import os
import struct
import sys
from typing import Any, Callable, Generator, Iterable, List, TextIO, Union

from phasm import compiler
from phasm.build import builtins
from phasm.codestyle import phasm_render
from phasm.type3 import types as type3types
from phasm.type3.routers import NoRouteForTypeException, TypeApplicationRouter
from phasm.wasm import (
    WasmTypeFloat32,
    WasmTypeFloat64,
    WasmTypeInt32,
    WasmTypeInt64,
    WasmTypeNone,
)

from . import runners

DASHES = '-' * 16

class InvalidArgumentException(Exception):
    pass

class SuiteResult:
    def __init__(self) -> None:
        self.returned_value = None

RUNNER_CLASS_MAP = {
    'wasmtime': runners.RunnerWasmtime,
}

TRACE_CODE_PREFIX = """
@imported
def trace_adr(adr: i32) -> i32:
    pass

@imported
def trace_i32(x: i32) -> i32:
    pass

"""

def make_int_trace(prefix: str) -> Callable[[int], int]:
    def trace_helper(adr: int) -> int:
        sys.stderr.write(f'{prefix} {adr}\n')
        sys.stderr.flush()
        return adr

    return trace_helper

class Suite:
    """
    WebAssembly test suite
    """
    def __init__(self, code_py: str) -> None:
        self.code_py = code_py

    def run_code(
            self,
            *args: Any,
            runtime: str = 'wasmtime',
            func_name: str = 'testEntry',
            imports: runners.Imports = None,
            do_format_check: bool = True,
            verbose: bool | None = None,
            with_traces: bool = False,
        ) -> Any:
        """
        Compiles the given python code into wasm and
        then runs it

        Returned is an object with the results set
        """
        if verbose is None:
            verbose = bool(os.environ.get('VERBOSE'))

        code_prefix = ''

        if with_traces:
            assert do_format_check is False

            if imports is None:
                imports = {}

            imports.update({
                'trace_adr': make_int_trace('ADR'),
                'trace_i32': make_int_trace('i32'),
            })

            code_prefix = TRACE_CODE_PREFIX

        class_ = RUNNER_CLASS_MAP[runtime]

        runner = class_(code_prefix + self.code_py)

        if verbose:
            write_header(sys.stderr, 'Phasm')
            runner.dump_phasm_code(sys.stderr)

        runner.parse(verbose=verbose)
        runner.compile_ast()
        runner.optimise_wasm_ast()
        runner.compile_wat()

        if verbose:
            write_header(sys.stderr, 'Assembly')
            runner.dump_wasm_wat(sys.stderr)

        runner.interpreter_setup()
        runner.interpreter_load(imports)

        # Check if code formatting works
        if do_format_check:
            assert self.code_py == '\n' + phasm_render(runner.phasm_ast) # \n for formatting in tests

        func_args = [x.type3 for x in runner.phasm_ast.functions[func_name].posonlyargs]
        if len(func_args) != len(args):
            raise RuntimeError(f'Invalid number of args for {func_name}')

        wasm_args: List[Union[float, int]] = []
        if args:
            if verbose:
                write_header(sys.stderr, 'Memory (pre alloc)')
                runner.interpreter_dump_memory(sys.stderr)

            for arg, arg_typ in zip(args, func_args, strict=True):
                arg_typ_info = runner.phasm_ast.build.type_info_map.get(arg_typ.name)

                if arg_typ_info and (arg_typ_info.wasm_type is WasmTypeInt32 or arg_typ_info.wasm_type is WasmTypeInt64):
                    assert isinstance(arg, int)
                    wasm_args.append(arg)
                    continue

                if arg_typ_info and (arg_typ_info.wasm_type is WasmTypeFloat32 or arg_typ_info.wasm_type is WasmTypeFloat64):
                    assert isinstance(arg, float)
                    wasm_args.append(arg)
                    continue

                try:
                    adr = ALLOCATE_MEMORY_STORED_ROUTER((runner, arg), arg_typ)
                    wasm_args.append(adr)
                except NoRouteForTypeException:
                    raise NotImplementedError(arg_typ, arg)

        if verbose:
            write_header(sys.stderr, 'Memory (pre run)')
            runner.interpreter_dump_memory(sys.stderr)

        result = SuiteResult()
        result.returned_value = runner.call(func_name, *wasm_args)

