"""
Quality Metrics - Response quality scoring algorithms

This module provides comprehensive quality assessment for RAG responses
including relevance, completeness, coherence, and source fidelity scoring.
"""

import logging
import re
from dataclasses import dataclass
from typing import Any, Dict, List, Optional, Set, Tuple

logger = logging.getLogger(__name__)


@dataclass
class QualityScore:
    """Comprehensive quality score for RAG response."""

    overall_score: float
    relevance_score: float
    completeness_score: float
    coherence_score: float
    source_fidelity_score: float
    professionalism_score: float

    # Additional metrics
    response_length: int
    citation_count: int
    source_count: int
    confidence_level: str  # "high", "medium", "low"

    # Quality indicators
    meets_threshold: bool
    strengths: List[str]
    weaknesses: List[str]
    recommendations: List[str]


class QualityMetrics:
    """
    Comprehensive quality assessment system for RAG responses.

    Provides detailed scoring across multiple dimensions:
    - Relevance: How well response addresses the query
    - Completeness: Adequacy of information provided
    - Coherence: Logical structure and flow
    - Source Fidelity: Alignment with source documents
    - Professionalism: Appropriate business tone
    """

    def __init__(self, config: Optional[Dict[str, Any]] = None):
        """
        Initialize QualityMetrics with configuration.

        Args:
            config: Configuration dictionary for quality thresholds
        """
        self.config = config or self._get_default_config()
        logger.info("QualityMetrics initialized")

    def _get_default_config(self) -> Dict[str, Any]:
        """Get default quality assessment configuration."""
        return {
            "quality_threshold": 0.7,
            "relevance_weight": 0.3,
            "completeness_weight": 0.25,
            "coherence_weight": 0.2,
            "source_fidelity_weight": 0.25,
            "min_response_length": 50,
            "target_response_length": 300,
            "max_response_length": 1000,
            "min_citation_count": 1,
            "preferred_source_count": 3,
            "enable_detailed_analysis": True,
        }

    def calculate_quality_score(
        self,
        response: str,
        query: str,
        sources: List[Dict[str, Any]],
        context: Optional[str] = None,
    ) -> QualityScore:
        """
        Calculate comprehensive quality score for response.

        Args:
            response: Generated response text
            query: Original user query
            sources: Source documents used
            context: Optional additional context

        Returns:
            QualityScore with detailed metrics and recommendations
        """
        try:
            # Calculate individual dimension scores
            relevance = self._calculate_relevance_score(response, query)
            completeness = self._calculate_completeness_score(response, query)
            coherence = self._calculate_coherence_score(response)
            source_fidelity = self._calculate_source_fidelity_score(response, sources)
            professionalism = self._calculate_professionalism_score(response)

            # Calculate weighted overall score
            overall = self._calculate_overall_score(
                relevance, completeness, coherence, source_fidelity, professionalism
            )

            # Analyze response characteristics
            response_analysis = self._analyze_response_characteristics(response, sources)

            # Determine confidence level
            confidence_level = self._determine_confidence_level(overall, response_analysis)

            # Generate insights
            strengths, weaknesses, recommendations = self._generate_quality_insights(
                relevance,
                completeness,
                coherence,
                source_fidelity,
                professionalism,
                response_analysis,
            )

            return QualityScore(
                overall_score=overall,
                relevance_score=relevance,
                completeness_score=completeness,
                coherence_score=coherence,
                source_fidelity_score=source_fidelity,
                professionalism_score=professionalism,
                response_length=response_analysis["length"],
                citation_count=response_analysis["citation_count"],
                source_count=response_analysis["source_count"],
                confidence_level=confidence_level,
                meets_threshold=overall >= self.config["quality_threshold"],
                strengths=strengths,
                weaknesses=weaknesses,
                recommendations=recommendations,
            )

        except Exception as e:
            logger.error(f"Quality scoring error: {e}")
            return QualityScore(
                overall_score=0.0,
                relevance_score=0.0,
                completeness_score=0.0,
                coherence_score=0.0,
                source_fidelity_score=0.0,
                professionalism_score=0.0,
                response_length=len(response),
                citation_count=0,
                source_count=len(sources),
                confidence_level="low",
                meets_threshold=False,
                strengths=[],
                weaknesses=["Error in quality assessment"],
                recommendations=["Retry quality assessment"],
            )

    def _calculate_relevance_score(self, response: str, query: str) -> float:
        """Calculate how well response addresses the query."""
        if not query.strip():
            return 1.0  # No query to compare against

