from dataclasses import dataclass, asdict, field
from typing import Dict, Optional, List, Any
from datetime import datetime
import os
from .model_utils import determine_base_model


@dataclass
class BaseModelMetadata:
    """Base class for all model metadata structures"""

    file_name: str  # The filename without extension
    model_name: str  # The model's name defined by the creator
    file_path: str  # Full path to the model file
    size: int  # File size in bytes
    modified: float  # Timestamp when the model was added to the management system
    sha256: str  # SHA256 hash of the file
    base_model: str  # Base model type (SD1.5/SD2.1/SDXL/etc.)
    preview_url: str  # Preview image URL
    preview_nsfw_level: int = 0  # NSFW level of the preview image
    notes: str = ""  # Additional notes
    from_civitai: bool = True  # Whether from Civitai
    civitai: Dict[str, Any] = field(
        default_factory=dict
    )  # Civitai API data if available
    tags: List[str] = None  # Model tags
    modelDescription: str = ""  # Full model description
    civitai_deleted: bool = False  # Whether deleted from Civitai
    favorite: bool = False  # Whether the model is a favorite
    exclude: bool = False  # Whether to exclude this model from the cache
    db_checked: bool = False  # Whether checked in archive DB
    skip_metadata_refresh: bool = (
        False  # Whether to skip this model during bulk metadata refresh
    )
    metadata_source: Optional[str] = None  # Last provider that supplied metadata
    last_checked_at: float = 0  # Last checked timestamp
    hash_status: str = "completed"  # Hash calculation status: pending | calculating | completed | failed
    _unknown_fields: Dict[str, Any] = field(
        default_factory=dict, repr=False, compare=False
    )  # Store unknown fields

    def __post_init__(self):
        # Initialize empty lists to avoid mutable default parameter issue
        if self.civitai is None:
            self.civitai = {}

        if self.tags is None:
            self.tags = []

    @classmethod
    def from_dict(cls, data: Dict) -> "BaseModelMetadata":
        """Create instance from dictionary"""
        data_copy = data.copy()

        # Use cached fields if available, otherwise compute them
        if not hasattr(cls, "_known_fields_cache"):
            known_fields = set()
            for c in cls.mro():
                if hasattr(c, "__annotations__"):
                    known_fields.update(c.__annotations__.keys())
            cls._known_fields_cache = known_fields

        known_fields = cls._known_fields_cache

        # Extract fields that match our class attributes
        fields_to_use = {k: v for k, v in data_copy.items() if k in known_fields}

        # Store unknown fields separately
        unknown_fields = {
            k: v
            for k, v in data_copy.items()
            if k not in known_fields and not k.startswith("_")
        }

        # Create instance with known fields
        instance = cls(**fields_to_use)

        # Add unknown fields as a separate attribute
        instance._unknown_fields = unknown_fields

        return instance

    def to_dict(self) -> Dict:
        """Convert to dictionary for JSON serialization"""
        result = asdict(self)

        # Remove private fields
        result = {k: v for k, v in result.items() if not k.startswith("_")}

        # Add back unknown fields if they exist
        if hasattr(self, "_unknown_fields"):
            result.update(self._unknown_fields)

        return result

    def update_civitai_info(self, civitai_data: Dict) -> None:
        """Update Civitai information"""
        self.civitai = civitai_data

    def update_file_info(self, file_path: str, update_timestamps: bool = False) -> None:
        """
        Update metadata with actual file information.

        Args:
            file_path: Path to the model file
            update_timestamps: If True, update size and modified from filesystem.
                              If False (default), only update file_path and file_name.
                              Set to True only when file has been moved/relocated.
        """
        if os.path.exists(file_path):
            if update_timestamps:
                # Only update size and modified when file has been relocated
                self.size = os.path.getsize(file_path)
                self.modified = os.path.getmtime(file_path)
            # Always update paths when this method is called
            self.file_path = file_path.replace(os.sep, "/")
            self.file_name = os.path.splitext(os.path.basename(file_path))[0]

    @staticmethod
    def generate_unique_filename(
        target_dir: str, base_name: str, extension: str, hash_provider: callable = None
    ) -> str:
        """Generate a unique filename to avoid conflicts

        Args:
            target_dir: Target directory path
            base_name: Base filename without extension
            extension: File extension including the dot
            hash_provider: A callable that returns the SHA256 hash when needed

        Returns:
            str: Unique filename that doesn't conflict with existing files
        """
        original_filename = f"{base_name}{extension}"
        target_path = os.path.join(target_dir, original_filename)

        # If no conflict, return original filename
        if not os.path.exists(target_path):
            return original_filename

        # Only compute hash when needed
        if hash_provider:
            sha256_hash = hash_provider()
        else:
            sha256_hash = "0000"

