# vim: ts=4:et:sw=4:

# ----------------------------------------------------------------------
# Copyleft (K), Jose M. Rodriguez-Rosa (a.k.a. Boriel)
#
# This program is Free Software and is released under the terms of
#                    the GNU General License
# ----------------------------------------------------------------------

import sys
from collections.abc import Callable
from functools import wraps

from src.api import config, global_
from src.api.constants import CLASS

# Exports only these functions. Others
__all__ = (
    "error",
    "is_valid_warning_code",
    "register_warning",
    "warning",
    "warning_not_used",
)


WARNING_PREFIX: str = ""  # will be prepended to warning messages
ERROR_PREFIX: str = ""  # will be prepended to error messages


def msg_output(msg: str) -> None:
    if msg in global_.error_msg_cache:
        return

    config.OPTIONS.stderr.write("%s\n" % msg)
    global_.error_msg_cache.add(msg)


def info(msg: str) -> None:
    if config.OPTIONS.debug_level < 1:
        return
    config.OPTIONS.stderr.write("info: %s\n" % msg)


def error(lineno: int, msg: str, fname: str | None = None) -> None:
    """Generic syntax error routine"""
    if fname is None:
        fname = global_.FILENAME

    if global_.has_errors > config.OPTIONS.max_syntax_errors:
        msg = "Too many errors. Giving up!"

    msg = "%s:%i: error:%s %s" % (fname, lineno, ERROR_PREFIX, msg)
    msg_output(msg)

    if global_.has_errors > config.OPTIONS.max_syntax_errors:
        sys.exit(1)

    global_.has_errors += 1


def warning(lineno: int, msg: str, fname: str | None = None) -> None:
    """Generic warning error routine"""
    global_.has_warnings += 1
    if global_.has_warnings <= config.OPTIONS.expected_warnings:
        return

    if fname is None:
        fname = global_.FILENAME

    msg = "%s:%i: %s %s" % (fname, lineno, WARNING_PREFIX or "warning:", msg)
    msg_output(msg)


def is_valid_warning_code(code: str) -> bool:
    return code in global_.ENABLED_WARNINGS


def assert_is_valid_warning_code(code: str):
    assert is_valid_warning_code(code), f"Invalid warning code '{code}'"


def enable_warning(code: str):
    assert_is_valid_warning_code(code)
    global_.ENABLED_WARNINGS[code] = True


def disable_warning(code: str):
    assert_is_valid_warning_code(code)
    global_.ENABLED_WARNINGS[code] = False


def register_warning(code: str) -> Callable:
    assert code not in global_.ENABLED_WARNINGS, f"Duplicated warning code '{code}'"
    global_.ENABLED_WARNINGS[code] = True

    def decorator(func: Callable) -> Callable:
        def wrapper(*args, **kwargs):
            global WARNING_PREFIX
            if global_.ENABLED_WARNINGS.get(code, True):
                if not config.OPTIONS.hide_warning_codes:
                    WARNING_PREFIX = f"warning: [W{code}]"
                func(*args, **kwargs)
                WARNING_PREFIX = ""

        return wraps(func)(wrapper)

    return decorator


def warning_command_line_flag_deprecation(flag: str) -> None:
    """Warning signaling command line flag is deprecated.
    This is a special warning that can't be silenced, and needs no line number nor filename.
    """
    msg_output(f"WARNING: deprecated flag {flag}")  # TODO: To be enabled upon 1.18+


# region [Warnings]
@register_warning("100")
def warning_implicit_type(lineno: int, id_: str, type_: str = None):
    """Warning: Using default implicit type 'x'"""
    if config.OPTIONS.strict:
        syntax_error_undeclared_type(lineno, id_)
        return

    if type_ is None:
        type_ = global_.DEFAULT_TYPE.name

    warning(lineno, "Using default implicit type '%s' for '%s'" % (type_, id_))


@register_warning("110")
def warning_condition_is_always(lineno: int, cond: bool = False):
    """Warning: Condition is always false/true"""
    warning(lineno, "Condition is always %s" % cond)


@register_warning("120")
def warning_conversion_lose_digits(lineno: int):
    """Warning: Conversion may lose significant digits"""
    warning(lineno, "Conversion may lose significant digits")


@register_warning("130")
def warning_empty_loop(lineno: int):
    """Warning: Empty loop"""
    warning(lineno, "Empty loop")


@register_warning("140")
def warning_empty_if(lineno: int):
    """Warning: Useless empty IF ignored"""
    warning(lineno, "Useless empty IF ignored")


@register_warning("150")
def warning_not_used(lineno: int, id_: str, kind: str = "Variable", fname: str | None = None):
    """Emits an optimization warning"""
    if config.OPTIONS.optimization_level > 0:
        warning(lineno, "%s '%s' is never used" % (kind, id_), fname=fname)


@register_warning("160")
def warning_fastcall_with_N_parameters(lineno: int, kind: str, id_: str, num_params: int):
    """Warning: SUB/FUNCTION declared as FASTCALL with N parameters"""
    warning(lineno, f"{kind} '{id_}' declared as FASTCALL with {num_params} parameters")


@register_warning("170")
def warning_func_is_never_called(lineno: int, func_name: str, fname: str | None = None):
    warning(lineno, f"Function '{func_name}' is never called and has been ignored", fname=fname)


@register_warning("180")
def warning_unreachable_code(lineno: int, fname: str | None = None):
    warning(lineno, "Unreachable code", fname=fname)


@register_warning("190")
def warning_function_should_return_a_value(lineno: int, func_name: str, fname: str | None = None):
    warning(lineno, f"Function '{func_name}' should return a value", fname=fname)


