import { chain, cloneDeep, defaults, find } from 'lodash';

import { PanelPluginMeta } from '@grafana/data';
import { locationService } from '@grafana/runtime';
import config from 'app/core/config';
import { LS_PANEL_COPY_KEY } from 'app/core/constants';
import store from 'app/core/store';
import { DashboardModel } from 'app/features/dashboard/state/DashboardModel';
import { PanelModel } from 'app/features/dashboard/state/PanelModel';
import { calculateNewPanelGridPos } from 'app/features/dashboard/utils/panel';

export const NEW_PANEL_TITLE = 'Panel Title';

export function onCreateNewPanel(dashboard: DashboardModel, datasource?: string): number | undefined {
  const newPanel: Partial<PanelModel> = {
    type: 'timeseries',
    title: NEW_PANEL_TITLE,
    gridPos: calculateNewPanelGridPos(dashboard),
    datasource: datasource ? { uid: datasource } : null,
    isNew: true,
  };

  dashboard.addPanel(newPanel);
  return newPanel.id;
}

export function onCreateNewWidgetPanel(dashboard: DashboardModel, widgetType: string): number | undefined {
  const newPanel: Partial<PanelModel> = {
    type: widgetType,
    title: 'Widget title',
    gridPos: calculateNewPanelGridPos(dashboard),
    datasource: null,
    isNew: true,
  };

  dashboard.addPanel(newPanel);
  return newPanel.id;
}

export function onCreateNewRow(dashboard: DashboardModel) {
  const newRow = {
    type: 'row',
    title: 'Row title',
    gridPos: { x: 0, y: 0 },
  };

  dashboard.addPanel(newRow);
}

export function onImportDashboard() {
  locationService.push('/dashboard/import');
}

export function onAddLibraryPanel(dashboard: DashboardModel) {
  const newPanel = {
    type: 'add-library-panel',
    gridPos: calculateNewPanelGridPos(dashboard),
  };

  dashboard.addPanel(newPanel);
}

type PanelPluginInfo = { defaults: { gridPos: { w: number; h: number }; title: string } };

export function onPasteCopiedPanel(dashboard: DashboardModel, panelPluginInfo?: PanelPluginMeta & PanelPluginInfo) {
  if (!panelPluginInfo) {
    return;
  }

  const gridPos = calculateNewPanelGridPos(dashboard);

  const newPanel = {
    type: panelPluginInfo.id,
    title: NEW_PANEL_TITLE,
    gridPos: {
      x: gridPos.x,
      y: gridPos.y,
      w: panelPluginInfo.defaults.gridPos.w,
      h: panelPluginInfo.defaults.gridPos.h,
    },
  };

  // apply panel template / defaults
  if (panelPluginInfo.defaults) {
    defaults(newPanel, panelPluginInfo.defaults);
    newPanel.title = panelPluginInfo.defaults.title;
    store.delete(LS_PANEL_COPY_KEY);
  }

  dashboard.addPanel(newPanel);
}

export function getCopiedPanelPlugin(): (PanelPluginMeta & PanelPluginInfo) | undefined {
  const panels = chain(config.panels)
    .filter({ hideFromList: false })
    .map((item) => item)
    .value();

  const copiedPanelJson = store.get(LS_PANEL_COPY_KEY);
  if (copiedPanelJson) {
    const copiedPanel = JSON.parse(copiedPanelJson);

    const pluginInfo = find(panels, { id: copiedPanel.type });
    if (pluginInfo) {
      const pluginCopy: PanelPluginMeta = cloneDeep(pluginInfo);
      pluginCopy.name = copiedPanel.title;
      pluginCopy.sort = -1;

      return { ...pluginCopy, defaults: { ...copiedPanel } };
    }
  }

  return undefined;
}

type LastUsedDatasource =
  | {
      dashboardUid: string;
      datasourceUid: string;
    }
  | undefined;

export const PANEL_EDIT_LAST_USED_DATASOURCE = 'grafana.dashboards.panelEdit.lastUsedDatasource';

// Function that returns last used datasource from local storage
export function getLastUsedDatasourceFromStorage(dashboardUid: string): LastUsedDatasource {
  // Check if user has any local storage associated with this dashboard
  if (store.exists(PANEL_EDIT_LAST_USED_DATASOURCE)) {
    const lastUsedDatasource: LastUsedDatasource = store.getObject(PANEL_EDIT_LAST_USED_DATASOURCE);
    if (lastUsedDatasource?.dashboardUid === dashboardUid) {
      return lastUsedDatasource;
    }
  }
  return undefined;
}

// Function that updates local storage with new dashboard uid and keeps existing datasource
export function updateDashboardUidLastUsedDatasource(dashUid: string) {
  // Check if user has any datasource uid in local storage
  if (!store.exists(PANEL_EDIT_LAST_USED_DATASOURCE)) {
    return;
  }
  const oldRegistryLastUsedDatasource: LastUsedDatasource = store.getObject(PANEL_EDIT_LAST_USED_DATASOURCE);
  //keep existing datasource uid
  const datasourceUid = oldRegistryLastUsedDatasource?.datasourceUid ?? '';
  updatePropsLastUsedDatasourceKey(dashUid, datasourceUid);
}

// Function that updates local storage with new dashboard uid and resets datasource to empty
export function initLastUsedDatasourceKeyForDashboard(dashboardUid: string | undefined) {
  store.setObject(PANEL_EDIT_LAST_USED_DATASOURCE, { dashboardUid: dashboardUid, datasourceUid: '' });
}

// Function that updates local storage with new datasource uid and keeps existing dashboard when there is dash uid key in local storage
// or sets new local storage with new dashboard uid and existing datasource
export function setLastUsedDatasourceKeyForDashboard(dashUid: string, dsUid: string) {
  // Check if user has any datasource uid in local storage
  const lastUsedDatasource = getLastUsedDatasourceFromStorage(dashUid);
  if (!lastUsedDatasource) {
    updatePropsLastUsedDatasourceKey(dashUid, dsUid);
  } else {
    // set new local storage with new dashboard uid and existing datasource
    const dashboardUid = lastUsedDatasource?.dashboardUid ?? '';
    updatePropsLastUsedDatasourceKey(dashboardUid, dsUid);
  }
}

// Function that updates local storage with new dashboard uid and datasource uid
function updatePropsLastUsedDatasourceKey(dashboardUid: string | undefined, datasourceUid: string) {
  store.setObject(PANEL_EDIT_LAST_USED_DATASOURCE, { dashboardUid: dashboardUid, datasourceUid: datasourceUid });
}