import { renderHeader } from '../components/header.js';
import { authService, state } from '../state.js';

export const pageMeta = { id: 'network-view', title: 'Связи' };

const GENDER_MALE = 'male';
const GENDER_FEMALE = 'female';
const GENDER_UNKNOWN = 'unknown';
const CENTER_NODE_ID = '__center__';

function normalizeLogin(value) {
  return String(value || '').trim();
}

function normKey(value) {
  return normalizeLogin(value).toLowerCase();
}

function uniqueLogins(list) {
  const out = [];
  const seen = new Set();
  (Array.isArray(list) ? list : []).forEach((item) => {
    const login = normalizeLogin(item);
    if (!login) return;
    const key = normKey(login);
    if (seen.has(key)) return;
    seen.add(key);
    out.push(login);
  });
  return out;
}

function normalizeGender(value) {
  const clean = String(value || '').trim().toLowerCase();
  if (clean === GENDER_MALE) return GENDER_MALE;
  if (clean === GENDER_FEMALE) return GENDER_FEMALE;
  return GENDER_UNKNOWN;
}

function toSet(list) {
  return new Set(uniqueLogins(list).map((value) => normKey(value)));
}

function hasLogin(setObj, login) {
  return setObj.has(normKey(login));
}

function getMarkByLogin(allUsers) {
  const map = new Map();
  (Array.isArray(allUsers) ? allUsers : []).forEach((row) => {
    const login = normalizeLogin(row?.login);
    if (!login) return;
    map.set(normKey(login), {
      login,
      official: Boolean(row?.official),
      shine: Boolean(row?.shine),
      officialLabel: String(row?.officialLabel || (row?.official ? 'официальный' : 'неофициальный')),
      shineLabel: String(row?.shineLabel || (row?.shine ? 'сияющий' : 'несияющий')),
    });
  });
  return map;
}

function applyRelativeGender(map, rows) {
  (Array.isArray(rows) ? rows : []).forEach((row) => {
    const login = normalizeLogin(row?.login);
    if (!login) return;
    const key = normKey(login);
    const gender = normalizeGender(row?.gender);
    const prev = map.get(key) || GENDER_UNKNOWN;
    if (prev === GENDER_UNKNOWN || gender !== GENDER_UNKNOWN) map.set(key, gender);
  });
}

function getRelativeGenderMap(graph) {
  const map = new Map();
  applyRelativeGender(map, graph?.parents);
  applyRelativeGender(map, graph?.children);
  applyRelativeGender(map, graph?.siblings);
  return map;
}

function spread(count, start, end) {
  if (count <= 0) return [];
  if (count === 1) return [(start + end) / 2];
  const out = [];
  const step = (end - start) / (count - 1);
  for (let i = 0; i < count; i += 1) out.push(start + step * i);
  return out;
}

function buildNodeElement({ login, kind = 'friend', isCenter = false, mark = null }) {
  const node = document.createElement('button');
  node.type = 'button';
  const classes = [
    'node',
    isCenter ? 'center' : '',
    kind === 'relative' ? 'is-relative' : 'is-friend',
    mark?.shine ? 'is-shine' : '',
    mark?.official ? 'is-official' : '',
  ].filter(Boolean);
  node.className = classes.join(' ');
  node.dataset.nodeLogin = login;

  const metaParts = [];
  if (mark?.officialLabel) metaParts.push(mark.officialLabel);
  if (mark?.shineLabel) metaParts.push(mark.shineLabel);
  const metaText = metaParts.join(', ');
  node.title = metaText ? `${login}\n${metaText}` : login;

  const officialBadge = mark?.official ? '<span class="node-badge-official" aria-hidden="true">ОФ</span>' : '';
  node.innerHTML = `
    ${officialBadge}
    <span class="node-dot">${(login[0] || '?').toUpperCase()}</span>
    <span class="node-label">${login}</span>
  `;
  return node;
}

function buildGraphModel(graph, centerLogin) {
  const login = normalizeLogin(graph?.login || centerLogin || state.session.login);
  const outFriends = toSet(graph?.outFriends);
  const inFriends = toSet(graph?.inFriends);
  const outParents = toSet(graph?.outParents);
  const inParents = toSet(graph?.inParents);
  const outChildren = toSet(graph?.outChildren);
  const inChildren = toSet(graph?.inChildren);
  const outSiblings = toSet(graph?.outSiblings);
  const inSiblings = toSet(graph?.inSiblings);

  const relativesGender = getRelativeGenderMap(graph);
  const allMarks = getMarkByLogin(graph?.allUsers);

