// Setup type definitions for built-in Supabase Runtime APIs
import "@supabase/functions-js/edge-runtime.d.ts";
import { corsHeaders } from "../_shared/cors.ts";
import { OpenAIService } from "../_shared/openai-service.ts";
import { createClient } from "https://esm.sh/@supabase/supabase-js@2";

type WebhookPayload = {
  type: "INSERT" | "UPDATE" | "DELETE";
  table: string;
  schema: string;
  record: Record<string, unknown> | null;
  old_record: Record<string, unknown> | null;
};

const SUPABASE_URL = Deno.env.get("SUPABASE_URL") ?? "";
const SUPABASE_SERVICE_ROLE_KEY =
  Deno.env.get("SUPABASE_SERVICE_ROLE_KEY") ?? "";

const ALLOWED_SCHEMA = "public";
const ALLOWED_TABLES = new Set(["planes_estudio", "asignaturas"]);

const supabase = createClient(SUPABASE_URL, SUPABASE_SERVICE_ROLE_KEY, {
  auth: { persistSession: false },
});

function jsonResponse(status: number, body: Record<string, unknown>) {
  return new Response(JSON.stringify(body), {
    status,
    headers: { "Content-Type": "application/json", ...corsHeaders },
  });
}

async function createConversationId(
  openaiService: OpenAIService,
  metadata: Record<string, string>,
) {
  const conversation = await openaiService.createConversation(metadata);
  const conversationId = conversation?.id as string | undefined;

  if (!conversationId) {
    throw new Error("OpenAI response missing conversation id");
  }

  return conversationId;
}

Deno.serve(async (req) => {
  if (req.method !== "POST") {
    return jsonResponse(405, { error: "Method not allowed" });
  }

  if (!SUPABASE_URL || !SUPABASE_SERVICE_ROLE_KEY) {
    return jsonResponse(500, { error: "Supabase env vars missing" });
  }

  const openaiService = OpenAIService.fromEnv();
  if (!(openaiService instanceof OpenAIService)) {
    return jsonResponse(500, { error: openaiService.message });
  }

  let payload: WebhookPayload;
  try {
    payload = await req.json();
  } catch {
    return jsonResponse(400, { error: "Invalid JSON body" });
  }

  const { type, table, schema, record } = payload;

  if (schema !== ALLOWED_SCHEMA || !ALLOWED_TABLES.has(table)) {
    return jsonResponse(400, { error: "Table not allowed" });
  }

  if (type !== "INSERT") {
    return jsonResponse(200, { status: "ignored", reason: "event_type" });
  }

  if (!record || typeof record !== "object") {
    return jsonResponse(400, { error: "Missing record" });
  }

  const recordId = record["id"] as string | number | undefined;
  if (!recordId) {
    return jsonResponse(400, { error: "Record id missing" });
  }

  const existingConversationId = record["conversation_id"] as
    | string
    | null
    | undefined;
  if (existingConversationId) {
    return jsonResponse(200, {
      status: "skipped",
      conversation_id: existingConversationId,
    });
  }

  let conversationId: string;
  try {
    conversationId = await createConversationId(openaiService, {
      table,
      record_id: String(recordId),
    });
  } catch (error) {
    return jsonResponse(502, { error: (error as Error).message });
  }

  const { error } = await supabase
    .from(table)
    .update({ conversation_id: conversationId })
    .eq("id", recordId);

  if (error) {
    return jsonResponse(500, { error: error.message });
  }

  return jsonResponse(200, {
    status: "updated",
    table,
    record_id: recordId,
    conversation_id: conversationId,
  });
});