"""
Modular strategy that demonstrates usage of the new constraint_checking and candidate_exploration modules.
Enhanced with LLM-driven constraint processing, early rejection, and immediate evaluation.
"""

import asyncio
import json
from concurrent.futures import ThreadPoolExecutor, as_completed
from dataclasses import dataclass
from typing import Dict, List, Optional, Tuple

from loguru import logger

from ...utilities.search_cache import get_search_cache, normalize_entity_query
from ..candidate_exploration import (
    AdaptiveExplorer,
    ConstraintGuidedExplorer,
    DiversityExplorer,
    ParallelExplorer,
)
from ..constraint_checking import (
    DualConfidenceChecker,
    StrictChecker,
    ThresholdChecker,
)
from ..constraints import ConstraintAnalyzer
from ..questions import StandardQuestionGenerator
from .base_strategy import BaseSearchStrategy


@dataclass
class CandidateConfidence:
    """Track candidate confidence levels for early rejection"""

    candidate: object
    positive_confidence: float
    negative_confidence: float
    rejection_reason: Optional[str] = None
    should_continue: bool = True


class LLMConstraintProcessor:
    """LLM-driven intelligent constraint processing"""

    def __init__(self, model):
        self.model = model

    async def decompose_constraints_intelligently(self, constraints):
        """Let LLM intelligently break down constraints into searchable elements"""
        constraint_text = "\n".join([f"- {c.description}" for c in constraints])

        prompt = f"""
        I have these constraints from a search query:
        {constraint_text}

        Please intelligently decompose these constraints into atomic, searchable elements that can be combined in different ways.

        For each constraint, provide:
        1. **Atomic elements** - Break it into smallest meaningful parts
        2. **Variations** - Different ways to express the same concept
        3. **Granular specifics** - Specific values, years, numbers, etc.

        Example for a time-based constraint:
        - Atomic elements: Break down the main subject into searchable terms
        - Time variations: Different ways to express time periods
        - Granular specifics: Individual years, dates, or specific values mentioned

        Return as valid JSON format:
        {{
            "constraint_1": {{
                "atomic_elements": [...],
                "variations": [...],
                "granular_specifics": [...]
            }},
            "constraint_2": {{
                "atomic_elements": [...],
                "variations": [...],
                "granular_specifics": [...]
            }}
        }}
        """

        response = await self.model.ainvoke(prompt)
        return self._parse_decomposition(response.content)

    async def generate_intelligent_combinations(
        self, decomposed_constraints, existing_queries=None, original_query=None
    ):
        """LLM generates smart combinations of atomic elements"""

        if existing_queries is None:
            existing_queries = []

        existing_queries_str = (
            "\n".join([f"- {q}" for q in existing_queries])
            if existing_queries
            else "None yet"
        )

        # Store all queries we've used to avoid repeats
        if existing_queries is None:
            existing_queries = []

        # Add the original query as first in our tracking
        all_queries_used = (
            [original_query] + existing_queries
            if original_query
            else existing_queries
        )
        existing_queries_str = (
            "\n".join([f"- {q}" for q in all_queries_used])
            if all_queries_used
            else "None yet"
        )

        prompt = f"""
        Create search query variations using TWO strategies:

        ORIGINAL QUERY: "{original_query if original_query else "Not provided"}"

        ALREADY USED QUERIES (DO NOT REPEAT):
        {existing_queries_str}

        **STRATEGY 1: QUERY REFORMULATION** (5-8 variations)
        Keep ALL key information but rephrase the entire query:
        - Change word order and sentence structure
        - Use synonyms for key terms
        - Convert questions to statements or keyword phrases
        - Maintain all specific details (names, dates, numbers)

        **STRATEGY 2: RANGE SPLITTING** (10-15 variations)
        For any time periods, ranges, or multiple options, create separate specific searches:
        - Split year ranges into individual years
        - Split time periods into specific decades/years
        - Split "between X and Y" into individual values
        - Create one search per specific value in any range

        **EXAMPLES:**
        Original: "Who won Nobel Prize between 1960-1965?"
        - Reformulations: "Nobel Prize winner 1960-1965", "Nobel laureate from 1960 to 1965"
        - Range splits: "Nobel Prize winner 1960", "Nobel Prize winner 1961", "Nobel Prize winner 1962", "Nobel Prize winner 1963", "Nobel Prize winner 1964", "Nobel Prize winner 1965"

        Generate 15-25 search queries total (reformulations + range splits).
        Focus on maximum specificity through systematic coverage.