        # Extract key terms from query
        query_terms = self._extract_key_terms(query)
        response_terms = self._extract_key_terms(response)

        if not query_terms:
            return 1.0

        # Calculate term overlap
        overlap = len(query_terms.intersection(response_terms))
        term_coverage = overlap / len(query_terms)

        # Check for semantic relevance patterns
        semantic_relevance = self._check_semantic_relevance(response, query)

        # Combine scores
        relevance = (term_coverage * 0.6) + (semantic_relevance * 0.4)
        return min(relevance, 1.0)

    def _calculate_completeness_score(self, response: str, query: str) -> float:
        """Calculate how completely the response addresses the query."""
        response_length = len(response)
        target_length = self.config["target_response_length"]
        min_length = self.config["min_response_length"]

        # Length-based completeness
        if response_length < min_length:
            length_score = response_length / min_length * 0.5
        elif response_length <= target_length:
            length_score = 0.5 + (response_length - min_length) / (target_length - min_length) * 0.5
        else:
            # Diminishing returns for very long responses
            excess = response_length - target_length
            penalty = min(excess / target_length * 0.2, 0.3)
            length_score = 1.0 - penalty

        # Structure-based completeness
        structure_score = self._assess_response_structure(response)

        # Information density
        density_score = self._assess_information_density(response, query)

        # Combine scores
        completeness = (length_score * 0.4) + (structure_score * 0.3) + (density_score * 0.3)
        return min(max(completeness, 0.0), 1.0)

    def _calculate_coherence_score(self, response: str) -> float:
        """Calculate logical structure and coherence of response."""
        sentences = [s.strip() for s in response.split(".") if s.strip()]

        if len(sentences) < 2:
            return 0.8  # Short responses are typically coherent

        # Check for logical flow indicators
        flow_indicators = [
            "however",
            "therefore",
            "additionally",
            "furthermore",
            "consequently",
            "moreover",
            "nevertheless",
            "in addition",
            "as a result",
            "for example",
        ]

        response_lower = response.lower()
        flow_score = sum(1 for indicator in flow_indicators if indicator in response_lower)
        flow_score = min(flow_score / 3, 1.0)  # Normalize

        # Check for repetition (negative indicator)
        unique_sentences = len(set(s.lower() for s in sentences))
        repetition_score = unique_sentences / len(sentences)

        # Check for topic consistency
        consistency_score = self._assess_topic_consistency(sentences)

        # Check for clear conclusion/summary
        conclusion_score = self._has_clear_conclusion(response)

        # Combine scores
        coherence = flow_score * 0.3 + repetition_score * 0.3 + consistency_score * 0.2 + conclusion_score * 0.2

        return min(coherence, 1.0)

    def _calculate_source_fidelity_score(self, response: str, sources: List[Dict[str, Any]]) -> float:
        """Calculate alignment between response and source documents."""
        if not sources:
            return 0.5  # Neutral score if no sources

        # Citation presence and quality
        citation_score = self._assess_citation_quality(response, sources)

        # Content alignment with sources
        alignment_score = self._assess_content_alignment(response, sources)

        # Source coverage (how many sources are referenced)
        coverage_score = self._assess_source_coverage(response, sources)

        # Factual consistency check
        consistency_score = self._check_factual_consistency(response, sources)

        # Combine scores
        fidelity = citation_score * 0.3 + alignment_score * 0.4 + coverage_score * 0.15 + consistency_score * 0.15

        return min(fidelity, 1.0)

    def _calculate_professionalism_score(self, response: str) -> float:
        """Calculate professional tone and appropriateness."""
        # Check for professional language patterns
        professional_indicators = [
            r"\b(?:please|thank you|according to|based on|our policy|guidelines)\b",
            r"\b(?:recommend|suggest|advise|ensure|confirm)\b",
            r"\b(?:appropriate|professional|compliance|requirements)\b",
        ]

        professional_count = sum(
            len(re.findall(pattern, response, re.IGNORECASE)) for pattern in professional_indicators
        )

        professional_score = min(professional_count / 3, 1.0)