  const allLogins = uniqueLogins([
    ...(graph?.outFriends || []),
    ...(graph?.inFriends || []),
    ...(graph?.outParents || []),
    ...(graph?.inParents || []),
    ...(graph?.outChildren || []),
    ...(graph?.inChildren || []),
    ...(graph?.outSiblings || []),
    ...(graph?.inSiblings || []),
  ]).filter((entry) => normKey(entry) !== normKey(login));

  const relations = allLogins.map((targetLogin) => {
    const parentOut = hasLogin(outParents, targetLogin);
    const parentIn = hasLogin(inChildren, targetLogin);
    const childOut = hasLogin(outChildren, targetLogin);
    const childIn = hasLogin(inParents, targetLogin);
    const siblingOut = hasLogin(outSiblings, targetLogin);
    const siblingIn = hasLogin(inSiblings, targetLogin);
    const friendOut = hasLogin(outFriends, targetLogin);
    const friendIn = hasLogin(inFriends, targetLogin);

    let role = 'friend';
    if (parentOut || parentIn) role = 'parent';
    else if (childOut || childIn) role = 'child';
    else if (siblingOut || siblingIn) role = 'sibling';

    let forward = friendOut;
    let backward = friendIn;
    if (role === 'parent') {
      forward = parentOut;
      backward = parentIn;
    } else if (role === 'child') {
      forward = childOut;
      backward = childIn;
    } else if (role === 'sibling') {
      forward = siblingOut;
      backward = siblingIn;
    }

    return {
      login: targetLogin,
      key: normKey(targetLogin),
      role,
      isRelative: role !== 'friend',
      gender: normalizeGender(relativesGender.get(normKey(targetLogin))),
      forward: Boolean(forward),
      backward: Boolean(backward),
      mark: allMarks.get(normKey(targetLogin)) || null,
    };
  });

  return {
    centerLogin: login,
    centerMark: allMarks.get(normKey(login)) || null,
    relations,
  };
}

function splitByGender(list) {
  const left = [];
  const right = [];
  const center = [];
  list.forEach((item) => {
    if (item.gender === GENDER_FEMALE) left.push(item);
    else if (item.gender === GENDER_MALE) right.push(item);
    else center.push(item);
  });
  return { left, right, center };
}

function sortByLogin(items) {
  return [...items].sort((a, b) => a.login.localeCompare(b.login, 'ru', { sensitivity: 'base' }));
}

function positionRows(nodes, x, yStart, yEnd) {
  const ys = spread(nodes.length, yStart, yEnd);
  return nodes.map((node, index) => ({ ...node, x, y: ys[index] }));
}

function layoutNodes(model) {
  const centerNode = {
    id: CENTER_NODE_ID,
    login: model.centerLogin,
    x: 50,
    y: 50,
    isCenter: true,
    kind: 'center',
    relation: null,
    mark: model.centerMark,
  };

  const parents = sortByLogin(model.relations.filter((item) => item.role === 'parent'));
  const children = sortByLogin(model.relations.filter((item) => item.role === 'child'));
  const siblings = sortByLogin(model.relations.filter((item) => item.role === 'sibling'));
  const friends = sortByLogin(model.relations.filter((item) => item.role === 'friend'));

  const parentSplit = splitByGender(parents);
  const childSplit = splitByGender(children);
  const siblingSplit = splitByGender(siblings);

  const friendLeft = [];
  const friendRight = [];
  friends.forEach((item, index) => {
    if (index % 2 === 0) friendLeft.push(item);
    else friendRight.push(item);
  });

  const positioned = [
    ...positionRows(parentSplit.left, 28, 14, 30),
    ...positionRows(parentSplit.right, 72, 14, 30),
    ...positionRows(parentSplit.center, 50, 10, 22),
    ...positionRows(friendLeft, 12, 28, 72),
    ...positionRows(friendRight, 88, 28, 72),
    ...positionRows(siblingSplit.left, 30, 48, 70),
    ...positionRows(siblingSplit.right, 70, 48, 70),
    ...positionRows(siblingSplit.center, 50, 58, 74),
    ...positionRows(childSplit.left, 28, 70, 90),
    ...positionRows(childSplit.right, 72, 70, 90),
    ...positionRows(childSplit.center, 50, 82, 94),
  ];

  const nodes = [centerNode];
  const edges = [];

  positioned.forEach((item) => {
    const nodeId = item.key;
    nodes.push({
      id: nodeId,
      login: item.login,
      x: item.x,
      y: item.y,
      isCenter: false,
      kind: item.isRelative ? 'relative' : 'friend',
      relation: item.role,
      mark: item.mark,
    });
    edges.push({
      from: item.forward ? CENTER_NODE_ID : nodeId,
      to: item.forward ? nodeId : CENTER_NODE_ID,
      mutual: item.forward && item.backward,
      isRelative: item.isRelative,
      exists: item.forward || item.backward,
    });
  });

