# Conversation Context and Follow-up Prompts

## Overview

This document describes how the template-based SPARQL system handles **follow-up prompts** - short questions that only make sense in the context of previous conversation turns. DSPy's `History` mechanism is crucial for resolving these elliptical references.

## The Problem: Elliptical Follow-up Questions

Consider this conversation:

```
User: Welke archieven zijn er in Den Haag?
System: In Den Haag zijn de volgende archieven: Nationaal Archief, Haags Gemeentearchief...

User: En in Enschede?
```

The second prompt "En in Enschede?" is **elliptical** - it omits information that must be inferred from context:
- **What** is being asked about? → archives (from previous question)
- **What kind** of question? → geographic listing (same intent)
- **Full resolved question** → "Welke archieven zijn er in Enschede?"

Without context resolution, "En in Enschede?" would be unmatchable to any template.

## DSPy History Integration

### The History Object

DSPy provides a `History` class for conversation context:

```python
from dspy import History

# History contains previous turns as messages
history = History(messages=[
    {"role": "user", "content": "Welke archieven zijn er in Den Haag?"},
    {"role": "assistant", "content": "In Den Haag zijn de volgende archieven: ..."},
])
```

### Context Resolution Signature

```python
"""DSPy signatures for conversation context resolution."""

import dspy
from dspy import History
from pydantic import BaseModel, Field


class ResolvedQuestion(BaseModel):
    """Resolved question with context filled in."""
    
    original_question: str = Field(
        description="The original (possibly elliptical) question"
    )
    resolved_question: str = Field(
        description="Fully resolved question with all implicit references expanded"
    )
    is_follow_up: bool = Field(
        description="Whether this was a follow-up to a previous question"
    )
    inherited_intent: str | None = Field(
        default=None,
        description="Intent inherited from previous turn (if follow-up)"
    )
    inherited_entities: list[str] = Field(
        default_factory=list,
        description="Entities inherited from previous turns"
    )
    slot_overrides: dict[str, str] = Field(
        default_factory=dict,
        description="Slots that changed from the previous question"
    )
    confidence: float = Field(
        ge=0.0, le=1.0,
        description="Confidence in the resolution"
    )


class ContextResolutionSignature(dspy.Signature):
    """Resolve elliptical follow-up questions using conversation history.
    
    Users often ask follow-up questions that omit information from previous turns.
    Your task is to resolve these elliptical references into fully specified questions.
    
    EXAMPLES OF ELLIPTICAL PATTERNS:
    
    1. Location change (most common):
       Previous: "Welke archieven zijn er in Den Haag?"
       Follow-up: "En in Enschede?"
       Resolved: "Welke archieven zijn er in Enschede?"
       
    2. Type change:
       Previous: "Hoeveel musea zijn er in Utrecht?"
       Follow-up: "En bibliotheken?"
       Resolved: "Hoeveel bibliotheken zijn er in Utrecht?"
       
    3. Pronoun reference:
       Previous: "Wat is het oudste archief in Nederland?"
       Follow-up: "Wie is daar de directeur?"
       Resolved: "Wie is de directeur van [oldest archive name]?"
       
    4. Implicit continuation:
       Previous: "Welke musea zijn er in Amsterdam?"
       Follow-up: "Met een Van Gogh collectie?"
       Resolved: "Welke musea in Amsterdam hebben een Van Gogh collectie?"
       
    5. Comparative follow-up:
       Previous: "Hoeveel archieven zijn er in Noord-Holland?"
       Follow-up: "En in Zuid-Holland?"
       Resolved: "Hoeveel archieven zijn er in Zuid-Holland?"
       
    6. Detail request:
