const request = require('requestretry')
const env = require('./env.js')
const logger = require('./logger.js')('api.js')

async function execute(uri, method, form) {
    return new Promise((resolve, reject) => {
        request({
            url: 'http://' + env.server.host + uri,
            method: method,
            json: true,
            timeout: 10000,
            form: form || {},
            headers: {
                'auth-info': 'loginname=' + env.loginName + ';password=' + env.password
            },
            maxAttempts: 50,
            retryDelay: 500,
            retryStrategy: request.RetryStrategies.HTTPOrNetworkError
        }, function (error, response, body) {
            if (response.statusCode == 200) {
                resolve(body);
            } else {
                let message = response.statusCode + ' ' + (error || '') + (response.headers['error-info'] || '')
                logger.error(message)
                reject(message)
            }
        })
    })
}

module.exports.login = function () {
    return execute('/api/user/login', 'GET');
}

module.exports.getExams = function (pageNumber, pageSize) {
    let uri = '/api/exams'
    let param = [];
    if (pageNumber != undefined) {
        param.push('pageNumber=' + pageNumber)
    }
    if (pageSize != undefined) {
        param.push('pageSize=' + pageSize)
    }
    if (param.length > 0) {
        uri = uri + '?' + param.join('&')
    }
    return execute(uri, 'GET');
}

module.exports.getStudents = function (examId, pageNumber, pageSize, params) {
    let form = {
        examId: examId,
        pageNumber: pageNumber,
        pageSize: pageSize
    }
    if (params != undefined) {
        for (let key in params) {
            if (params[key] && params[key] != '') {
                form[key] = params[key]
            }
        }
    }
    return execute('/api/exam/students', 'POST', form);
}

module.exports.countStudents = function (examId, upload, absent) {
    let uri = '/api/students/count/' + examId
    let param = []
    if (upload != undefined) {
        param.push('upload=' + (upload ? 'true' : 'false'))
    }
    if (absent != undefined) {
        param.push('absent=' + (absent ? 'true' : 'false'))
    }
    if (param.length > 0) {
        uri = uri + '?' + param.join('&')
    }
    return execute(uri, 'GET')
}

module.exports.getPackages = function (examId, upload, withUrl) {
    let uri = '/api/package/count/' + examId
    let param = []
    if (upload != undefined) {
        param.push('upload=' + (upload ? 'true' : 'false'))
    }
    if (withUrl != undefined) {
        param.push('withUrl=' + (withUrl ? 'true' : 'false'))
    }
    if (param.length > 0) {
        uri = uri + '?' + param.join('&')
    }
    return execute(uri, 'GET')
}