"""
Main Searcher module - executes search queries against Elasticsearch.

Handles query parsing, boolean expressions, ranking, and result formatting.
"""

from typing import Dict, Any, List, Optional, Union
import time

from config import SearchConfig
from utils.es_client import ESClient
from query import QueryParser, ParsedQuery
from indexer import MappingGenerator
from .boolean_parser import BooleanParser, QueryNode
from .es_query_builder import ESQueryBuilder
from .multilang_query_builder import MultiLanguageQueryBuilder
from .rerank_engine import RerankEngine
from context.request_context import RequestContext, RequestContextStage, create_request_context
from api.models import FacetResult, FacetValue
from api.result_formatter import ResultFormatter


class SearchResult:
    """Container for search results (外部友好格式)."""

    def __init__(
        self,
        results: List[Any],  # List[ProductResult]
        total: int,
        max_score: float,
        took_ms: int,
        facets: Optional[List[FacetResult]] = None,
        query_info: Optional[Dict[str, Any]] = None,
        suggestions: Optional[List[str]] = None,
        related_searches: Optional[List[str]] = None,
        debug_info: Optional[Dict[str, Any]] = None
    ):
        self.results = results
        self.total = total
        self.max_score = max_score
        self.took_ms = took_ms
        self.facets = facets
        self.query_info = query_info or {}
        self.suggestions = suggestions or []
        self.related_searches = related_searches or []
        self.debug_info = debug_info

    def to_dict(self) -> Dict[str, Any]:
        """Convert to dictionary representation."""
        result = {
            "results": [r.model_dump() if hasattr(r, 'model_dump') else r for r in self.results],
            "total": self.total,
            "max_score": self.max_score,
            "took_ms": self.took_ms,
            "facets": [f.model_dump() for f in self.facets] if self.facets else None,
            "query_info": self.query_info,
            "suggestions": self.suggestions,
            "related_searches": self.related_searches
        }
        if self.debug_info is not None:
            result["debug_info"] = self.debug_info
        return result


class Searcher:
    """
    Main search engine class.

    Handles:
    - Query parsing and translation
    - Boolean expression parsing
    - ES query building
    - Result ranking and formatting
    """

    def __init__(
        self,
        config: SearchConfig,
        es_client: ESClient,
        query_parser: Optional[QueryParser] = None
    ):
        """
        Initialize searcher.

        Args:
            config: Search configuration
            es_client: Elasticsearch client
            query_parser: Query parser (created if not provided)
        """
        self.config = config
        self.es_client = es_client
        self.query_parser = query_parser or QueryParser(config)

        # Initialize components
        self.boolean_parser = BooleanParser()
        self.rerank_engine = RerankEngine(config.ranking.expression, enabled=False)

        # Get mapping info
        mapping_gen = MappingGenerator(config)
        self.match_fields = mapping_gen.get_match_fields_for_domain("default")
        self.text_embedding_field = mapping_gen.get_text_embedding_field()
        self.image_embedding_field = mapping_gen.get_image_embedding_field()

        # Query builder - use multi-language version
        self.query_builder = MultiLanguageQueryBuilder(
            config=config,
            index_name=config.es_index_name,
            text_embedding_field=self.text_embedding_field,
            image_embedding_field=self.image_embedding_field,
            source_fields=config.query_config.source_fields
        )

    def search(
        self,
        query: str,
        tenant_id: str,
        size: int = 10,
        from_: int = 0,
        filters: Optional[Dict[str, Any]] = None,
        range_filters: Optional[Dict[str, Any]] = None,
        facets: Optional[List[Any]] = None,
        min_score: Optional[float] = None,
        context: Optional[RequestContext] = None,
        sort_by: Optional[str] = None,
        sort_order: Optional[str] = "desc",
        debug: bool = False
    ) -> SearchResult:
        """
        Execute search query (外部友好格式).