       Previous: "Welke bibliotheken zijn er in Rotterdam?"
       Follow-up: "Meer informatie over de eerste"
       Resolved: "Meer informatie over [first library name from results]"
    
    IMPORTANT:
    - If the question is self-contained, return it unchanged
    - Only inherit context when the question is clearly elliptical
    - Preserve the user's language (Dutch/English)
    - Include ALL necessary information in the resolved question
    """
    
    question: str = dspy.InputField(
        desc="Current user question (may be elliptical)"
    )
    history: History = dspy.InputField(
        desc="Previous conversation turns",
        default=History(messages=[])
    )
    language: str = dspy.InputField(
        desc="Language code (nl, en, de, fr)",
        default="nl"
    )
    previous_results: str = dspy.InputField(
        desc="Results from the previous query (for pronoun resolution)",
        default=""
    )
    
    resolved: ResolvedQuestion = dspy.OutputField(
        desc="Fully resolved question with context"
    )


class ConversationContextResolver(dspy.Module):
    """Resolve elliptical follow-up questions to full questions.
    
    This module is critical for template matching: templates match against
    resolved questions, not the original elliptical input.
    """
    
    def __init__(self, fast_lm: dspy.LM | None = None):
        """Initialize the context resolver.
        
        Args:
            fast_lm: Optional fast LM for context resolution.
                     Recommended: gpt-4o-mini for speed while maintaining quality.
        """
        super().__init__()
        self.fast_lm = fast_lm
        self.resolver = dspy.TypedPredictor(ContextResolutionSignature)
    
    def forward(
        self,
        question: str,
        history: History | None = None,
        language: str = "nl",
        previous_results: str = "",
    ) -> dspy.Prediction:
        """Resolve elliptical question using conversation context.
        
        Args:
            question: Current user question
            history: Previous conversation turns
            language: Language code
            previous_results: Formatted results from previous query
            
        Returns:
            Prediction with resolved question and metadata
        """
        if history is None:
            history = History(messages=[])
        
        # Quick check: if no history, question is self-contained
        if not history.messages:
            return dspy.Prediction(
                original_question=question,
                resolved_question=question,
                is_follow_up=False,
                inherited_intent=None,
                inherited_entities=[],
                slot_overrides={},
                confidence=1.0,
            )
        
        # Use fast LM if configured
        if self.fast_lm:
            with dspy.settings.context(lm=self.fast_lm):
                result = self.resolver(
                    question=question,
                    history=history,
                    language=language,
                    previous_results=previous_results,
                )
        else:
            result = self.resolver(
                question=question,
                history=history,
                language=language,
                previous_results=previous_results,
            )
        
        resolved = result.resolved
        
        return dspy.Prediction(
            original_question=resolved.original_question,
            resolved_question=resolved.resolved_question,
            is_follow_up=resolved.is_follow_up,
            inherited_intent=resolved.inherited_intent,
            inherited_entities=resolved.inherited_entities,
            slot_overrides=resolved.slot_overrides,
            confidence=resolved.confidence,
        )
```