        Return as a valid JSON list of search queries:
        ["query1", "query2", "query3"]
        """

        response = await self.model.ainvoke(prompt)
        return self._parse_combinations(response.content)

    def _parse_decomposition(self, content):
        """Parse LLM decomposition response"""
        try:
            start = content.find("{")
            end = content.rfind("}") + 1
            if start != -1 and end != -1:
                json_str = content[start:end]
                return json.loads(json_str)
        except Exception:
            logger.exception("Failed to parse decomposition")

        # If parsing fails, return empty dict - let the system handle gracefully
        logger.warning(
            "Failed to parse constraint decomposition, returning empty dict"
        )
        return {}

    def _parse_combinations(self, content):
        """Parse LLM combinations response"""
        try:
            start = content.find("[")
            end = content.rfind("]") + 1
            if start != -1 and end != -1:
                json_str = content[start:end]
                return json.loads(json_str)
        except Exception:
            logger.exception("Failed to parse combinations")

        # If parsing fails, return empty list - let the system handle gracefully
        logger.warning("Failed to parse LLM combinations, returning empty list")
        return []


class EarlyRejectionManager:
    """Manages early rejection and confidence tracking"""

    def __init__(self, model, positive_threshold=0.6, negative_threshold=0.3):
        self.model = model
        self.positive_threshold = positive_threshold
        self.negative_threshold = negative_threshold
        self.rejected_candidates = set()

    async def quick_confidence_check(self, candidate, constraints):
        """Quick confidence assessment for early rejection"""

        prompt = f"""
        Quickly assess if this candidate matches the search criteria:

        Candidate: {candidate.name}
        Available info: {getattr(candidate, "metadata", {})}

        Constraints to match:
        {[c.description for c in constraints]}

        Provide:
        1. **Positive confidence** (0.0-1.0): How likely this candidate matches
        2. **Negative confidence** (0.0-1.0): How likely this candidate does NOT match
        3. **Quick reasoning**: Brief explanation

        Return as JSON:
        {{
            "positive_confidence": 0.X,
            "negative_confidence": 0.X,
            "reasoning": "brief explanation"
        }}
        """

        try:
            response = await self.model.ainvoke(prompt)
            return self._parse_confidence(response.content)
        except Exception:
            logger.exception("Quick confidence check failed")
            return {
                "positive_confidence": 0.5,
                "negative_confidence": 0.3,
                "reasoning": "fallback",
            }

    def should_reject_early(self, confidence_result):
        """Determine if candidate should be rejected early"""
        # positive = confidence_result.get("positive_confidence", 0.5)  # Not currently used
        negative = confidence_result.get("negative_confidence", 0.3)

        # Only reject if we have strong negative evidence (not just lack of positive evidence)
        if negative > 0.85:
            return (
                True,
                f"High negative confidence ({negative:.2f})",
            )

        return False, None

    def should_continue_search(self, all_candidates, high_confidence_count):
        """Determine if we should continue searching"""
        # Stop if we have enough high-confidence candidates
        if high_confidence_count >= 5:
            return False, "Found sufficient high-confidence candidates"

        # Stop if we have many candidates but low quality
        if len(all_candidates) > 50 and high_confidence_count == 0:
            return False, "Too many low-quality candidates"

        return True, None

    def _parse_confidence(self, content):
        """Parse confidence assessment"""
        try:
            start = content.find("{")
            end = content.rfind("}") + 1
            if start != -1 and end != -1:
                json_str = content[start:end]
                return json.loads(json_str)
        except Exception:
            logger.exception("Failed to parse confidence")

        return {
            "positive_confidence": 0.5,
            "negative_confidence": 0.3,
            "reasoning": "parse_error",
        }


class ModularStrategy(BaseSearchStrategy):
    """
    A strategy that showcases the new modular architecture using:
    - constraint_checking module for candidate evaluation
    - candidate_exploration module for search execution
    - constraints module for constraint analysis
    - LLM-driven intelligent constraint processing
    - Early rejection and confidence-based filtering
    - Immediate candidate evaluation
    """