        result.returned_value = _load_memory_stored_returned_value(
            runner,
            func_name,
            result.returned_value,
        )

        if verbose:
            write_header(sys.stderr, 'Memory (post run)')
            runner.interpreter_dump_memory(sys.stderr)

        return result

def write_header(textio: TextIO, msg: str) -> None:
    textio.write(f'{DASHES} {msg.ljust(16)}  {DASHES}\n')

def _write_memory_stored_value(
        runner: runners.RunnerBase,
        adr: int,
        val_typ: type3types.Type3,
        val: Any,
    ) -> int:
    try:
        adr2 = ALLOCATE_MEMORY_STORED_ROUTER((runner, val), val_typ)

        ptr_type_info = runner.phasm_ast.build.type_info_map['ptr']
        to_write = compiler.module_data_primitive(ptr_type_info, adr2)
        runner.interpreter_write_memory(adr, to_write)
        return runner.phasm_ast.build.type_info_constructed.alloc_size
    except NoRouteForTypeException:
        val_typ_info = runner.phasm_ast.build.type_info_map[val_typ.name]
        to_write = compiler.module_data_primitive(val_typ_info, val)
        runner.interpreter_write_memory(adr, to_write)
        return len(to_write)

def _allocate_memory_stored_bytes(attrs: tuple[runners.RunnerBase, bytes]) -> int:
    runner, val = attrs

    assert isinstance(val, bytes)

    adr = runner.call('stdlib.types.__alloc_bytes__', len(val))
    assert isinstance(adr, int)

    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')
    runner.interpreter_write_memory(adr + 4, val)
    return adr

def _allocate_memory_stored_dynamic_array(attrs: tuple[runners.RunnerBase, Any], da_args: tuple[type3types.Type3]) -> int:
    runner, val = attrs

    da_type, = da_args

    if da_type.name == 'u8':
        return _allocate_memory_stored_bytes(attrs)

    if not isinstance(val, tuple):
        raise InvalidArgumentException(f'Expected tuple; got {val!r} instead')

    alloc_size = 4 + len(val) * runner.phasm_ast.build.calculate_alloc_size(da_type, True)
    adr = runner.call('stdlib.alloc.__alloc__', alloc_size)
    assert isinstance(adr, int)  # Type int
    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')

    offset = adr
    offset += _write_memory_stored_value(runner, offset, runner.phasm_ast.build.types['u32'], len(val))
    for val_el_val in val:
        offset += _write_memory_stored_value(runner, offset, da_type, val_el_val)
    return adr

def _allocate_memory_stored_static_array(attrs: tuple[runners.RunnerBase, Any], sa_args: tuple[type3types.Type3, type3types.IntType3]) -> int:
    runner, val = attrs

    sa_type, sa_len = sa_args

    if not isinstance(val, tuple):
        raise InvalidArgumentException(f'Expected tuple of length {sa_len.value}; got {val!r} instead')
    if sa_len.value != len(val):
        raise InvalidArgumentException(f'Expected tuple of length {sa_len.value}; got {val!r} instead')

    alloc_size = runner.phasm_ast.build.calculate_alloc_size_static_array(sa_args)
    adr = runner.call('stdlib.alloc.__alloc__', alloc_size)
    assert isinstance(adr, int)  # Type int
    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')

    offset = adr
    for val_el_val in val:
        offset += _write_memory_stored_value(runner, offset, sa_type, val_el_val)
    return adr

def _allocate_memory_stored_struct(attrs: tuple[runners.RunnerBase, Any], st_args: tuple[tuple[str, type3types.Type3], ...]) -> int:
    runner, val = attrs

    assert isinstance(val, dict)

    alloc_size = runner.phasm_ast.build.calculate_alloc_size_struct(st_args)
    adr = runner.call('stdlib.alloc.__alloc__', alloc_size)
    assert isinstance(adr, int)
    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')

    offset = adr
    for val_el_name, val_el_typ in st_args:
        assert val_el_name in val, f'Missing key value {val_el_name}'
        val_el_val = val.pop(val_el_name)
        offset += _write_memory_stored_value(runner, offset, val_el_typ, val_el_val)

    assert not val, f'Additional values: {list(val)!r}'

    return adr

def _allocate_memory_stored_tuple(attrs: tuple[runners.RunnerBase, Any], tp_args: tuple[type3types.Type3, ...]) -> int:
    runner, val = attrs

    assert isinstance(val, tuple)

    alloc_size = runner.phasm_ast.build.calculate_alloc_size_tuple(tp_args)
    adr = runner.call('stdlib.alloc.__alloc__', alloc_size)
    assert isinstance(adr, int)
    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')

    assert len(val) == len(tp_args)

    offset = adr
    for val_el_val, val_el_typ in zip(val, tp_args, strict=True):
        offset += _write_memory_stored_value(runner, offset, val_el_typ, val_el_val)
    return adr