## Template Matching with Context

### Integration Flow

```
User Follow-up: "En in Enschede?"
        |
        v
+------------------------+
| ConversationContext    |  <-- Resolve elliptical reference
| Resolver               |
+------------------------+
        |
        | resolved_question = "Welke archieven zijn er in Enschede?"
        v
+------------------------+
| TemplateClassifier     |  <-- Match against resolved question
+------------------------+
        |
        | template_id = "city_institution_search"
        | slots = {city: "Enschede", type: "A"}
        v
+------------------------+
| TemplateInstantiator   |  <-- Generate SPARQL
+------------------------+
        |
        v
Valid SPARQL Query
```

### Slot Override Detection

When a follow-up changes just one slot, we can optimize by detecting the change:

```python
"""Detect which slots changed in a follow-up question."""

from dataclasses import dataclass


@dataclass
class SlotChange:
    """A change in slot value between turns."""
    
    slot_name: str
    previous_value: str
    new_value: str


class SlotChangeDetector:
    """Detect slot changes between conversation turns."""
    
    # Patterns that indicate slot changes
    LOCATION_CHANGE_PATTERNS = [
        r"^en in (.+)\??$",  # "en in Enschede?"
        r"^in (.+)\??$",     # "in Utrecht?"
        r"^(.+) dan\??$",    # "Utrecht dan?"
    ]
    
    TYPE_CHANGE_PATTERNS = [
        r"^en (.+)\??$",     # "en bibliotheken?"
        r"^(.+) dan\??$",    # "bibliotheken dan?"
    ]
    
    def detect_changes(
        self,
        current_question: str,
        previous_slots: dict[str, str],
        resolved_slots: dict[str, str],
    ) -> list[SlotChange]:
        """Detect which slots changed between turns.
        
        Args:
            current_question: The follow-up question
            previous_slots: Slots from the previous turn
            resolved_slots: Slots extracted from resolved question
            
        Returns:
            List of slot changes
        """
        changes = []
        
        for slot_name, new_value in resolved_slots.items():
            old_value = previous_slots.get(slot_name)
            if old_value and old_value != new_value:
                changes.append(SlotChange(
                    slot_name=slot_name,
                    previous_value=old_value,
                    new_value=new_value,
                ))
        
        return changes


# Example
detector = SlotChangeDetector()

previous_slots = {"institution_type_code": "A", "city_lower": "den haag"}
resolved_slots = {"institution_type_code": "A", "city_lower": "enschede"}

changes = detector.detect_changes(
    "En in Enschede?",
    previous_slots,
    resolved_slots,
)
# -> [SlotChange(slot_name="city_lower", previous_value="den haag", new_value="enschede")]
```

## Conversation State Management

### Tracking Previous Turn Context

```python
"""Manage conversation state for follow-up handling."""

from dataclasses import dataclass, field
from datetime import datetime
from typing import Any


@dataclass
class ConversationTurn:
    """A single turn in the conversation."""
    
    timestamp: datetime
    question: str
    resolved_question: str
    intent: str
    template_id: str | None
    slots: dict[str, str]
    sparql_query: str | None
    results: list[dict]
    answer: str


@dataclass
class ConversationState:
    """State of an ongoing conversation."""
    
    session_id: str
    turns: list[ConversationTurn] = field(default_factory=list)
    current_intent: str | None = None
    current_slots: dict[str, str] = field(default_factory=dict)
    entity_cache: dict[str, Any] = field(default_factory=dict)
    
    def add_turn(self, turn: ConversationTurn) -> None:
        """Add a turn and update current state."""
        self.turns.append(turn)
        self.current_intent = turn.intent
        self.current_slots = turn.slots.copy()
        
        # Cache entities from results for pronoun resolution
        for i, result in enumerate(turn.results[:5]):
            key = f"result_{i}"
            self.entity_cache[key] = result
            
            # Also cache by name for "het eerste" / "the first" references
            if name := result.get("name"):
                self.entity_cache[f"name:{name.lower()}"] = result
    
    def get_previous_turn(self) -> ConversationTurn | None:
        """Get the most recent turn."""
        return self.turns[-1] if self.turns else None
    
    def get_history(self, max_turns: int = 5) -> dspy.History:
        """Get conversation history for DSPy."""
        messages = []
        for turn in self.turns[-max_turns:]:
            messages.append({"role": "user", "content": turn.question})
            messages.append({"role": "assistant", "content": turn.answer})
        return dspy.History(messages=messages)
    
    def format_previous_results(self, max_results: int = 5) -> str:
        """Format previous results for pronoun resolution."""
        prev = self.get_previous_turn()
        if not prev or not prev.results:
            return ""
        
        lines = ["Previous results:"]
        for i, result in enumerate(prev.results[:max_results], 1):
            name = result.get("name", "Unknown")
            typ = result.get("type", "")
            lines.append(f"{i}. {name} ({typ})")
        
        return "\n".join(lines)
```