        Args:
            query: Search query string
            tenant_id: Tenant ID (required for filtering)
            size: Number of results to return
            from_: Offset for pagination
            filters: Exact match filters
            range_filters: Range filters for numeric fields
            facets: Facet configurations for faceted search
            min_score: Minimum score threshold
            context: Request context for tracking (created if not provided)
            sort_by: Field name for sorting
            sort_order: Sort order: 'asc' or 'desc'
            debug: Enable debug information output

        Returns:
            SearchResult object with formatted results
        """
        # Create context if not provided (backward compatibility)
        if context is None:
            context = create_request_context()

        # Always use config defaults (these are backend configuration, not user parameters)
        enable_translation = self.config.query_config.enable_translation
        enable_embedding = self.config.query_config.enable_text_embedding
        enable_rerank = False  # Temporarily disabled

        # Start timing
        context.start_stage(RequestContextStage.TOTAL)

        context.logger.info(
            f"开始搜索请求 | 查询: '{query}' | 参数: size={size}, from_={from_}, "
            f"enable_translation={enable_translation}, enable_embedding={enable_embedding}, "
            f"enable_rerank={enable_rerank}, min_score={min_score}",
            extra={'reqid': context.reqid, 'uid': context.uid}
        )

        # Store search parameters in context
        context.metadata['search_params'] = {
            'size': size,
            'from_': from_,
            'filters': filters,
            'range_filters': range_filters,
            'facets': facets,
            'enable_translation': enable_translation,
            'enable_embedding': enable_embedding,
            'enable_rerank': enable_rerank,
            'min_score': min_score,
            'sort_by': sort_by,
            'sort_order': sort_order
        }

        context.metadata['feature_flags'] = {
            'translation_enabled': enable_translation,
            'embedding_enabled': enable_embedding,
            'rerank_enabled': enable_rerank
        }

        # Step 1: Parse query
        context.start_stage(RequestContextStage.QUERY_PARSING)
        try:
            parsed_query = self.query_parser.parse(
                query,
                generate_vector=enable_embedding,
                context=context
            )
            # Store query analysis results in context
            context.store_query_analysis(
                original_query=parsed_query.original_query,
                normalized_query=parsed_query.normalized_query,
                rewritten_query=parsed_query.rewritten_query,
                detected_language=parsed_query.detected_language,
                translations=parsed_query.translations,
                query_vector=parsed_query.query_vector.tolist() if parsed_query.query_vector is not None else None,
                domain=parsed_query.domain,
                is_simple_query=self.boolean_parser.is_simple_query(parsed_query.rewritten_query)
            )

            context.logger.info(
                f"查询解析完成 | 原查询: '{parsed_query.original_query}' | "
                f"重写后: '{parsed_query.rewritten_query}' | "
                f"语言: {parsed_query.detected_language} | "
                f"域: {parsed_query.domain} | "
                f"向量: {'是' if parsed_query.query_vector is not None else '否'}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
        except Exception as e:
            context.set_error(e)
            context.logger.error(
                f"查询解析失败 | 错误: {str(e)}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            raise
        finally:
            context.end_stage(RequestContextStage.QUERY_PARSING)

        # Step 2: Boolean parsing
        context.start_stage(RequestContextStage.BOOLEAN_PARSING)
        try:
            query_node = None
            if self.boolean_parser.is_simple_query(parsed_query.rewritten_query):
                # Simple query
                query_text = parsed_query.rewritten_query
                context.logger.debug(
                    f"简单查询 | 无布尔表达式",
                    extra={'reqid': context.reqid, 'uid': context.uid}
                )
            else:
                # Complex boolean query
                query_node = self.boolean_parser.parse(parsed_query.rewritten_query)
                query_text = parsed_query.rewritten_query
                context.store_intermediate_result('query_node', query_node)
                context.store_intermediate_result('boolean_ast', str(query_node))
                context.logger.info(
                    f"布尔表达式解析 | AST: {query_node}",
                    extra={'reqid': context.reqid, 'uid': context.uid}
                )
        except Exception as e:
            context.set_error(e)
            context.logger.error(
                f"布尔表达式解析失败 | 错误: {str(e)}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            raise
        finally:
            context.end_stage(RequestContextStage.BOOLEAN_PARSING)

