package com.rssuper.search

import com.rssuper.database.daos.FeedItemDao
import com.rssuper.database.entities.FeedItemEntity

/**
 * SearchResultProvider - Provides search results from the database
 */
class SearchResultProvider(
    private val feedItemDao: FeedItemDao
) {
    suspend fun search(query: String, limit: Int = 20): List<SearchResult> {
        // Use FTS query to search feed items
        val results = feedItemDao.searchByFts(query, limit)
        
        return results.mapIndexed { index, item ->
            SearchResult(
                feedItem = item,
                relevanceScore = calculateRelevance(query, item, index),
                highlight = generateHighlight(item)
            )
        }
    }
    
    suspend fun searchBySubscription(query: String, subscriptionId: String, limit: Int = 20): List<SearchResult> {
        val results = feedItemDao.searchByFts(query, limit)
        
        return results.filter { it.subscriptionId == subscriptionId }.mapIndexed { index, item ->
            SearchResult(
                feedItem = item,
                relevanceScore = calculateRelevance(query, item, index),
                highlight = generateHighlight(item)
            )
        }
    }
    
    private fun calculateRelevance(query: String, item: FeedItemEntity, position: Int): Float {
        val queryLower = query.lowercase()
        var score = 0.0f
        
        // Title match (highest weight)
        if (item.title.lowercase().contains(queryLower)) {
            score += 1.0f
        }
        
        // Author match
        if (item.author?.lowercase()?.contains(queryLower) == true) {
            score += 0.5f
        }
        
        // Position bonus (earlier results are more relevant)
        score += (1.0f / (position + 1)) * 0.3f
        
        return score.coerceIn(0.0f, 1.0f)
    }
    
    private fun generateHighlight(item: FeedItemEntity): String? {
        val maxLength = 200
        var text = item.title
        
        if (item.description?.isNotEmpty() == true) {
            text += " ${item.description}"
        }
        
        if (text.length > maxLength) {
            text = text.substring(0, maxLength) + "..."
        }
        
        return text
    }
}