    def __init__(
        self,
        model,
        search,
        all_links_of_system=None,
        constraint_checker_type: str = "dual_confidence",  # dual_confidence, strict, threshold
        exploration_strategy: str = "adaptive",  # parallel, adaptive, constraint_guided, diversity
        early_rejection: bool = True,  # Enable early rejection by default
        early_stopping: bool = True,  # Enable early stopping by default
        llm_constraint_processing: bool = True,  # Enable LLM-driven constraint processing by default
        immediate_evaluation: bool = True,  # Enable immediate candidate evaluation by default
        settings_snapshot=None,
        **kwargs,
    ):
        super().__init__(
            all_links_of_system=all_links_of_system,
            settings_snapshot=settings_snapshot,
        )

        self.model = model
        self.search_engine = search
        self.search_engines = getattr(search, "search_engines", [])

        # Initialize constraint analyzer
        self.constraint_analyzer = ConstraintAnalyzer(self.model)

        # Initialize LLM constraint processor if enabled
        self.llm_processor = (
            LLMConstraintProcessor(self.model)
            if llm_constraint_processing
            else None
        )

        # Initialize early rejection manager if enabled
        self.early_rejection_manager = (
            EarlyRejectionManager(self.model) if early_rejection else None
        )

        # Initialize constraint checker based on type (default to dual confidence)
        self.constraint_checker = self._create_constraint_checker(
            constraint_checker_type
        )

        # Initialize candidate explorer based on strategy
        self.candidate_explorer = self._create_candidate_explorer(
            exploration_strategy
        )

        # Initialize question generator
        self.question_generator = StandardQuestionGenerator(model=self.model)

        # Strategy configuration
        self.constraint_checker_type = constraint_checker_type
        self.exploration_strategy = exploration_strategy
        self.early_rejection = early_rejection
        self.early_stopping = early_stopping
        self.llm_constraint_processing = llm_constraint_processing
        self.immediate_evaluation = immediate_evaluation

        logger.info(
            f"Initialized ModularStrategy with {constraint_checker_type} checker, {exploration_strategy} explorer, "
            f"early_rejection={early_rejection}, early_stopping={early_stopping}, "
            f"llm_processing={llm_constraint_processing}, immediate_eval={immediate_evaluation}"
        )

    def _create_constraint_checker(self, checker_type: str):
        """Create the appropriate constraint checker."""
        if checker_type == "dual_confidence":
            return DualConfidenceChecker(
                model=self.model,
                evidence_gatherer=self._gather_evidence_for_constraint,
                negative_threshold=0.75,
                positive_threshold=0.2,
                uncertainty_penalty=0.1,
                negative_weight=1.5,
            )
        elif checker_type == "strict":
            return StrictChecker(
                model=self.model,
                evidence_gatherer=self._gather_evidence_for_constraint,
            )
        elif checker_type == "threshold":
            return ThresholdChecker(
                model=self.model,
                evidence_gatherer=self._gather_evidence_for_constraint,
                acceptance_threshold=0.7,
            )
        else:
            raise ValueError(f"Unknown constraint checker type: {checker_type}")

    def _create_candidate_explorer(self, strategy_type: str):
        """Create the appropriate candidate explorer."""
        if strategy_type == "parallel":
            return ParallelExplorer(
                search_engine=self.search_engine,
                model=self.model,
                max_workers=4,
            )
        elif strategy_type == "adaptive":
            return AdaptiveExplorer(
                search_engine=self.search_engine,
                model=self.model,
                learning_rate=0.1,
            )
        elif strategy_type == "constraint_guided":
            return ConstraintGuidedExplorer(
                search_engine=self.search_engine, model=self.model
            )
        elif strategy_type == "diversity":
            return DiversityExplorer(
                search_engine=self.search_engine,
                model=self.model,
                diversity_factor=0.3,
            )
        else:
            raise ValueError(f"Unknown exploration strategy: {strategy_type}")

    async def search(
        self,
        query: str,
        search_engines: List[str] = None,
        progress_callback=None,
        **kwargs,
    ) -> Tuple[str, Dict]:
        """
        Execute the modular search strategy.
        """
        try:
            logger.info(f"Starting enhanced modular search for: {query}")

