import { el, mount } from '../dom.js';
import { api } from '../api.js';
import { renderHealthBand, stopHealthBand } from './health_band.js';
import { renderDevicesBand, stopDevicesBand } from './devices_band.js';
import { svCard } from '../components/sv_card.js';
import clock from './cards/clock.js';
import weather from './cards/weather.js';
import hostPerf from './cards/host_perf.js';
import jobs from './cards/jobs.js';
import inbox from './cards/inbox.js';
import search from './cards/search.js';
import speedtest from './cards/speedtest.js';
import aiUsage from './cards/ai_usage.js';
import cluster from './cards/cluster.js';
import storage from './cards/storage.js';
import backups from './cards/backups.js';
import { blankCard } from './cards/blank.js';
import { blackflameCard } from './cards/blackflame.js';

const CARD_MODULES = [clock, weather, hostPerf, cluster, storage, backups, jobs, inbox, search, speedtest, aiUsage];
const BUILTIN_BY_ID = new Map(CARD_MODULES.map(d => [d.id, d]));

// ---- hybrid canvas geometry ----
// Cards are absolutely placed on a 12-column grid. {x,y,w,h} are in grid units
// (x,w in columns; y,h in rows of ROW_H px). Snap mode keeps them integer; a
// per-card `free` flag (or holding Alt while dragging) allows fractional
// placement + overlap. Everything scales with board width, so x/w stay relative.
const COLS = 12;
const ROW_H = 28;     // px per grid row
const GUTTER = 12;    // visual gap baked into each card's rendered size
const SIZE_W = { s: 3, m: 4, l: 6 };
const SIZE_H = { s: 6, m: 8, l: 10 };

let active = [];                 // mounted cards needing stop()
let renderGen = 0;               // guards overlapping async renders
let editing = false;
let mainEl;
let layout = { hidden: [], geom: {}, extras: [] };

const grid = () => document.getElementById('sv-cards');

function defFor(extra) {
  if (extra.type === 'blank') return blankCard(extra.id);
  if (extra.type === 'blackflame') return blackflameCard(extra.id);
  return null;
}

function visibleDefs() {
  const hidden = new Set(layout.hidden || []);
  const builtins = CARD_MODULES.filter(d => !hidden.has(d.id));
  const extras = (layout.extras || []).map(defFor).filter(Boolean);
  return [...builtins, ...extras];
}

function defaultSize(def) {
  if (def.type === 'blackflame') return { w: 6, h: 10 };
  if (def.type === 'blank') return { w: 3, h: 4 };
  return { w: SIZE_W[def.size] || 4, h: SIZE_H[def.size] || 8 };
}

function geomOf(def) {
  const g = (layout.geom || {})[def.id];
  if (g) return g;
  const { w, h } = defaultSize(def);
  return { x: 0, y: 0, w, h };
}

async function saveLayout() {
  try {
    await api.put('/api/dashboard/layout', {
      card_order: [], sizes: {},
      hidden: layout.hidden || [], geom: layout.geom || {}, extras: layout.extras || []
    });
  } catch (e) { console.error('save layout', e); }
}

// Backfill geometry for any visible card lacking it (first load / migration /
// a newly-shipped built-in). New cards flow below whatever already has a spot.
function autoPlaceMissing(defs) {
  const geom = { ...(layout.geom || {}) };
  let baseY = 0;
  for (const id in geom) baseY = Math.max(baseY, geom[id].y + geom[id].h);
  let cx = 0, cy = baseY, rowH = 0;
  for (const d of defs) {
    if (geom[d.id]) continue;
    const { w, h } = defaultSize(d);
    if (cx + w > COLS) { cx = 0; cy += rowH; rowH = 0; }
    geom[d.id] = { x: cx, y: cy, w, h };
    cx += w; rowH = Math.max(rowH, h);
  }
  layout.geom = geom;
}

function cellW() { return grid().clientWidth / COLS; }

function applyGeom(node, g) {
  const cw = cellW();
  node.style.position = 'absolute';
  node.style.left = (g.x * cw) + 'px';
  node.style.top = (g.y * ROW_H) + 'px';
  node.style.width = Math.max(40, g.w * cw - GUTTER) + 'px';
  node.style.height = Math.max(40, g.h * ROW_H - GUTTER) + 'px';
  node.style.zIndex = g.free ? 5 : 1;
  node.classList.toggle('free', !!g.free);
}

function fitBoard() {
  let max = 0;
  grid().querySelectorAll('.sv-card').forEach(n => { max = Math.max(max, n.offsetTop + n.offsetHeight); });
  grid().style.height = (max + GUTTER) + 'px';
}

function relayout() {
  active.forEach(def => {
    const n = grid().querySelector(`.sv-card[data-card-id="${def.id}"]`);
    if (n) applyGeom(n, geomOf(def));
  });
  fitBoard();
}

