"""
LoreService for retrieving contextual lore for NPC conversations.

This module provides an interface for lore retrieval that will be
implemented with Weaviate in Phase 6. For now, it provides a mock
implementation that returns embedded lore from quest definitions.

The service follows a three-tier knowledge hierarchy:
1. World Lore - Global history, mythology, kingdoms
2. Regional Lore - Local history, landmarks, rumors
3. NPC Persona - Individual NPC knowledge (already in NPC YAML)
"""

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Dict, List, Any, Optional, Protocol
import structlog

from app.models.quest import Quest, QuestLoreContext
from app.models.npc import NPC

logger = structlog.get_logger(__name__)


@dataclass
class LoreEntry:
    """
    A single piece of lore information.

    Attributes:
        content: The lore text content
        title: Optional title for the lore entry
        knowledge_type: Type of knowledge (common, academic, secret)
        source: Where this lore came from (world, regional, quest)
        metadata: Additional metadata for filtering
    """

    content: str
    title: str = ""
    knowledge_type: str = "common"
    source: str = "quest"
    metadata: Dict[str, Any] = field(default_factory=dict)

    def to_dict(self) -> Dict[str, Any]:
        """Serialize to dictionary."""
        return {
            "content": self.content,
            "title": self.title,
            "knowledge_type": self.knowledge_type,
            "source": self.source,
            "metadata": self.metadata,
        }


@dataclass
class LoreContext:
    """
    Aggregated lore context for AI prompts.

    Contains lore from multiple sources, filtered for the current
    NPC and conversation context.

    Attributes:
        world_lore: Global world knowledge entries
        regional_lore: Local/regional knowledge entries
        quest_lore: Quest-specific lore entries
    """

    world_lore: List[LoreEntry] = field(default_factory=list)
    regional_lore: List[LoreEntry] = field(default_factory=list)
    quest_lore: List[LoreEntry] = field(default_factory=list)

    def to_dict(self) -> Dict[str, Any]:
        """Serialize to dictionary for AI prompt injection."""
        return {
            "world": [entry.to_dict() for entry in self.world_lore],
            "regional": [entry.to_dict() for entry in self.regional_lore],
            "quest": [entry.to_dict() for entry in self.quest_lore],
        }

    def has_content(self) -> bool:
        """Check if any lore content is available."""
        return bool(self.world_lore or self.regional_lore or self.quest_lore)


class LoreServiceInterface(ABC):
    """
    Abstract interface for lore services.

    This interface allows swapping between MockLoreService (current)
    and WeaviateLoreService (Phase 6) without changing calling code.
    """

    @abstractmethod
    def get_lore_context(
        self,
        npc: NPC,
        quest: Optional[Quest] = None,
        topic: str = "",
        region_id: str = "",
    ) -> LoreContext:
        """
        Get lore context for an NPC conversation.

        Args:
            npc: The NPC in the conversation
            quest: Optional quest being discussed
            topic: Topic of conversation for semantic search
            region_id: Region to filter lore by

        Returns:
            LoreContext with relevant lore entries
        """
        pass

    @abstractmethod
    def filter_lore_for_npc(
        self,
        lore_entries: List[LoreEntry],
        npc: NPC,
    ) -> List[LoreEntry]:
        """
        Filter lore entries based on what an NPC would know.

        Args:
            lore_entries: Raw lore entries
            npc: The NPC to filter for

        Returns:
            Filtered list of lore entries
        """
        pass


class MockLoreService(LoreServiceInterface):
    """
    Mock implementation of LoreService using embedded quest lore.

    This implementation returns lore directly from quest YAML files
    until Weaviate is implemented in Phase 6. It provides a working
    lore system without external dependencies.
    """

    # NPC roles that have access to academic knowledge
    ACADEMIC_ROLES = ["scholar", "wizard", "sage", "librarian", "priest", "mage"]

    # NPC roles that might know secrets
    SECRET_KEEPER_ROLES = ["mayor", "noble", "spy", "elder", "priest"]

    def __init__(self):
        """Initialize the mock lore service."""
        logger.info("MockLoreService initialized")

    def get_lore_context(
        self,
        npc: NPC,
        quest: Optional[Quest] = None,
        topic: str = "",
        region_id: str = "",
    ) -> LoreContext:
        """
        Get lore context for an NPC conversation.

        For the mock implementation, this primarily returns quest
        embedded lore and some static regional/world hints.

