import sys

import pytest

import wasm3

from phasm.compiler import phasm_compile
from phasm.parser import phasm_parse

from .helpers import DASHES, wat2wasm, _dump_memory, _write_numbered_lines

def setup_interpreter(code_phasm):
    phasm_module = phasm_parse(code_phasm)
    wasm_module = phasm_compile(phasm_module)
    code_wat = wasm_module.to_wat()

    sys.stderr.write(f'{DASHES} Assembly {DASHES}\n')
    _write_numbered_lines(code_wat)

    code_wasm = wat2wasm(code_wat)

    env = wasm3.Environment()
    mod = env.parse_module(code_wasm)

    rtime = env.new_runtime(1024 * 1024)
    rtime.load(mod)

    return rtime

@pytest.mark.integration_test
def test___init__():
    code_py = """
@exported
def testEntry() -> u8:
    return 13
"""

    rtime = setup_interpreter(code_py)

    for idx in range(128):
        rtime.get_memory(0)[idx] = idx

    sys.stderr.write(f'{DASHES} Memory (pre run)  {DASHES}\n')
    _dump_memory(rtime.get_memory(0))

    rtime.find_function('stdlib.alloc.__init__')()

    sys.stderr.write(f'{DASHES} Memory (pre run)  {DASHES}\n')
    _dump_memory(rtime.get_memory(0))

    memory = rtime.get_memory(0).tobytes()

    assert (
        b'\xC0\xA1\x00\x00'
        b'\x00\x00\x00\x00'
        b'\x00\x00\x00\x00'
        b'\x10\x00\x00\x00'
        b'\x10\x11\x12\x13' # Untouched because unused
    ) == memory[0:20]

@pytest.mark.integration_test
def test___alloc___no_init():
    code_py = """
@exported
def testEntry() -> u8:
    return 13
"""

    rtime = setup_interpreter(code_py)

    for idx in range(128):
        rtime.get_memory(0)[idx] = idx

    sys.stderr.write(f'{DASHES} Memory (pre run)  {DASHES}\n')
    _dump_memory(rtime.get_memory(0))

    with pytest.raises(RuntimeError, match='unreachable executed'):
        rtime.find_function('stdlib.alloc.__alloc__')(32)

@pytest.mark.integration_test
def test___alloc___ok():
    code_py = """
@exported
def testEntry() -> u8:
    return 13
"""

    rtime = setup_interpreter(code_py)

    for idx in range(128):
        rtime.get_memory(0)[idx] = idx

    sys.stderr.write(f'{DASHES} Memory (pre run)  {DASHES}\n')
    _dump_memory(rtime.get_memory(0))

    rtime.find_function('stdlib.alloc.__init__')()
    offset0 = rtime.find_function('stdlib.alloc.__alloc__')(32)
    offset1 = rtime.find_function('stdlib.alloc.__alloc__')(32)
    offset2 = rtime.find_function('stdlib.alloc.__alloc__')(32)

    sys.stderr.write(f'{DASHES} Memory (pre run)  {DASHES}\n')
    _dump_memory(rtime.get_memory(0))

    memory = rtime.get_memory(0).tobytes()

    assert b'\xC0\xA1\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' == memory[0:12]

    assert 0x14 == offset0
    assert 0x38 == offset1
    assert 0x5C == offset2