### Session-Aware RAG Module

```python
"""Heritage RAG with conversation context handling."""

import dspy
from uuid import uuid4


class ConversationAwareHeritageRAG(dspy.Module):
    """Heritage RAG that handles follow-up questions using DSPy History."""
    
    def __init__(self):
        super().__init__()
        self.context_resolver = ConversationContextResolver()
        self.fyke = FykeFilter()
        self.router = HeritageQueryRouter()
        self.template_classifier = TemplateClassifier()
        self.template_instantiator = TemplateInstantiator()
        self.answer_generator = dspy.ChainOfThought(HeritageAnswerGenerator)
        
        # Session storage (in production: Redis or similar)
        self._sessions: dict[str, ConversationState] = {}
    
    def get_or_create_session(self, session_id: str | None = None) -> ConversationState:
        """Get existing session or create new one."""
        if session_id is None:
            session_id = str(uuid4())
        
        if session_id not in self._sessions:
            self._sessions[session_id] = ConversationState(session_id=session_id)
        
        return self._sessions[session_id]
    
    async def answer(
        self,
        question: str,
        session_id: str | None = None,
        language: str = "nl",
    ) -> dspy.Prediction:
        """Answer question with conversation context awareness.
        
        Args:
            question: User's current question (may be elliptical)
            session_id: Session ID for conversation continuity
            language: Language code
            
        Returns:
            Prediction with answer and metadata
        """
        # Get session state
        session = self.get_or_create_session(session_id)
        
        # Step 1: Resolve elliptical references using DSPy History
        history = session.get_history()
        previous_results = session.format_previous_results()
        
        resolution = self.context_resolver(
            question=question,
            history=history,
            language=language,
            previous_results=previous_results,
        )
        
        resolved_question = resolution.resolved_question
        
        # Step 2: Check relevance (fyke)
        relevance = self.fyke(question=resolved_question, language=language)
        
        if relevance.caught_by_fyke:
            return dspy.Prediction(
                answer=relevance.fyke_response,
                caught_by_fyke=True,
                session_id=session.session_id,
            )
        
        # Step 3: Route using resolved question
        routing = self.router(
            question=resolved_question,
            language=language,
            history=history,  # Pass history to router for additional context
        )
        
        # Step 4: Template classification
        # Use inherited intent from context resolution if available
        effective_intent = resolution.inherited_intent or routing.intent
        
        template_match = self.template_classifier(
            question=resolved_question,
            intent=effective_intent,
            entities=routing.entities,
        )
        
        # Step 5: Handle slot inheritance for follow-ups
        if resolution.is_follow_up and session.current_slots:
            # Merge: current slots from session + overrides from new question
            merged_slots = session.current_slots.copy()
            merged_slots.update(resolution.slot_overrides)
            merged_slots.update(template_match.slots)
            effective_slots = merged_slots
        else:
            effective_slots = template_match.slots
        
        # Step 6: Generate and execute SPARQL
        sparql_query = None
        results = []
        
        if template_match.template_id and template_match.confidence > 0.7:
            try:
                sparql_query = self.template_instantiator.instantiate(
                    template_id=template_match.template_id,
                    slots=effective_slots,
                )
                results = await self.execute_sparql(sparql_query)
            except Exception as e:
                logger.warning(f"Template instantiation failed: {e}")
        
        # Step 7: Fallback to vector search if needed
        if not results:
            results = await self.qdrant_search(resolved_question)
        
        # Step 8: Generate answer
        context = self._format_results(results)
        answer_result = self.answer_generator(
            question=resolved_question,
            context=context,
            history=history,
            sources=["sparql" if sparql_query else "qdrant"],
            language=language,
        )
        
        # Step 9: Update session state
        turn = ConversationTurn(
            timestamp=datetime.now(),
            question=question,  # Original question
            resolved_question=resolved_question,
            intent=effective_intent,
            template_id=template_match.template_id,
            slots=effective_slots,
            sparql_query=sparql_query,
            results=results,
            answer=answer_result.answer,
        )
        session.add_turn(turn)
        
        return dspy.Prediction(
            answer=answer_result.answer,
            original_question=question,
            resolved_question=resolved_question,
            is_follow_up=resolution.is_follow_up,
            slot_changes=resolution.slot_overrides,
            template_id=template_match.template_id,
            sparql_query=sparql_query,
            confidence=answer_result.confidence,
            session_id=session.session_id,
            citations=answer_result.citations,
            follow_up_suggestions=answer_result.follow_up,
        )
```

