import { CONFIG } from './config.js';
import { getApi } from './api.js';
import { el } from './dom.js';
import { showSignedInUser } from './signed-in.js';
import {
  parseDate, formatDateTime, formatTime, formatRelative, formatDuration, formatBytes,
} from './format.js';

const api = await getApi();

// ---------- Domain ----------
// rank drives default sort: worst first
const STATUS = {
  failed:  { label: 'Failed',  icon: '✕', rank: 0 },
  warning: { label: 'Warning', icon: '!', rank: 1 },
  unknown: { label: 'Unknown', icon: '?', rank: 2 },
  running: { label: 'Running', icon: '↻', rank: 3 },
  success: { label: 'Success', icon: '✓', rank: 4 },
};

// Anything the backend sends that we don't recognise becomes "unknown" rather than breaking the UI
function normalizeStatus(raw) {
  const s = String(raw ?? '').toLowerCase();
  return Object.hasOwn(STATUS, s) ? s : 'unknown';
}

function normalizeJob(j) {
  return {
    id: String(j.id),
    company: j.company_name ?? '',
    name: j.job_name ?? '',
    status: normalizeStatus(j.status),
    message: j.message ?? '',
    runningSince: parseDate(j.running_since),
    // When the most recent run *finished*; a job that's running keeps showing its previous finish
    lastRun: parseDate(j.last_run_at),
    nextRun: parseDate(j.next_run_at),
  };
}

// A running job isn't silently dead, so it's never overdue (a long run can pass its next slot)
const isOverdue = (job, now = Date.now()) =>
  job.status !== 'running' && !!job.nextRun && job.nextRun.getTime() + CONFIG.overdueGraceMinutes * 60_000 < now;

// ---------- State ----------
const state = {
  jobs: [],
  filter: 'all',
  search: '',
  sort: { key: 'status', dir: 1 },
  lastSuccess: null,
};

// ---------- DOM ----------
const $ = (sel) => document.querySelector(sel);
const dom = {
  tbody: $('#jobs-body'),
  empty: $('#empty-state'),
  search: $('#search'),
  refreshBtn: $('#refresh-btn'),
  signedIn: $('#signed-in'),
  signedInEmail: $('#signed-in-email'),
  signOut: $('#sign-out'),
  adminLink: $('#admin-link'),
  lastUpdated: $('#last-updated'),
  errorBanner: $('#error-banner'),
  dialog: $('#detail-dialog'),
  detailTitle: $('#detail-title'),
  detailSubtitle: $('#detail-subtitle'),
  detailBody: $('#detail-body'),
};

// ---------- Rendering ----------
function statusBadge(status, { asButton = false, opensDialog = false, dataset = null, title = null } = {}) {
  const { label, icon } = STATUS[status];
  const content = [el('span', { class: 'badge__icon', 'aria-hidden': 'true' }, icon), label];
  return asButton
    ? el('button', {
        type: 'button',
        class: `badge badge--${status}`,
        'aria-haspopup': opensDialog ? 'dialog' : null,
        'aria-label': `${label} – view details`,
        title,
        dataset,
      }, content)
    : el('span', { class: `badge badge--${status}`, title }, content);
}

const runningTitle = (since) => (since ? `Running since ${formatDateTime(since)}` : null);

function timeCell(date, { extra = null, emptyLabel = 'Never' } = {}) {
  if (!date) return el('td', {}, el('span', { class: 'muted' }, emptyLabel));
  return el('td', {},
    el('time', { class: 'time', datetime: date.toISOString(), title: date.toString() },
      el('span', {}, formatDateTime(date), extra),
      el('span', { class: 'time__rel' }, formatRelative(date))));
}

function renderRow(job) {
  const overdueTag = isOverdue(job) ? el('span', { class: 'tag-overdue' }, 'Overdue') : null;
  return el('tr', {},
    el('td', {}, job.company),
    el('td', {}, job.name),
    el('td', {}, statusBadge(job.status, {
      asButton: true, opensDialog: true, dataset: { jobId: job.id }, title: runningTitle(job.runningSince),
    })),
    timeCell(job.lastRun),
    // No next run: unscheduled, or e.g. a Veeam copy job in immediate mode
    timeCell(job.nextRun, { extra: overdueTag, emptyLabel: 'Not scheduled' }));
}