  return { nodes, edges };
}

function marker(svg, id, color) {
  const el = document.createElementNS('http://www.w3.org/2000/svg', 'marker');
  el.setAttribute('id', id);
  el.setAttribute('viewBox', '0 0 10 10');
  el.setAttribute('refX', '9');
  el.setAttribute('refY', '5');
  el.setAttribute('markerUnits', 'strokeWidth');
  el.setAttribute('markerWidth', '6');
  el.setAttribute('markerHeight', '6');
  el.setAttribute('orient', 'auto');

  const path = document.createElementNS('http://www.w3.org/2000/svg', 'path');
  path.setAttribute('d', 'M 0 0 L 10 5 L 0 10 z');
  path.setAttribute('fill', color);
  el.append(path);
  svg.append(el);
}

function getNodeCenter(boardRect, node) {
  const dot = node.querySelector('.node-dot');
  if (!(dot instanceof HTMLElement)) return null;
  const rect = dot.getBoundingClientRect();
  return {
    x: rect.left - boardRect.left + (rect.width / 2),
    y: rect.top - boardRect.top + (rect.height / 2),
    radius: rect.width / 2,
  };
}

function shortenLine(fromPoint, toPoint, fromOffset, toOffset) {
  const dx = toPoint.x - fromPoint.x;
  const dy = toPoint.y - fromPoint.y;
  const len = Math.hypot(dx, dy);
  if (len < 1) return null;
  const ux = dx / len;
  const uy = dy / len;
  return {
    x1: fromPoint.x + (ux * fromOffset),
    y1: fromPoint.y + (uy * fromOffset),
    x2: toPoint.x - (ux * toOffset),
    y2: toPoint.y - (uy * toOffset),
  };
}

function renderEdges(svg, board, nodeElements, edges) {
  svg.innerHTML = '';
  const defs = document.createElementNS('http://www.w3.org/2000/svg', 'defs');
  marker(defs, 'network-arrow-friend', 'rgba(120, 179, 255, 0.95)');
  marker(defs, 'network-arrow-relative', 'rgba(255, 159, 94, 0.95)');
  svg.append(defs);

  const boardRect = board.getBoundingClientRect();
  const centers = new Map();
  nodeElements.forEach((value, key) => {
    const pt = getNodeCenter(boardRect, value);
    if (pt) centers.set(key, pt);
  });

  edges.forEach((edge) => {
    if (!edge.exists) return;
    const from = centers.get(edge.from);
    const to = centers.get(edge.to);
    if (!from || !to) return;

    const cut = shortenLine(from, to, from.radius + 3, to.radius + 3);
    if (!cut) return;

    const line = document.createElementNS('http://www.w3.org/2000/svg', 'line');
    line.setAttribute('x1', String(cut.x1));
    line.setAttribute('y1', String(cut.y1));
    line.setAttribute('x2', String(cut.x2));
    line.setAttribute('y2', String(cut.y2));
    line.setAttribute('class', `network-link ${edge.isRelative ? 'is-relative' : 'is-friend'}`);

    if (!edge.mutual) {
      line.setAttribute('marker-end', `url(#${edge.isRelative ? 'network-arrow-relative' : 'network-arrow-friend'})`);
    }
    svg.append(line);
  });
}

export function render({ navigate }) {
  const screen = document.createElement('section');
  screen.className = 'stack';

  const board = document.createElement('div');
  board.className = 'network-board';
  board.style.height = 'calc(100dvh - 170px)';

  const note = document.createElement('p');
  note.className = 'meta-muted';
  note.textContent = 'Загрузка связей...';

  const legend = document.createElement('div');
  legend.className = 'network-legend';
  legend.innerHTML = `
    <span><i class="legend-line friend"></i> Близкие друзья</span>
    <span><i class="legend-line relative"></i> Родственники</span>
    <span><i class="legend-arrow"></i> Односторонняя связь</span>
  `;

  let activeMenu = null;
  let centerLogin = state.session.login || '';
  let redrawEdges = () => {};
  let loadSeq = 0;

  function closeNodeMenu() {
    if (!activeMenu) return;
    activeMenu.remove();
    activeMenu = null;
  }

  function openNodeMenu(node, login) {
    closeNodeMenu();
    const menu = document.createElement('div');
    menu.className = 'node-menu card';
    menu.innerHTML = `
      <div class="node-menu-actions">
        <button class="ghost-btn" type="button" data-menu-action="show-info">Показать информацию</button>
        <button class="ghost-btn" type="button" data-menu-action="show-graph">Показать связи</button>
      </div>
    `;