## Follow-up Pattern Taxonomy

### Common Elliptical Patterns

| Pattern | Example | Resolution Strategy |
|---------|---------|---------------------|
| **Location swap** | "En in Enschede?" | Replace location slot, keep other slots |
| **Type swap** | "En bibliotheken?" | Replace type slot, keep location |
| **Comparative** | "En in Zuid-Holland?" | Replace region, keep intent and type |
| **Pronoun reference** | "Wie is daar de directeur?" | Resolve "daar" to entity from results |
| **Ordinal reference** | "Meer over de eerste" | Map "eerste" to first result |
| **Implicit continuation** | "Met een Van Gogh collectie?" | Add filter to previous query |
| **Negation** | "Welke niet?" | Negate previous filter |
| **Quantifier change** | "Hoeveel dan?" | Change SELECT to COUNT |

### Pattern Detection Rules

```python
"""Rules for detecting follow-up patterns."""

import re
from dataclasses import dataclass
from enum import Enum


class FollowUpPattern(Enum):
    """Types of follow-up patterns."""
    
    LOCATION_SWAP = "location_swap"
    TYPE_SWAP = "type_swap"
    PRONOUN_REFERENCE = "pronoun_reference"
    ORDINAL_REFERENCE = "ordinal_reference"
    IMPLICIT_CONTINUATION = "implicit_continuation"
    NEGATION = "negation"
    QUANTIFIER_CHANGE = "quantifier_change"
    DETAIL_REQUEST = "detail_request"
    SELF_CONTAINED = "self_contained"


@dataclass
class PatternRule:
    """Rule for detecting a follow-up pattern."""
    
    pattern: FollowUpPattern
    regex: str
    slot_affected: str | None
    description: str


# Dutch follow-up pattern rules
DUTCH_PATTERN_RULES = [
    PatternRule(
        pattern=FollowUpPattern.LOCATION_SWAP,
        regex=r"^en\s+in\s+(.+?)\??$",
        slot_affected="location",
        description="Location change: 'en in X?'",
    ),
    PatternRule(
        pattern=FollowUpPattern.LOCATION_SWAP,
        regex=r"^in\s+(.+?)\??$",
        slot_affected="location",
        description="Location query: 'in X?'",
    ),
    PatternRule(
        pattern=FollowUpPattern.TYPE_SWAP,
        regex=r"^en\s+(musea|bibliotheken|archieven|galerieën)\??$",
        slot_affected="institution_type",
        description="Type change: 'en bibliotheken?'",
    ),
    PatternRule(
        pattern=FollowUpPattern.PRONOUN_REFERENCE,
        regex=r".*(daar|die|deze|dat|daarin|hiervan).*",
        slot_affected=None,
        description="Pronoun reference requiring entity resolution",
    ),
    PatternRule(
        pattern=FollowUpPattern.ORDINAL_REFERENCE,
        regex=r".*(eerste|tweede|derde|laatste|vorige).*",
        slot_affected=None,
        description="Ordinal reference to results",
    ),
    PatternRule(
        pattern=FollowUpPattern.DETAIL_REQUEST,
        regex=r"^meer\s+(informatie|details|over)\s+.*$",
        slot_affected=None,
        description="Request for more details",
    ),
    PatternRule(
        pattern=FollowUpPattern.QUANTIFIER_CHANGE,
        regex=r"^hoeveel\s+(dan|er)?\??$",
        slot_affected=None,
        description="Change to count query",
    ),
]


class FollowUpPatternDetector:
    """Detect follow-up patterns in questions."""
    
    def __init__(self, language: str = "nl"):
        self.language = language
        self.rules = DUTCH_PATTERN_RULES  # Could extend for other languages
    
    def detect(self, question: str) -> tuple[FollowUpPattern, re.Match | None]:
        """Detect the follow-up pattern in a question.
        
        Args:
            question: The user's question
            
        Returns:
            Tuple of (pattern_type, regex_match)
        """
        question_lower = question.lower().strip()
        
        for rule in self.rules:
            match = re.match(rule.regex, question_lower, re.IGNORECASE)
            if match:
                return rule.pattern, match
        
        return FollowUpPattern.SELF_CONTAINED, None
    
    def get_slot_to_change(self, pattern: FollowUpPattern) -> str | None:
        """Get which slot should change for a pattern."""
        for rule in self.rules:
            if rule.pattern == pattern:
                return rule.slot_affected
        return None
```