            # Phase 1: Extract base constraints
            if progress_callback:
                progress_callback(
                    {
                        "phase": "constraint_analysis",
                        "progress": 5,
                        "message": "Analyzing query constraints",
                    }
                )

            base_constraints = self.constraint_analyzer.extract_constraints(
                query
            )
            logger.info(f"Extracted {len(base_constraints)} base constraints")

            # Phase 2: LLM constraint processing (if enabled)
            all_search_queries = []
            if self.llm_constraint_processing and self.llm_processor:
                if progress_callback:
                    progress_callback(
                        {
                            "phase": "llm_processing",
                            "progress": 15,
                            "message": "LLM processing constraints intelligently",
                        }
                    )

                logger.info("🤖 LLM CONSTRAINT PROCESSING ACTIVATED")
                # LLM decomposition and combination
                decomposed = await self.llm_processor.decompose_constraints_intelligently(
                    base_constraints
                )

                # Pass existing base constraint queries to avoid duplication
                existing_queries = [c.description for c in base_constraints]
                logger.info("📋 BASE CONSTRAINT QUERIES:")
                for i, base_query in enumerate(existing_queries, 1):
                    logger.info(f"   BASE-{i:02d}: {base_query}")

                intelligent_combinations = (
                    await self.llm_processor.generate_intelligent_combinations(
                        decomposed, existing_queries, query
                    )
                )

                logger.info("🧠 LLM-GENERATED INTELLIGENT QUERIES:")
                logger.info("### START_LLM_QUERIES ###")  # Grep-friendly marker
                for i, llm_query in enumerate(intelligent_combinations, 1):
                    logger.info(f"   LLM-{i:02d}: {llm_query}")
                logger.info("### END_LLM_QUERIES ###")  # Grep-friendly marker

                # OPTIMIZATION: Start with original query, then use LLM-generated targeted queries
                # This ensures we search for the exact question first, then explore variations
                all_search_queries = (
                    [query] + intelligent_combinations
                )  # Original query first, then LLM combinations
                logger.info(
                    f"🎯 Using original query + {len(intelligent_combinations)} targeted LLM search combinations (skipping broad base constraints)"
                )
                logger.info(
                    f"📊 Optimized search strategies: {len(all_search_queries)} (original + {len(intelligent_combinations)} LLM queries)"
                )
            else:
                logger.warning(
                    "⚠️  LLM constraint processing is DISABLED - falling back to basic searches"
                )
                # Fallback to basic constraint searches
                all_search_queries = [c.description for c in base_constraints]

            # Phase 3: Enhanced candidate exploration with immediate evaluation
            if progress_callback:
                progress_callback(
                    {
                        "phase": "candidate_exploration",
                        "progress": 25,
                        "message": f"🔍 Exploring with {len(all_search_queries)} enhanced search strategies",
                    }
                )

            all_candidates = []
            high_confidence_count = 0
            search_progress = 30

            # DECOUPLED APPROACH: Separate search execution from candidate evaluation
            candidate_evaluation_queue = asyncio.Queue()
            evaluation_results = []
            rejected_candidates = []  # Store rejected candidates for potential recovery

            # Execute searches in parallel batches with decoupled evaluation
            batch_size = 8  # Optimized for parallel execution
            logger.info(
                f"🚀 Starting enhanced exploration with {len(all_search_queries)} search queries (8 concurrent, decoupled evaluation)"
            )

            # Start background candidate evaluation task
            evaluation_task = asyncio.create_task(
                self._background_candidate_evaluation(
                    candidate_evaluation_queue,
                    base_constraints,
                    evaluation_results,
                    query,
                    rejected_candidates,
                )
            )

            for i in range(0, len(all_search_queries), batch_size):
                batch = all_search_queries[i : i + batch_size]

                if progress_callback:
                    progress_callback(
                        {
                            "phase": "search_batch",
                            "progress": search_progress,
                            "message": f"🔍 Executing search batch {i // batch_size + 1}",
                        }
                    )

                logger.info(
                    f"📦 Processing batch {i // batch_size + 1}: {batch}"
                )

                # Execute batch searches in parallel using ThreadPoolExecutor
                batch_results = []
                with ThreadPoolExecutor(max_workers=8) as executor:
                    # Submit all searches in the batch concurrently
                    future_to_query = {
                        executor.submit(
                            self.candidate_explorer._execute_search, query
                        ): query
                        for query in batch
                    }

