import { loadState, saveState } from "./state.ts";
import sendMessage from "./webhook.ts";

// grab this from https://octopus.energy/dashboard/new/accounts/personal-details/api-access
const OCTOPUS_API_KEY = Deno.env.get("OCTOPUS_API_KEY");
// grab this from octopus dashboard - looks something like A-XXXXXXXX
const OCTOPUS_ACCOUNT_NUMBER = Deno.env.get("OCTOPUS_ACCOUNT_NUMBER");
// webhook url
const WEBHOOK_URL = Deno.env.get("WEBHOOK_URL");

const OCTOPUS_API_ENDPOINT = "https://api.octopus.energy/v1/graphql/";

const OFFER_SLUG_MAP: { [slug: string]: string } = {
  "greggs": "Greegs",
  "caffe-nero": "Caffè Nero"
};

if (OCTOPUS_API_KEY === undefined || OCTOPUS_ACCOUNT_NUMBER === undefined) {
  throw new Error("Octopus API key and account number are required!");
}

if (WEBHOOK_URL === undefined) {
  throw new Error("Webhook URL is required!");
}

async function graphQlRequest(query: string, variables: { [key: string]: any }, auth?: string): Promise<any> {
  const headers: Headers = new Headers({ "Content-Type": "application/json" });

  if (auth) {
    headers.set("Authorization", auth);
  }

  const res = await fetch(OCTOPUS_API_ENDPOINT, {
    method: "POST",
    body: JSON.stringify({
      query,
      variables
    }),
    headers
  });

  if (res.status !== 200) {
    throw new Error(`GraphQL request failed with status ${res.status}`);
  }

  const jsonData = await res.json();

  if (jsonData.errors) {
    // deno-lint-ignore no-explicit-any
    const errorMessages = jsonData.errors.map((m: any) => m.message);
    throw new Error(`GraphQL request failed: ${errorMessages.join(". ")}.`);
  }

  return jsonData.data;
}

async function checkCoffee(): Promise<void> {
  console.log("Fetching API token...");
  const token = (await graphQlRequest(
  /* GraphQL */ `
  mutation ($apiKey: String!) {
    obtainKrakenToken(input: {
        APIKey: $apiKey
    }) {
      token
    }
  }`,
    { apiKey: OCTOPUS_API_KEY }
  )).obtainKrakenToken.token;

  const state = await loadState();

  console.log("Fetching offers...");
  const offers = await graphQlRequest(
  /* GraphQL */ `
  query ($accountNumber: String!, $first: Int!) {
    octoplusOfferGroups(accountNumber: $accountNumber, first: $first) {
      edges {
        node {
          octoplusOffers {
            slug
            claimAbility {
              canClaimOffer
              cannotClaimReason
            }
            claimBy
          }
        }
      }
    }
  }`,
    {
      accountNumber: OCTOPUS_ACCOUNT_NUMBER,
      first: 12,
    },
    token,
  );

  console.log(`Found ${offers.octoplusOfferGroups.edges.length} offers`);

  const messages = [];

  for (const { node } of offers.octoplusOfferGroups.edges) {
    for (const offer of node.octoplusOffers) {
      if (offer.slug !== "greggs" && offer.slug !== "caffe-nero") continue;

      const friendlyName = `${OFFER_SLUG_MAP[offer.slug]} coffee offer`;

      if (offer.slug in state) {
        if (offer.claimAbility.canClaimOffer !== state[offer.slug].canClaimOffer) {
          if (offer.claimAbility.canClaimOffer) {
            messages.push(`${friendlyName} is now claimable! Claim by ${offer.claimBy}`);
          } else {
            messages.push(`${friendlyName} is no longer claimable (${offer.claimAbility.cannotClaimReason})`);
          }
        } else if (offer.claimBy !== state[offer.slug].claimBy) {
          messages.push(`${friendlyName} must be claimed by ${offer.claimBy}.`);
        }
      } else if (offer.claimAbility.canClaimOffer) {
        messages.push(`New ${friendlyName} found! Claim it by ${offer.claimBy}`);
      }

      state[offer.slug] = {
        canClaimOffer: offer.claimAbility.canClaimOffer,
        claimBy: offer.claimBy,
        cannotClaimReason: offer.claimAbility.cannotClaimReason,
      }
    }
  }

  console.log(`Sending ${messages.length} notifications...`);

  for (const msg of messages) {
    await sendMessage(WEBHOOK_URL!, msg);
  }

  await saveState(state);
}

if (import.meta.main) {
  try {
    checkCoffee();
  } catch (ex) {
    await sendMessage(WEBHOOK_URL!, `Failed to check for coffee: ${ex}`);
    throw ex;
  }
}