        # Check for unprofessional patterns
        unprofessional_patterns = [
            r"\b(?:yo|hey|wassup|gonna|wanna)\b",
            r"\b(?:lol|omg|wtf|tbh|idk)\b",
            r"[!]{2,}|[?]{2,}",
            r"\b(?:stupid|dumb|crazy|insane)\b",
        ]

        unprofessional_count = sum(
            len(re.findall(pattern, response, re.IGNORECASE)) for pattern in unprofessional_patterns
        )

        unprofessional_penalty = min(unprofessional_count * 0.3, 0.8)

        # Check tone appropriateness
        tone_score = self._assess_tone_appropriateness(response)

        # Combine scores
        professionalism = professional_score + tone_score - unprofessional_penalty
        return min(max(professionalism, 0.0), 1.0)

    def _calculate_overall_score(
        self,
        relevance: float,
        completeness: float,
        coherence: float,
        source_fidelity: float,
        professionalism: float,
    ) -> float:
        """Calculate weighted overall quality score."""
        weights = self.config

        overall = (
            relevance * weights["relevance_weight"]
            + completeness * weights["completeness_weight"]
            + coherence * weights["coherence_weight"]
            + source_fidelity * weights["source_fidelity_weight"]
            + professionalism * 0.0  # Not weighted in overall for now
        )

        return min(max(overall, 0.0), 1.0)

    def _extract_key_terms(self, text: str) -> Set[str]:
        """Extract key terms from text for relevance analysis."""
        # Simple keyword extraction (can be enhanced with NLP)
        words = re.findall(r"\b\w+\b", text.lower())

        # Filter out common stop words
        stop_words = {
            "the",
            "a",
            "an",
            "and",
            "or",
            "but",
            "in",
            "on",
            "at",
            "to",
            "for",
            "of",
            "with",
            "by",
            "from",
            "up",
            "about",
            "into",
            "through",
            "during",
            "before",
            "after",
            "above",
            "below",
            "between",
            "among",
            "is",
            "are",
            "was",
            "were",
            "be",
            "been",
            "being",
            "have",
            "has",
            "had",
            "do",
            "does",
            "did",
            "will",
            "would",
            "could",
            "should",
            "may",
            "might",
            "can",
            "what",
            "where",
            "when",
            "why",
            "how",
            "this",
            "that",
            "these",
            "those",
        }

        return {word for word in words if len(word) > 2 and word not in stop_words}

    def _check_semantic_relevance(self, response: str, query: str) -> float:
        """Check semantic relevance between response and query."""
        # Look for question-answer patterns
        query_lower = query.lower()
        response_lower = response.lower()

        relevance_patterns = [
            (r"\bwhat\b", r"\b(?:is|are|include|involves)\b"),
            (r"\bhow\b", r"\b(?:by|through|via|process|step)\b"),
            (r"\bwhen\b", r"\b(?:during|after|before|time|date)\b"),
            (r"\bwhere\b", r"\b(?:at|in|location|place)\b"),
            (r"\bwhy\b", r"\b(?:because|due to|reason|purpose)\b"),
            (r"\bpolicy\b", r"\b(?:policy|guideline|rule|procedure)\b"),
        ]

        relevance_score = 0.0
        for query_pattern, response_pattern in relevance_patterns:
            if re.search(query_pattern, query_lower) and re.search(response_pattern, response_lower):
                relevance_score += 0.2

        return min(relevance_score, 1.0)

    def _assess_response_structure(self, response: str) -> float:
        """Assess structural completeness of response."""
        structure_score = 0.0

        # Check for introduction/context
        intro_patterns = [r"according to", r"based on", r"our policy", r"the guideline"]
        if any(re.search(pattern, response, re.IGNORECASE) for pattern in intro_patterns):
            structure_score += 0.3

