# [DEF:backend.src.services.mapping_service:Module]
#
# @SEMANTICS: service, mapping, fuzzy-matching, superset
# @PURPOSE:   Orchestrates database fetching and fuzzy matching suggestions.
# @LAYER:     Service
# @RELATION:  DEPENDS_ON -> backend.src.core.superset_client
# @RELATION:  DEPENDS_ON -> backend.src.core.utils.matching
#
# @INVARIANT: Suggestions are based on database names.

# [SECTION: IMPORTS]
from typing import List, Dict
from backend.src.core.superset_client import SupersetClient
from backend.src.core.utils.matching import suggest_mappings
from superset_tool.models import SupersetConfig
# [/SECTION]

# [DEF:MappingService:Class]
# @PURPOSE: Service for handling database mapping logic.
class MappingService:
    
    # [DEF:MappingService.__init__:Function]
    def __init__(self, config_manager):
        self.config_manager = config_manager

    # [DEF:MappingService._get_client:Function]
    # @PURPOSE: Helper to get an initialized SupersetClient for an environment.
    def _get_client(self, env_id: str) -> SupersetClient:
        envs = self.config_manager.get_environments()
        env = next((e for e in envs if e.id == env_id), None)
        if not env:
            raise ValueError(f"Environment {env_id} not found")
        
        superset_config = SupersetConfig(
            env=env.name,
            base_url=env.url,
            auth={
                "provider": "db",
                "username": env.username,
                "password": env.password,
                "refresh": "false"
            }
        )
        return SupersetClient(superset_config)

    # [DEF:MappingService.get_suggestions:Function]
    # @PURPOSE: Fetches databases from both environments and returns fuzzy matching suggestions.
    # @PARAM:   source_env_id (str) - Source environment ID.
    # @PARAM:   target_env_id (str) - Target environment ID.
    # @RETURN:  List[Dict] - Suggested mappings.
    async def get_suggestions(self, source_env_id: str, target_env_id: str) -> List[Dict]:
        """
        Get suggested mappings between two environments.
        """
        source_client = self._get_client(source_env_id)
        target_client = self._get_client(target_env_id)
        
        source_dbs = source_client.get_databases_summary()
        target_dbs = target_client.get_databases_summary()
        
        return suggest_mappings(source_dbs, target_dbs)
    # [/DEF:MappingService.get_suggestions]

# [/DEF:MappingService]

# [/DEF:backend.src.services.mapping_service]