import { SupabaseClient, createClient } from "https://esm.sh/@supabase/supabase-js@2";

interface StraetoVariables {
  [key: string]: number | string;
}

interface StraetoQuery {
  operationName: string;
  variables: StraetoVariables;
  extensions: StraetoQueryExtensions;
}

interface StraetoQueryExtensions {
  persistedQuery: StraetoPersistedQuery;
}

interface StraetoPersistedQuery {
  version: number;
  sha256Hash: string;
}

interface StraetoBusStop {
  id: number;
  name: string;
  lat: number;
  lon: number;
  type: number;
  rotation: number;
  code: string | null;
  isTerminal: boolean;
  routes: Array<string>;
  alerts: Array<string>;
  __typename: string;
}

interface DbBusStop {
  id: number;
  stop_name: string;
  coords: string; // TODO better geometry type representation
  type: number;
  rotation: number;
  code: string | null;
  is_terminal: boolean;
  routes: Array<string>;
}

function toDbBusStop(straetoStop: StraetoBusStop): DbBusStop {
  return {
    id: straetoStop.id,
    code: straetoStop.code,
    stop_name: straetoStop.name,
    coords: `POINT(${straetoStop.lat} ${straetoStop.lon})`,
    type: straetoStop.type,
    rotation: straetoStop.rotation,
    is_terminal: straetoStop.isTerminal,
    routes: straetoStop.routes,
  };
}

function toQuerystring(obj: StraetoQuery) {
  return Object.keys(obj).map(function (variableName) {
    const variableValue = obj[variableName as keyof typeof obj];
    if (typeof variableValue == "object") {
      return encodeURIComponent(variableName) + "=" +
        encodeURIComponent(JSON.stringify(variableValue));
    } else {
      return encodeURIComponent(variableName) + "=" +
        encodeURIComponent(variableValue);
    }
  }).join("&");
}

const graphqlParams: StraetoQuery = {
  operationName: "Stops",
  variables: {},
  extensions: {
    persistedQuery: {
      version: 1,
      sha256Hash:
        "6303de055cc42db47a4e1f1cc941b8c86d11c147903bed231e6d4bddcf0e1312",
    },
  },
};

async function getStops(): Promise<Array<StraetoBusStop>> {
  const apiUrl = `https://straeto.is/graphql?${toQuerystring(graphqlParams)}`;

  const opts = {
    method: "GET",
    headers: {
      "Content-Type": "application/json",
    },
  };

  const resp = await fetch(apiUrl, opts);
  const body = await resp.json();
  return body.data.GtfsStops.results;
}

async function verifyUserIsAdmin(userClient: SupabaseClient): Promise<boolean> {
  const user = await userClient.auth.getUser();
  const metadata = user.data.user?.app_metadata;

  if (!metadata  || (metadata && !metadata.claims_admin)) {
    return false;
  }

  return true;
}

Deno.serve(async (req) => {
  const authHeader = req.headers.get("Authorization")!;

  const userClient = createClient(
    Deno.env.get("SUPABASE_URL") ?? "",
    Deno.env.get("SUPABASE_SERVICE_ROLE_KEY") ?? "",
    { global: { headers: { Authorization: authHeader } } },
  );

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

  if (!(await verifyUserIsAdmin(userClient))) {
    return new Response(
      JSON.stringify({ status: "denied", error: "must be an admin" }),
      { status: 403, headers: { "Content-Type": "application/json" } },
    );
  }

  const busStops = await getStops();

  console.log("inserting", busStops.length, "rows");
  const toInsert = busStops.map(toDbBusStop);

  const insert = await secureClient.from("bus_stops")
    .upsert(toInsert, { ignoreDuplicates: true });

  console.log(insert.statusText, insert.error?.code, insert.error?.message);

  return new Response(
    JSON.stringify({
      "status": insert.statusText,
      "inserted": toInsert.length,
      "error": insert.error,
    }),
    { headers: { "Content-Type": "application/json" } },
  );
});

/* To invoke locally:

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

  curl -i --location --request POST 'http://127.0.0.1:54321/functions/v1/download-bus-stops' \
    --header 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6ImFub24iLCJleHAiOjE5ODM4MTI5OTZ9.CRXP1A7WOeoJeXxjNni43kdQwgnWNReilDMblYTn_I0' \
    --header 'Content-Type: application/json'

*/