## DSPy Optimization for Context Resolution

### Training Data for Context Resolver

```python
"""Training examples for context resolution optimization."""

CONTEXT_RESOLUTION_TRAINING = [
    # Location swap examples
    dspy.Example(
        question="En in Enschede?",
        history=dspy.History(messages=[
            {"role": "user", "content": "Welke archieven zijn er in Den Haag?"},
            {"role": "assistant", "content": "In Den Haag zijn de volgende archieven: ..."},
        ]),
        language="nl",
        resolved=ResolvedQuestion(
            original_question="En in Enschede?",
            resolved_question="Welke archieven zijn er in Enschede?",
            is_follow_up=True,
            inherited_intent="geographic",
            inherited_entities=["archive"],
            slot_overrides={"city_lower": "enschede"},
            confidence=0.95,
        ),
    ).with_inputs("question", "history", "language"),
    
    # Type swap examples
    dspy.Example(
        question="En bibliotheken?",
        history=dspy.History(messages=[
            {"role": "user", "content": "Hoeveel musea zijn er in Utrecht?"},
            {"role": "assistant", "content": "Er zijn 15 musea in Utrecht."},
        ]),
        language="nl",
        resolved=ResolvedQuestion(
            original_question="En bibliotheken?",
            resolved_question="Hoeveel bibliotheken zijn er in Utrecht?",
            is_follow_up=True,
            inherited_intent="statistical",
            inherited_entities=["library", "Utrecht"],
            slot_overrides={"institution_type_code": "L"},
            confidence=0.95,
        ),
    ).with_inputs("question", "history", "language"),
    
    # Pronoun resolution
    dspy.Example(
        question="Wie is daar de directeur?",
        history=dspy.History(messages=[
            {"role": "user", "content": "Wat is het oudste archief in Nederland?"},
            {"role": "assistant", "content": "Het oudste archief is het Nationaal Archief, opgericht in 1802."},
        ]),
        previous_results="Previous results:\n1. Nationaal Archief (Archive)",
        language="nl",
        resolved=ResolvedQuestion(
            original_question="Wie is daar de directeur?",
            resolved_question="Wie is de directeur van het Nationaal Archief?",
            is_follow_up=True,
            inherited_intent="entity_lookup",
            inherited_entities=["Nationaal Archief"],
            slot_overrides={"institution_slug": "nationaal-archief"},
            confidence=0.90,
        ),
    ).with_inputs("question", "history", "language", "previous_results"),
    
    # Self-contained question (no context needed)
    dspy.Example(
        question="Hoeveel musea zijn er in Amsterdam?",
        history=dspy.History(messages=[
            {"role": "user", "content": "Welke archieven zijn er in Den Haag?"},
            {"role": "assistant", "content": "In Den Haag zijn de volgende archieven: ..."},
        ]),
        language="nl",
        resolved=ResolvedQuestion(
            original_question="Hoeveel musea zijn er in Amsterdam?",
            resolved_question="Hoeveel musea zijn er in Amsterdam?",
            is_follow_up=False,
            inherited_intent=None,
            inherited_entities=[],
            slot_overrides={},
            confidence=0.98,
        ),
    ).with_inputs("question", "history", "language"),
]


def optimize_context_resolver():
    """Optimize the context resolver using GEPA."""
    
    resolver = ConversationContextResolver()
    
    # Define metric
    def resolution_metric(example: dspy.Example, prediction: dspy.Prediction) -> float:
        """Score context resolution quality."""
        score = 0.0
        
        # Check resolved question matches
        if prediction.resolved_question == example.resolved.resolved_question:
            score += 0.4
        elif example.resolved.resolved_question.lower() in prediction.resolved_question.lower():
            score += 0.2
        
        # Check is_follow_up detection
        if prediction.is_follow_up == example.resolved.is_follow_up:
            score += 0.2
        
        # Check inherited intent
        if prediction.inherited_intent == example.resolved.inherited_intent:
            score += 0.2
        
        # Check slot overrides
        expected_overrides = set(example.resolved.slot_overrides.items())
        actual_overrides = set(prediction.slot_overrides.items())
        if expected_overrides == actual_overrides:
            score += 0.2
        elif expected_overrides & actual_overrides:
            score += 0.1
        
        return score
    
    # Optimize
    from dspy import GEPA
    
    optimizer = GEPA(
        metric=resolution_metric,
        auto="light",
    )
    
    optimized_resolver = optimizer.compile(
        resolver,
        trainset=CONTEXT_RESOLUTION_TRAINING,
    )
    
    return optimized_resolver
```

