import json
import uuid
from datetime import datetime
from pathlib import Path
from typing import Optional, List, Any

# iottb modules
from iottb.definitions import ReturnCodes

# 3rd party libs
from pydantic import BaseModel, Field

IMMUTABLE_FIELDS = {"device_name", "device_short_name", "device_id", "date_created"}


class DeviceMetadata(BaseModel):
    # Required fields
    device_name: str
    device_short_name: str
    device_id: str = Field(default_factory=lambda: str(uuid.uuid4()))
    date_created: str = Field(default_factory=lambda: datetime.now().strftime('%d-%m-%YT%H:%M:%S').lower())

    # Optional Fields
    device_type: Optional[str] = None
    device_serial_number: Optional[str] = None
    device_firmware_version: Optional[str] = None
    date_updated: Optional[str] = None

    capture_files: Optional[List[str]] = []

    def __init__(self, device_name: str, /, **data: Any):
        super().__init__(**data)
        self.device_name = device_name
        self.device_short_name = device_name.lower().replace(" ", "_")

    @classmethod
    def load_from_json(cls, file_path: Path):
        assert file_path.is_file()
        with file_path.open('r') as file:
            metadata_json = json.load(file)
        metadata_model_obj = cls.model_validate_json(metadata_json)
        return metadata_model_obj

    def save_to_json(self, file_path: Path):
        if file_path.is_file():
            print(f"File {file_path} already exists, update instead.")
            return ReturnCodes.FILE_ALREADY_EXISTS
        metadata = self.model_dump_json(indent=2)
        with file_path.open('w') as file:
            json.dump(metadata, file)
            return ReturnCodes.SUCCESS

    @classmethod
    def update_metadata_in_json(cls, file_path: Path, **kwargs):
        # TODO Maybe not needed at all.
        assert file_path.is_file()
        for field in IMMUTABLE_FIELDS:
            if field in kwargs:
                print(f"Field {field} is immutable")
                return ReturnCodes.IMMUTABLE
        metadata = cls.load_from_json(file_path)
        for field, value in kwargs.items():
            if field in metadata.model_fields_set:
                setattr(metadata, field, value)
        metadata.date_updated = datetime.now().strftime('%d-%m-%YT%H:%M:%S').lower()
        pass