import React, { PureComponent } from 'react';
import AutoSizer from 'react-virtualized-auto-sizer';

import { AppEvents, DataFrameJSON, dataFrameToJSON, DataTopic, PanelData, SelectableValue } from '@grafana/data';
import { selectors } from '@grafana/e2e-selectors';
import { Button, CodeEditor, Field, Select } from '@grafana/ui';
import { appEvents } from 'app/core/core';
import { DashboardModel, PanelModel } from 'app/features/dashboard/state';

import { getPanelInspectorStyles } from '../inspector/styles';

enum ShowContent {
  PanelJSON = 'panel',
  PanelData = 'data',
  DataFrames = 'frames',
}

const options: Array<SelectableValue<ShowContent>> = [
  {
    label: 'Panel JSON',
    description: 'The model saved in the dashboard JSON that configures how everything works.',
    value: ShowContent.PanelJSON,
  },
  {
    label: 'Panel data',
    description: 'The raw model passed to the panel visualization',
    value: ShowContent.PanelData,
  },
  {
    label: 'DataFrame JSON',
    description: 'JSON formatted DataFrames',
    value: ShowContent.DataFrames,
  },
];

interface Props {
  onClose: () => void;
  dashboard?: DashboardModel;
  panel?: PanelModel;
  data?: PanelData;
}

interface State {
  show: ShowContent;
  text: string;
}

export class InspectJSONTab extends PureComponent<Props, State> {
  hasPanelJSON: boolean;

  constructor(props: Props) {
    super(props);
    this.hasPanelJSON = !!(props.panel && props.dashboard);
    // If we are in panel, we want to show PanelJSON, otherwise show DataFrames
    this.state = {
      show: this.hasPanelJSON ? ShowContent.PanelJSON : ShowContent.DataFrames,
      text: this.hasPanelJSON ? getPrettyJSON(props.panel!.getSaveModel()) : getPrettyJSON(props.data),
    };
  }

  onSelectChanged = (item: SelectableValue<ShowContent>) => {
    const show = this.getJSONObject(item.value!);
    const text = getPrettyJSON(show);
    this.setState({ text, show: item.value! });
  };

  // Called onBlur
  onTextChanged = (text: string) => {
    this.setState({ text });
  };

  getJSONObject(show: ShowContent) {
    const { data, panel } = this.props;
    if (show === ShowContent.PanelData) {
      return data;
    }

    if (show === ShowContent.DataFrames) {
      return getPanelDataFrames(data);
    }

    if (this.hasPanelJSON && show === ShowContent.PanelJSON) {
      return panel!.getSaveModel();
    }

    return { note: `Unknown Object: ${show}` };
  }

  onApplyPanelModel = () => {
    const { panel, dashboard, onClose } = this.props;
    if (this.hasPanelJSON) {
      try {
        if (!dashboard!.meta.canEdit) {
          appEvents.emit(AppEvents.alertError, ['Unable to apply']);
        } else {
          const updates = JSON.parse(this.state.text);
          dashboard!.shouldUpdateDashboardPanelFromJSON(updates, panel!);
          panel!.restoreModel(updates);
          panel!.refresh();
          appEvents.emit(AppEvents.alertSuccess, ['Panel model updated']);
        }
      } catch (err) {
        console.error('Error applying updates', err);
        appEvents.emit(AppEvents.alertError, ['Invalid JSON text']);
      }

      onClose();
    }
  };

  render() {
    const { dashboard } = this.props;
    const { show, text } = this.state;
    const jsonOptions = this.hasPanelJSON ? options : options.slice(1, options.length);
    const selected = options.find((v) => v.value === show);
    const isPanelJSON = show === ShowContent.PanelJSON;
    const canEdit = dashboard && dashboard.meta.canEdit;
    const styles = getPanelInspectorStyles();

    return (
      <div className={styles.wrap}>
        <div className={styles.toolbar} aria-label={selectors.components.PanelInspector.Json.content}>
          <Field label="Select source" className="flex-grow-1">
            <Select
              inputId="select-source-dropdown"
              options={jsonOptions}
              value={selected}
              onChange={this.onSelectChanged}
            />
          </Field>
          {this.hasPanelJSON && isPanelJSON && canEdit && (
            <Button className={styles.toolbarItem} onClick={this.onApplyPanelModel}>
              Apply
            </Button>
          )}
        </div>
        <div className={styles.content}>
          <AutoSizer disableWidth>
            {({ height }) => (
              <CodeEditor
                width="100%"
                height={height}
                language="json"
                showLineNumbers={true}
                showMiniMap={(text && text.length) > 100}
                value={text || ''}
                readOnly={!isPanelJSON}
                onBlur={this.onTextChanged}
              />
            )}
          </AutoSizer>
        </div>
      </div>
    );
  }
}

function getPanelDataFrames(data?: PanelData): DataFrameJSON[] {
  const frames: DataFrameJSON[] = [];
  if (data?.series) {
    for (const f of data.series) {
      frames.push(dataFrameToJSON(f));
    }
  }
  if (data?.annotations) {
    for (const f of data.annotations) {
      const json = dataFrameToJSON(f);
      if (!json.schema?.meta) {
        json.schema!.meta = {};
      }
      json.schema!.meta.dataTopic = DataTopic.Annotations;
      frames.push(json);
    }
  }
  return frames;
}

function getPrettyJSON(obj: any): string {
  return JSON.stringify(obj, null, 2);
}