        # Step 3: Query building
        context.start_stage(RequestContextStage.QUERY_BUILDING)
        try:
            # Add tenant_id to filters (required)
            if filters is None:
                filters = {}
            filters['tenant_id'] = tenant_id

            es_query = self.query_builder.build_multilang_query(
                parsed_query=parsed_query,
                query_vector=parsed_query.query_vector if enable_embedding else None,
                query_node=query_node,
                filters=filters,
                range_filters=range_filters,
                size=size,
                from_=from_,
                enable_knn=enable_embedding and parsed_query.query_vector is not None,
                min_score=min_score
            )

            # Add SPU collapse if configured
            if self.config.spu_config.enabled:
                es_query = self.query_builder.add_spu_collapse(
                    es_query,
                    self.config.spu_config.spu_field,
                    self.config.spu_config.inner_hits_size
                )

            # Add facets for faceted search
            if facets:
                facet_aggs = self.query_builder.build_facets(facets)
                if facet_aggs:
                    if "aggs" not in es_query:
                        es_query["aggs"] = {}
                    es_query["aggs"].update(facet_aggs)

            # Add sorting if specified
            if sort_by:
                es_query = self.query_builder.add_sorting(es_query, sort_by, sort_order)

            # Extract size and from from body for ES client parameters
            body_for_es = {k: v for k, v in es_query.items() if k not in ['size', 'from']}

            # Store ES query in context
            context.store_intermediate_result('es_query', es_query)
            context.store_intermediate_result('es_body_for_search', body_for_es)

            context.logger.info(
                f"ES查询构建完成 | 大小: {len(str(es_query))}字符 | "
                f"KNN: {'是' if enable_embedding and parsed_query.query_vector is not None else '否'} | "
                f"分面: {'是' if facets else '否'}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            context.logger.debug(
                f"ES查询详情: {es_query}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
        except Exception as e:
            context.set_error(e)
            context.logger.error(
                f"ES查询构建失败 | 错误: {str(e)}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            raise
        finally:
            context.end_stage(RequestContextStage.QUERY_BUILDING)

        # Step 4: Elasticsearch search
        context.start_stage(RequestContextStage.ELASTICSEARCH_SEARCH)
        try:
            es_response = self.es_client.search(
                index_name=self.config.es_index_name,
                body=body_for_es,
                size=size,
                from_=from_
            )

            # Store ES response in context
            context.store_intermediate_result('es_response', es_response)

            # Extract timing from ES response
            es_took = es_response.get('took', 0)
            context.logger.info(
                f"ES搜索完成 | 耗时: {es_took}ms | "
                f"命中数: {es_response.get('hits', {}).get('total', {}).get('value', 0)} | "
                f"最高分: {(es_response.get('hits', {}).get('max_score') or 0):.3f}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
        except Exception as e:
            context.set_error(e)
            context.logger.error(
                f"ES搜索执行失败 | 错误: {str(e)}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            raise
        finally:
            context.end_stage(RequestContextStage.ELASTICSEARCH_SEARCH)

        # Step 5: Result processing
        context.start_stage(RequestContextStage.RESULT_PROCESSING)
        try:
            # Extract ES hits
            es_hits = []
            if 'hits' in es_response and 'hits' in es_response['hits']:
                es_hits = es_response['hits']['hits']

            # Extract total and max_score
            total = es_response.get('hits', {}).get('total', {})
            if isinstance(total, dict):
                total_value = total.get('value', 0)
            else:
                total_value = total

            max_score = es_response.get('hits', {}).get('max_score') or 0.0

            # Format results using ResultFormatter
            formatted_results = ResultFormatter.format_search_results(es_hits, max_score)

            # Format facets
            standardized_facets = None
            if facets:
                standardized_facets = ResultFormatter.format_facets(
                    es_response.get('aggregations', {}),
                    facets
                )

