import config from "$config";
import { fail, sleep } from "$lib/utils";
import { createClient, defineScript } from "redis";
import { warn, err } from "$lib/logging";

const DEBIT = `
local balanceKey = KEYS[1]
local creditKey = KEYS[2]
local insufficientString = KEYS[3];
local amount = tonumber(ARGV[1])
local tip = tonumber(ARGV[2])
local fee = tonumber(ARGV[3])
local ourfee = tonumber(ARGV[4])
local frozen = tonumber(ARGV[5])

local balance = tonumber(redis.call('get', balanceKey) or '0')
local credit = tonumber(redis.call('get', creditKey) or '0')

local covered = math.min(credit, ourfee)
ourfee = ourfee - covered

if balance - frozen < amount + tip + fee + ourfee then
    return {err = insufficientString .. ' ⚡️' .. balance - frozen .. ' / ' .. amount + tip + fee + ourfee}
end

redis.call('decrby', creditKey, tostring(math.floor(covered)))
redis.call('decrby', balanceKey, tostring(math.floor(amount + tip + fee + ourfee)))

return ourfee
`;

const REVERSE = `
local paymentKey = KEYS[1]
local balanceKey = KEYS[2]
local creditKey = KEYS[3]
local hashKey = KEYS[4]
local paymentsKey = KEYS[5]
local pid = KEYS[6]

local total = tonumber(ARGV[1])
local credit = tonumber(ARGV[2])
local hash = ARGV[3]

if redis.call('exists', paymentKey) == 1 then
    redis.call('del', paymentKey)
    redis.call('srem', 'pending', hash)
    redis.call('incrby', balanceKey, total)
    redis.call('incrby', creditKey, credit)
    redis.call('del', hashKey)
    redis.call('lrem', paymentsKey, 0, pid)
    redis.call('lrem', 'payments', 0, pid)
    return pid
else
    error("Payment has already been reversed" .. paymentKey)
end
`;

const debit = defineScript({
  NUMBER_OF_KEYS: 3,
  SCRIPT: DEBIT,
  transformArguments: (...args) => args.map((a) => a.toString()),
});

const reverse = defineScript({
  NUMBER_OF_KEYS: 6,
  SCRIPT: REVERSE,
  transformArguments: (...args) => args.map((a) => a.toString()),
});

export const db = createClient({
  url: config.db,
  scripts: { debit, reverse },
  socket: {
    reconnectStrategy: (retries) => Math.min(retries * 50, 5000),
  },
});

export const archive = createClient({
  url: config.archive,
  socket: {
    reconnectStrategy: (retries) => Math.min(retries * 50, 5000),
  },
});

export const arc2 = createClient({
  url: config.arc2,
  socket: {
    reconnectStrategy: (retries) => Math.min(retries * 50, 5000),
  },
});

async function dbReconnect() {
  try {
    await db.connect();
  } catch (err) {
    console.error("Failed to connect to Redis, retrying...", err);
    setTimeout(dbReconnect, 5000); // Retry after 5 seconds
  }
}

async function archiveReconnect() {
  try {
    if (!archive.isOpen) await archive.connect();
  } catch (err) {
    console.error("Failed to connect to Redis, retrying...", err);
    setTimeout(archiveReconnect, 5000); // Retry after 5 seconds
  }
}

dbReconnect();
archiveReconnect();

db.on("error", (e) => {
  if (e.message.startsWith("getaddr")) return;
  err("Redis error", e.message);
});

db.on("end", () => {
  warn("Redis connection ended");
});

export default db;

export const g = async (k) => {
  const v = await db.get(k);
  try {
    return JSON.parse(v);
  } catch (e) {
    return v;
  }
};

export const s = (k, v) => {
  if (k === "user:null" || k === "user:undefined") fail("null user");
  db.set(k, JSON.stringify(v));
};

export const ga = async (k) => {
  const v = await archive.get(k);
  try {
    return JSON.parse(v);
  } catch (e) {
    return v;
  }
};

export const sa = (k, v) => {
  if (k === "user:null" || k === "user:undefined") {
    warn("###### NULL USER #######");
    console.trace();
  }
  archive.set(k, JSON.stringify(v));
};

// Get with fallback to archive
export const gf = async (k) => {
  let v = await db.get(k);
  if (v === null) v = await archive.get(k);
  try {
    return JSON.parse(v);
  } catch (e) {
    return v;
  }
};

// lRange with fallback to archive for missing items
export const lRangeWithArchive = async (k, start, end) => {
  const items = await db.lRange(k, start, end);
  return items || [];
};

// Get payment/invoice with archive fallback - for individual lookups
export const getWithArchive = async (prefix, id) => {
  let v = await db.get(`${prefix}:${id}`);
  if (v === null) v = await archive.get(`${prefix}:${id}`);
  if (v === null) return null;
  try {
    const parsed = JSON.parse(v);
    // If it's a reference to another key, follow it
    if (typeof parsed === "string") {
      let ref = await db.get(`${prefix}:${parsed}`);
      if (ref === null) ref = await archive.get(`${prefix}:${parsed}`);
      if (ref === null) return null;
      return JSON.parse(ref);
    }
    return parsed;
  } catch (e) {
    return v;
  }
};

const retries = {};
export const t = async (k, f) => {
  try {
    await db.watch(k);
    await f(await db.get(k), db);
  } catch (err) {
    if (!err.message.includes("watch")) throw err;

    const r = retries[k] || 0;
    retries[k] = r + 1;

    if (r < 10) {
      await sleep(100);
      await t(k, f);
    } else {
      delete retries[k];
      fail("unable to obtain lock");
    }
  }

  delete retries[k];
};