import io
import subprocess
import sys
from tempfile import NamedTemporaryFile

from pywasm import binary
from pywasm import Runtime

from py2wasm.utils import process

def wat2wasm(code_wat):
    with NamedTemporaryFile('w+t') as input_fp:
        input_fp.write(code_wat)
        input_fp.flush()

        with NamedTemporaryFile('w+b') as output_fp:
            result = subprocess.run(
                [
                    'wat2wasm',
                    input_fp.name,
                    '-o',
                    output_fp.name,
                ],
                check=True,
            )

            output_fp.seek(0)

            return output_fp.read()

class SuiteResult:
    def __init__(self):
        self.log_int32_list = []

    def callback_log_int32(self, store, value):
        del store # auto passed by pywasm

        self.log_int32_list.append(value)

    def make_imports(self):
        return {
            'console': {
                'logInt32': self.callback_log_int32,
            }
        }

class Suite:
    def __init__(self, code_py, test_name):
        self.code_py = code_py
        self.test_name = test_name

    def run_code(self, *args):
        """
        Compiles the given python code into wasm and
        then runs it

        Returned is an object with the results set
        """
        code_wat = process(self.code_py, self.test_name)

        line_list = code_wat.split('\n')
        line_no_width = len(str(len(line_list)))
        for line_no, line_txt in enumerate(line_list):
            sys.stderr.write('{}  {}\n'.format(
                str(line_no + 1).zfill(line_no_width),
                line_txt,
            ))

        code_wasm = wat2wasm(code_wat)
        module = binary.Module.from_reader(io.BytesIO(code_wasm))

        result = SuiteResult()
        runtime = Runtime(module, result.make_imports(), {})

        result.returned_value = runtime.exec('testEntry', args)

        return result