"use strict";

const faunadb = require("faunadb"),
  q = faunadb.query;
const numeral = require("numeral");
const pluralize = require("pluralize");
require("dotenv").config();

// .....??????
// https://github.com/netlify/netlify-lambda/issues/201
require("encoding");

exports.handler = async (event, context) => {
  // some rudimentary error handling
  const { slug } = event.queryStringParameters;
  if (!slug || slug === "/") {
    return {
      statusCode: 400,
      body: JSON.stringify({
        message: "Page slug required.",
      }),
    };
  }

  try {
    const client = new faunadb.Client({
      secret: process.env.FAUNADB_SERVER_SECRET,
    });

    const result = await client.query(
      q.Let(
        {
          match: q.Match(q.Index("hits_by_slug"), slug),
        },
        q.If(
          q.Exists(q.Var("match")),
          q.Let(
            {
              ref: q.Select("ref", q.Get(q.Var("match"))),
              hits: q.ToInteger(q.Select("hits", q.Select("data", q.Get(q.Var("match"))))),
            },
            q.Update(q.Var("ref"), {
              data: {
                hits: q.Add(q.Var("hits"), 1),
              },
            })
          ),
          q.Create(q.Collection("hits"), {
            data: {
              slug: slug,
              hits: 1,
            },
          })
        )
      )
    );

    // send client the new hit count
    return {
      statusCode: 200,
      headers: {
        "Cache-Control": "private, no-cache, no-store, must-revalidate",
        Expires: "0",
        Pragma: "no-cache",
      },
      body: JSON.stringify({
        slug: result.data.slug,
        hits: result.data.hits,
        pretty_hits: numeral(result.data.hits).format("0,0"),
        pretty_unit: pluralize("hit", result.data.hits),
      }),
    };
  } catch (error) {
    console.error(error);

    return {
      statusCode: 400,
      body: JSON.stringify({
        message: error.message,
      }),
    };
  }
};