from .operation import *


def get_emitter_schema(name: str) -> dict[str, dict[str, Any]]:
    return { 'junction'    : {'type': 'str'   , 'optional': False , 'readonly': True },
             'coefficient' : {'type': 'float' , 'optional': True ,  'readonly': False} }


def get_emitter(name: str, junction: str) -> dict[str, Any]:
    e = try_read(name, f"select * from emitters where junction = '{junction}'")
    if e == None:
        return { 'junction': junction, 'coefficient': None }
    d = {}
    d['junction'] = str(e['junction'])
    d['coefficient'] = float(e['coefficient']) if e['coefficient'] != None else None
    return d


class Emitter(object):
    def __init__(self, input: dict[str, Any]) -> None:
        self.type = 'emitter'
        self.junction = str(input['junction'])
        self.coefficient = float(input['coefficient']) if 'coefficient' in input and input['coefficient'] != None else None

        self.f_type = f"'{self.type}'"
        self.f_junction = f"'{self.junction}'"
        self.f_coefficient = self.coefficient if self.coefficient != None else 'null'

    def as_dict(self) -> dict[str, Any]:
        return { 'type': self.type, 'junction': self.junction, 'coefficient': self.coefficient }


def set_emitter(name: str, cs: ChangeSet) -> ChangeSet:
    old = Emitter(get_emitter(name, cs.operations[0]['junction']))
    raw_new = get_emitter(name, cs.operations[0]['junction'])

    new_dict = cs.operations[0]
    schema = get_emitter_schema(name)
    for key, value in schema.items():
        if key in new_dict and not value['readonly']:
            raw_new[key] = new_dict[key]
    new = Emitter(raw_new)

    redo_sql = f"delete from emitters where junction = {new.f_junction};"
    if new.coefficient != None:
        redo_sql += f"\ninsert into emitters (junction, coefficient) values ({new.f_junction}, {new.f_coefficient});"

    undo_sql = f"delete from emitters where junction = {old.f_junction};"
    if old.coefficient != None:
        undo_sql += f"\ninsert into emitters (junction, coefficient) values ({old.f_junction}, {old.f_coefficient});"

    redo_cs = g_update_prefix | new.as_dict()
    undo_cs = g_update_prefix | old.as_dict()

    return execute_command(name, redo_sql, undo_sql, redo_cs, undo_cs)