/**
 * javascript/app.js
 *
 * Shared runtime for the Podman plugin page: the AJAX helper every panel
 * module uses to talk to webui/plugins/podman/ajax/*.php, small DOM
 * utilities to avoid repeating the same escaping/formatting logic in ten
 * places, and the sub-tab router that shows/hides panels and lazily
 * initializes each one's module the first time it's opened.
 *
 * Loaded first (before any panel module) — see Podman.page.
 */
window.Podman = (function () {
  'use strict';

  const BASE = '/plugins/podman/ajax/';

  /**
   * Calls one ajax/<file>.php?action=<action> endpoint and resolves with
   * response.data, or rejects with an Error carrying the server's message
   * — every ajax/*.php endpoint replies with the same {ok, data|error}
   * envelope (see include/helpers.php's podman_json_response/_error), so
   * this one function is the only place that envelope shape is known.
   *
   * @param {string} file      e.g. "containers"
   * @param {string} action    e.g. "list"
   * @param {('GET'|'POST')} method
   * @param {object|null} body sent as JSON for POST
   * @param {object} query     extra query-string params (e.g. {id: "..."})
   */
  function call(file, action, method, body, query) {
    const params = new URLSearchParams(Object.assign({ action: action }, query || {}));
    const url = BASE + file + '.php?' + params.toString();

    const opts = { method: method, headers: {} };
    if (body !== undefined && body !== null) {
      opts.headers['Content-Type'] = 'application/json';
      opts.body = JSON.stringify(body);
    }
    // Unraid's own webGui/include/local_prepend.php (auto_prepend_file on
    // every PHP request, not something this plugin controls) kills any
    // POST request with no output at all unless it carries the page's
    // CSRF token — either as a "csrf_token" POST field or this header.
    // `csrf_token` itself is a global var HeadInlineJS.php sets on every
    // Unraid page before plugin JS loads (verified live: without this
    // header, every mutating action failed with "JSON.parse: unexpected
    // end of data", i.e. an empty response body from csrf_terminate()).
    if (method === 'POST' && typeof window.csrf_token === 'string') {
      opts.headers['X-CSRF-Token'] = window.csrf_token;
    }

    return fetch(url, opts)
      .then(function (res) {
        return res.json().then(function (envelope) {
          if (!envelope.ok) {
            throw new Error(envelope.error || ('Request failed (' + res.status + ')'));
          }
          return envelope.data;
        });
      });
  }

  function get(file, action, query) {
    return call(file, action, 'GET', null, query);
  }

  function post(file, action, body) {
    return call(file, action, 'POST', body || {}, {});
  }

  // --- DOM helpers ---------------------------------------------------------

  function escapeHtml(value) {
    return String(value == null ? '' : value).replace(/[&<>"']/g, function (c) {
      return { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c];
    });
  }

  function el(id) {
    return document.getElementById(id);
  }

  function formatBytes(bytes) {
    if (!bytes || bytes <= 0) return '0 B';
    const units = ['B', 'KB', 'MB', 'GB', 'TB'];
    const i = Math.min(Math.floor(Math.log(bytes) / Math.log(1024)), units.length - 1);
    const value = bytes / Math.pow(1024, i);
    return (value >= 100 || i === 0 ? value.toFixed(0) : value.toFixed(1)) + ' ' + units[i];
  }

  function formatDuration(seconds) {
    if (seconds == null) return '—';
    if (seconds < 60) return seconds + 's';
    const days = Math.floor(seconds / 86400);
    const hours = Math.floor((seconds % 86400) / 3600);
    const minutes = Math.floor((seconds % 3600) / 60);
    if (days > 0) return days + 'd ' + hours + 'h';
    if (hours > 0) return hours + 'h ' + minutes + 'm';
    return minutes + 'm';
  }

  function formatRelativeTime(unixSeconds) {
    if (!unixSeconds) return '—';
    const diff = Math.max(0, Math.floor(Date.now() / 1000) - unixSeconds);
    if (diff < 60) return 'just now';
    if (diff < 3600) return Math.floor(diff / 60) + 'm ago';
    if (diff < 86400) return Math.floor(diff / 3600) + 'h ago';
    return Math.floor(diff / 86400) + 'd ago';
  }

  /** Status string (from libpod's container "State") -> chip color class. */
  function stateChipClass(state) {
    switch (state) {
      case 'running': return 'podman-chip-good';
      case 'paused': return 'podman-chip-warn';
      case 'exited':
      case 'created': return 'podman-chip-neutral';
      default: return 'podman-chip-bad';
    }
  }

  function loadingRow(colspan, label) {
    return '<tr><td colspan="' + colspan + '" class="podman-loading">' + escapeHtml(label || 'Loading…') + '</td></tr>';
  }

  function errorRow(colspan, message) {
    return '<tr><td colspan="' + colspan + '" class="podman-error">' + escapeHtml(message) + '</td></tr>';
  }