            # Generate suggestions and related searches
            query_text = parsed_query.original_query if parsed_query else query
            suggestions = ResultFormatter.generate_suggestions(query_text, formatted_results)
            related_searches = ResultFormatter.generate_related_searches(query_text, formatted_results)

            context.logger.info(
                f"结果处理完成 | 返回: {len(formatted_results)}条 | 总计: {total_value}条",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )

        except Exception as e:
            context.set_error(e)
            context.logger.error(
                f"结果处理失败 | 错误: {str(e)}",
                extra={'reqid': context.reqid, 'uid': context.uid}
            )
            raise
        finally:
            context.end_stage(RequestContextStage.RESULT_PROCESSING)

        # End total timing and build result
        total_duration = context.end_stage(RequestContextStage.TOTAL)
        context.performance_metrics.total_duration = total_duration

        # Collect debug information if requested
        debug_info = None
        if debug:
            debug_info = {
                "query_analysis": {
                    "original_query": context.query_analysis.original_query,
                    "normalized_query": context.query_analysis.normalized_query,
                    "rewritten_query": context.query_analysis.rewritten_query,
                    "detected_language": context.query_analysis.detected_language,
                    "translations": context.query_analysis.translations,
                    "has_vector": context.query_analysis.query_vector is not None,
                    "is_simple_query": context.query_analysis.is_simple_query,
                    "boolean_ast": context.get_intermediate_result('boolean_ast'),
                    "domain": context.query_analysis.domain
                },
                "es_query": context.get_intermediate_result('es_query', {}),
                "es_response": {
                    "took_ms": es_response.get('took', 0),
                    "total_hits": total_value,
                    "max_score": max_score,
                    "shards": es_response.get('_shards', {})
                },
                "feature_flags": context.metadata.get('feature_flags', {}),
                "stage_timings": {
                    k: round(v, 2) for k, v in context.performance_metrics.stage_timings.items()
                },
                "search_params": context.metadata.get('search_params', {})
            }

        # Build result
        result = SearchResult(
            results=formatted_results,
            total=total_value,
            max_score=max_score,
            took_ms=int(total_duration),
            facets=standardized_facets,
            query_info=parsed_query.to_dict(),
            suggestions=suggestions,
            related_searches=related_searches,
            debug_info=debug_info
        )

        # Log complete performance summary
        context.log_performance_summary()

        return result

    def search_by_image(
        self,
        image_url: str,
        tenant_id: str,
        size: int = 10,
        filters: Optional[Dict[str, Any]] = None,
        range_filters: Optional[Dict[str, Any]] = None
    ) -> SearchResult:
        """
        Search by image similarity (外部友好格式).

        Args:
            image_url: URL of query image
            tenant_id: Tenant ID (required for filtering)
            size: Number of results
            filters: Exact match filters
            range_filters: Range filters for numeric fields

        Returns:
            SearchResult object with formatted results
        """
        if not self.image_embedding_field:
            raise ValueError("Image embedding field not configured")

        # Generate image embedding
        from embeddings import CLIPImageEncoder
        image_encoder = CLIPImageEncoder()
        image_vector = image_encoder.encode_image_from_url(image_url)

        if image_vector is None:
            raise ValueError(f"Failed to encode image: {image_url}")

        # Add tenant_id to filters (required)
        if filters is None:
            filters = {}
        filters['tenant_id'] = tenant_id

        # Build KNN query
        es_query = {
            "size": size,
            "knn": {
                "field": self.image_embedding_field,
                "query_vector": image_vector.tolist(),
                "k": size,
                "num_candidates": size * 10
            }
        }

        # Add _source filtering if source_fields are configured
        if self.config.query_config.source_fields:
            es_query["_source"] = {
                "includes": self.config.query_config.source_fields
            }

        if filters or range_filters:
            filter_clauses = self.query_builder._build_filters(filters, range_filters)
            if filter_clauses:
                es_query["query"] = {
                    "bool": {
                        "filter": filter_clauses
                    }
                }

