const formatRegExp = /%[sdj%]/g;

export let warning = () => {
};

export function format(...args) {
  let i = 1;
  const f = args[0];
  const len = args.length;
  if (typeof f === 'function') {
    return f.apply(null, args.slice(1));
  }
  if (typeof f === 'string') {
    let str = String(f).replace(formatRegExp, (x) => {
      if (x === '%%') {
        return '%';
      }
      if (i >= len) {
        return x;
      }
      switch (x) {
      case '%s':
        return String(args[i++]);
      case '%d':
        return Number(args[i++]);
      case '%j':
        try {
          return JSON.stringify(args[i++]);
        } catch (_) {
          return '[Circular]';
        }
      default:
        return x;
      }
    });
    for (let arg = args[i]; i < len; arg = args[++i]) {
      str += ` ${arg}`;
    }
    return str;
  }
  return f;
}

function isNativeStringType(type) {
  return type === 'string' ||
    type === 'url' ||
    type === 'hex' ||
    type === 'email' ||
    type === 'pattern';
}

export function isEmptyValue(value, type) {
  if (value === undefined || value === null) {
    return true;
  }
  if (type === 'array' && Array.isArray(value) && !value.length) {
    return true;
  }
  if (isNativeStringType(type) && typeof value === 'string' && !value) {
    return true;
  }
  return false;
}

export function isEmptyObject(obj) {
  return Object.keys(obj).length === 0;
}

function asyncParallelArray(arr, func, callback) {
  const results = [];
  let total = 0;
  const arrLength = arr.length;

  function count(errors) {
    results.push.apply(results, errors);
    total++;
    if (total === arrLength) {
      callback(results);
    }
  }

  arr.forEach((a) => {
    func(a, count);
  });
}

function asyncSerialArray(arr, func, callback) {
  let index = 0;
  const arrLength = arr.length;

  function next(errors) {
    if (errors && errors.length) {
      callback(errors);
      return;
    }
    const original = index;
    index = index + 1;
    if (original < arrLength) {
      func(arr[original], next);
    } else {
      callback([]);
    }
  }

  next([]);
}

function flattenObjArr(objArr) {
  const ret = [];
  Object.keys(objArr).forEach((k) => {
    ret.push.apply(ret, objArr[k]);
  });
  return ret;
}

export function asyncMap(objArr, option, func, callback) {
  if (option.first) {
    const flattenArr = flattenObjArr(objArr);
    return asyncSerialArray(flattenArr, func, callback);
  }
  let firstFields = option.firstFields || [];
  if (firstFields === true) {
    firstFields = Object.keys(objArr);
  }
  const objArrKeys = Object.keys(objArr);
  const objArrLength = objArrKeys.length;
  let total = 0;
  const results = [];
  const next = (errors) => {
    results.push.apply(results, errors);
    total++;
    if (total === objArrLength) {
      callback(results);
    }
  };
  objArrKeys.forEach((key) => {
    const arr = objArr[key];
    if (firstFields.indexOf(key) !== -1) {
      asyncSerialArray(arr, func, next);
    } else {
      asyncParallelArray(arr, func, next);
    }
  });
}

export function complementError(rule) {
  return (oe) => {
    if (oe && oe.message) {
      oe.field = oe.field || rule.fullField;
      return oe;
    }
    return {
      message: oe,
      field: oe.field || rule.fullField,
    };
  };
}

export function deepMerge(target, source) {
  if (source) {
    for (const s in source) {
      if (source.hasOwnProperty(s)) {
        const value = source[s];
        if (typeof value === 'object' && typeof target[s] === 'object') {
          target[s] = {
            ...target[s],
            ...value,
          };
        } else {
          target[s] = value;
        }
      }
    }
  }
  return target;
}