ALLOCATE_MEMORY_STORED_ROUTER = TypeApplicationRouter[tuple[runners.RunnerBase, Any], Any]()
# ALLOCATE_MEMORY_STORED_ROUTER.add_n(prelude.bytes_, _allocate_memory_stored_bytes)
ALLOCATE_MEMORY_STORED_ROUTER.add(builtins.dynamic_array, _allocate_memory_stored_dynamic_array)
ALLOCATE_MEMORY_STORED_ROUTER.add(builtins.static_array, _allocate_memory_stored_static_array)
ALLOCATE_MEMORY_STORED_ROUTER.add(builtins.struct, _allocate_memory_stored_struct)
ALLOCATE_MEMORY_STORED_ROUTER.add(builtins.tuple_, _allocate_memory_stored_tuple)

def _load_memory_stored_returned_value(
        runner: runners.RunnerBase,
        func_name: str,
        wasm_value: Any,
    ) -> Any:
    ret_type3 = runner.phasm_ast.functions[func_name].returns_type3

    if ret_type3.name in runner.phasm_ast.build.type_info_map:
        type_info = runner.phasm_ast.build.type_info_map[ret_type3.name]

        if type_info.wasm_type is WasmTypeNone:
            return None

        if type_info.wasm_type is WasmTypeInt32 or type_info.wasm_type is WasmTypeInt64:
            assert isinstance(wasm_value, int), wasm_value

            if type_info.signed is None:
                # Must be bool type
                return 0 != wasm_value

            if not type_info.signed and wasm_value < 0:
                data = wasm_value.to_bytes(type_info.alloc_size, 'big', signed=True)
                wasm_value = int.from_bytes(data, 'big', signed=False)

            return wasm_value

        if type_info.wasm_type is WasmTypeFloat32 or type_info.wasm_type is WasmTypeFloat64:
            assert isinstance(wasm_value, float), wasm_value
            return wasm_value

    assert isinstance(wasm_value, int), wasm_value

    return LOAD_FROM_ADDRESS_ROUTER((runner, wasm_value), ret_type3)

def _unpack(runner: runners.RunnerBase, typ: type3types.Type3, inp: bytes) -> Any:
    typ_info = runner.phasm_ast.build.type_info_map.get(typ.name)

    if typ_info is None:
        assert len(inp) == 4

        # Note: For applied types, inp should contain a 4 byte pointer
        adr = struct.unpack('<I', inp)[0]

        return LOAD_FROM_ADDRESS_ROUTER((runner, adr), typ)

    assert len(inp) == typ_info.alloc_size

    if typ.name == 'u8':
        return struct.unpack('<B', inp)[0]

    if typ.name == 'u16':
        return struct.unpack('<H', inp)[0]

    if typ.name == 'u32':
        return struct.unpack('<I', inp)[0]

    if typ.name == 'u64':
        return struct.unpack('<Q', inp)[0]

    if typ.name == 'i8':
        return struct.unpack('<b', inp)[0]

    if typ.name == 'i16':
        return struct.unpack('<h', inp)[0]

    if typ.name == 'i32':
        return struct.unpack('<i', inp)[0]

    if typ.name == 'i64':
        return struct.unpack('<q', inp)[0]

    if typ.name == 'f32':
        return struct.unpack('<f', inp)[0]

    if typ.name == 'f64':
        return struct.unpack('<d', inp)[0]

    raise NotImplementedError(typ, inp)

def _load_bytes_from_address(attrs: tuple[runners.RunnerBase, int]) -> bytes:
    runner, adr = attrs

    sys.stderr.write(f'Reading 0x{adr:08x} bytes\n')
    read_bytes = runner.interpreter_read_memory(adr, 4)
    bytes_len,  = struct.unpack('<I', read_bytes)