        # Execute search
        es_response = self.es_client.search(
            index_name=self.config.es_index_name,
            body=es_query,
            size=size
        )

        # Extract ES hits
        es_hits = []
        if 'hits' in es_response and 'hits' in es_response['hits']:
            es_hits = es_response['hits']['hits']

        # Extract total and max_score
        total = es_response.get('hits', {}).get('total', {})
        if isinstance(total, dict):
            total_value = total.get('value', 0)
        else:
            total_value = total

        max_score = es_response.get('hits', {}).get('max_score') or 0.0

        # Format results using ResultFormatter
        formatted_results = ResultFormatter.format_search_results(es_hits, max_score)

        return SearchResult(
            results=formatted_results,
            total=total_value,
            max_score=max_score,
            took_ms=es_response.get('took', 0),
            facets=None,
            query_info={'image_url': image_url, 'search_type': 'image_similarity'},
            suggestions=[],
            related_searches=[]
        )

    def get_domain_summary(self) -> Dict[str, Any]:
        """
        Get summary of all configured domains.

        Returns:
            Dictionary with domain information
        """
        return self.query_builder.get_domain_summary()

    def get_document(self, doc_id: str) -> Optional[Dict[str, Any]]:
        """
        Get single document by ID.

        Args:
            doc_id: Document ID

        Returns:
            Document or None if not found
        """
        try:
            response = self.es_client.client.get(
                index=self.config.es_index_name,
                id=doc_id
            )
            return response.get('_source')
        except Exception as e:
            print(f"[Searcher] Failed to get document {doc_id}: {e}")
            return None

    def _standardize_facets(
        self,
        es_aggregations: Dict[str, Any],
        facet_configs: Optional[List[Union[str, Any]]],
        current_filters: Optional[Dict[str, Any]]
    ) -> Optional[List[FacetResult]]:
        """
        将 ES 聚合结果转换为标准化的分面格式（返回 Pydantic 模型）。
        
        Args:
            es_aggregations: ES 原始聚合结果
            facet_configs: 分面配置列表（str 或 FacetConfig）
            current_filters: 当前应用的过滤器
        
        Returns:
            标准化的分面结果列表（FacetResult 对象）
        """
        if not es_aggregations or not facet_configs:
            return None
        
        standardized_facets: List[FacetResult] = []
        
        for config in facet_configs:
            # 解析配置
            if isinstance(config, str):
                field = config
                facet_type = "terms"
            else:
                # FacetConfig 对象
                field = config.field
                facet_type = config.type
            
            agg_name = f"{field}_facet"
            
            if agg_name not in es_aggregations:
                continue
            
            agg_result = es_aggregations[agg_name]
            
            # 获取当前字段的选中值
            selected_values = set()
            if current_filters and field in current_filters:
                filter_value = current_filters[field]
                if isinstance(filter_value, list):
                    selected_values = set(filter_value)
                else:
                    selected_values = {filter_value}
            
            # 转换 buckets 为 FacetValue 对象
            facet_values: List[FacetValue] = []
            if 'buckets' in agg_result:
                for bucket in agg_result['buckets']:
                    value = bucket.get('key')
                    count = bucket.get('doc_count', 0)
                    
                    facet_values.append(FacetValue(
                        value=value,
                        label=str(value),
                        count=count,
                        selected=value in selected_values
                    ))
            
            # 构建 FacetResult 对象
            facet_result = FacetResult(
                field=field,
                label=self._get_field_label(field),
                type=facet_type,
                values=facet_values
            )
            
            standardized_facets.append(facet_result)
        
        return standardized_facets if standardized_facets else None

    def _get_field_label(self, field: str) -> str:
        """获取字段的显示标签"""
        # 从配置中获取字段标签
        for field_config in self.config.fields:
            if field_config.name == field:
                # 尝试获取 label 属性
                return getattr(field_config, 'label', field)
        # 如果没有配置，返回字段名
        return field