                    # Collect results as they complete
                    for future in as_completed(future_to_query):
                        query = future_to_query[future]
                        try:
                            result = future.result()
                            batch_results.append(result)
                        except Exception as e:
                            logger.exception(
                                f"❌ Parallel search failed for '{query[:30]}...': {e}"
                            )
                            batch_results.append(e)

                        # CRITICAL: Yield control to allow background evaluation task to run
                        await asyncio.sleep(0)

                # Process batch results - QUEUE CANDIDATES FOR BACKGROUND EVALUATION
                for j, result in enumerate(batch_results):
                    if isinstance(result, Exception):
                        logger.exception(
                            f"❌ Search failed: {batch[j]} - {result}"
                        )
                        continue

                    candidates = self.candidate_explorer._extract_candidates_from_results(
                        result, original_query=query
                    )

                    logger.info(
                        f"🎯 Found {len(candidates)} candidates from query: '{batch[j][:50]}...'"
                    )

                    # QUEUE CANDIDATES for background evaluation (non-blocking)
                    for candidate in candidates:
                        await candidate_evaluation_queue.put(candidate)

                # Progress tracking without blocking on evaluation
                total_candidates = sum(
                    len(
                        self.candidate_explorer._extract_candidates_from_results(
                            result, original_query=query
                        )
                    )
                    for result in batch_results
                    if not isinstance(result, Exception)
                )

                logger.info(
                    f"📦 Batch {i // batch_size + 1}: queued {total_candidates} candidates for evaluation"
                )

                # CRITICAL: Yield control after each batch to allow background evaluation
                await asyncio.sleep(
                    0.1
                )  # Small delay to let background task process

                search_progress = min(search_progress + 10, 75)

            # Signal completion to background evaluation and wait for final results
            await candidate_evaluation_queue.put(
                None
            )  # Sentinel to signal completion

            # Wait for background evaluation to complete
            try:
                await asyncio.wait_for(
                    evaluation_task, timeout=30.0
                )  # 30s timeout
            except asyncio.TimeoutError:
                logger.warning(
                    "⚠️ Background evaluation timed out, using partial results"
                )
                evaluation_task.cancel()

            # Collect all evaluated candidates
            all_candidates = [
                result for result in evaluation_results if result is not None
            ]

            logger.info(
                f"🏁 Search completed: {len(all_candidates)} total candidates, {high_confidence_count} high-confidence"
            )

            # Phase 4: Final candidate evaluation (if immediate evaluation was disabled)
            evaluated_candidates = all_candidates
            if not self.immediate_evaluation:
                if progress_callback:
                    progress_callback(
                        {
                            "phase": "candidate_evaluation",
                            "progress": 80,
                            "message": f"🔍 Evaluating {len(all_candidates)} candidates",
                        }
                    )

                evaluated_candidates = []
                for candidate in all_candidates[:20]:  # Limit to top 20
                    try:
                        result = self.constraint_checker.check_candidate(
                            candidate, base_constraints
                        )
                        candidate.evaluation_results = result.detailed_results
                        candidate.score = result.total_score
                        candidate.should_reject = result.should_reject

                        if not result.should_reject:
                            evaluated_candidates.append(candidate)

                    except Exception as e:
                        logger.exception(
                            f"💥 Error evaluating candidate {candidate.name}: {e}"
                        )
                        continue

            # Phase 5: Select best candidate
            if progress_callback:
                progress_callback(
                    {
                        "phase": "result_selection",
                        "progress": 90,
                        "message": "🏆 Selecting best result",
                    }
                )

            if not evaluated_candidates:
                # Check all candidates including rejected ones
                all_scored_candidates = []

                # Add all candidates with scores
                for c in all_candidates:
                    if hasattr(c, "score") and c.score > 0:
                        all_scored_candidates.append(c)

                # Add rejected candidates with scores
                for c in rejected_candidates:
                    if hasattr(c, "score") and c.score > 0:
                        all_scored_candidates.append(c)

                if all_scored_candidates:
                    # Sort by score
                    all_scored_candidates.sort(
                        key=lambda x: x.score, reverse=True
                    )
                    best_candidate = all_scored_candidates[0]