    adr += 4
    return runner.interpreter_read_memory(adr, bytes_len)

def _split_read_bytes(all_bytes: bytes, split_sizes: Iterable[int]) -> Generator[bytes, None, None]:
    offset = 0
    for size in split_sizes:
        yield all_bytes[offset:offset + size]
        offset += size

def _load_dynamic_array_from_address(attrs: tuple[runners.RunnerBase, int], da_args: tuple[type3types.Type3]) -> Any:
    runner, adr = attrs
    da_type, = da_args

    if da_type.name == 'u8':
        return _load_bytes_from_address(attrs)

    sys.stderr.write(f'Reading 0x{adr:08x} {da_type:s}[...]\n')

    read_bytes = runner.interpreter_read_memory(adr, 4)
    array_len,  = struct.unpack('<I', read_bytes)
    adr += 4

    arg_size_1 = runner.phasm_ast.build.calculate_alloc_size(da_type, is_member=True)
    arg_sizes = [arg_size_1 for _ in range(array_len)] # _split_read_bytes requires one arg per value

    read_bytes = runner.interpreter_read_memory(adr, sum(arg_sizes))

    return tuple(
        _unpack(runner, da_type, arg_bytes)
        for arg_bytes in _split_read_bytes(read_bytes, arg_sizes)
    )

def _load_static_array_from_address(attrs: tuple[runners.RunnerBase, int], sa_args: tuple[type3types.Type3, type3types.IntType3]) -> Any:
    runner, adr = attrs
    sub_typ, len_typ = sa_args

    sys.stderr.write(f'Reading 0x{adr:08x} {sub_typ:s} {len_typ:s}\n')

    sa_len = len_typ.value

    arg_size_1 = runner.phasm_ast.build.calculate_alloc_size(sub_typ, is_member=True)
    arg_sizes = [arg_size_1 for _ in range(sa_len)] # _split_read_bytes requires one arg per value

    read_bytes = runner.interpreter_read_memory(adr, sum(arg_sizes))

    return tuple(
        _unpack(runner, sub_typ, arg_bytes)
        for arg_bytes in _split_read_bytes(read_bytes, arg_sizes)
    )

def _load_struct_from_address(attrs: tuple[runners.RunnerBase, int], st_args: tuple[tuple[str, type3types.Type3], ...]) -> dict[str, Any]:
    runner, adr = attrs

    sys.stderr.write(f'Reading 0x{adr:08x} struct {list(st_args)}\n')

    arg_sizes = [
        runner.phasm_ast.build.calculate_alloc_size(x, is_member=True)
        for _, x in st_args
    ]

    read_bytes = runner.interpreter_read_memory(adr, sum(arg_sizes))

    return {
        arg_name: _unpack(runner, arg_typ, arg_bytes)
        for (arg_name, arg_typ, ), arg_bytes in zip(st_args, _split_read_bytes(read_bytes, arg_sizes), strict=True)
    }

def _load_tuple_from_address(attrs: tuple[runners.RunnerBase, int], tp_args: tuple[type3types.Type3, ...]) -> Any:
    runner, adr = attrs

    sys.stderr.write(f'Reading 0x{adr:08x} tuple {len(tp_args)}\n')

    arg_sizes = [
        runner.phasm_ast.build.calculate_alloc_size(x, is_member=True)
        for x in tp_args
    ]

    read_bytes = runner.interpreter_read_memory(adr, sum(arg_sizes))

    return tuple(
        _unpack(runner, arg_typ, arg_bytes)
        for arg_typ, arg_bytes in zip(tp_args, _split_read_bytes(read_bytes, arg_sizes), strict=True)
    )

LOAD_FROM_ADDRESS_ROUTER = TypeApplicationRouter[tuple[runners.RunnerBase, int], Any]()
LOAD_FROM_ADDRESS_ROUTER.add(builtins.dynamic_array, _load_dynamic_array_from_address)
LOAD_FROM_ADDRESS_ROUTER.add(builtins.static_array, _load_static_array_from_address)
LOAD_FROM_ADDRESS_ROUTER.add(builtins.struct, _load_struct_from_address)
LOAD_FROM_ADDRESS_ROUTER.add(builtins.tuple_, _load_tuple_from_address)