// ---- drag / resize (pointer-based; snap unless free or Alt held) ----
function beginDrag(ev, def, mode) {
  if (!editing) return;
  ev.preventDefault(); ev.stopPropagation();
  const node = grid().querySelector(`.sv-card[data-card-id="${def.id}"]`);
  if (!node) return;
  const g = { ...geomOf(def) };
  const start = { px: ev.clientX, py: ev.clientY, x: g.x, y: g.y, w: g.w, h: g.h };
  node.classList.add('dragging');
  const cw = cellW();

  function moveTo(e) {
    const dxc = (e.clientX - start.px) / cw;
    const dyc = (e.clientY - start.py) / ROW_H;
    const freeNow = g.free || e.altKey;
    if (mode === 'move') {
      let nx = start.x + dxc, ny = start.y + dyc;
      if (!freeNow) { nx = Math.round(nx); ny = Math.round(ny); }
      g.x = Math.max(0, Math.min(COLS - g.w, nx));
      g.y = Math.max(0, ny);
    } else {
      let nw = start.w + dxc, nh = start.h + dyc;
      if (!freeNow) { nw = Math.round(nw); nh = Math.round(nh); }
      g.w = Math.max(2, Math.min(COLS - g.x, nw));
      g.h = Math.max(2, nh);
    }
    applyGeom(node, g); fitBoard();
  }
  function end() {
    document.removeEventListener('pointermove', moveTo);
    document.removeEventListener('pointerup', end);
    node.classList.remove('dragging');
    layout.geom = { ...layout.geom, [def.id]: g };
    applyGeom(node, g);
    saveLayout();
  }
  document.addEventListener('pointermove', moveTo);
  document.addEventListener('pointerup', end);
}

function toggleFree(id) {
  const g = { ...(layout.geom[id] || geomOf({ id })) };
  g.free = !g.free;
  layout.geom = { ...layout.geom, [id]: g };
  const n = grid().querySelector(`.sv-card[data-card-id="${id}"]`);
  if (n) applyGeom(n, g);
  saveLayout();
}

function editOverlay(def) {
  const grip = el('span', { class: 'sv-grip', title: 'Drag to move' }, '⠿');
  grip.addEventListener('pointerdown', e => beginDrag(e, def, 'move'));
  const free = el('button', { class: 'sv-ed-free', title: 'Free / snap placement', onclick: () => toggleFree(def.id) }, '⤢');
  const hide = el('button', { class: 'sv-ed-hide', title: def.decorative ? 'Delete card' : 'Hide card', onclick: () => removeCard(def) }, '✕');
  const resize = el('span', { class: 'sv-resize', title: 'Drag to resize' });
  resize.addEventListener('pointerdown', e => beginDrag(e, def, 'resize'));
  const frag = document.createDocumentFragment();
  frag.append(el('div', { class: 'sv-card-edit' }, grip, free, hide), resize);
  return frag;
}

function mountOne(def) {
  const { root, body } = svCard(def);
  if (def.decorative) root.classList.add('sv-card-decor');
  root.appendChild(editOverlay(def));
  applyGeom(root, geomOf(def));
  grid().appendChild(root);
  try { def.mount(body); def.start && def.start(); active.push(def); }
  catch (e) { body.appendChild(el('span', { class: 'muted' }, 'card failed')); console.error(def.id, e); }
}

function placeNew(def) {
  let maxBottom = 0;
  for (const id in layout.geom) { const g = layout.geom[id]; maxBottom = Math.max(maxBottom, g.y + g.h); }
  const { w, h } = defaultSize(def);
  layout.geom = { ...layout.geom, [def.id]: { x: 0, y: maxBottom, w, h } };
}

