# Copyright 2023, Lincoln D. Stein and the InvokeAI Team
"""
Abstract base class and implementation for recursive directory search for models.

Example usage:
```
  from invokeai.backend.model_manager import ModelSearch, ModelProbe

  def find_main_models(model: Path) -> bool:
    info = ModelProbe.probe(model)
    if info.model_type == 'main' and info.base_type == 'sd-1':
        return True
    else:
        return False

  search = ModelSearch(on_model_found=report_it)
  found = search.search('/tmp/models')
  print(found)   #  list of matching model paths
  print(search.stats)  #  search stats
```
"""

import os
from abc import ABC, abstractmethod
from logging import Logger
from pathlib import Path
from typing import Callable, Optional, Set, Union

from pydantic import BaseModel, Field

from invokeai.app.services.config import InvokeAIAppConfig
from invokeai.backend.util.logging import InvokeAILogger

default_logger: Logger = InvokeAILogger.get_logger()


class SearchStats(BaseModel):
    items_scanned: int = 0
    models_found: int = 0
    models_filtered: int = 0


class ModelSearchBase(ABC, BaseModel):
    """
    Abstract directory traversal model search class

    Usage:
       search = ModelSearchBase(
            on_search_started = search_started_callback,
            on_search_completed = search_completed_callback,
            on_model_found = model_found_callback,
       )
       models_found = search.search('/path/to/directory')
    """

    # fmt: off
    on_search_started   : Optional[Callable[[Path], None]]      = Field(default=None, description="Called just before the search starts.")  # noqa E221
    on_model_found      : Optional[Callable[[Path], bool]]      = Field(default=None, description="Called when a model is found.")          # noqa E221
    on_search_completed : Optional[Callable[[Set[Path]], None]] = Field(default=None, description="Called when search is complete.")        # noqa E221
    stats               : SearchStats                           = Field(default_factory=SearchStats, description="Summary statistics after search")  # noqa E221
    logger              : Logger                                = Field(default=default_logger, description="Logger instance.")     # noqa E221
    # fmt: on

    class Config:
        arbitrary_types_allowed = True

    @abstractmethod
    def search_started(self) -> None:
        """
        Called before the scan starts.

        Passes the root search directory to the Callable `on_search_started`.
        """
        pass

    @abstractmethod
    def model_found(self, model: Path) -> None:
        """
        Called when a model is found during search.

        :param model: Model to process - could be a directory or checkpoint.

        Passes the model's Path to the Callable `on_model_found`.
        This Callable receives the path to the model and returns a boolean
        to indicate whether the model should be returned in the search
        results.
        """
        pass

    @abstractmethod
    def search_completed(self) -> None:
        """
        Called before the scan starts.

        Passes the Set of found model Paths to the Callable `on_search_completed`.
        """
        pass

    @abstractmethod
    def search(self, directory: Union[Path, str]) -> Set[Path]:
        """
        Recursively search for models in `directory` and return a set of model paths.

        If provided, the `on_search_started`, `on_model_found` and `on_search_completed`
        Callables will be invoked during the search.
        """
        pass


class ModelSearch(ModelSearchBase):
    """
    Implementation of ModelSearch with callbacks.
    Usage:
       search = ModelSearch()
       search.model_found = lambda path : 'anime' in path.as_posix()
       found = search.list_models(['/tmp/models1','/tmp/models2'])
       # returns all models that have 'anime' in the path
    """

    models_found: Set[Path] = Field(default_factory=set)
    config: InvokeAIAppConfig = InvokeAIAppConfig.get_config()

    def search_started(self) -> None:
        self.models_found = set()
        if self.on_search_started:
            self.on_search_started(self._directory)

    def model_found(self, model: Path) -> None:
        self.stats.models_found += 1
        if self.on_model_found is None or self.on_model_found(model):
            self.stats.models_filtered += 1
            self.models_found.add(model)

    def search_completed(self) -> None:
        if self.on_search_completed is not None:
            self.on_search_completed(self.models_found)

    def search(self, directory: Union[Path, str]) -> Set[Path]:
        self._directory = Path(directory)
        if not self._directory.is_absolute():
            self._directory = self.config.models_path / self._directory
        self.stats = SearchStats()  # zero out
        self.search_started()  # This will initialize _models_found to empty
        self._walk_directory(self._directory)
        self.search_completed()
        return self.models_found

    def _walk_directory(self, path: Union[Path, str], max_depth: int = 20) -> None:
        absolute_path = Path(path)
        if (
            len(absolute_path.parts) - len(self._directory.parts) > max_depth
            or not absolute_path.exists()
            or absolute_path.parent in self.models_found
        ):
            return
        entries = os.scandir(absolute_path.as_posix())
        entries = [entry for entry in entries if not entry.name.startswith(".")]
        dirs = [entry for entry in entries if entry.is_dir()]
        file_names = [entry.name for entry in entries if entry.is_file()]
        if any(
            x in file_names
            for x in [
                "config.json",
                "model_index.json",
                "learned_embeds.bin",
                "pytorch_lora_weights.bin",
                "image_encoder.txt",
            ]
        ):
            try:
                self.model_found(absolute_path)
                return
            except KeyboardInterrupt:
                raise
            except Exception as e:
                self.logger.warning(str(e))
                return

        for n in file_names:
            if n.endswith((".ckpt", ".bin", ".pth", ".safetensors", ".pt")):
                try:
                    self.model_found(absolute_path / n)
                except KeyboardInterrupt:
                    raise
                except Exception as e:
                    self.logger.warning(str(e))

        for d in dirs:
            self._walk_directory(absolute_path / d)