import Tools from '../tools';

function mergeConfig (defaultConfig, instanceConfig = {}) {
    const CONFIG_KEY_LIST = ['url', 'method', 'data', 'dataType', 'responseType', 'params', 'isProxy'];
    const CONFIG_MERGE_DEEP_KEY_LIST = ['header'];
    const CONFIG_OPTIONAL_KEY_LIST = ['baseURL'];
    const CONFIG_ALL_KEY_LIST = [...CONFIG_KEY_LIST, ...CONFIG_MERGE_DEEP_KEY_LIST, ...CONFIG_OPTIONAL_KEY_LIST];
    const ARGS_ALL_KEY_LIST = [...new Set([...Object.keys(instanceConfig), ...Object.keys(defaultConfig)])];
    const REMAINDER_KEY_LIST = ARGS_ALL_KEY_LIST.filter(key => !CONFIG_ALL_KEY_LIST.includes(key));
    let newConfig = {}

    // 必要参数
    CONFIG_KEY_LIST.forEach(prop => {
        const val = instanceConfig[prop] || defaultConfig[prop];

        !Tools.isType('Undefined', val) && (newConfig[prop] = val);
    });

    // 必要深拷贝参数
    CONFIG_MERGE_DEEP_KEY_LIST.forEach(prop => {
        const defaultVal = defaultConfig[prop];
        const instanceVal = instanceConfig[prop];

        if (Tools.isType('Object', instanceVal)) {
            newConfig[prop] = Tools.deepCopy(defaultVal, instanceVal);
        } else if (Tools.isType('Object', defaultVal)) {
            newConfig[prop] = Tools.deepCopy(defaultVal);
        }
    });

    // 配置文件中可选参数
    CONFIG_OPTIONAL_KEY_LIST.forEach(prop => {
        const val = defaultConfig[prop];

        if (!Tools.isType('Undefined', val)) {
            newConfig[prop] = defaultConfig[prop];
        }
    });

    // 合并未出现在上述列表中的参数
    REMAINDER_KEY_LIST.forEach(prop => {
        const defaultVal = defaultConfig[prop];
        const instanceVal = instanceConfig[prop];

        if (!Tools.isType('Undefined', instanceVal)) {
            newConfig[prop] = instanceVal;
        } else if (!Tools.isType('Undefined', defaultVal)) {
            newConfig[prop] = defaultVal;
        }
    });

    newConfig.instanceURL = instanceConfig.url;
    newConfig.url = Tools.getFullURL(newConfig.baseURL, newConfig.url);
    newConfig.url = Tools.paramsToURL(newConfig);
    newConfig.header = Tools.adapterContentType(defaultConfig.header, instanceConfig.header, newConfig.header);

    return newConfig;
}

export default mergeConfig;