                    # Accept if score is above minimum threshold (20%)
                    if best_candidate.score >= 0.20:
                        logger.info(
                            f"🎯 Accepting best available candidate (recovered from rejected): {best_candidate.name} with score {best_candidate.score:.2%}"
                        )
                        evaluated_candidates = [best_candidate]
                    else:
                        logger.warning(
                            f"❌ Best candidate {best_candidate.name} has too low score: {best_candidate.score:.2%}"
                        )

                if not evaluated_candidates:
                    logger.warning(
                        "❌ No valid candidates found after evaluation"
                    )
                    return "No valid candidates found after evaluation", {
                        "strategy": "enhanced_modular",
                        "constraint_checker": self.constraint_checker_type,
                        "exploration_strategy": self.exploration_strategy,
                        "early_rejection": self.early_rejection,
                        "llm_processing": self.llm_constraint_processing,
                        "total_searches": len(all_search_queries),
                        "candidates_found": len(all_candidates),
                        "candidates_valid": 0,
                        "high_confidence_count": high_confidence_count,
                    }

            # Sort by score and select best
            evaluated_candidates.sort(
                key=lambda x: getattr(x, "score", 0), reverse=True
            )
            best_candidate = evaluated_candidates[0]

            logger.info(
                f"🏆 Best candidate: {best_candidate.name} with score {getattr(best_candidate, 'score', 0):.2%}"
            )

            # Phase 6: Generate final answer
            if progress_callback:
                progress_callback(
                    {
                        "phase": "final_answer",
                        "progress": 95,
                        "message": "📝 Generating final answer",
                    }
                )

            answer = await self._generate_final_answer(
                query, best_candidate, base_constraints
            )

            # Search Query Analysis Summary for easy analysis
            logger.info("=" * 80)
            logger.info("🔍 SEARCH QUERY ANALYSIS SUMMARY")
            logger.info("=" * 80)
            logger.info(
                f"📊 TOTAL QUERIES GENERATED: {len(all_search_queries)}"
            )
            logger.info(
                f"📋 BASE CONSTRAINT QUERIES: {len(existing_queries) if 'existing_queries' in locals() else 0}"
            )
            logger.info(
                f"🧠 LLM INTELLIGENT QUERIES: {len(intelligent_combinations) if 'intelligent_combinations' in locals() else 0}"
            )

            if (
                "intelligent_combinations" in locals()
                and intelligent_combinations
            ):
                logger.info("\n🎯 SAMPLE LLM-GENERATED QUERIES (first 10):")
                for i, query in enumerate(intelligent_combinations[:10], 1):
                    logger.info(f"   SAMPLE-{i:02d}: {query}")

            logger.info("=" * 80)

            metadata = {
                "strategy": "enhanced_modular",
                "constraint_checker": self.constraint_checker_type,
                "exploration_strategy": self.exploration_strategy,
                "early_rejection_enabled": self.early_rejection,
                "early_stopping_enabled": self.early_stopping,
                "llm_processing_enabled": self.llm_constraint_processing,
                "immediate_evaluation_enabled": self.immediate_evaluation,
                "total_searches_generated": len(all_search_queries),
                "candidates_found": len(all_candidates),
                "candidates_evaluated": len(evaluated_candidates),
                "high_confidence_count": high_confidence_count,
                "best_candidate": best_candidate.name,
                "best_score": getattr(best_candidate, "score", 0),
            }

            return answer, metadata

        except Exception:
            logger.exception("💥 Error in enhanced modular search")
            return "Search failed", {"error": "Search failed"}

    async def _generate_final_answer(
        self, query: str, best_candidate, constraints
    ) -> str:
        """Generate the final answer using the best candidate."""

        constraint_info = "\n".join(
            [f"- {c.description} (weight: {c.weight})" for c in constraints]
        )

        evaluation_info = ""
        if hasattr(best_candidate, "evaluation_results"):
            evaluation_info = "\n".join(
                [
                    f"- {result.get('constraint', 'Unknown')}: {result.get('score', 0):.0%}"
                    for result in best_candidate.evaluation_results
                ]
            )

        prompt = f"""Based on the search results, provide a comprehensive answer to: {query}

Best candidate found: {best_candidate.name}
Score: {best_candidate.score:.0%}

Constraints analyzed:
{constraint_info}

Constraint evaluation results:
{evaluation_info}

Evidence summary: {getattr(best_candidate, "summary", "No summary available")}

Provide a clear, factual answer that addresses the original question and explains how the candidate satisfies the constraints."""