const collator = new Intl.Collator(undefined, { sensitivity: 'base', numeric: true });

function cmpDate(a, b) {
  if (!a && !b) return 0;
  if (!a) return 1;
  if (!b) return -1;
  return a - b;
}

const SORTERS = {
  company: (a, b) => collator.compare(a.company, b.company),
  name: (a, b) => collator.compare(a.name, b.name),
  status: (a, b) => STATUS[a.status].rank - STATUS[b.status].rank,
  lastRun: (a, b) => cmpDate(a.lastRun, b.lastRun),
  nextRun: (a, b) => cmpDate(a.nextRun, b.nextRun),
};

function visibleJobs() {
  const q = state.search.trim().toLowerCase();
  const now = Date.now();
  const { key, dir } = state.sort;
  return state.jobs
    .filter((j) => {
      if (state.filter === 'overdue') return isOverdue(j, now);
      return state.filter === 'all' || j.status === state.filter;
    })
    .filter((j) => !q || j.company.toLowerCase().includes(q) || j.name.toLowerCase().includes(q))
    // Stable tie-breakers keep row order from jumping around on each refresh
    .sort((a, b) => SORTERS[key](a, b) * dir || SORTERS.company(a, b) || SORTERS.name(a, b));
}

function renderSummary() {
  const now = Date.now();
  const counts = { all: state.jobs.length, failed: 0, warning: 0, running: 0, success: 0, overdue: 0 };
  for (const j of state.jobs) {
    if (j.status in counts) counts[j.status]++;
    if (isOverdue(j, now)) counts.overdue++;
  }
  for (const [k, v] of Object.entries(counts)) {
    const node = document.querySelector(`[data-count="${k}"]`);
    if (node) node.textContent = v;
  }
  document.querySelectorAll('.summary-card').forEach((card) => {
    card.setAttribute('aria-pressed', String(card.dataset.filter === state.filter));
  });
}

function renderSortHeaders() {
  document.querySelectorAll('th[aria-sort]').forEach((th) => {
    const key = th.querySelector('.sort').dataset.sort;
    th.setAttribute('aria-sort',
      key === state.sort.key ? (state.sort.dir === 1 ? 'ascending' : 'descending') : 'none');
  });
}

function render() {
  const rows = visibleJobs();
  dom.tbody.replaceChildren(...rows.map(renderRow));
  dom.empty.hidden = rows.length > 0;
  renderSummary();
  renderSortHeaders();
}

// ---------- Data loading ----------
let inFlight = null;
let pollTimer = null;

function refresh() {
  if (inFlight) return inFlight; // de-dupe overlapping manual + scheduled refreshes
  dom.refreshBtn.disabled = true;
  inFlight = (async () => {
    try {
      const data = await api.listJobs();
      state.jobs = data.jobs.map(normalizeJob);
      state.lastSuccess = new Date();
      dom.errorBanner.hidden = true;
      dom.lastUpdated.textContent = `Updated ${formatTime(state.lastSuccess)}`;
    } catch (err) {
      // Keep showing stale data, but make it obvious it's stale
      dom.errorBanner.textContent = state.lastSuccess
        ? `Couldn't refresh (${err.message}). Showing data from ${formatTime(state.lastSuccess)}.`
        : `Couldn't load backup status (${err.message}).`;
      dom.errorBanner.hidden = false;
      dom.lastUpdated.textContent = 'Update failed';
      console.error(err);
    } finally {
      render();
      dom.refreshBtn.disabled = false;
      inFlight = null;
    }
  })();
  return inFlight;
}

function schedulePoll() {
  clearTimeout(pollTimer);
  pollTimer = setTimeout(async () => {
    await refresh();
    schedulePoll();
  }, CONFIG.refreshIntervalMs);
}

// Don't poll from background tabs (e.g. a wall display that's been switched away); catch up on return
document.addEventListener('visibilitychange', () => {
  if (document.hidden) clearTimeout(pollTimer);
  else refresh().then(schedulePoll);
});