        # Check for main content/explanation
        if len(response.split(".")) >= 2:
            structure_score += 0.4

        # Check for conclusion/summary
        conclusion_patterns = [
            r"in summary",
            r"therefore",
            r"as a result",
            r"please contact",
        ]
        if any(re.search(pattern, response, re.IGNORECASE) for pattern in conclusion_patterns):
            structure_score += 0.3

        return min(structure_score, 1.0)

    def _assess_information_density(self, response: str, query: str) -> float:
        """Assess information density relative to query complexity."""
        # Simple heuristic based on content richness
        words = len(response.split())
        sentences = len([s for s in response.split(".") if s.strip()])

        if sentences == 0:
            return 0.0

        avg_sentence_length = words / sentences

        # Optimal range: 15-25 words per sentence for policy content
        if 15 <= avg_sentence_length <= 25:
            density_score = 1.0
        elif avg_sentence_length < 15:
            density_score = avg_sentence_length / 15
        else:
            density_score = max(0.5, 1.0 - (avg_sentence_length - 25) / 25)

        return min(density_score, 1.0)

    def _assess_topic_consistency(self, sentences: List[str]) -> float:
        """Assess topic consistency across sentences."""
        if len(sentences) < 2:
            return 1.0

        # Extract key terms from each sentence
        sentence_terms = [self._extract_key_terms(sentence) for sentence in sentences]

        # Calculate overlap between consecutive sentences
        consistency_scores = []
        for i in range(len(sentence_terms) - 1):
            current_terms = sentence_terms[i]
            next_terms = sentence_terms[i + 1]

            if current_terms and next_terms:
                overlap = len(current_terms.intersection(next_terms))
                total = len(current_terms.union(next_terms))
                consistency = overlap / total if total > 0 else 0
                consistency_scores.append(consistency)

        return sum(consistency_scores) / len(consistency_scores) if consistency_scores else 0.5

    def _has_clear_conclusion(self, response: str) -> float:
        """Check if response has a clear conclusion."""
        conclusion_indicators = [
            r"in summary",
            r"in conclusion",
            r"therefore",
            r"as a result",
            r"please contact",
            r"for more information",
            r"if you have questions",
        ]

        response_lower = response.lower()
        has_conclusion = any(re.search(pattern, response_lower) for pattern in conclusion_indicators)

        return 1.0 if has_conclusion else 0.5

    def _assess_citation_quality(self, response: str, sources: List[Dict[str, Any]]) -> float:
        """Assess quality and presence of citations."""
        if not sources:
            return 0.5

        citation_patterns = [
            r"\[.*?\]",  # [source]
            r"\(.*?\)",  # (source)
            r"according to.*?",  # according to X
            r"based on.*?",  # based on X
            r"as stated in.*?",  # as stated in X
        ]

        citations_found = sum(len(re.findall(pattern, response, re.IGNORECASE)) for pattern in citation_patterns)

        # Score based on citation density
        min_citations = self.config["min_citation_count"]
        citation_score = min(citations_found / min_citations, 1.0)

        return citation_score

    def _assess_content_alignment(self, response: str, sources: List[Dict[str, Any]]) -> float:
        """Assess how well response content aligns with sources."""
        if not sources:
            return 0.5

        # Extract content from sources
        source_content = " ".join(source.get("content", "") for source in sources).lower()

        response_terms = self._extract_key_terms(response)
        source_terms = self._extract_key_terms(source_content)

        if not source_terms:
            return 0.5

        # Calculate alignment
        alignment = len(response_terms.intersection(source_terms)) / len(response_terms)
        return min(alignment, 1.0)

    def _assess_source_coverage(self, response: str, sources: List[Dict[str, Any]]) -> float:
        """Assess how many sources are referenced in response."""
        response_lower = response.lower()

        referenced_sources = 0
        for source in sources:
            doc_name = source.get("metadata", {}).get("filename", "").lower()
            if doc_name and doc_name in response_lower:
                referenced_sources += 1

        preferred_count = min(self.config["preferred_source_count"], len(sources))
        if preferred_count == 0:
            return 1.0

        coverage = referenced_sources / preferred_count
        return min(coverage, 1.0)

    def _check_factual_consistency(self, response: str, sources: List[Dict[str, Any]]) -> float:
        """Check factual consistency between response and sources."""
        # Simple consistency check (can be enhanced with fact-checking models)
        # For now, assume consistency if no obvious contradictions