        response = await self.model.ainvoke(prompt)
        return response.content

    def _gather_evidence_for_constraint(self, candidate, constraint):
        """Gather evidence for a constraint using actual search with caching."""
        # Check cache first
        cache = get_search_cache()
        cache_key = normalize_entity_query(candidate.name, constraint.value)

        cached_results = cache.get(cache_key, "modular_strategy")
        if cached_results is not None:
            logger.debug(
                f"Using cached evidence for {candidate.name} - {constraint.value[:30]}..."
            )
            return cached_results

        try:
            # Build search query intelligently based on constraint type
            query_parts = []

            # Add candidate name
            query_parts.append(f'"{candidate.name}"')

            # Parse constraint value for key terms
            constraint_value = constraint.value

            # Remove common prefixes
            prefixes_to_remove = [
                "The individual is associated with",
                "The answer must be",
                "The character must be",
                "The entity must be",
                "Must be",
                "Should be",
                "Is",
            ]

            for prefix in prefixes_to_remove:
                if constraint_value.startswith(prefix):
                    constraint_value = constraint_value[len(prefix) :].strip()
                    break

            # Handle different constraint types
            if constraint.type.value == "TEMPORAL":
                # For temporal constraints, extract years/dates and search specifically
                import re

                years = re.findall(r"\b(19\d{2}|20\d{2})\b", constraint_value)
                decades = re.findall(
                    r"\b(19\d{2}s|20\d{2}s)\b", constraint_value
                )

                if years:
                    for year in years:
                        query_parts.append(year)
                elif decades:
                    for decade in decades:
                        query_parts.append(decade)
                else:
                    query_parts.append(constraint_value)

            elif constraint.type.value == "PROPERTY":
                # For properties, focus on the specific characteristic
                query_parts.append(constraint_value)

            elif constraint.type.value == "STATISTIC":
                # For statistics, include numbers and comparisons
                query_parts.append(constraint_value)

            else:
                # Default: use the constraint value as-is
                query_parts.append(constraint_value)

            # Build final query
            query = " ".join(query_parts)
            logger.debug(f"Evidence search query: {query}")

            # Execute search using the appropriate method
            results = None

            # Try different search methods based on what's available
            if hasattr(self.search_engine, "run"):
                results = self.search_engine.run(query)
            elif hasattr(self.search_engine, "search"):
                results = self.search_engine.search(query)
            elif callable(self.search_engine):
                results = self.search_engine(query)
            else:
                logger.error(
                    f"Search engine has no callable method: {type(self.search_engine)}"
                )
                return []

            # Process results
            evidence = []

            # Handle different result formats
            if results is None:
                logger.warning("Search returned None")
                return []

            if isinstance(results, list):
                result_list = results
            elif isinstance(results, dict):
                # Try common keys for results
                result_list = (
                    results.get("results")
                    or results.get("items")
                    or results.get("data")
                    or []
                )
            else:
                logger.warning(f"Unknown search result type: {type(results)}")
                result_list = []

            # Extract top evidence (limit to 5 for better quality)
            for i, result in enumerate(result_list[:5]):
                if isinstance(result, dict):
                    # Extract text content
                    text = (
                        result.get("snippet")
                        or result.get("content")
                        or result.get("description")
                        or result.get("text")
                        or ""
                    )

                    # Extract source information
                    source = (
                        result.get("url")
                        or result.get("link")
                        or result.get("source")
                        or f"search_result_{i + 1}"
                    )

                    # Extract title
                    title = result.get("title", "")

                    # Calculate confidence based on result position and content
                    base_confidence = 0.8 - (i * 0.1)  # Decay by position

                    # Boost confidence if key terms are present
                    if candidate.name.lower() in text.lower():
                        base_confidence += 0.1
                    if any(
                        term.lower() in text.lower()
                        for term in constraint_value.split()
                    ):
                        base_confidence += 0.1

                    confidence = min(base_confidence, 0.95)

                    evidence.append(
                        {
                            "text": text[:500],  # Limit text length
                            "source": source,
                            "confidence": confidence,
                            "title": title,
                            "full_text": text,  # Keep full text for detailed analysis
                        }
                    )
                else:
                    # Handle string results
                    evidence.append(
                        {
                            "text": str(result)[:500],
                            "source": f"search_result_{i + 1}",
                            "confidence": 0.6,
                            "title": "",
                        }
                    )

            logger.debug(
                f"Gathered {len(evidence)} evidence items for {candidate.name} - {constraint.value[:50]}..."
            )

