// server/supabase/functions/search-knowledge/index.ts
// Composition root: wires the real adapters into the search-knowledge use case.

import { createClient } from '@supabase/supabase-js'
import { requireUser } from '../_shared/auth.ts'
import { createServiceRoleClient } from '../_shared/quota.ts'
import { readProviderKey } from '../_shared/provider-key.ts'
import { createOpenAIEmbeddingProvider } from '../_shared/openai-embeddings.ts'
import { createSupabaseEmbeddingUsageStore } from '../_shared/embedding-quota.ts'
import { type ChunkSearcher, createSearchKnowledgeHandler, SIMILARITY_THRESHOLD } from './handler.ts'

let serviceClient: ReturnType<typeof createServiceRoleClient> | null = null
function service(): ReturnType<typeof createServiceRoleClient> {
  serviceClient ??= createServiceRoleClient()
  return serviceClient
}

/** match_knowledge_chunks runs as the caller so RLS limits results to their own chunks. */
const searchChunks: ChunkSearcher = async (req, embedding, count) => {
  const authHeader = req.headers.get('Authorization') ?? ''
  const supabaseUrl = Deno.env.get('SUPABASE_URL') ?? ''
  const anonKey = Deno.env.get('SUPABASE_ANON_KEY') ?? ''
  if (!supabaseUrl || !anonKey) return { ok: false, reason: 'unavailable' }

  const userClient = createClient(supabaseUrl, anonKey, {
    global: { headers: { Authorization: authHeader } },
    auth: { persistSession: false, autoRefreshToken: false },
  })
  const result = await userClient.rpc('match_knowledge_chunks', {
    query_embedding: embedding,
    match_count: count,
    similarity_threshold: SIMILARITY_THRESHOLD,
  })
  if (result.error) return { ok: false, reason: 'failed' }
  return { ok: true, results: Array.isArray(result.data) ? result.data : [] }
}

Deno.serve(createSearchKnowledgeHandler({
  authenticate: requireUser,
  embeddingProvider: () => {
    const key = readProviderKey('OPENAI_API_KEY')
    return key ? createOpenAIEmbeddingProvider(key) : null
  },
  usageStore: () => createSupabaseEmbeddingUsageStore(service()),
  searchChunks,
}))