        Args:
            npc: The NPC in the conversation
            quest: Optional quest being discussed
            topic: Topic of conversation (unused in mock)
            region_id: Region to filter by

        Returns:
            LoreContext with available lore
        """
        context = LoreContext()

        # Add quest-specific lore if a quest is provided
        if quest and quest.lore_context:
            quest_entries = self._extract_quest_lore(quest)
            context.quest_lore = self.filter_lore_for_npc(quest_entries, npc)

        # Add some mock regional lore based on NPC location
        regional_entries = self._get_mock_regional_lore(npc.location_id, region_id)
        context.regional_lore = self.filter_lore_for_npc(regional_entries, npc)

        # Add world lore if NPC is knowledgeable
        if npc.role in self.ACADEMIC_ROLES:
            world_entries = self._get_mock_world_lore()
            context.world_lore = self.filter_lore_for_npc(world_entries, npc)

        logger.debug(
            "Lore context built",
            npc_id=npc.npc_id,
            quest_lore_count=len(context.quest_lore),
            regional_lore_count=len(context.regional_lore),
            world_lore_count=len(context.world_lore),
        )

        return context

    def filter_lore_for_npc(
        self,
        lore_entries: List[LoreEntry],
        npc: NPC,
    ) -> List[LoreEntry]:
        """
        Filter lore entries based on what an NPC would know.

        Args:
            lore_entries: Raw lore entries
            npc: The NPC to filter for

        Returns:
            Filtered list of lore entries
        """
        filtered = []

        for entry in lore_entries:
            knowledge_type = entry.knowledge_type

            # Academic knowledge requires appropriate role
            if knowledge_type == "academic":
                if npc.role not in self.ACADEMIC_ROLES:
                    continue

            # Secret knowledge requires special role or tag
            if knowledge_type == "secret":
                if npc.role not in self.SECRET_KEEPER_ROLES:
                    if "secret_keeper" not in npc.tags:
                        continue

            filtered.append(entry)

        return filtered

    def _extract_quest_lore(self, quest: Quest) -> List[LoreEntry]:
        """
        Extract lore entries from a quest's embedded lore context.

        Args:
            quest: The quest to extract lore from

        Returns:
            List of LoreEntry objects
        """
        entries = []
        lore = quest.lore_context

        # Add backstory as a lore entry
        if lore.backstory:
            entries.append(LoreEntry(
                content=lore.backstory,
                title=f"Background: {quest.name}",
                knowledge_type="common",
                source="quest",
                metadata={"quest_id": quest.quest_id},
            ))

        # Add world connections
        for connection in lore.world_connections:
            entries.append(LoreEntry(
                content=connection,
                title="World Connection",
                knowledge_type="common",
                source="quest",
                metadata={"quest_id": quest.quest_id},
            ))

        # Add regional hints
        for hint in lore.regional_hints:
            entries.append(LoreEntry(
                content=hint,
                title="Local Knowledge",
                knowledge_type="common",
                source="quest",
                metadata={"quest_id": quest.quest_id},
            ))

        return entries

    def _get_mock_regional_lore(
        self,
        location_id: str,
        region_id: str,
    ) -> List[LoreEntry]:
        """
        Get mock regional lore for a location.

        This provides basic regional context until Weaviate is implemented.

        Args:
            location_id: Specific location
            region_id: Region identifier

        Returns:
            List of LoreEntry objects
        """
        entries = []

        # Crossville regional lore
        if "crossville" in location_id.lower() or region_id == "crossville":
            entries.extend([
                LoreEntry(
                    content="Crossville was founded two hundred years ago as a trading post.",
                    title="Crossville History",
                    knowledge_type="common",
                    source="regional",
                ),
                LoreEntry(
                    content="The Old Mines were sealed fifty years ago after a tragic accident.",
                    title="The Old Mines",
                    knowledge_type="common",
                    source="regional",
                ),
                LoreEntry(
                    content="The Thornwood family has led the village for three generations.",
                    title="Village Leadership",
                    knowledge_type="common",
                    source="regional",
                ),
            ])

        return entries

    def _get_mock_world_lore(self) -> List[LoreEntry]:
        """
        Get mock world-level lore.

        This provides basic world context until Weaviate is implemented.

        Returns:
            List of LoreEntry objects
        """
        return [
            LoreEntry(
                content="The Five Kingdoms united against the Shadow Empire two hundred years ago in a great war.",
                title="The Great War",
                knowledge_type="academic",
                source="world",
            ),
            LoreEntry(
                content="Magic flows from the ley lines that crisscross the land, concentrated at ancient sites.",
                title="The Nature of Magic",
                knowledge_type="academic",
                source="world",
            ),
            LoreEntry(
                content="The ancient ruins predate human settlement and are believed to be from the First Age.",
                title="First Age Ruins",
                knowledge_type="academic",
                source="world",
            ),
        ]


# Global singleton instance
_service_instance: Optional[LoreServiceInterface] = None


def get_lore_service() -> LoreServiceInterface:
    """
    Get the global LoreService instance.

    Currently returns MockLoreService. In Phase 6, this will
    be updated to return WeaviateLoreService.

    Returns:
        Singleton LoreService instance
    """
    global _service_instance
    if _service_instance is None:
        _service_instance = MockLoreService()
    return _service_instance