"""Small adapter for ML-ETLAgent to interact with ProjectService in a minimal way.

This file provides:
- ProjectAdapter: thin wrapper that exposes the tiny set of methods the agent needs.
- A small demo (runnable) that uses a MockStorage to show typical calls.

Keep this tiny and dependency-free so the agent can import and use it easily.
"""
from __future__ import annotations
import json
from typing import Literal, Optional

from ml_module.services.project_service import ProjectService
from ml_module.services.storage_service import MLStorageService
from ml_module.core.artifacts import StoredArtifactInfo


class ProjectAdapter:
    """Thin adapter exposing only the methods ML-ETLAgent typically needs.

    Methods intentionally keep semantics simple so the agent code stays readable.
    """
    def __init__(self, storage_service: MLStorageService):
        self.storage = storage_service
        self._svc = ProjectService(self.storage)

    def create_project(self, user_id: str, project_name: str):
        return self._svc.create_project(user_id, project_name)

    def get_project(self, user_id: str, project_id: str):
        return self._svc.get_project(user_id, project_id)

    def ensure_project(self, user_id: str, project_name: str):
        """Create a project if none exists for user with that name.

        Note: this simple implementation does a linear scan of the user's
        projects. For production you may want an indexed lookup.
        Returns: Project object
        """
        projects = self._svc.list_projects_for_user(user_id)
        for p in projects:
            if getattr(p, 'project_name', None) == project_name:
                return p
        return self._svc.create_project(user_id, project_name)

    def get_artifact_path(self, user_id: str, project_id: str, artifact_type: str, version: Optional[int] = None) -> str:
        return self._svc.get_artifact_path(user_id, project_id, artifact_type, version)

    def bump_version_and_get_path(self, user_id: str, project_id: str, artifact_type: str) -> str:
        """Increment the appropriate version and return the path where the
        agent should write the artifact.
        """
        # Map artifact_type to the semantic version type used by ProjectService
        version_map = {
            'raw': 'raw',
            'processed': 'processed',
            'model': 'model',
            'evaluation': 'evaluation'
        }
        if artifact_type not in version_map:
            # For artifact labels like 'processed_csv' or 'model_artifact'
            # try to match the prefix
            if artifact_type.startswith('processed'):
                v_type = 'processed'
            elif artifact_type.startswith('model'):
                v_type = 'model'
            else:
                v_type = 'processed'
        else:
            v_type = version_map[artifact_type]

        project = self._svc.bump_version(user_id, project_id, v_type)
        # After bump, return canonical path for the new version
        new_version = getattr(project.versions, v_type)
        return self._svc.get_artifact_path(user_id, project_id, artifact_type, version=new_version)

    def save_json(self, data, path: str) -> StoredArtifactInfo:
        return self.storage.save_json(data, path)

    def save_text(self, text: str, path: str) -> StoredArtifactInfo:
        return self.storage.save_text(text, path)

    def register_artifact(
        self,
        user_id: str,
        project_id: str,
        artifact_type: str,
        version: int,
        info: StoredArtifactInfo,
        *,
    version_scope: Optional[Literal["raw", "processed", "model", "evaluation", "draft"]] = None,
        extra_metadata: Optional[dict] = None,
        soft_delete: bool = True,
    ) -> dict:
        return self._svc.register_artifact(
            user_id,
            project_id,
            artifact_type,
            version,
            info,
            version_scope=version_scope,
            extra_metadata=extra_metadata,
            soft_delete=soft_delete,
        )


# ----------------- Demo / sanity runner -----------------
def _demo():
    """Run a tiny demo using an in-memory MockStorage to illustrate usage."""

    class MockStorage:
        def __init__(self):
            self._store = {}

        # The ProjectService expects these methods at minimum
        def save_json(self, data, path):
            self._store[path] = json.dumps(data)

        def load_json(self, path):
            raw = self._store[path]
            return json.loads(raw)

        def list_project_files(self, user_id, project_id):
            prefix = f"{user_id}/{project_id}/"
            return [ {"path": k} for k in self._store.keys() if k.startswith(prefix) ]

        # Minimal attributes used by other code
        client = None

    storage = MockStorage()
    adapter = ProjectAdapter(storage)  # type: ignore[arg-type]

    # Create project
    p = adapter.create_project('alice', 'demo')
    print('created project:', p.project_id)

    # Get canonical path for processed CSV (before any bump)
    path_before = adapter.get_artifact_path('alice', p.project_id, 'processed_csv')
    print('path before bump:', path_before)

    # Bump processed version and get writable path
    writable = adapter.bump_version_and_get_path('alice', p.project_id, 'processed')
    print('writable path after bump:', writable)

    # Save a tiny metadata JSON to that path
    adapter.save_json({'rows': 10}, writable)
    # Confirm stored
    print('stored keys:', list(storage._store.keys()))


if __name__ == '__main__':
    _demo()