import heurams.kernel.particles as pt
from .states import PhaserState, ProcessionState

class Procession():
    """队列: 标识单次记忆流程"""
    def __init__(self, atoms: list, phase: PhaserState, name: str = ""):
        self.atoms = atoms
        self.queue = atoms.copy()
        self.current_atom = atoms[0]
        self.cursor = 0
        self.name = name
        self.phase = phase
        self.state: ProcessionState = ProcessionState.RUNNING

    def forward(self, step = 1):
        self.cursor += step
        if self.cursor == len(self.queue):
            self.state: ProcessionState = ProcessionState.FINISHED
        else:
            self.state: ProcessionState = ProcessionState.RUNNING
        try:
            self.current_atom = self.queue[self.cursor]
            return 1 # 成功
        except IndexError:
            return 0

    def append(self, atom = None):
        if atom == None:
            self.queue.append(self.current_atom)
        else:
            self.queue.append(atom)

    def __len__(self):
        return (len(self.queue) - self.cursor)

    def is_empty(self):
        return len(self.queue)