// Follow this setup guide to integrate the Deno language server with your editor:
// https://deno.land/manual/getting_started/setup_your_environment
// This enables autocomplete, go to definition, etc.

// Setup type definitions for built-in Supabase Runtime APIs
import "@supabase/functions-js/edge-runtime.d.ts";
import { createClient } from "@supabase/supabase-js";
import { z } from "zod";
import { corsHeaders } from "../_shared/cors.ts";
import type { Database, Json } from "../_shared/database.types.ts";
import { HttpError, sendError } from "../_shared/utils.ts";
import { CarboneClient } from "./carbone.ts";

const ActionSchema = z.object({
  action: z.string().min(1),
});

const DownloadReportSchema = z.object({
  action: z.literal("downloadReport"),
  plan_estudio_id: z.string().min(1),
});

type DownloadReportInput = z.infer<typeof DownloadReportSchema>;

function getAuthHeader(req: Request): string | null {
  return req.headers.get("Authorization") ?? req.headers.get("authorization");
}

async function loadPlanDatos(
  supabase: ReturnType<typeof createClient<Database>>,
  planEstudioId: string,
): Promise<Json> {
  const { data, error } = await supabase
    .from("planes_estudio")
    .select("datos")
    .eq("id", planEstudioId)
    .maybeSingle();

  if (error) {
    throw new HttpError(
      500,
      "Error consultando el plan de estudios.",
      "DB_ERROR",
      { message: error.message, details: error.details, hint: error.hint },
    );
  }
  if (!data) {
    throw new HttpError(
      404,
      "Plan de estudios no encontrado.",
      "NOT_FOUND",
      { plan_estudio_id: planEstudioId },
    );
  }
  return data.datos;
}

Deno.serve(async (req: Request): Promise<Response> => {
  const url = new URL(req.url);
  const functionName = url.pathname.split("/").pop();
  console.log(
    `[${new Date().toISOString()}][${functionName}]: Request received`,
  );

  if (req.method === "OPTIONS") {
    return new Response(null, { status: 204, headers: corsHeaders });
  }

  try {
    if (req.method !== "POST") {
      throw new HttpError(
        405,
        "Método no permitido.",
        "METHOD_NOT_ALLOWED",
        { method: req.method },
      );
    }

    const authHeader = getAuthHeader(req);
    if (!authHeader) {
      throw new HttpError(401, "No autorizado.", "UNAUTHORIZED", {
        reason: "missing_authorization_header",
      });
    }

    const contentType = (req.headers.get("content-type") || "").toLowerCase();
    if (!contentType.startsWith("application/json")) {
      throw new HttpError(
        415,
        "Content-Type no soportado.",
        "UNSUPPORTED_MEDIA_TYPE",
        { contentType },
      );
    }

    const SUPABASE_URL = Deno.env.get("SUPABASE_URL");
    const SERVICE_ROLE_KEY = Deno.env.get("SUPABASE_SERVICE_ROLE_KEY");
    if (!SUPABASE_URL || !SERVICE_ROLE_KEY) {
      throw new HttpError(
        500,
        "Configuración del servidor incompleta.",
        "MISSING_ENV",
        {
          missing: [
            !SUPABASE_URL ? "SUPABASE_URL" : null,
            !SERVICE_ROLE_KEY ? "SUPABASE_SERVICE_ROLE_KEY" : null,
          ].filter(Boolean),
        },
      );
    }

    const CARBONE_API_TOKEN = Deno.env.get("CARBONE_API_TOKEN");
    const CARBONE_TEMPLATE_ID = Deno.env.get("CARBONE_TEMPLATE_ID");
    const CARBONE_BASE_URL = Deno.env.get("CARBONE_BASE_URL") ||
      "https://carbone.lci.ulsa.mx";
    if (!CARBONE_API_TOKEN || !CARBONE_TEMPLATE_ID) {
      throw new HttpError(
        500,
        "Configuración del servidor incompleta.",
        "MISSING_ENV",
        {
          missing: [
            !CARBONE_API_TOKEN ? "CARBONE_API_TOKEN" : null,
            !CARBONE_TEMPLATE_ID ? "CARBONE_TEMPLATE_ID" : null,
          ].filter(Boolean),
        },
      );
    }

    const bodyUnknown: unknown = await req.json();
    const { action } = ActionSchema.parse(bodyUnknown);

    const supabase = createClient<Database>(SUPABASE_URL, SERVICE_ROLE_KEY, {
      auth: { persistSession: false },
    });

    switch (action) {
      case "downloadReport": {
        const input: DownloadReportInput = DownloadReportSchema.parse(
          bodyUnknown,
        );

        const datos = await loadPlanDatos(supabase, input.plan_estudio_id);
        const carbone = new CarboneClient(CARBONE_BASE_URL, CARBONE_API_TOKEN);

        const result = await carbone.render(
          CARBONE_TEMPLATE_ID,
          { data: datos, convertTo: "pdf" },
          { download: true },
        );

        if (!(result && typeof result === "object" && "buffer" in result)) {
          throw new HttpError(
            502,
            "Respuesta inválida de Carbone.",
            "UPSTREAM_INVALID_RESPONSE",
          );
        }

        const download = result as {
          buffer: Uint8Array;
          contentType: string | null;
          contentDisposition: string | null;
        };

        const bytes = download.buffer;
        const arrayBuffer = bytes.buffer.slice(
          bytes.byteOffset,
          bytes.byteOffset + bytes.byteLength,
        ) as ArrayBuffer;
        const blob = new Blob([arrayBuffer], {
          type: download.contentType ?? "application/octet-stream",
        });

        const headers = new Headers({
          ...corsHeaders,
          "Content-Type": download.contentType ?? "application/octet-stream",
          Connection: "keep-alive",
        });
        if (download.contentDisposition) {
          headers.set("Content-Disposition", download.contentDisposition);
        }

        console.log(
          `[${
            new Date().toISOString()
          }][${functionName}]: Request processed successfully`,
        );
        return new Response(blob, { status: 200, headers });
      }
      default:
        throw new HttpError(
          400,
          "Acción no soportada.",
          "UNSUPPORTED_ACTION",
          { action },
        );
    }
  } catch (err) {
    const error = err instanceof HttpError ? err : new HttpError(
      500,
      "Error interno del servidor.",
      "INTERNAL_SERVER_ERROR",
      {
        original: err instanceof Error
          ? { message: err.message, stack: err.stack }
          : err,
      },
    );
    return sendError(error.status, error.message, error.code);
  }
});

/* To invoke locally:

  1. Run `supabase start` (see: https://supabase.com/docs/reference/cli/supabase-start)
  2. Make an HTTP request:

  # Requires secrets:
  # - CARBONE_API_TOKEN
  # - CARBONE_TEMPLATE_ID
  # Optional:
  # - CARBONE_BASE_URL (defaults to https://carbone.lci.ulsa.mx)

  curl -i --location --request POST 'http://127.0.0.1:54321/functions/v1/carbone-io-wrapper' \
    --header 'Authorization: Bearer <JWT>' \
    --header 'Content-Type: application/json' \
    --data '{"action":"downloadReport","plan_estudio_id":"<uuid>"}'

*/