    const rect = node.getBoundingClientRect();
    const boardRect = board.getBoundingClientRect();
    const x = rect.left + rect.width / 2 - boardRect.left;
    const y = rect.bottom - boardRect.top + 8;

    menu.style.left = `${Math.max(8, Math.min(x - 120, boardRect.width - 248))}px`;
    menu.style.top = `${Math.max(8, Math.min(y, boardRect.height - 58))}px`;

    const infoBtn = menu.querySelector('[data-menu-action="show-info"]');
    const graphBtn = menu.querySelector('[data-menu-action="show-graph"]');
    infoBtn?.addEventListener('click', () => {
      navigate(`user-profile-view/${encodeURIComponent(login)}/network-view`);
      closeNodeMenu();
    });
    graphBtn?.addEventListener('click', async () => {
      closeNodeMenu();
      await load(login);
    });

    board.append(menu);
    activeMenu = menu;
  }

  function bindNodeInteraction(node, login, onLongPress) {
    let timerId = 0;
    let startX = 0;
    let startY = 0;
    let longPressTriggered = false;

    const clearTimer = () => {
      if (!timerId) return;
      window.clearTimeout(timerId);
      timerId = 0;
    };

    node.addEventListener('pointerdown', (event) => {
      if (event.button !== 0) return;
      startX = event.clientX;
      startY = event.clientY;
      longPressTriggered = false;
      clearTimer();
      timerId = window.setTimeout(async () => {
        longPressTriggered = true;
        closeNodeMenu();
        await onLongPress(login);
      }, 500);
    });

    node.addEventListener('pointermove', (event) => {
      if (!timerId) return;
      const dx = Math.abs(event.clientX - startX);
      const dy = Math.abs(event.clientY - startY);
      if (dx > 8 || dy > 8) clearTimer();
    });

    node.addEventListener('pointerleave', clearTimer);
    node.addEventListener('pointercancel', clearTimer);
    node.addEventListener('pointerup', (event) => {
      if (event.button !== 0) return;
      clearTimer();
      if (longPressTriggered) return;
      openNodeMenu(node, login);
    });
  }

  async function load(nextCenterLogin = '') {
    const requestId = ++loadSeq;
    const targetCenter = normalizeLogin(nextCenterLogin || centerLogin || state.session.login);
    centerLogin = targetCenter;
    closeNodeMenu();
    note.textContent = 'Загрузка связей...';

    try {
      const graph = await authService.getUserConnectionsGraph(targetCenter);
      if (requestId !== loadSeq) return;

      const model = buildGraphModel(graph, targetCenter);
      const layout = layoutNodes(model);

      board.innerHTML = '';
      const svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
      svg.setAttribute('class', 'network-svg');
      board.append(svg);

      const nodeElements = new Map();
      layout.nodes.forEach((nodeModel) => {
        const node = buildNodeElement({
          login: nodeModel.login,
          kind: nodeModel.kind,
          isCenter: nodeModel.isCenter,
          mark: nodeModel.mark,
        });
        node.style.left = `${nodeModel.x}%`;
        node.style.top = `${nodeModel.y}%`;
        board.append(node);
        nodeElements.set(nodeModel.id, node);
        if (!nodeModel.isCenter) bindNodeInteraction(node, nodeModel.login, load);
      });

      redrawEdges = () => renderEdges(svg, board, nodeElements, layout.edges);
      requestAnimationFrame(() => redrawEdges());

      note.textContent = 'Тап по узлу: меню «Показать информацию» или «Показать связи». Долгое нажатие: сделать узел центром.';
    } catch (error) {
      if (requestId !== loadSeq) return;
      note.textContent = `Ошибка загрузки связей: ${error?.message || 'unknown'}`;
    }
  }

  const outsideTapHandler = (event) => {
    if (!activeMenu) return;
    if (!(event.target instanceof Node)) return;
    if (activeMenu.contains(event.target)) return;
    closeNodeMenu();
  };
  document.addEventListener('pointerdown', outsideTapHandler, true);

  const onResize = () => redrawEdges();
  window.addEventListener('resize', onResize);

  let observer = null;
  if (typeof ResizeObserver !== 'undefined') {
    observer = new ResizeObserver(() => redrawEdges());
    observer.observe(board);
  }

  screen.cleanup = () => {
    document.removeEventListener('pointerdown', outsideTapHandler, true);
    window.removeEventListener('resize', onResize);
    if (observer) observer.disconnect();
  };

  board.addEventListener('pointerdown', (event) => {
    const target = event.target;
    if (!(target instanceof Element)) return;
    if (target.closest('.node')) return;
    if (target.closest('.node-menu')) return;
    closeNodeMenu();
  });

  load();
  screen.append(renderHeader({ title: 'Связи' }), legend, board, note);
  return screen;
}