// ---------- Detail modal ----------
// Every async result checks reqId first, so a slow response for job A can never paint over job B.
const modal = {
  reqId: 0,
  job: null,
  detail: null,
  runs: null,          // null = loading, [] = none
  runsError: null,
  dayFilter: null,     // local YYYY-MM-DD, or null for all days
  selectedRunId: null, // null = the job's latest finished run (from the detail call)
  runMessage: null,    // { status, text, startedAt } for the selected run
  runMessageError: null,
};

// Colour of a day cell: the worst thing that happened that day
const DAY_SEVERITY = ['failed', 'warning', 'unknown', 'running', 'success'];

const pad2 = (n) => String(n).padStart(2, '0');
const localDayKey = (d) => `${d.getFullYear()}-${pad2(d.getMonth() + 1)}-${pad2(d.getDate())}`;
const dayLabelFmt = new Intl.DateTimeFormat(undefined, { weekday: 'short', month: 'short', day: 'numeric' });
const dayTickFmt = new Intl.DateTimeFormat(undefined, { month: 'short', day: 'numeric' });

function normalizeRun(r) {
  return {
    id: String(r.id),
    status: normalizeStatus(r.status),
    startedAt: parseDate(r.started_at),
    finishedAt: parseDate(r.finished_at),
    duration: r.duration_seconds,
    size: r.size_bytes,
  };
}

function buildDays(runs, count) {
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  const days = [];
  for (let i = count - 1; i >= 0; i--) {
    const date = new Date(today);
    date.setDate(date.getDate() - i);
    days.push({ key: localDayKey(date), date, counts: {}, total: 0 });
  }
  const byKey = new Map(days.map((d) => [d.key, d]));
  for (const run of runs) {
    const day = byKey.get(localDayKey(run.startedAt));
    if (!day) continue;
    day.counts[run.status] = (day.counts[run.status] ?? 0) + 1;
    day.total++;
  }
  for (const day of days) day.status = day.total ? DAY_SEVERITY.find((s) => day.counts[s]) : 'none';
  return days;
}

function describeCounts(counts) {
  return DAY_SEVERITY.filter((s) => counts[s])
    .map((s) => `${counts[s]} ${STATUS[s].label.toLowerCase()}`)
    .join(', ');
}

function detailRow(label, value) {
  if (value == null || value === '') return [];
  return [el('dt', {}, label), el('dd', {}, value)];
}

function renderSummarySection() {
  const { job, detail } = modal;
  const status = detail ? normalizeStatus(detail.status) : job.status;
  const runningSince = detail ? parseDate(detail.running_since) : job.runningSince;
  const lastStatus = detail?.last_status ? normalizeStatus(detail.last_status) : null;

  dom.detailTitle.textContent = detail?.job_name ?? job.name;
  dom.detailSubtitle.textContent = detail?.company_name ?? job.company;

  return el('section', {},
    el('div', { class: 'detail-status' },
      statusBadge(status),
      runningSince ? el('span', { class: 'muted' }, `since ${formatDateTime(runningSince)}`) : null),
    el('dl', { class: 'detail-grid' },
      // While a job is running, its "last run" is the previous one — say how that went
      status === 'running' && lastStatus ? detailRow('Previous result', STATUS[lastStatus].label) : [],
      detailRow('Last finished', formatDateTime(detail ? parseDate(detail.last_run_at) : job.lastRun)),
      detailRow('Next scheduled', formatDateTime(detail ? parseDate(detail.next_run_at) : job.nextRun, 'Not scheduled')),
      detailRow('Duration', formatDuration(detail?.duration_seconds)),
      detailRow('Size', formatBytes(detail?.size_bytes)),
      detailRow('Source', detail?.source_system)));
}

function renderHistorySection() {
  const section = el('section', { id: 'detail-history' },
    el('h3', { class: 'detail-section-title' }, `Last ${CONFIG.historyDays} days`));

  if (modal.runsError) {
    section.append(el('p', { class: 'banner banner--error' }, `Couldn't load run history: ${modal.runsError}`));
    return section;
  }
  if (!modal.runs) {
    section.append(el('p', { class: 'muted' }, 'Loading history…'));
    return section;
  }

  const days = buildDays(modal.runs, CONFIG.historyDays);
  const finished = modal.runs.filter((r) => r.finishedAt);
  const ok = finished.filter((r) => r.status === 'success').length;
  const totals = {};
  for (const r of modal.runs) totals[r.status] = (totals[r.status] ?? 0) + 1;

