/**
 * Duty list (timeline) rendering.
 */

import { getDutyListEl, state } from "./dom.js";
import { t } from "./i18n.js";
import { escapeHtml } from "./utils.js";
import { buildContactLinksHtml } from "./contactHtml.js";
import {
  localDateString,
  firstDayOfMonth,
  lastDayOfMonth,
  dateKeyToDDMM,
  formatHHMM,
  formatDateKey
} from "./dateUtils.js";

/** Phone icon SVG for flip button (show contacts). */
const ICON_PHONE =
  '<svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M22 16.92v3a2 2 0 0 1-2.18 2 19.79 19.79 0 0 1-8.63-3.07 19.5 19.5 0 0 1-6-6 19.79 19.79 0 0 1-3.07-8.67A2 2 0 0 1 4.11 2h3a2 2 0 0 1 2 1.72 12.84 12.84 0 0 0 .7 2.81 2 2 0 0 1-.45 2.11L8.09 9.91a16 16 0 0 0 6 6l1.27-1.27a2 2 0 0 1 2.11-.45 12.84 12.84 0 0 0 2.81.7A2 2 0 0 1 22 16.92z"/></svg>';

/** Back/arrow icon SVG for flip button (back to card). */
const ICON_BACK =
  '<svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><line x1="19" y1="12" x2="5" y2="12"/><polyline points="12 19 5 12 12 5"/></svg>';

/**
 * Build HTML for one timeline duty card: one-day "DD.MM, HH:MM – HH:MM" or multi-day.
 * When duty has phone or username, wraps in a flip-card (front: info + button; back: contacts).
 * Otherwise returns a plain card without flip wrapper.
 * @param {object} d - Duty
 * @param {boolean} isCurrent - Whether this is "current" duty
 * @returns {string}
 */
export function dutyTimelineCardHtml(d, isCurrent) {
  const startLocal = localDateString(new Date(d.start_at));
  const endLocal = localDateString(new Date(d.end_at));
  const startDDMM = dateKeyToDDMM(startLocal);
  const endDDMM = dateKeyToDDMM(endLocal);
  const startTime = formatHHMM(d.start_at);
  const endTime = formatHHMM(d.end_at);
  let timeStr;
  if (startLocal === endLocal) {
    timeStr = startDDMM + ", " + startTime + " – " + endTime;
  } else {
    timeStr = startDDMM + " " + startTime + " – " + endDDMM + " " + endTime;
  }
  const lang = state.lang;
  const typeLabel = isCurrent
    ? t(lang, "duty.now_on_duty")
    : (t(lang, "event_type." + (d.event_type || "duty")));
  const extraClass = isCurrent ? " duty-item--current" : "";
  const contactHtml = buildContactLinksHtml(lang, d.phone, d.username, {
    classPrefix: "duty-contact",
    showLabels: false,
    separator: " · "
  });
  const hasContacts = Boolean(
    (d.phone && String(d.phone).trim()) ||
    (d.username && String(d.username).trim())
  );

  if (!hasContacts) {
    return (
      '<div class="duty-item duty-item--duty duty-timeline-card' +
      extraClass +
      '"><span class="duty-item-type">' +
      escapeHtml(typeLabel) +
      '</span> <span class="name">' +
      escapeHtml(d.full_name) +
      '</span><div class="time">' +
      escapeHtml(timeStr) +
      "</div></div>"
    );
  }

  const showLabel = t(lang, "contact.show");
  const backLabel = t(lang, "contact.back");
  return (
    '<div class="duty-flip-card' +
    extraClass +
    '" data-flipped="false">' +
    '<div class="duty-flip-inner">' +
    '<div class="duty-flip-front duty-item duty-item--duty duty-timeline-card' +
    extraClass +
    '">' +
    '<span class="duty-item-type">' +
    escapeHtml(typeLabel) +
    '</span> <span class="name">' +
    escapeHtml(d.full_name) +
    '</span><div class="time">' +
    escapeHtml(timeStr) +
    '</div>' +
    '<button class="duty-flip-btn" type="button" aria-label="' +
    escapeHtml(showLabel) +
    '">' +
    ICON_PHONE +
    "</button>" +
    "</div>" +
    '<div class="duty-flip-back duty-item duty-item--duty duty-timeline-card' +
    extraClass +
    '">' +
    '<span class="name">' +
    escapeHtml(d.full_name) +
    "</span>" +
    contactHtml +
    '<button class="duty-flip-btn" type="button" aria-label="' +
    escapeHtml(backLabel) +
    '">' +
    ICON_BACK +
    "</button>" +
    "</div>" +
    "</div></div>"
  );
}