## Testing Follow-up Handling

### Test Cases

```python
"""Test cases for follow-up handling."""

import pytest


@pytest.mark.parametrize("question,history_q,expected_resolved", [
    # Location swap
    (
        "En in Enschede?",
        "Welke archieven zijn er in Den Haag?",
        "Welke archieven zijn er in Enschede?",
    ),
    # Type swap
    (
        "En bibliotheken?",
        "Hoeveel musea zijn er in Utrecht?",
        "Hoeveel bibliotheken zijn er in Utrecht?",
    ),
    # Province swap
    (
        "En in Zuid-Holland?",
        "Hoeveel archieven zijn er in Noord-Holland?",
        "Hoeveel archieven zijn er in Zuid-Holland?",
    ),
    # Self-contained (should not change)
    (
        "Hoeveel musea zijn er in Amsterdam?",
        "Welke archieven zijn er in Den Haag?",
        "Hoeveel musea zijn er in Amsterdam?",
    ),
])
def test_context_resolution(question, history_q, expected_resolved):
    """Test that follow-ups are correctly resolved."""
    resolver = ConversationContextResolver()
    
    history = dspy.History(messages=[
        {"role": "user", "content": history_q},
        {"role": "assistant", "content": "..."},
    ])
    
    result = resolver(question=question, history=history, language="nl")
    
    assert result.resolved_question == expected_resolved


@pytest.mark.parametrize("question,expected_pattern", [
    ("En in Enschede?", FollowUpPattern.LOCATION_SWAP),
    ("En bibliotheken?", FollowUpPattern.TYPE_SWAP),
    ("Wie is daar de directeur?", FollowUpPattern.PRONOUN_REFERENCE),
    ("Meer over de eerste", FollowUpPattern.DETAIL_REQUEST),
    ("Hoeveel dan?", FollowUpPattern.QUANTIFIER_CHANGE),
    ("Welke musea zijn er in Amsterdam?", FollowUpPattern.SELF_CONTAINED),
])
def test_pattern_detection(question, expected_pattern):
    """Test follow-up pattern detection."""
    detector = FollowUpPatternDetector(language="nl")
    pattern, _ = detector.detect(question)
    assert pattern == expected_pattern
```

## Summary

Handling follow-up prompts requires:

| Component | Purpose | DSPy Integration |
|-----------|---------|------------------|
| **ConversationContextResolver** | Resolve elliptical references | TypedPredictor with History |
| **ConversationState** | Track slots across turns | Enables slot inheritance |
| **FollowUpPatternDetector** | Detect pattern type | Guides resolution strategy |
| **SlotChangeDetector** | Identify changed slots | Enables efficient query modification |

### Key Principles

1. **Always resolve before matching** - Templates match against resolved questions
2. **Inherit slots from previous turns** - Only override what changed
3. **Use DSPy History** - Native support for conversation context
4. **Optimize with training data** - GEPA can improve resolution quality
5. **Cache entity results** - Enable pronoun/ordinal resolution

### Example Conversation Flow

```
Turn 1:
  User: "Welke archieven zijn er in Den Haag?"
  Resolved: "Welke archieven zijn er in Den Haag?"
  Template: region_institution_search
  Slots: {type: "A", city: "den haag"}

Turn 2:
  User: "En in Enschede?"
  Resolved: "Welke archieven zijn er in Enschede?"  <-- Context used
  Template: region_institution_search (same)
  Slots: {type: "A", city: "enschede"}  <-- Only city changed

Turn 3:
  User: "En bibliotheken?"
  Resolved: "Welke bibliotheken zijn er in Enschede?"  <-- Context used
  Template: region_institution_search (same)
  Slots: {type: "L", city: "enschede"}  <-- Only type changed
```