        # Look for absolute statements that might contradict sources
        absolute_patterns = [
            r"\b(?:never|always|all|none|every|no)\b",
            r"\b(?:definitely|certainly|absolutely)\b",
        ]

        absolute_count = sum(len(re.findall(pattern, response, re.IGNORECASE)) for pattern in absolute_patterns)

        # Penalize excessive absolute statements
        consistency_penalty = min(absolute_count * 0.1, 0.3)
        consistency_score = 1.0 - consistency_penalty

        return max(consistency_score, 0.0)

    def _assess_tone_appropriateness(self, response: str) -> float:
        """Assess appropriateness of tone for corporate communication."""
        # Check for appropriate corporate tone indicators
        corporate_tone_indicators = [
            r"\b(?:recommend|advise|suggest|ensure|comply)\b",
            r"\b(?:policy|procedure|guideline|requirement)\b",
            r"\b(?:appropriate|professional|please|thank you)\b",
        ]

        tone_score = 0.0
        for pattern in corporate_tone_indicators:
            matches = len(re.findall(pattern, response, re.IGNORECASE))
            tone_score += min(matches * 0.1, 0.3)

        return min(tone_score, 1.0)

    def _analyze_response_characteristics(self, response: str, sources: List[Dict[str, Any]]) -> Dict[str, Any]:
        """Analyze basic characteristics of the response."""
        # Count citations
        citation_patterns = [r"\[.*?\]", r"\(.*?\)", r"according to", r"based on"]
        citation_count = sum(len(re.findall(pattern, response, re.IGNORECASE)) for pattern in citation_patterns)

        return {
            "length": len(response),
            "word_count": len(response.split()),
            "sentence_count": len([s for s in response.split(".") if s.strip()]),
            "citation_count": citation_count,
            "source_count": len(sources),
        }

    def _determine_confidence_level(self, overall_score: float, characteristics: Dict[str, Any]) -> str:
        """Determine confidence level based on score and characteristics."""
        if overall_score >= 0.8 and characteristics["citation_count"] >= 1:
            return "high"
        elif overall_score >= 0.6:
            return "medium"
        else:
            return "low"

    def _generate_quality_insights(
        self,
        relevance: float,
        completeness: float,
        coherence: float,
        source_fidelity: float,
        professionalism: float,
        characteristics: Dict[str, Any],
    ) -> Tuple[List[str], List[str], List[str]]:
        """Generate strengths, weaknesses, and recommendations."""
        strengths = []
        weaknesses = []
        recommendations = []

        # Analyze strengths
        if relevance >= 0.8:
            strengths.append("Highly relevant to user query")
        if completeness >= 0.8:
            strengths.append("Comprehensive and complete response")
        if coherence >= 0.8:
            strengths.append("Well-structured and coherent")
        if source_fidelity >= 0.8:
            strengths.append("Strong alignment with source documents")
        if professionalism >= 0.8:
            strengths.append("Professional and appropriate tone")

        # Analyze weaknesses
        if relevance < 0.6:
            weaknesses.append("Limited relevance to user query")
            recommendations.append("Ensure response directly addresses the question")
        if completeness < 0.6:
            weaknesses.append("Incomplete or insufficient information")
            recommendations.append("Provide more comprehensive information")
        if coherence < 0.6:
            weaknesses.append("Poor logical structure or flow")
            recommendations.append("Improve logical organization and flow")
        if source_fidelity < 0.6:
            weaknesses.append("Weak alignment with source documents")
            recommendations.append("Include proper citations and source references")
        if professionalism < 0.6:
            weaknesses.append("Unprofessional tone or language")
            recommendations.append("Use more professional and appropriate language")

        # Length-based recommendations
        if characteristics["length"] < self.config["min_response_length"]:
            recommendations.append("Provide more detailed information")
        elif characteristics["length"] > self.config["max_response_length"]:
            recommendations.append("Consider condensing the response")

        return strengths, weaknesses, recommendations