// server/supabase/functions/search-knowledge/index.ts
// 쿼리 텍스트 → OpenAI 임베딩 → match_knowledge_chunks RPC → 상위 청크 반환.
//
// 요청:
//   POST { query: "...", count?: number }
// 응답:
//   { results: Array<{ id, document_id, chunk_index, content, similarity }> }

import { corsHeaders, handleCorsPreflightRequest } from '../_shared/cors.ts'
import { requireUser, authErrorResponse, type AuthError } from '../_shared/auth.ts'

interface SearchRequest {
  query: string
  count?: number
}

// @ts-expect-error — Deno
import { createClient } from 'https://esm.sh/@supabase/supabase-js@2.103.0'

// @ts-expect-error — Deno 런타임 전역
Deno.serve(async (req: Request) => {
  const preflight = handleCorsPreflightRequest(req)
  if (preflight) return preflight

  if (req.method !== 'POST') {
    return new Response(JSON.stringify({ error: 'Method not allowed' }), {
      status: 405,
      headers: { ...corsHeaders, 'Content-Type': 'application/json' }
    })
  }

  try {
    await requireUser(req) // 인증만 확인. RPC는 auth.uid() 기반 RLS

    const body = (await req.json()) as SearchRequest
    if (!body.query || body.query.trim().length === 0) {
      return new Response(JSON.stringify({ error: 'query 필요' }), {
        status: 400,
        headers: { ...corsHeaders, 'Content-Type': 'application/json' }
      })
    }

    // @ts-expect-error — Deno.env
    const openaiKey = Deno.env.get('OPENAI_API_KEY') ?? ''
    if (!openaiKey) {
      return new Response(
        JSON.stringify({ error: 'openai_not_configured' }),
        { status: 503, headers: { ...corsHeaders, 'Content-Type': 'application/json' } }
      )
    }

    // 1) 쿼리 임베딩
    const embedResp = await fetch('https://api.openai.com/v1/embeddings', {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${openaiKey}`,
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        model: 'text-embedding-3-small',
        input: body.query,
        dimensions: 1536
      })
    })

    if (!embedResp.ok) {
      const errText = await embedResp.text()
      throw new Error(`임베딩 실패: ${errText.slice(0, 200)}`)
    }

    const embedData = (await embedResp.json()) as {
      data: Array<{ embedding: number[] }>
    }
    const queryEmbedding = embedData.data[0]?.embedding
    if (!queryEmbedding) {
      throw new Error('임베딩 응답이 비어있음')
    }

    // 2) RLS 컨텍스트에서 RPC 호출 (authenticated 유저 토큰 사용)
    const authHeader = req.headers.get('Authorization') ?? ''
    // @ts-expect-error — Deno.env
    const supabaseUrl = Deno.env.get('SUPABASE_URL') ?? ''
    // @ts-expect-error — Deno.env
    const anonKey = Deno.env.get('SUPABASE_ANON_KEY') ?? ''

    const userClient = createClient(supabaseUrl, anonKey, {
      global: { headers: { Authorization: authHeader } }
    })

    const { data: matches, error: rpcErr } = await userClient.rpc('match_knowledge_chunks', {
      query_embedding: queryEmbedding,
      match_count: body.count ?? 5,
      similarity_threshold: 0.5
    })

    if (rpcErr) {
      throw new Error(`RPC 실패: ${rpcErr.message}`)
    }

    return new Response(JSON.stringify({ results: matches ?? [] }), {
      status: 200,
      headers: { ...corsHeaders, 'Content-Type': 'application/json' }
    })
  } catch (err) {
    if (err && typeof err === 'object' && 'status' in err && 'message' in err) {
      return authErrorResponse(err as AuthError, corsHeaders)
    }
    const message = err instanceof Error ? err.message : 'Unknown error'
    return new Response(JSON.stringify({ error: message }), {
      status: 500,
      headers: { ...corsHeaders, 'Content-Type': 'application/json' }
    })
  }
})