dialect."""

from sqlalchemy.ext.compiler import compiles

from geoalchemy2 import functions
from geoalchemy2.admin.dialects.common import compile_bin_literal
from geoalchemy2.admin.dialects.mysql import after_create  # noqa
from geoalchemy2.admin.dialects.mysql import after_drop  # noqa
from geoalchemy2.admin.dialects.mysql import before_create  # noqa
from geoalchemy2.admin.dialects.mysql import before_drop  # noqa
from geoalchemy2.admin.dialects.mysql import reflect_geometry_column  # noqa
from geoalchemy2.elements import WKBElement
from geoalchemy2.elements import WKTElement


def _cast(param):
    if isinstance(param, memoryview):
        param = param.tobytes()
    if isinstance(param, bytes):
        param = WKBElement(param)
    if isinstance(param, WKBElement):
        param = param.as_wkb().desc
    return param


def before_cursor_execute(
    conn, cursor, statement, parameters, context, executemany, convert=True
):  # noqa: D417
    """Event handler to cast the parameters properly.

    Args:
        convert (bool): Trigger the conversion.
    """
    if convert:
        if isinstance(parameters, (tuple, list)):
            parameters = tuple(_cast(x) for x in parameters)
        elif isinstance(parameters, dict):
            for k in parameters:
                parameters[k] = _cast(parameters[k])

    return statement, parameters


_MARIADB_FUNCTIONS = {
    "ST_AsEWKB": "ST_AsBinary",
}


def _compiles_mariadb(cls, fn):
    def _compile_mariadb(element, compiler, **kw):
        return "{}({})".format(fn, compiler.process(element.clauses, **kw))

    compiles(getattr(functions, cls), "mariadb")(_compile_mariadb)


def register_mariadb_mapping(mapping):
    """Register compilation mappings for the given functions.

    Args:
        mapping: Should have the following form::

                {
                    "function_name_1": "mariadb_function_name_1",
                    "function_name_2": "mariadb_function_name_2",
                    ...
                }
    """
    for cls, fn in mapping.items():
        _compiles_mariadb(cls, fn)


register_mariadb_mapping(_MARIADB_FUNCTIONS)


def _compile_GeomFromText_MariaDB(element, compiler, **kw):
    identifier = "ST_GeomFromText"
    compiled = compiler.process(element.clauses, **kw)
    try:
        clauses = list(element.clauses)
        data_element = WKTElement(clauses[0].value)
        srid = data_element.srid
        if srid <= 0:
            srid = element.type.srid
    except Exception:
        srid = element.type.srid

    if srid > 0:
        res = "{}({}, {})".format(identifier, compiled, srid)
    else:
        res = "{}({})".format(identifier, compiled)
    return res


def _compile_GeomFromWKB_MariaDB(element, compiler, **kw):
    identifier = "ST_GeomFromWKB"
    # Store the SRID
    clauses = list(element.clauses)
    try:
        srid = clauses[1].value
    except (IndexError, TypeError, ValueError):
        srid = element.type.srid

    if kw.get("literal_binds", False):
        wkb_clause = compile_bin_literal(clauses[0])
    else:
        wkb_clause = clauses[0]
    prefix = "unhex("
    suffix = ")"

    compiled = compiler.process(wkb_clause, **kw)

    if srid > 0:
        return "{}({}{}{}, {})".format(identifier, prefix, compiled, suffix, srid)
    else:
        return "{}({}{}{})".format(identifier, prefix, compiled, suffix)


@compiles(functions.ST_GeomFromText, "mariadb")  # type: ignore
def _MariaDB_ST_GeomFromText(element, compiler, **kw):
    return _compile_GeomFromText_MariaDB(element, compiler, **kw)


@compiles(functions.ST_GeomFromEWKT, "mariadb")  # type: ignore
def _MariaDB_ST_GeomFromEWKT(element, compiler, **kw):
    return _compile_GeomFromText_MariaDB(element, compiler, **kw)


@compiles(functions.ST_GeomFromWKB, "mariadb")  # type: ignore
def _MariaDB_ST_GeomFromWKB(element, compiler, **kw):
    return _compile_GeomFromWKB_MariaDB(element, compiler, **kw)


@compiles(functions.ST_GeomFromEWKB, "mariadb")  # type: ignore
def _MariaDB_ST_GeomFromEWKB(element, compiler, **kw):
    return _compile_GeomFromWKB_MariaDB(element, compiler, **kw)