  // --- Modal form dialog -----------------------------------------------------

  /**
   * Shows a small form modal in place of browser-native prompt()/confirm()
   * — needed for any action that takes more than one related value (e.g.
   * "New Volume" wants a name AND an optional host path together; chaining
   * prompt() calls for that is both bad UX and can't show both fields at
   * once, or offer a hint under the path field explaining what it does).
   *
   * @param {object} opts
   * @param {string} opts.title
   * @param {Array<{name:string, label:string, placeholder?:string, hint?:string, required?:boolean}>} opts.fields
   * @param {string} [opts.submitLabel]
   * @param {(values: Object<string,string>) => Promise<any>} opts.onSubmit
   *   Called with {fieldName: value}. Rejecting keeps the modal open and
   *   shows the error inline; resolving closes it.
   */
  function openFormModal(opts) {
    const backdrop = document.createElement('div');
    backdrop.className = 'podman-modal-backdrop';

    const fieldsHtml = opts.fields.map(function (f) {
      return '' +
        '<div class="podman-modal-field">' +
        '<label for="podman-modal-' + f.name + '">' + escapeHtml(f.label) + '</label>' +
        '<input type="text" id="podman-modal-' + f.name + '" name="' + f.name + '"' +
        (f.placeholder ? ' placeholder="' + escapeHtml(f.placeholder) + '"' : '') + '>' +
        (f.hint ? '<div class="hint">' + escapeHtml(f.hint) + '</div>' : '') +
        '</div>';
    }).join('');

    backdrop.innerHTML = '' +
      '<div class="podman-modal" role="dialog" aria-modal="true">' +
      '<div class="podman-modal-head"><h3>' + escapeHtml(opts.title) + '</h3></div>' +
      '<form class="podman-modal-body">' + fieldsHtml + '</form>' +
      '<div class="podman-modal-actions">' +
      '<button type="button" class="podman-btn podman-btn-ghost" data-role="cancel">Cancel</button>' +
      '<button type="button" class="podman-btn podman-btn-primary" data-role="submit">' +
      escapeHtml(opts.submitLabel || 'Create') + '</button>' +
      '</div></div>';

    // Appended inside .podman-plugin, not document.body: the --surface/
    // --border/etc. custom properties this modal's CSS relies on are
    // scoped to .podman-plugin (see podman.css's token strategy comment),
    // so a modal appended to body would resolve none of them — verified
    // live: the backdrop dimming and card background were both missing,
    // only the (inherited-from-body) text was visible. position:fixed
    // still overlays the full viewport regardless of this nesting.
    (document.querySelector('.podman-plugin') || document.body).appendChild(backdrop);

    const firstInput = backdrop.querySelector('input');
    if (firstInput) firstInput.focus();

    function close() {
      backdrop.remove();
    }

    function submit() {
      const values = {};
      opts.fields.forEach(function (f) {
        values[f.name] = backdrop.querySelector('#podman-modal-' + f.name).value.trim();
      });
      for (const f of opts.fields) {
        if (f.required && !values[f.name]) {
          showError('"' + f.label + '" is required.');
          return;
        }
      }
      const submitBtn = backdrop.querySelector('[data-role="submit"]');
      submitBtn.disabled = true;
      Promise.resolve(opts.onSubmit(values)).then(close).catch(function (err) {
        submitBtn.disabled = false;
        showError(err.message || String(err));
      });
    }

    function showError(message) {
      let box = backdrop.querySelector('.podman-modal-error');
      if (!box) {
        box = document.createElement('div');
        box.className = 'podman-modal-error';
        backdrop.querySelector('.podman-modal-body').appendChild(box);
      }
      box.textContent = message;
    }

    backdrop.querySelector('[data-role="cancel"]').addEventListener('click', close);
    backdrop.querySelector('[data-role="submit"]').addEventListener('click', submit);
    backdrop.querySelector('form').addEventListener('submit', function (e) {
      e.preventDefault();
      submit();
    });
    backdrop.addEventListener('click', function (e) {
      if (e.target === backdrop) close();
    });
    document.addEventListener('keydown', function onKey(e) {
      if (e.key === 'Escape') {
        close();
        document.removeEventListener('keydown', onKey);
      }
    });
  }

