import ctypes
import platform
import os
import sys 
sys.path.append("..") 
from api import project
from api import parser


def _verify_platform():
    _platform = platform.system()
    if _platform != "Windows":
        raise Exception(f'Platform {_platform} unsupported (not yet)')


class Output:
    def __init__(self, name: str) -> None:
        self._name = name

        self._lib = ctypes.CDLL(os.path.join(os.getcwd(), 'epanet-output.dll'))

        self._handle = ctypes.c_void_p()
        self._check(self._lib.ENR_init(ctypes.byref(self._handle)))

        dir = os.path.dirname(os.getcwd())
        opt = os.path.join(os.path.join(dir, 'temp'), self._name + '.db.opt')
        self._check(self._lib.ENR_open(self._handle, ctypes.c_char_p(opt.encode())))


    def _check(self, result):
        if result != 0:
            msg = ctypes.c_char_p()
            code = self._lib.ENR_checkError(self._handle, ctypes.byref(msg))
            assert code == result

            error = f'Failed to read project [{self._name}] output, message [{msg.value.decode()}]'

            self._lib.ENR_free(ctypes.byref(msg))

            raise Exception(error)


    def version(self) -> int:
        v = ctypes.c_int()
        self._check(self._lib.ENR_getVersion(self._handle, ctypes.byref(v)))
        return v.value


    def net_size(self) -> dict[str, int]:
        element_count = ctypes.POINTER(ctypes.c_int)()
        length = ctypes.c_int()
        self._check(self._lib.ENR_getNetSize(self._handle, ctypes.byref(element_count), ctypes.byref(length)))
        assert length.value == 5
        category = ['node', 'tank', 'link', 'pump', 'valve']
        counts = {}
        for i in range(length.value):
            counts[category[i]] = element_count[i]
        self._lib.ENR_free(ctypes.byref(element_count))
        return counts


    def units(self) -> dict[str, str]:
        f_us = ['CFS', 'GPM', 'MGD', 'IMGD', 'AFD', 'LPS', 'LPM', 'MLD', 'CMH', 'CMD']
        p_us = ['PSI', 'MTR', 'KPA']
        q_us = ['NONE', 'MGL', 'UGL', 'HOURS', 'PRCNT']
        f, p, q = ctypes.c_int(1), ctypes.c_int(2), ctypes.c_int(3)
        f_u, p_u, q_u = ctypes.c_int(), ctypes.c_int(), ctypes.c_int()
        self._check(self._lib.ENR_getUnits(self._handle, f, ctypes.byref(f_u)))
        self._check(self._lib.ENR_getUnits(self._handle, p, ctypes.byref(p_u)))
        self._check(self._lib.ENR_getUnits(self._handle, q, ctypes.byref(q_u)))
        return { 'flow': f_us[f_u.value], 'pressure': p_us[p_u.value], 'quality': q_us[q_u.value] }


    def __del__(self):
        # throw exception in destructor ? :)
        self._check(self._lib.ENR_close(ctypes.byref(self._handle)))


def _read_output(name: str) -> str:
    opt = Output(name)
    print(opt.version())
    print(opt.net_size())
    print(opt.units())
    return ''


# readable True => json, False => binary output
def run_project(name: str, readable: bool = True) -> str:
    if not project.have_project(name):
        raise Exception(f'Not found project [{name}]')

    dir = os.path.dirname(os.getcwd())

    db_inp = os.path.join(os.path.join(dir, 'db_inp'), name + '.db.inp')
    parser.dump_inp(name, db_inp)

    input = name + '.db'
    exe = os.path.join(os.path.join(dir, 'epanet'), 'runepanet.exe')
    inp = os.path.join(os.path.join(dir, 'db_inp'), input + '.inp')
    rpt = os.path.join(os.path.join(dir, 'temp'), input + '.rpt')
    opt = os.path.join(os.path.join(dir, 'temp'), input + '.opt')
    command = f'{exe} {inp} {rpt} {opt}'

    result = os.system(command)
    if result != 0:
        raise Exception("Failed to run simulation for project [{name}]")

    return _read_output(name)


if __name__ == '__main__':
    _verify_platform()
    _read_output('net3')