import { kintonePrettyFields } from './fields.js';
import { getGuestSpaceId, createFieldWithLabels, createFieldLabels, getColumnWidths } from './dom.js';
import { KintoneRestAPIClient } from '@kintone/rest-api-client';
import { COLORS } from './constants.js';

/**
 * Fetches form data from Kintone API
 * @param {number} appId - The application ID
 * @param {string} language - User language setting
 * @returns {Promise<Object>} Form fields and layout data
 */
const fetchFormData = async (appId, language) => {
  const client = new KintoneRestAPIClient({
    guestSpaceId: getGuestSpaceId(),
  });

  const isPreview = false;

  try {
    const [formFieldsResult, layoutResult] = await Promise.all([
      client.app.getFormFields({
        app: appId,
        lang: language,
        preview: isPreview,
      }),
      client.app.getFormLayout({
        app: appId,
        preview: isPreview,
      }),
    ]);

    return {
      formFields: formFieldsResult.properties,
      layout: layoutResult.layout,
    };
  } catch (error) {
    console.error('Failed to fetch form data:', error);
    throw new Error('Could not retrieve form configuration');
  }
};

/**
 * Adds label to a subtable field element
 * @param {Object} field - Field configuration
 * @param {HTMLElement} fieldElement - The field DOM element
 */
const addSubtableLabel = (field, fieldElement) => {
  // Add field code label above the table
  fieldElement.before(
    createFieldWithLabels({
      code: field.code,
      type: field.type,
    })
  );

  // Add column labels below the table
  const fieldNames = Object.keys(field.fields);
  const columnWidths = getColumnWidths(fieldElement, field.type);
  fieldElement.after(
    createFieldLabels(fieldNames, columnWidths, field.type)
  );
};

/**
 * Adds label to a reference table field element
 * @param {Object} field - Field configuration
 * @param {HTMLElement} fieldElement - The field DOM element
 */
const addReferenceTableLabel = (field, fieldElement) => {
  // Add field code label above the reference table
  fieldElement.before(
    createFieldWithLabels({
      code: field.code,
      type: field.type,
    })
  );

  // Add display field labels if available
  if (field.referenceTable?.displayFields) {
    const displayFields = field.referenceTable.displayFields;
    const columnWidths = getColumnWidths(fieldElement, field.type);
    fieldElement.appendChild(
      createFieldLabels(displayFields, columnWidths, field.type)
    );
  }
};

/**
 * Adds label to a group field element
 * @param {Object} field - Field configuration
 * @param {HTMLElement} fieldElement - The field DOM element
 */
const addGroupLabel = (field, fieldElement) => {
  fieldElement.parentElement?.before(
    createFieldWithLabels({
      code: field.code,
      type: field.type,
    })
  );
};

/**
 * Adds label to a standard field element
 * @param {Object} field - Field configuration
 * @param {HTMLElement} fieldElement - The field DOM element
 */
const addStandardFieldLabel = (field, fieldElement) => {
  fieldElement.before(
    createFieldWithLabels({
      code: field.code,
      type: field.type,
    })
  );
};

/**
 * Processes and adds labels to all field elements on the page
 * @param {Array} fieldsWithLabels - Processed field objects with label info
 */
const processFieldLabels = (fieldsWithLabels) => {
  for (const field of fieldsWithLabels) {
    const fieldElement = kintone.app.record.getFieldElement(field.code);
    if (!fieldElement) continue;

    // Handle different field types with appropriate label placement
    if (kintonePrettyFields.isSubtable(field)) {
      addSubtableLabel(field, fieldElement);
    } else if (kintonePrettyFields.isReferenceTable(field)) {
      addReferenceTableLabel(field, fieldElement);
    } else if (kintonePrettyFields.isGroup(field)) {
      addGroupLabel(field, fieldElement);
    } else {
      addStandardFieldLabel(field, fieldElement);
    }
  }
};

/**
 * Processes and adds labels to spacer elements on the page
 * @param {Array} spacerElements - Spacer element configurations
 */
const processSpacerLabels = (spacerElements) => {
  for (const spacer of spacerElements) {
    const spacerElement = kintone.app.record.getSpaceElement(spacer.elementId);
    if (!spacerElement) continue;

    // Add label and blue border to spacer elements
    spacerElement.appendChild(
      createFieldWithLabels({
        code: spacer.elementId,
      })
    );
    spacerElement.style.border = COLORS.SPACER_BORDER;
  }
};

/**
 * Main function to enhance Kintone forms with labels and visual helpers
 * @returns {Promise<void>}
 */
export const runKintoneHelper = async () => {
  try {
    // Early return if not in a valid app context
    const appId = kintone.app.getId();
    if (!appId) {
      console.log('Not in a valid Kintone app context');
      return;
    }

    // Fetch necessary form configuration
    const language = kintone.getLoginUser().language;
    const { formFields, layout } = await fetchFormData(appId, language);

    // Process fields and generate label data
    const { fields: fieldsWithLabels, spacers: spacerElements } =
      kintonePrettyFields.generateFields(formFields, layout);

    // Apply labels to field elements
    processFieldLabels(fieldsWithLabels);

    // Apply visual indicators to spacer elements
    processSpacerLabels(spacerElements);

    console.log('Kintone helper labels applied successfully');
  } catch (error) {
    console.error('Failed to run Kintone helper:', error);
    // Could implement user-friendly error notification here
  }
};

// Execute helper function immediately when the script is injected
runKintoneHelper();