import type { NextApiRequest, NextApiResponse } from "next"
import { db, schema } from '../../../lib/db/connection'
import { eq, and, or, like, gte, lte, desc, count, sql } from 'drizzle-orm'

export default async function handler(req: NextApiRequest, res: NextApiResponse) {
  if (req.method !== "GET") return res.status(405).json({ error: "Method not allowed" })
  
  const { 
    q, 
    category, 
    risk_level_min, 
    risk_level_max,
    status = 'verified',
    page = '1',
    limit = '20'
  } = req.query
  
  try {
    let whereConditions = [eq(schema.sources.status, status as string)]
    
    if (q) {
      whereConditions.push(
        or(
          like(schema.sources.domain, `%${q}%`),
          like(schema.sources.title, `%${q}%`),
          like(schema.sources.description, `%${q}%`)
        )
      )
    }
    
    if (risk_level_min) {
      whereConditions.push(gte(schema.sources.riskLevel, parseInt(risk_level_min as string)))
    }
    
    if (risk_level_max) {
      whereConditions.push(lte(schema.sources.riskLevel, parseInt(risk_level_max as string)))
    }
    
    const offset = (parseInt(page as string) - 1) * parseInt(limit as string)
    const limitInt = parseInt(limit as string)
    
    // Build the base query
    let query = db
      .select({
        id: schema.sources.id,
        domain: schema.sources.domain,
        title: schema.sources.title,
        riskLevel: schema.sources.riskLevel,
        description: schema.sources.description,
        createdAt: schema.sources.createdAt,
        categories: sql<string>`string_agg(${schema.categories.name}, ',')`
      })
      .from(schema.sources)
      .leftJoin(schema.sourceCategories, eq(schema.sources.id, schema.sourceCategories.sourceId))
      .leftJoin(schema.categories, eq(schema.sourceCategories.categoryId, schema.categories.id))
      .where(and(...whereConditions))
      .groupBy(schema.sources.id, schema.sources.domain, schema.sources.title, schema.sources.riskLevel, schema.sources.description, schema.sources.createdAt)
      .orderBy(desc(schema.sources.riskLevel), desc(schema.sources.createdAt))
      .limit(limitInt)
      .offset(offset)
    
    // Apply category filter if provided
    if (category) {
      query = db
        .select({
          id: schema.sources.id,
          domain: schema.sources.domain,
          title: schema.sources.title,
          riskLevel: schema.sources.riskLevel,
          description: schema.sources.description,
          createdAt: schema.sources.createdAt,
          categories: sql<string>`string_agg(${schema.categories.name}, ',')`
        })
        .from(schema.sources)
        .innerJoin(schema.sourceCategories, eq(schema.sources.id, schema.sourceCategories.sourceId))
        .innerJoin(schema.categories, eq(schema.sourceCategories.categoryId, schema.categories.id))
        .where(and(...whereConditions, eq(schema.categories.name, category as string)))
        .groupBy(schema.sources.id, schema.sources.domain, schema.sources.title, schema.sources.riskLevel, schema.sources.description, schema.sources.createdAt)
        .orderBy(desc(schema.sources.riskLevel), desc(schema.sources.createdAt))
        .limit(limitInt)
        .offset(offset)
    }
    
    const results = await query
    
    // Get total count for pagination
    let countQuery = db
      .select({ count: count() })
      .from(schema.sources)
      .where(and(...whereConditions))
    
    if (category) {
      countQuery = db
        .select({ count: count() })
        .from(schema.sources)
        .innerJoin(schema.sourceCategories, eq(schema.sources.id, schema.sourceCategories.sourceId))
        .innerJoin(schema.categories, eq(schema.sourceCategories.categoryId, schema.categories.id))
        .where(and(...whereConditions, eq(schema.categories.name, category as string)))
    }
    
    const [totalResult] = await countQuery
    const total = totalResult.count
    const totalPages = Math.ceil(total / limitInt)
    
    res.json({
      results: results.map(row => ({
        id: row.id,
        domain: row.domain,
        title: row.title,
        risk_level: row.riskLevel,
        categories: row.categories ? row.categories.split(',').filter(Boolean) : [],
        description: row.description,
        created_at: row.createdAt
      })),
      pagination: {
        page: parseInt(page as string),
        limit: limitInt,
        total,
        totalPages
      }
    })
    
  } catch (error) {
    console.error('Search error:', error)
    res.status(500).json({ error: "Search failed" })
  }
}