import { NestedStyle } from './src/types';
import {
  ignoredKeys,
  specialShorthandKeys,
  shorthandHandlers,
  capitalize,
  handleSharedStyles,
  isObject,
  assignFlatStyle,
  assignIgnoredKeyStyle
} from './src/utils';

export function sassy<T extends NestedStyle>(
  nestedStyles: T,
  parentKey: string = ''
): Record<string, any> {
  const nativeStyles: Record<string, any> = {};
  const sharedStylesMap: {
    [key: string]: NestedStyle;
  } = {};

  // Traverse each key-value pair in the nested styles object
  for (const key in nestedStyles) {
    const value = nestedStyles[key];

    // Handle comma-separated keys (shared styles)
    if (key.includes(',')) {
      handleSharedStyles(key, parentKey, value, sharedStylesMap);
      continue;
    }

    // Check for special shorthand keys
    if (specialShorthandKeys.includes(key)) {
      const handler = shorthandHandlers[key];

      if (!nativeStyles[parentKey]) nativeStyles[parentKey] = {};

      Object.assign(nativeStyles[parentKey], handler(key, value as NestedStyle));
      continue;
    }

    // Assign flat styles and non-objects directly
    if (!isObject(value)) {
      assignFlatStyle(nativeStyles, parentKey, key, value);
      continue;
    }

    // Assign ignored keys directly
    if (ignoredKeys.includes(key)) {
      assignIgnoredKeyStyle(nativeStyles, parentKey, key, value);
      continue;
    }

    // Recursively flatten nested styles
    const newKey = parentKey ? `${parentKey}${capitalize(key)}` : key;
    const nestedNativeStyles = sassy(value as NestedStyle, newKey);
    Object.assign(nativeStyles, nestedNativeStyles);
  }

  // Apply shared styles within the appropriate nested contexts
  for (const selector in sharedStylesMap) {
    if (!nativeStyles[selector]) nativeStyles[selector] = {};
    Object.assign(nativeStyles[selector], sharedStylesMap[selector]);
  };

  // Return the flattened stylesheet
  return nativeStyles;
}