  section.append(
    el('p', { class: 'history-stats' },
      modal.runs.length
        ? `${modal.runs.length} runs · ${finished.length ? Math.round((ok / finished.length) * 100) : 0}% successful · ${describeCounts(totals)}`
        : 'No runs recorded in this period.'),
    el('div', { class: 'day-strip', role: 'group', 'aria-label': 'Daily results, oldest to newest. Select a day to filter runs.' },
      days.map((d) => {
        const label = `${dayLabelFmt.format(d.date)}: ${d.total ? describeCounts(d.counts) : 'no runs'}`;
        return el('button', {
          type: 'button',
          class: `day day--${d.status}`,
          title: label,
          'aria-label': label,
          'aria-pressed': String(modal.dayFilter === d.key),
          disabled: !d.total,
          dataset: { day: d.key },
        });
      })),
    el('div', { class: 'day-strip__ticks muted', 'aria-hidden': 'true' },
      el('span', {}, dayTickFmt.format(days[0].date)),
      el('span', {}, 'Today')),
  );

  const rows = modal.dayFilter
    ? modal.runs.filter((r) => localDayKey(r.startedAt) === modal.dayFilter)
    : modal.runs;
  if (!rows.length) return section;

  if (modal.dayFilter) {
    const date = days.find((d) => d.key === modal.dayFilter)?.date;
    section.append(el('p', { class: 'muted history-filter' },
      `Showing ${dayLabelFmt.format(date)} · `,
      el('button', { type: 'button', class: 'link', dataset: { day: modal.dayFilter } }, 'Show all days')));
  }

  section.append(el('div', { class: 'runs-wrap' },
    el('table', { class: 'runs' },
      el('thead', {}, el('tr', {},
        ['Status', 'Started', 'Finished', 'Duration', 'Size'].map((h) => el('th', { scope: 'col' }, h)))),
      el('tbody', {}, rows.map((r) => el('tr', { class: r.id === modal.selectedRunId ? 'is-selected' : null },
        el('td', {}, statusBadge(r.status, { asButton: true, dataset: { runId: r.id } })),
        el('td', {}, formatDateTime(r.startedAt)),
        el('td', {}, r.finishedAt ? formatDateTime(r.finishedAt) : el('span', { class: 'muted' }, 'In progress')),
        el('td', {}, formatDuration(r.duration) ?? '—'),
        el('td', {}, formatBytes(r.size) ?? '—')))))));
  return section;
}

function renderMessageSection() {
  const { detail, job } = modal;
  let status;
  let text;
  let heading = 'Message';
  if (modal.selectedRunId) {
    const run = modal.runs?.find((r) => r.id === modal.selectedRunId);
    heading = `Message · run started ${formatDateTime(run?.startedAt)}`;
    status = run?.status ?? 'unknown';
    text = modal.runMessageError
      ? `Couldn't load this run: ${modal.runMessageError}`
      : modal.runMessage?.text ?? 'Loading…';
  } else {
    status = detail?.last_status ? normalizeStatus(detail.last_status) : job.status;
    text = detail?.message ?? job.message;
  }

  const extras = !modal.selectedRunId && detail?.details && typeof detail.details === 'object'
    ? Object.entries(detail.details).flatMap(([k, v]) =>
        detailRow(k.replace(/_/g, ' '), typeof v === 'object' ? JSON.stringify(v) : String(v)))
    : modal.runMessage?.extras ?? [];

  return el('section', { id: 'detail-message' },
    el('h3', { class: 'detail-section-title' }, heading),
    el('pre', { class: `message message--${status}` }, text || 'No message reported.'),
    extras.length ? el('h3', { class: 'detail-section-title' }, 'Additional details') : null,
    extras.length ? el('dl', { class: 'detail-grid' }, extras) : null);
}

function renderModal({ loading = false, error = null } = {}) {
  dom.detailBody.replaceChildren(...[
    renderSummarySection(),
    loading ? el('p', { class: 'muted' }, 'Loading full details…') : null,
    error ? el('p', { class: 'banner banner--error' }, `Couldn't load full details: ${error}`) : null,
    renderMessageSection(),
    renderHistorySection(),
  ].filter(Boolean));
}