            # Cache the results for future use
            cache.put(
                cache_key, evidence, "modular_strategy", ttl=1800
            )  # 30 minutes TTL

            return evidence

        except Exception:
            logger.exception("Error gathering evidence")
            # Return empty list instead of mock evidence
            return []

    async def _background_candidate_evaluation(
        self,
        queue,
        constraints,
        results,
        original_query=None,
        rejected_candidates=None,
    ):
        """Background task to evaluate candidates without blocking search progress."""
        logger.info("🔄 Started background candidate evaluation")

        # Use provided rejected_candidates list or create new one
        if rejected_candidates is None:
            rejected_candidates = []

        while True:
            try:
                # Get candidate from queue
                candidate = await queue.get()

                # Check for completion sentinel
                if candidate is None:
                    logger.info("🏁 Background evaluation completed")
                    break

                # Evaluate candidate with LLM pre-screening
                try:
                    # Always do full constraint evaluation to get scores
                    result = self.constraint_checker.check_candidate(
                        candidate, constraints, original_query=original_query
                    )
                    candidate.evaluation_results = result.detailed_results
                    candidate.score = result.total_score
                    candidate.should_reject = result.should_reject

                    # Now check early rejection AFTER we have a score
                    if self.early_rejection_manager:
                        confidence = await self.early_rejection_manager.quick_confidence_check(
                            candidate, constraints
                        )

                        should_reject, reason = (
                            self.early_rejection_manager.should_reject_early(
                                confidence
                            )
                        )
                        if (
                            should_reject and candidate.score < 0.5
                        ):  # Only early reject if score is also low
                            logger.debug(
                                f"⚡ Early rejected {candidate.name}: {reason} (score: {candidate.score:.2%})"
                            )
                            # Store the candidate anyway for potential best candidate recovery
                            rejected_candidates.append(candidate)
                            continue

                    if not result.should_reject:
                        results.append(candidate)
                        logger.info(
                            f"✅ Accepted: {candidate.name} (score: {result.total_score:.2%})"
                        )

                        # Check for excellent candidates
                        if result.total_score > 0.9:
                            logger.info(
                                f"🏆 EXCELLENT: {candidate.name} with {result.total_score:.1%} score"
                            )
                    else:
                        # Store rejected candidates with scores for potential recovery
                        rejected_candidates.append(candidate)
                        logger.debug(
                            f"❌ Rejected: {candidate.name} (score: {candidate.score:.2%})"
                        )

                except Exception as e:
                    logger.exception(
                        f"💥 Error evaluating {candidate.name}: {e}"
                    )

            except Exception:
                logger.exception("💥 Background evaluation error")

    def analyze_topic(self, query: str) -> Dict:
        """
        Analyze a topic using the modular strategy.

        This is the main entry point that implements the BaseSearchStrategy interface.
        """
        try:
            # Run the search asynchronously
            import asyncio

            # Create a new event loop if none exists or if the current loop is running
            try:
                loop = asyncio.get_event_loop()
                if loop.is_running():
                    # If we're already in an async context, run in a new thread
                    import concurrent.futures

                    with concurrent.futures.ThreadPoolExecutor() as executor:
                        future = executor.submit(
                            lambda: asyncio.run(self.search(query))
                        )
                        answer, metadata = future.result()
                else:
                    # If not in async context, run directly
                    answer, metadata = loop.run_until_complete(
                        self.search(query)
                    )
            except RuntimeError:
                # No event loop, create one
                answer, metadata = asyncio.run(self.search(query))

            return {
                "findings": [{"content": answer}],
                "iterations": 1,
                "final_answer": answer,
                "current_knowledge": answer,
                "metadata": metadata,
                "links": getattr(self, "all_links_of_system", []),
                "questions_by_iteration": getattr(
                    self, "questions_by_iteration", []
                ),
            }

        except Exception as e:
            logger.exception("Error in analyze_topic")
            return {
                "findings": [],
                "iterations": 0,
                "final_answer": f"Analysis failed: {e!s}",
                "metadata": {"error": str(e)},
                "links": [],
                "questions_by_iteration": [],
            }
