import type {
  JSONDataType,
  JSONFlattenOptions,
  JSONFlattenReturnType
} from "../type";

export function emitError(message: string): void {
  throw new Error(`[JsonPretty] ${message}`);
}

export function getDataType(value: unknown): string {
  return Object.prototype.toString.call(value).slice(8, -1).toLowerCase();
}

export function jsonFlatten(
  data: JSONDataType,
  path = "root",
  level = 0,
  options?: JSONFlattenOptions
): JSONFlattenReturnType[] {
  const {
    key,
    index,
    type = "content",
    showComma = false,
    length = 1
  } = options || ({} as JSONFlattenOptions);
  const dataType = getDataType(data);

  if (dataType === "array") {
    const inner = arrFlat(
      (data as JSONDataType[]).map((item, idx, arr) =>
        jsonFlatten(item, `${path}[${idx}]`, level + 1, {
          index: idx,
          showComma: idx !== arr.length - 1,
          length,
          type
        })
      )
    ) as JSONFlattenReturnType[];
    return [
      jsonFlatten("[", path, level, {
        showComma: false,
        key,
        length: (data as unknown[]).length,
        type: "arrayStart"
      })[0]
    ].concat(
      inner,
      jsonFlatten("]", path, level, {
        showComma,
        length: (data as unknown[]).length,
        type: "arrayEnd"
      })[0]
    );
  } else if (dataType === "object") {
    const keys = Object.keys(data as Record<string, JSONDataType>);
    const inner = arrFlat(
      keys.map((objKey, idx, arr) =>
        jsonFlatten(
          (data as Record<string, JSONDataType>)[objKey],
          /^[a-zA-Z_]\w*$/.test(objKey)
            ? `${path}.${objKey}`
            : `${path}["${objKey}"]`,
          level + 1,
          {
            key: objKey,
            showComma: idx !== arr.length - 1,
            length,
            type
          }
        )
      )
    ) as JSONFlattenReturnType[];
    return [
      jsonFlatten("{", path, level, {
        showComma: false,
        key,
        index,
        length: keys.length,
        type: "objectStart"
      })[0]
    ].concat(
      inner,
      jsonFlatten("}", path, level, {
        showComma,
        length: keys.length,
        type: "objectEnd"
      })[0]
    );
  }

  return [
    {
      content: data as JSONFlattenReturnType["content"],
      level,
      key,
      index,
      path,
      showComma,
      length,
      type
    }
  ];
}

export function arrFlat<T extends unknown[]>(arr: T): unknown[] {
  if (typeof Array.prototype.flat === "function") {
    return arr.flat();
  }
  const stack = [...arr];
  const result = [];
  while (stack.length) {
    const first = stack.shift();
    if (Array.isArray(first)) {
      stack.unshift(...first);
    } else {
      result.push(first);
    }
  }
  return result;
}

export function cloneDeep<T extends unknown>(
  source: T,
  hash = new WeakMap()
): T {
  if (source === null || source === undefined) return source;
  if (source instanceof Date) return new Date(source) as T;
  if (source instanceof RegExp) return new RegExp(source) as T;
  if (typeof source !== "object") return source;
  if (hash.get(source as Record<string, unknown>))
    return hash.get(source as Record<string, unknown>);

  if (Array.isArray(source)) {
    const output = source.map((item) => cloneDeep(item, hash));
    hash.set(source, output);
    return output as T;
  }
  const output = {} as T;
  for (const key in source) {
    output[key] = cloneDeep(source[key], hash);
  }
  hash.set(source as Record<string, unknown>, output);
  return output as T;
}

export function stringToAutoType(source: string): unknown {
  let value;
  if (source === "null") value = null;
  else if (source === "undefined") value = undefined;
  else if (source === "true") value = true;
  else if (source === "false") value = false;
  else if (
    source[0] + source[source.length - 1] === '""' ||
    source[0] + source[source.length - 1] === "''"
  ) {
    value = source.slice(1, -1);
  } else if (
    (typeof Number(source) === "number" && !isNaN(Number(source))) ||
    source === "NaN"
  ) {
    value = Number(source);
  } else {
    value = source;
  }
  return value;
}

export function isFunction(value: unknown): value is Function {
  return typeof value === "function";
}