function addBuiltin(id) {
  layout.hidden = (layout.hidden || []).filter(x => x !== id);
  const def = BUILTIN_BY_ID.get(id);
  if (!def) return;
  placeNew(def); mountOne(def); relayout(); renderTray(); saveLayout();
}

function addDecor(type) {
  const id = `${type}-${Date.now().toString(36)}`;
  const def = defFor({ id, type });
  if (!def) return;
  layout.extras = [...(layout.extras || []), { id, type }];
  placeNew(def); mountOne(def); relayout(); renderTray(); saveLayout();
}

function removeCard(def) {
  const d = active.find(a => a.id === def.id);
  if (d && d.stop) d.stop();
  active = active.filter(a => a.id !== def.id);
  grid().querySelector(`.sv-card[data-card-id="${def.id}"]`)?.remove();
  if (def.decorative) {
    layout.extras = (layout.extras || []).filter(e => e.id !== def.id);
    const g = { ...layout.geom }; delete g[def.id]; layout.geom = g;
  } else if (!(layout.hidden || []).includes(def.id)) {
    layout.hidden = [...(layout.hidden || []), def.id];
  }
  renderTray(); fitBoard(); saveLayout();
}

function renderTray() {
  const tray = document.getElementById('sv-tray');
  if (!tray) return;
  const hidden = (layout.hidden || []).map(id => BUILTIN_BY_ID.get(id)).filter(Boolean);
  mount(tray,
    el('span', { class: 'sv-tray-label' }, 'Add card:'),
    el('button', { class: 'sv-tray-chip', onclick: () => addDecor('blank') }, '+ Blank'),
    el('button', { class: 'sv-tray-chip', onclick: () => addDecor('blackflame') }, '+ Blackflame'),
    hidden.length ? el('span', { class: 'sv-tray-label', style: { marginLeft: '8px' } }, 'Restore:') : null,
    ...hidden.map(def => el('button', { class: 'sv-tray-chip', onclick: () => addBuiltin(def.id) }, '+ ' + def.title)),
    el('span', { class: 'sv-tray-hint muted' }, 'drag ⠿ to move · corner to resize · ⤢ = free/overlap · Alt = no-snap'));
  tray.style.display = editing ? 'flex' : 'none';
}

function toggleEdit() {
  editing = !editing;
  grid().classList.toggle('editing', editing);
  const btn = document.getElementById('sv-edit-btn');
  if (btn) btn.textContent = editing ? 'Done' : 'Edit layout';
  const reset = document.getElementById('sv-reset-btn');
  if (reset) reset.style.display = editing ? '' : 'none';
  renderTray();
}

async function resetLayout() {
  layout = { hidden: [], geom: {}, extras: [] };
  await saveLayout();
  render(mainEl);
}

export async function render(main) {
  mainEl = main;
  const myGen = ++renderGen;
  active.forEach(c => c.stop && c.stop()); active = []; stopHealthBand(); stopDevicesBand();
  editing = false;
  mount(main,
    el('h1', { class: 'view-h1' }, 'Sacred Valley'),
    el('div', { class: 'sv-head' },
      el('p', { class: 'view-sub', style: { margin: 0 } }, 'The homelab, at a glance.'),
      el('div', { class: 'sv-toolbar' },
        el('button', { class: 'sv-reset-btn', id: 'sv-reset-btn', style: { display: 'none' }, onclick: resetLayout }, 'Reset'),
        el('button', { class: 'sv-edit-btn', id: 'sv-edit-btn', onclick: toggleEdit }, 'Edit layout'))),
    el('div', { id: 'sv-cards' }),
    el('div', { id: 'sv-tray', style: { display: 'none' } }),
    el('div', { id: 'sv-health' }),
    el('div', { id: 'sv-devices' })
  );

  layout = { hidden: [], geom: {}, extras: [] };
  try {
    const l = await api.get('/api/dashboard/layout');
    layout = { hidden: l.hidden || [], geom: l.geom || {}, extras: l.extras || [] };
  } catch { /* defaults */ }
  if (myGen !== renderGen) return;

  const defs = visibleDefs();
  autoPlaceMissing(defs);
  for (const def of defs) mountOne(def);
  relayout();
  renderTray();
  window.removeEventListener('resize', relayout);
  window.addEventListener('resize', relayout);

  renderHealthBand(document.getElementById('sv-health'));
  renderDevicesBand(document.getElementById('sv-devices'));
}