import dataclasses
import importlib
import os
import subprocess
import threading

import scene_plugin


@dataclasses.dataclass
class Scene:
    name: str
    launch_file: str = None
    scripts: dict = None


class SceneManager:
    def __init__(self):
        self.scene_dict = {}
        self.running_scene = None
        self.sim_process = None
        self.sim_thread = None
        self.scene_plugin = None

    def load_scene(self):
        """
        从场景文件夹加载场景。
        """
        scene_dir = os.path.join(os.path.dirname(__file__), 'scene')
        if not os.path.exists(scene_dir):
            raise RuntimeError('no scene exist')
        names = [name for name in os.listdir(
            scene_dir) if os.path.isdir(os.path.join(scene_dir, name))]
        for name in names:
            scene = Scene(name)
            scene.launch_file = os.path.join(scene_dir, name, 'launch.sh')
            scene.scripts = {}
            if not os.path.exists(scene.launch_file):
                continue
            for script_name in os.listdir(os.path.join(scene_dir, name, 'scripts')):
                if script_name.endswith('.sh'):
                    script_name_only = os.path.splitext(script_name)[0]
                    scene.scripts[script_name_only] = os.path.join(
                        scene_dir, name, 'scripts', script_name)
            self.scene_dict[name] = scene

    def get_scene(self):
        return list(self.scene_dict.keys())
    
    def get_scripts(self, name):
        return list(self.scene_dict[name].scripts.keys())

    def start_scene(self, name):
        if self.running_scene:
            raise RuntimeError(
                f'scene {self.running_scene} is already running')
        if name not in self.scene_dict:
            raise ValueError(f'scene {name} not found')
        scene_plugin_module = importlib.import_module(f'scene.{name}.plugin')
        self.scene_plugin = scene_plugin_module.Plugin(name)
        self.running_scene = name
        self.sim_process = subprocess.Popen(
                ['bash', self.scene_dict[name].launch_file],
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE
            )

    def shut_scene(self):
        # TODO: 并没有正确终止仿真系列进程
        self.sim_process.terminate()
        self.sim_process = None
        self.running_scene = None
        self.scene_plugin = None

    def run_script(self, name):
        if not self.running_scene:
            raise RuntimeError('no scene running')
        script_path = self.scene_dict[self.running_scene].scripts.get(name, None)
        if not script_path:
            raise ValueError(f'script {name} not found')
        subprocess.Popen(['bash', script_path])

if __name__ == '__main__':
    mgr = SceneManager()
    mgr.load_scene()
    print(mgr.get_scene())
    print(mgr.get_scripts('grasp-box'))
    mgr.start_scene('grasp-box')
    import time
    time.sleep(20)
    mgr.run_script('grasp_box_example')
    time.sleep(60)
    mgr.shut_scene()