import dayjs from "dayjs";
import utc from "dayjs/plugin/utc";
import timezone from "dayjs/plugin/timezone";

dayjs.extend(utc);
dayjs.extend(timezone);

const PAGE_URL = "https://bimasislam.kemenag.go.id/jadwalshalat";
const API_URL = "https://bimasislam.kemenag.go.id/ajax/getShalatbln";

/** Default Kemenag hashes: DKI Jakarta / Kota Jakarta. */
const DEFAULT_X = "c51ce410c124a10e0db5e4b97fc2af39";
const DEFAULT_Y = "58a2fc6ed39fd083f55d4182bf88826d";
const DEFAULT_TIMEZONE = "Asia/Jakarta";

const BROWSER_HEADERS = {
  accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
  "accept-language": "en-US,en;q=0.9,id;q=0.8",
  "cache-control": "no-cache",
  pragma: "no-cache",
};

function passContext(ctx) {
  if (ctx?.context != null && typeof ctx.context === "object" && !Array.isArray(ctx.context)) {
    return { ...ctx.context };
  }
  return {};
}

function unwrapScalar(value) {
  if (value == null) return "";
  if (typeof value === "string") return value.trim();
  if (typeof value === "number" || typeof value === "boolean") return String(value);
  return "";
}

function monthKey(d) {
  return `${d.year()}-${d.month() + 1}`;
}

function parseCookies(setCookie) {
  if (!setCookie) return "";
  return setCookie
    .split(/,(?=[^;,]+=)/)
    .map((cookie) => cookie.split(";")[0])
    .join("; ");
}

async function getSessionCookie() {
  const cookieFetch = await fetch(PAGE_URL, {
    method: "GET",
    headers: {
      ...BROWSER_HEADERS,
      "upgrade-insecure-requests": "1",
    },
  });

  const cookies = parseCookies(cookieFetch.headers.get("set-cookie"));
  if (!cookies) {
    throw new Error(
      `Prayer-time session cookie missing (HTTP ${cookieFetch.status})`,
    );
  }
  return cookies;
}

async function fetchPrayerMonth(cookies, month, year, x, y) {
  const resp = await fetch(API_URL, {
    method: "POST",
    headers: {
      accept: "application/json, text/javascript, */*; q=0.01",
      "accept-language": BROWSER_HEADERS["accept-language"],
      "cache-control": "no-cache",
      "content-type": "application/x-www-form-urlencoded; charset=UTF-8",
      pragma: "no-cache",
      "x-requested-with": "XMLHttpRequest",
      cookie: cookies,
      Referer: PAGE_URL,
    },
    body: new URLSearchParams({
      x,
      y,
      bln: String(month),
      thn: String(year),
    }).toString(),
  });

  const responseText = await resp.text();
  let responseData;
  try {
    responseData = JSON.parse(responseText);
  } catch {
    throw new Error(
      `Prayer-time API returned invalid JSON (HTTP ${resp.status}) for ${year}-${month}`,
    );
  }

  if (!resp.ok) {
    throw new Error(
      `Prayer-time API request failed with HTTP ${resp.status} for ${year}-${month}`,
    );
  }

  return {
    data: responseData,
    status: resp.status,
    month: Number(month),
    year: Number(year),
  };
}

/**
 * Resolve one day's record from a monthly API payload.
 * Accepts `{ data: { "YYYY-MM-DD": {...} } }` or a date-keyed object.
 */
function getDateData(monthResponse, dateKey) {
  const candidates = [
    monthResponse?.data?.data,
    monthResponse?.data,
    monthResponse,
  ];
  for (const map of candidates) {
    if (map && typeof map === "object" && !Array.isArray(map) && map[dateKey]) {
      const day = map[dateKey];
      if (typeof day === "object" && !Array.isArray(day)) {
        return day;
      }
    }
  }
  throw new Error(`No prayer times for ${dateKey}`);
}

async function fetchPrayerTimes(ctx) {
  const timezoneName = unwrapScalar(ctx.config?.timezone) || DEFAULT_TIMEZONE;
  const x = unwrapScalar(ctx.config?.x) || DEFAULT_X;
  const y = unwrapScalar(ctx.config?.y) || DEFAULT_Y;

  const today = dayjs().tz(timezoneName);
  if (!today.isValid()) {
    throw new Error(`invalid timezone "${timezoneName}"`);
  }
  const tomorrow = today.add(1, "day");
  const todayDate = today.format("YYYY-MM-DD");
  const tomorrowDate = tomorrow.format("YYYY-MM-DD");

  log.info(
    { today: todayDate, tomorrow: tomorrowDate, timezone: timezoneName },
    "jakarta-prayer-time-today-and-tomorrow: fetching",
  );

  const cookies = await getSessionCookie();

  const needed = [
    { key: monthKey(today), month: today.month() + 1, year: today.year() },
    { key: monthKey(tomorrow), month: tomorrow.month() + 1, year: tomorrow.year() },
  ];
  const unique = [];
  const seen = new Set();
  for (const item of needed) {
    if (seen.has(item.key)) continue;
    seen.add(item.key);
    unique.push(item);
  }

  const monthResponses = {};
  await Promise.all(
    unique.map(async (item) => {
      monthResponses[item.key] = await fetchPrayerMonth(
        cookies,
        item.month,
        item.year,
        x,
        y,
      );
    }),
  );

  const todayData = getDateData(monthResponses[monthKey(today)], todayDate);
  const tomorrowData = getDateData(
    monthResponses[monthKey(tomorrow)],
    tomorrowDate,
  );

  const output = {
    ok: true,
    today: todayData,
    tomorrow: tomorrowData,
    todayDate,
    tomorrowDate,
    timezone: timezoneName,
  };

  log.info(
    {
      todayFound: Boolean(output.today),
      tomorrowFound: Boolean(output.tomorrow),
      monthsFetched: unique.length,
    },
    "jakarta-prayer-time-today-and-tomorrow: extracted",
  );

  return {
    output,
    context: { ...passContext(ctx), ...output },
  };
}

fetchPrayerTimes.meta = {
  description:
    "Fetch Kemenag Bimas Islam prayer times for today and tomorrow (Asia/Jakarta by default).",
  previewConfigKey: "timezone",
  tags: ["HTTP", "Prayer Times"],
  config: {
    timezone: {
      type: "string",
      default: DEFAULT_TIMEZONE,
      description: "IANA timezone used to pick today/tomorrow",
    },
    x: {
      type: "string",
      default: DEFAULT_X,
      description: "Kemenag kabupaten hash (x). Default is DKI Jakarta",
    },
    y: {
      type: "string",
      default: DEFAULT_Y,
      description: "Kemenag kota hash (y). Default is Kota Jakarta",
    },
  },
  input: {},
  output: {
    ok: { type: "boolean" },
    today: { type: "any", description: "Prayer-time record for today" },
    tomorrow: { type: "any", description: "Prayer-time record for tomorrow" },
    todayDate: { type: "string", description: "YYYY-MM-DD in the configured timezone" },
    tomorrowDate: { type: "string", description: "YYYY-MM-DD in the configured timezone" },
    timezone: { type: "string" },
  },
  context: {
    ok: { type: "boolean" },
    today: { type: "any" },
    tomorrow: { type: "any" },
    todayDate: { type: "string" },
    tomorrowDate: { type: "string" },
    timezone: { type: "string" },
  },
  example: {
    data: {},
    config: {
      timezone: "Asia/Jakarta",
    },
  },
};

export default fetchPrayerTimes;