from dataclasses import dataclass, field

from typing import List, Optional

from gbso.cpu.cpu import CPU
from gbso.cpu.state import CPUState
from gbso.cpu.insn import Insn, UNUSED


@dataclass
class Program:
    insns: List[Insn] = field(default_factory=list)

    def execute(self, init_state: Optional[CPUState] = None) -> CPU:
        cpu = CPU(state=init_state)
        for insn in self.insns:
            insn.exec(cpu)
        return cpu

    def perf(self) -> int:
        return sum([insn.cycles() for insn in self.insns])

    def display(self) -> None:
        print("=" * 10)
        for insn in self.insns:
            print(insn.pretty())
        print("=" * 10)

    def pad(self, max_bytes: int) -> "Program":
        if len(self.insns) > max_bytes:
            raise ValueError("larger than amount to pad to")

        insns = self.insns.copy() + [UNUSED()] * (max_bytes - len(self.insns))
        return Program(insns=insns)