// Re-render just the history section, keeping the runs table's scroll position
function renderHistory() {
  const wrap = dom.detailBody.querySelector('.runs-wrap');
  const scrollTop = wrap?.scrollTop ?? 0;
  dom.detailBody.querySelector('#detail-history')?.replaceWith(renderHistorySection());
  const newWrap = dom.detailBody.querySelector('.runs-wrap');
  if (newWrap) newWrap.scrollTop = scrollTop;
}

function renderMessage() {
  dom.detailBody.querySelector('#detail-message')?.replaceWith(renderMessageSection());
}

async function openDetail(jobId) {
  const job = state.jobs.find((j) => j.id === jobId);
  if (!job) return;
  const reqId = ++modal.reqId;
  Object.assign(modal, {
    job, detail: null, runs: null, runsError: null, dayFilter: null,
    selectedRunId: null, runMessage: null, runMessageError: null,
  });
  renderModal({ loading: true }); // show what we have immediately
  if (!dom.dialog.open) dom.dialog.showModal();

  const current = () => reqId === modal.reqId && dom.dialog.open;
  const detailP = api.getJob(jobId).then(
    (detail) => { if (current()) { modal.detail = detail; renderModal(); } },
    (err) => { if (current()) renderModal({ error: err.message }); },
  );
  const runsP = api.listRuns(jobId, CONFIG.historyDays).then(
    (data) => {
      if (!current()) return;
      modal.runs = (data.runs ?? []).map(normalizeRun).filter((r) => r.startedAt);
      renderHistory();
    },
    (err) => { if (current()) { modal.runsError = err.message; renderHistory(); } },
  );
  await Promise.all([detailP, runsP]);
}

async function selectRun(runId) {
  const reqId = modal.reqId;
  modal.selectedRunId = runId;
  modal.runMessage = null;
  modal.runMessageError = null;
  renderHistory();
  renderMessage();
  try {
    const run = await api.getRun(runId);
    if (reqId !== modal.reqId || modal.selectedRunId !== runId) return;
    modal.runMessage = {
      text: run.message,
      extras: Object.entries(run.details ?? {}).flatMap(([k, v]) =>
        detailRow(k.replace(/_/g, ' '), typeof v === 'object' ? JSON.stringify(v) : String(v))),
    };
  } catch (err) {
    if (reqId !== modal.reqId || modal.selectedRunId !== runId) return;
    modal.runMessageError = err.message;
  }
  renderMessage();
  dom.detailBody.querySelector('#detail-message')?.scrollIntoView({ block: 'nearest', behavior: 'smooth' });
}

// ---------- Events ----------
dom.tbody.addEventListener('click', (e) => {
  const btn = e.target.closest('button[data-job-id]');
  if (btn) openDetail(btn.dataset.jobId);
});

dom.dialog.addEventListener('click', (e) => {
  // Click on the backdrop (the dialog element itself, outside its content) or the close button
  if (e.target === dom.dialog || e.target.closest('[data-close]')) dom.dialog.close();
});

dom.detailBody.addEventListener('click', (e) => {
  const day = e.target.closest('button[data-day]');
  if (day) {
    modal.dayFilter = modal.dayFilter === day.dataset.day ? null : day.dataset.day;
    renderHistory();
    return;
  }
  const run = e.target.closest('button[data-run-id]');
  if (run) selectRun(run.dataset.runId);
});

document.querySelector('.summary').addEventListener('click', (e) => {
  const card = e.target.closest('.summary-card');
  if (!card) return;
  state.filter = card.dataset.filter;
  render();
});

document.querySelector('.jobs thead').addEventListener('click', (e) => {
  const btn = e.target.closest('.sort');
  if (!btn) return;
  const key = btn.dataset.sort;
  state.sort = state.sort.key === key ? { key, dir: -state.sort.dir } : { key, dir: 1 };
  render();
});

dom.search.addEventListener('input', () => {
  state.search = dom.search.value;
  render();
});

dom.refreshBtn.addEventListener('click', () => refresh().then(schedulePoll));

// ---------- Boot ----------
api.getMe().then(
  (me) => showSignedInUser(me, dom),
  (err) => console.error(err),  // not worth a banner: the jobs request will surface real problems
);
refresh().then(schedulePoll);