@register_warning("200")
def warning_value_will_be_truncated(lineno: int, fname: str | None = None):
    warning(lineno, "Value will be truncated", fname=fname)


@register_warning("300")
def warning_ignoring_unknown_pragma(lineno: int, pragma_name: str):
    warning(lineno, f"Ignoring unknown pragma '{pragma_name}'")


# endregion

# region [Syntax Errors]


# ----------------------------------------
# Syntax error: Expected string instead of
#               numeric expression.
# ----------------------------------------
def syntax_error_expected_string(lineno: int, _type: str):
    error(lineno, "Expected a 'string' type expression, got '%s' instead" % _type)


# ----------------------------------------
# Syntax error: FOR variable should be X
#               instead of Y
# ----------------------------------------
def syntax_error_wrong_for_var(lineno: int, x: str, y: str):
    error(lineno, "FOR variable should be '%s' instead of '%s'" % (x, y))


# ----------------------------------------
# Syntax error: Initializer expression is
#               not constant
# ----------------------------------------
def syntax_error_not_constant(lineno: int):
    error(lineno, "Initializer expression is not constant.")


# ----------------------------------------
# Syntax error: Id is neither an array nor
#               a function
# ----------------------------------------
def syntax_error_not_array_nor_func(lineno: int, varname: str):
    error(lineno, "'%s' is neither an array nor a function." % varname)


# ----------------------------------------
# Syntax error: Id is neither an array nor
#               a function
# ----------------------------------------
def syntax_error_not_an_array(lineno: int, varname: str):
    error(lineno, "'%s' is not an array (or has not been declared yet)" % varname)


# ----------------------------------------
# Syntax error: function redefinition type
#               mismatch
# ----------------------------------------
def syntax_error_func_type_mismatch(lineno: int, entry):
    error(lineno, "Function '%s' (previously declared at %i) type mismatch" % (entry.name, entry.lineno))


# ----------------------------------------
# Syntax error: function redefinition parm.
#               mismatch
# ----------------------------------------
def syntax_error_parameter_mismatch(lineno: int, entry):
    error(lineno, "Function '%s' (previously declared at %i) parameter mismatch" % (entry.name, entry.lineno))


# ----------------------------------------
# Syntax error: can't convert value to the
#               given type.
# ----------------------------------------
def syntax_error_cant_convert_to_type(lineno: int, expr_str: str, type_: str):
    error(lineno, "Cant convert '%s' to type %s" % (expr_str, type_))


# ----------------------------------------
# Syntax error: is a SUB not a FUNCTION
# ----------------------------------------
def syntax_error_is_a_sub_not_a_func(lineno: int, name: str):
    error(lineno, "'%s' is a SUB not a FUNCTION" % name)


# ----------------------------------------
# Syntax error: strict mode: missing type declaration
# ----------------------------------------
def syntax_error_undeclared_type(lineno: int, id_: str):
    error(lineno, "strict mode: missing type declaration for '%s'" % id_)


# ----------------------------------------
#  Cannot assign a value to 'var'. It's not a variable
# ----------------------------------------
def syntax_error_cannot_assign_not_a_var(lineno: int, id_: str):
    error(lineno, "Cannot assign a value to '%s'. It's not a variable" % id_)


# ----------------------------------------
#  Cannot assign a value to 'var'. It's not a variable
# ----------------------------------------
def syntax_error_address_must_be_constant(lineno: int):
    error(lineno, "Address must be a numeric constant expression")


# ----------------------------------------
#  Cannot pass an array by value
# ----------------------------------------
def syntax_error_cannot_pass_array_by_value(lineno: int, id_: str):
    error(lineno, "Array parameter '%s' must be passed ByRef" % id_)


# ----------------------------------------
#  Cannot pass an array by value
# ----------------------------------------
def syntax_error_no_data_defined(lineno: int):
    error(lineno, "No DATA defined")


# ----------------------------------------
#  Cannot pass an array by value
# ----------------------------------------
def syntax_error_cannot_initialize_array_of_type(lineno: int, type_name: str):
    error(lineno, f"Cannot initialize array of type {type_name}")


# ----------------------------------------
#  Cannot define a default array argument
# ----------------------------------------
def syntax_error_cannot_define_default_array_argument(lineno: int):
    error(lineno, "Cannot define default array argument")


# ----------------------------------------
#  Error, ID is a ... not a ...
# ----------------------------------------
def syntax_error_unexpected_class(lineno: int, id_name: str, wrong_class: CLASS, good_class: CLASS):
    n1 = "n" if wrong_class[0] in "aeiou" else ""
    n2 = "n" if good_class[0] in "aeiou" else ""
    error(lineno, f"'{id_name}' is a{n1} {wrong_class.upper()}, not a{n2} {good_class.upper()}")


# ----------------------------------------
#  ID already declared as <class> at <line>
# ----------------------------------------
def syntax_error_already_declared(lineno: int, id_name: str, as_class: CLASS, at_lineno: int):
    error(lineno, f"'{id_name}' already declared as {as_class} at {at_lineno}")


# ----------------------------------------
#  Can't declare a mandatory parameter after an optional one
# ----------------------------------------
def syntax_error_mandatory_param_after_optional(lineno: int, param1: str, param2: str):
    error(lineno, f"Can't declare mandatory param '{param2}' after optional param '{param1}'")


# ----------------------------------------
# FOR without NEXT
# ----------------------------------------
def syntax_error_for_without_next(lineno: int):
    error(lineno, "FOR without NEXT")


# ----------------------------------------
# FOR without NEXT
# ----------------------------------------
def syntax_error_loop_not_closed(lineno: int, loop_type: str):
    error(lineno, f"{loop_type} loop not closed")


# endregion
