/**
 * UI for managing granular ACLs.
 */
import {GristDoc} from 'app/client/components/GristDoc';
import {createObsArray} from 'app/client/lib/koArrayWrap';
import {shadowScroll} from 'app/client/ui/shadowScroll';
import {primaryButton} from 'app/client/ui2018/buttons';
import {colors} from 'app/client/ui2018/cssVars';
import {icon} from 'app/client/ui2018/icons';
import {menu, menuItem, select} from 'app/client/ui2018/menus';
import {arrayRepeat, setDifference} from 'app/common/gutil';
import {Computed, Disposable, dom, ObsArray, obsArray, Observable, styled} from 'grainjs';
import isEqual = require('lodash/isEqual');

interface AclState {
  ownerOnlyTableIds: Set<string>;
  ownerOnlyStructure: boolean;
}

function buildAclState(gristDoc: GristDoc): AclState {
  const ownerOnlyTableIds = new Set<string>();
  let ownerOnlyStructure = false;
  const tableData = gristDoc.docModel.aclResources.tableData;
  for (const res of tableData.getRecords()) {
    const code = String(res.colIds);
    if (res.tableId && code === '~o') {
      ownerOnlyTableIds.add(String(res.tableId));
    }
    if (!res.tableId && code === '~o structure') {
      ownerOnlyStructure = true;
    }
  }
  return {ownerOnlyTableIds, ownerOnlyStructure};
}

export class AccessRules extends Disposable {
  public isAnythingChanged: Computed<boolean>;

  // NOTE: For the time being, rules correspond one to one with resources.
  private _initialState: AclState = buildAclState(this._gristDoc);
  private _allTableIds: ObsArray<string> = createObsArray(this, this._gristDoc.docModel.allTableIds);

  private _ownerOnlyTableIds = this.autoDispose(obsArray([...this._initialState.ownerOnlyTableIds]));
  private _ownerOnlyStructure = Observable.create<boolean>(this, this._initialState.ownerOnlyStructure);
  private _currentState = Computed.create<AclState>(this, (use) => ({
      ownerOnlyTableIds: new Set(use(this._ownerOnlyTableIds)),
      ownerOnlyStructure: use(this._ownerOnlyStructure),
  }));

  constructor(private _gristDoc: GristDoc) {
    super();
    this.isAnythingChanged = Computed.create(this, (use) =>
      !isEqual(use(this._currentState), this._initialState));
  }

  public async save(): Promise<void> {
    if (!this.isAnythingChanged.get()) { return; }
    // If anything has changed, we re-fetch the state from the current docModel (it may have been
    // changed by other users), and apply changes, if any, relative to that.
    const latestState = buildAclState(this._gristDoc);
    const currentState = this._currentState.get();
    const tableData = this._gristDoc.docModel.aclResources.tableData;
    await tableData.docData.bundleActions('Update Access Rules', async () => {
      // If ownerOnlyStructure flag changed, add or remove the relevant resource record.
      if (currentState.ownerOnlyStructure !== latestState.ownerOnlyStructure) {
        if (currentState.ownerOnlyStructure) {
          await tableData.sendTableAction(['AddRecord', null, {tableId: "", colIds: "~o structure"}]);
        } else {
          const rowId = tableData.findMatchingRowId({tableId: '', colIds: '~o structure'});
          if (rowId) {
            await this._gristDoc.docModel.aclResources.sendTableAction(['RemoveRecord', rowId]);
          }
        }
      }

      // Handle tables added to ownerOnlyTableIds.
      const tablesAdded = setDifference(currentState.ownerOnlyTableIds, latestState.ownerOnlyTableIds);
      if (tablesAdded.size) {
        await tableData.sendTableAction(['BulkAddRecord', arrayRepeat(tablesAdded.size, null), {
          tableId: [...tablesAdded],
          colIds: arrayRepeat(tablesAdded.size, "~o"),
        }]);
      }

      // Handle table removed from ownerOnlyTaleIds.
      const tablesRemoved = setDifference(latestState.ownerOnlyTableIds, currentState.ownerOnlyTableIds);
      if (tablesRemoved.size) {
        const rowIds = Array.from(tablesRemoved, t => tableData.findRow('tableId', t)).filter(r => r);
        await tableData.sendTableAction(['BulkRemoveRecord', rowIds]);
      }
    });
  }

  public buildDom() {
    return [
      cssAddTableRow(
        primaryButton(icon('Plus'), 'Add Table Rules',
          menu(() => [
            dom.forEach(this._allTableIds, (tableId) =>
              // Add the table on a timeout, to avoid disabling the clicked menu item
              // synchronously, which prevents the menu from closing on click.
              menuItem(() => setTimeout(() => this._ownerOnlyTableIds.push(tableId), 0),
                tableId,
                dom.cls('disabled', (use) => use(this._ownerOnlyTableIds).includes(tableId)),
              )
            ),
          ]),
        ),
      ),
      shadowScroll(
        dom.forEach(this._ownerOnlyTableIds, (tableId) => {
          return cssTableRule(
            cssTableHeader(
              dom('div', 'Rules for ', dom('b', dom.text(tableId))),
              cssRemove(icon('Remove'),
                dom.on('click', () =>
                  this._ownerOnlyTableIds.splice(this._ownerOnlyTableIds.get().indexOf(tableId), 1))
              ),
            ),
            cssTableBody(
              cssPermissions('All Access'),
              cssPrincipals('Owners'),
            ),
          );
        }),
        cssTableRule(
          cssTableHeader('Default Rule'),
          cssTableBody(
            cssPermissions('Schema Edit'),
            cssPrincipals(
              select(this._ownerOnlyStructure, [
                {label: 'Owners Only', value: true},
                {label: 'Owners & Editors', value: false}
              ]),
            )
          ),
        ),
      ),
    ];
  }
}

const cssAddTableRow = styled('div', `
  margin: 0 64px 16px 64px;
  display: flex;
  justify-content: flex-end;
`);

const cssTableRule = styled('div', `
  margin: 16px 64px;
  border: 1px solid ${colors.darkGrey};
  border-radius: 4px;
  padding: 8px 16px 16px 16px;
`);

const cssTableHeader = styled('div', `
  display: flex;
  align-items: center;
  margin-bottom: 8px;
`);

const cssTableBody = styled('div', `
  display: flex;
  align-items: center;
`);

const  cssPermissions = styled('div', `
  flex: 1;
  white-space: nowrap;
  color: ${colors.lightGreen};
`);

const  cssPrincipals = styled('div', `
  flex: 1;
  color: ${colors.lightGreen};
`);

const cssRemove = styled('div', `
  flex: none;
  margin: 0 4px 0 auto;
  height: 24px;
  width: 24px;
  padding: 4px;
  border-radius: 3px;
  cursor: default;
  --icon-color: ${colors.slate};
  &:hover {
    background-color: ${colors.darkGrey};
    --icon-color: ${colors.slate};
  }
`);