/**
 * Build HTML for one duty card.
 * @param {object} d - Duty
 * @param {string} [typeLabelOverride] - e.g. "Сейчас дежурит"
 * @param {boolean} [showUntilEnd] - Show "до HH:MM" instead of range
 * @param {string} [extraClass] - e.g. "duty-item--current"
 * @returns {string}
 */
export function dutyItemHtml(d, typeLabelOverride, showUntilEnd, extraClass) {
  const lang = state.lang;
  const typeLabel =
    typeLabelOverride != null
      ? typeLabelOverride
      : (t(lang, "event_type." + (d.event_type || "duty")));
  let itemClass = "duty-item duty-item--" + (d.event_type || "duty");
  if (extraClass) itemClass += " " + extraClass;
  let timeOrRange = "";
  if (showUntilEnd && d.event_type === "duty") {
    timeOrRange = t(lang, "duty.until", { time: formatHHMM(d.end_at) });
  } else if (d.event_type === "vacation" || d.event_type === "unavailable") {
    const startStr = formatDateKey(d.start_at);
    const endStr = formatDateKey(d.end_at);
    timeOrRange = startStr === endStr ? startStr : startStr + " – " + endStr;
  } else {
    timeOrRange =
      formatHHMM(d.start_at) + " – " + formatHHMM(d.end_at);
  }
  return (
    '<div class="' +
    itemClass +
    '"><span class="duty-item-type">' +
    escapeHtml(typeLabel) +
    '</span> <span class="name">' +
    escapeHtml(d.full_name) +
    '</span><div class="time">' +
    escapeHtml(timeOrRange) +
    "</div></div>"
  );
}

/** Whether the delegated flip-button click listener has been attached to duty list element. */
let flipListenerAttached = false;

/**
 * Render duty list (timeline) for current month; scroll to today if visible.
 * @param {object[]} duties - Duties (only duty type used for timeline)
 */
export function renderDutyList(duties) {
  const dutyListEl = getDutyListEl();
  if (!dutyListEl) return;

  if (!flipListenerAttached) {
    flipListenerAttached = true;
    dutyListEl.addEventListener("click", (e) => {
      const btn = e.target.closest(".duty-flip-btn");
      if (!btn) return;
      const card = btn.closest(".duty-flip-card");
      if (!card) return;
      const flipped = card.getAttribute("data-flipped") === "true";
      card.setAttribute("data-flipped", String(!flipped));
    });
  }
  const filtered = duties.filter((d) => d.event_type === "duty");
  if (filtered.length === 0) {
    dutyListEl.classList.remove("duty-timeline");
    dutyListEl.innerHTML = '<p class="muted">' + t(state.lang, "duty.none_this_month") + "</p>";
    return;
  }
  dutyListEl.classList.add("duty-timeline");
  const current = state.current;
  const todayKey = localDateString(new Date());
  const firstKey = localDateString(firstDayOfMonth(current));
  const lastKey = localDateString(lastDayOfMonth(current));
  const showTodayInMonth = todayKey >= firstKey && todayKey <= lastKey;
  const dateSet = new Set();
  filtered.forEach((d) => {
    dateSet.add(localDateString(new Date(d.start_at)));
  });
  if (showTodayInMonth) dateSet.add(todayKey);
  const dates = Array.from(dateSet).sort();
  const now = new Date();
  let fullHtml = "";
  dates.forEach((date) => {
    const isToday = date === todayKey;
    const dayClass =
      "duty-timeline-day" + (isToday ? " duty-timeline-day--today" : "");
    const dateLabel = dateKeyToDDMM(date);
    const dateCellHtml = isToday
      ? '<span class="duty-timeline-date"><span class="duty-timeline-date-label">' +
        escapeHtml(t(state.lang, "duty.today")) +
        '</span><span class="duty-timeline-date-day">' +
        escapeHtml(dateLabel) +
        '</span><span class="duty-timeline-date-dot" aria-hidden="true"></span></span>'
      : '<span class="duty-timeline-date">' + escapeHtml(dateLabel) + "</span>";
    const dayDuties = filtered
      .filter((d) => localDateString(new Date(d.start_at)) === date)
      .sort((a, b) => new Date(a.start_at) - new Date(b.start_at));
    let dayHtml = "";
    dayDuties.forEach((d) => {
      const start = new Date(d.start_at);
      const end = new Date(d.end_at);
      const isCurrent = start <= now && now < end;
      dayHtml +=
        '<div class="duty-timeline-row">' +
        dateCellHtml +
        '<span class="duty-timeline-track" aria-hidden="true"></span><div class="duty-timeline-card-wrap">' +
        dutyTimelineCardHtml(d, isCurrent) +
        "</div></div>";
    });
    if (dayDuties.length === 0 && isToday) {
      dayHtml +=
        '<div class="duty-timeline-row duty-timeline-row--empty">' +
        dateCellHtml +
        '<span class="duty-timeline-track" aria-hidden="true"></span><div class="duty-timeline-card-wrap"></div></div>';
    }
    fullHtml +=
      '<div class="' +
      dayClass +
      '" data-date="' +
      escapeHtml(date) +
      '">' +
      dayHtml +
      "</div>";
  });
  dutyListEl.innerHTML = fullHtml;
  const calendarSticky = document.getElementById("calendarSticky");
  const scrollToEl = (el) => {
    if (!el) return;
    if (calendarSticky) {
      requestAnimationFrame(() => {
        const calendarHeight = calendarSticky.offsetHeight;
        const top = el.getBoundingClientRect().top + window.scrollY;
        const scrollTop = Math.max(0, top - calendarHeight);
        window.scrollTo({ top: scrollTop, behavior: "smooth" });
      });
    } else {
      el.scrollIntoView({ behavior: "smooth", block: "start" });
    }
  };
  const listEl = getDutyListEl();
  const currentDutyCard = listEl ? listEl.querySelector(".duty-item--current") : null;
  const todayBlock = listEl ? listEl.querySelector(".duty-timeline-day--today") : null;
  if (currentDutyCard) {
    scrollToEl(currentDutyCard);
  } else if (todayBlock) {
    scrollToEl(todayBlock);
  }
}