  /**
   * Small anchored dropdown menu — used for secondary per-row actions
   * (pause/kill/rename/...) that would otherwise clutter a table row with
   * one icon button each. Only one menu is ever open at a time.
   *
   * @param {HTMLElement} anchorEl button the menu opens from/closes on
   * @param {Array<{label:string, danger?:boolean, disabled?:boolean, onClick?:Function}|'separator'>} items
   */
  let openMenuCloser = null;
  function openContextMenu(anchorEl, items) {
    if (openMenuCloser) {
      openMenuCloser();
      return;
    }

    const menu = document.createElement('div');
    menu.className = 'podman-context-menu';
    menu.innerHTML = items.map(function (item) {
      if (item === 'separator') return '<div class="podman-context-menu-sep"></div>';
      return '<button type="button" class="' + (item.danger ? 'danger' : '') + '"' +
        (item.disabled ? ' disabled' : '') + '>' + escapeHtml(item.label) + '</button>';
    }).join('');

    // Viewport-relative (see the "position: fixed" comment on
    // .podman-context-menu in podman.css) — no scrollY/scrollX added.
    const rect = anchorEl.getBoundingClientRect();
    menu.style.top = (rect.bottom + 4) + 'px';
    menu.style.left = (rect.right - 180) + 'px';
    (document.querySelector('.podman-plugin') || document.body).appendChild(menu);

    // menu.children includes the separator <div>s too, so indexing into it
    // directly (by a counter that only advances for real items) drifts by
    // one after every separator — e.g. "Remove" (after a separator) ended
    // up wired to the separator <div> instead of its own <button>, so
    // clicking it did nothing. querySelectorAll('button') only ever
    // returns the actual buttons, in the same order as the non-separator
    // items, so indexing into that stays aligned regardless of separators.
    const buttons = menu.querySelectorAll('button');
    let buttonIndex = 0;
    items.forEach(function (item) {
      if (item === 'separator') return;
      const btn = buttons[buttonIndex];
      buttonIndex++;
      if (item.disabled) return;
      btn.addEventListener('click', function (e) {
        e.stopPropagation();
        close();
        if (item.onClick) item.onClick();
      });
    });

    function close() {
      menu.remove();
      document.removeEventListener('click', onOutsideClick);
      document.removeEventListener('keydown', onKey);
      openMenuCloser = null;
    }
    function onOutsideClick(e) {
      if (!menu.contains(e.target)) close();
    }
    function onKey(e) {
      if (e.key === 'Escape') close();
    }

    openMenuCloser = close;
    // Deferred so the click that opened the menu doesn't immediately
    // trigger onOutsideClick via event bubbling.
    setTimeout(function () {
      document.addEventListener('click', onOutsideClick);
      document.addEventListener('keydown', onKey);
    }, 0);
  }

  // --- Panel router ----------------------------------------------------------

  const panelModules = {};
  const initialized = {};

  /** Called by each panel's own JS file (e.g. containers.js) to register itself. */
  function registerPanel(name, module) {
    panelModules[name] = module;
  }

  function activatePanel(name) {
    document.querySelectorAll('.podman-subnav button').forEach(function (btn) {
      btn.classList.toggle('active', btn.dataset.panel === name);
    });
    document.querySelectorAll('.podman-panel').forEach(function (panel) {
      panel.classList.toggle('active', panel.id === 'podman-panel-' + name);
    });

    const module = panelModules[name];
    if (!module) return;

    if (!initialized[name]) {
      initialized[name] = true;
      if (typeof module.init === 'function') module.init();
    } else if (typeof module.refresh === 'function') {
      module.refresh();
    }
  }

  function boot() {
    const subnav = document.querySelector('.podman-subnav');
    if (!subnav) return;

    subnav.addEventListener('click', function (e) {
      const btn = e.target.closest('button[data-panel]');
      if (btn) activatePanel(btn.dataset.panel);
    });

    const refreshBtn = el('podman-refresh-all');
    if (refreshBtn) {
      refreshBtn.addEventListener('click', function () {
        const active = document.querySelector('.podman-subnav button.active');
        if (active) activatePanel(active.dataset.panel);
      });
    }

    // Activate whichever panel is marked active in the initial HTML
    // (Dashboard, by default — see Podman.page).
    const initial = document.querySelector('.podman-subnav button.active');
    activatePanel(initial ? initial.dataset.panel : 'dashboard');
  }

  document.addEventListener('DOMContentLoaded', boot);

  return {
    get: get,
    post: post,
    escapeHtml: escapeHtml,
    el: el,
    formatBytes: formatBytes,
    formatDuration: formatDuration,
    formatRelativeTime: formatRelativeTime,
    stateChipClass: stateChipClass,
    loadingRow: loadingRow,
    errorRow: errorRow,
    openFormModal: openFormModal,
    openContextMenu: openContextMenu,
    registerPanel: registerPanel,
    activatePanel: activatePanel,
  };
})();