        # Generate short hash (first 4 characters of SHA256)
        short_hash = sha256_hash[:4] if sha256_hash else "0000"

        # Try with short hash suffix
        unique_filename = f"{base_name}-{short_hash}{extension}"
        unique_path = os.path.join(target_dir, unique_filename)

        # If still conflicts, add incremental number
        counter = 1
        while os.path.exists(unique_path):
            unique_filename = f"{base_name}-{short_hash}-{counter}{extension}"
            unique_path = os.path.join(target_dir, unique_filename)
            counter += 1

        return unique_filename


@dataclass
class LoraMetadata(BaseModelMetadata):
    """Represents the metadata structure for a Lora model"""

    usage_tips: str = "{}"  # Usage tips for the model, json string

    @classmethod
    def from_civitai_info(
        cls, version_info: Dict, file_info: Dict, save_path: str
    ) -> "LoraMetadata":
        """Create LoraMetadata instance from Civitai version info"""
        file_name = file_info.get("name", "")
        base_model = determine_base_model(version_info.get("baseModel", ""))

        # Extract tags and description if available
        tags = []
        description = ""
        model_data = version_info.get("model") or {}
        if "tags" in model_data:
            tags = model_data["tags"]
        if "description" in model_data:
            description = model_data["description"]

        return cls(
            file_name=os.path.splitext(file_name)[0],
            model_name=model_data.get("name", os.path.splitext(file_name)[0]),
            file_path=save_path.replace(os.sep, "/"),
            size=file_info.get("sizeKB", 0) * 1024,
            modified=datetime.now().timestamp(),
            sha256=(file_info.get("hashes") or {}).get("SHA256", "").lower(),
            base_model=base_model,
            preview_url="",  # Will be updated after preview download
            preview_nsfw_level=0,  # Will be updated after preview download
            from_civitai=True,
            civitai=version_info,
            tags=tags,
            modelDescription=description,
        )


@dataclass
class CheckpointMetadata(BaseModelMetadata):
    """Represents the metadata structure for a Checkpoint model"""

    sub_type: str = "checkpoint"  # Model sub-type (checkpoint, diffusion_model, etc.)

    @classmethod
    def from_civitai_info(
        cls, version_info: Dict, file_info: Dict, save_path: str
    ) -> "CheckpointMetadata":
        """Create CheckpointMetadata instance from Civitai version info"""
        file_name = file_info.get("name", "")
        base_model = determine_base_model(version_info.get("baseModel", ""))
        sub_type = version_info.get("type", "checkpoint")

        # Extract tags and description if available
        tags = []
        description = ""
        model_data = version_info.get("model") or {}
        if "tags" in model_data:
            tags = model_data["tags"]
        if "description" in model_data:
            description = model_data["description"]

        return cls(
            file_name=os.path.splitext(file_name)[0],
            model_name=model_data.get("name", os.path.splitext(file_name)[0]),
            file_path=save_path.replace(os.sep, "/"),
            size=file_info.get("sizeKB", 0) * 1024,
            modified=datetime.now().timestamp(),
            sha256=(file_info.get("hashes") or {}).get("SHA256", "").lower(),
            base_model=base_model,
            preview_url="",  # Will be updated after preview download
            preview_nsfw_level=0,
            from_civitai=True,
            civitai=version_info,
            sub_type=sub_type,
            tags=tags,
            modelDescription=description,
        )


@dataclass
class EmbeddingMetadata(BaseModelMetadata):
    """Represents the metadata structure for an Embedding model"""

    sub_type: str = "embedding"

    @classmethod
    def from_civitai_info(
        cls, version_info: Dict, file_info: Dict, save_path: str
    ) -> "EmbeddingMetadata":
        """Create EmbeddingMetadata instance from Civitai version info"""
        file_name = file_info.get("name", "")
        base_model = determine_base_model(version_info.get("baseModel", ""))
        sub_type = version_info.get("type", "embedding")

        # Extract tags and description if available
        tags = []
        description = ""
        model_data = version_info.get("model") or {}
        if "tags" in model_data:
            tags = model_data["tags"]
        if "description" in model_data:
            description = model_data["description"]

        return cls(
            file_name=os.path.splitext(file_name)[0],
            model_name=model_data.get("name", os.path.splitext(file_name)[0]),
            file_path=save_path.replace(os.sep, "/"),
            size=file_info.get("sizeKB", 0) * 1024,
            modified=datetime.now().timestamp(),
            sha256=(file_info.get("hashes") or {}).get("SHA256", "").lower(),
            base_model=base_model,
            preview_url="",  # Will be updated after preview download
            preview_nsfw_level=0,
            from_civitai=True,
            civitai=version_info,
            sub_type=sub_type,
            tags=tags,
            modelDescription=description,
        )