import {BasicSyncProviderInterface, ProviderGlobalOptions, ProviderSourceConfig} from '../Controller';
import {ContainerProps, getRuntimeContext} from '../../Container/types';
import {isExpression, parseExpressionString} from '../../../util/vm';
import {isEmpty} from 'lodash';

export interface LocalStorageConfig extends ProviderSourceConfig {
    config: string[];
}

export class LocalStorageDataProvider implements BasicSyncProviderInterface {
    configCheck(provider: LocalStorageConfig) {
        return provider.config instanceof Array;
    }

    parse(provider: LocalStorageConfig, props: ContainerProps, context: any) {
        let config = provider.config;
        let runtime = getRuntimeContext(props, context);

        provider.config = config.map(key => {
            if (isExpression(key)) {
                return parseExpressionString(key, runtime);
            }

            return key;
        });

        return provider;
    }

    retCheck(ret: Object, provider: LocalStorageConfig) {
        return !isEmpty(ret);
    }

    retParse(ret: Object, provider: LocalStorageConfig, props: ContainerProps, context: any) {
        return ret;
    }

    run (provider: LocalStorageConfig, options?: ProviderGlobalOptions) {
        let items = provider.config;
        let ret = {};

        items.forEach(key => {
            let result = localStorage.getItem(key);

            if (typeof result === 'string') {
                try {
                    result = JSON.parse(result);
                } catch (e) {}
            }

            ret[key] = result;
        });

        return ret;
    }

    onError(errmsg: string) {
        console.error(errmsg);
    }
}