/**
 * WebUtils.js
 *
 * @author realor
 */

class WebUtils {
    static getHttpStatusMessage(status) {
        let message

        switch (status) {
            case 200:
                message = 'OK'
                break
            case 400:
                message = 'Bad request'
                break
            case 401:
                message = 'Unathorized'
                break
            case 403:
                message = 'Access forbidden'
                break
            case 404:
                message = 'Not found'
                break
            case 405:
                message = 'Not allowed'
                break
            case 500:
                message = 'Internal server error'
                break
            case 501:
                message = 'Not implemented'
                break
            default:
                message = ''
        }
        return message
    }

    static setBasicAuthorization(request, username, password) {
        if (username !== null && username.length > 0 && password !== null && password.length > 0) {
            const userPass = username + ':' + password
            request.setRequestHeader('Authorization', 'Basic ' + btoa(userPass))
        }
    }

    static getQueryParams() {
        var queryString = {}
        var query = window.location.search.substring(1)
        var pairs = query.split('&')
        for (var i = 0; i < pairs.length; i++) {
            var index = pairs[i].indexOf('=')
            if (index !== -1) {
                var name = decodeURIComponent(pairs[i].substring(0, index))
                var value = decodeURIComponent(pairs[i].substring(index + 1))
                if (typeof queryString[name] === 'undefined') {
                    queryString[name] = value
                } else if (typeof queryString[name] === 'string') {
                    var arr = [queryString[name], value]
                    queryString[name] = arr
                } else {
                    queryString[name].push(value)
                }
            }
        }
        return queryString
    }

    static toHTML(text) {
        var html = ''
        var ch, i
        for (i = 0; i < text.length; i++) {
            ch = text.charAt(i)
            if (ch === '<') html += '&lt;'
            else if (ch === '>') html += '&gt;'
            else if (ch === '&') html += '&amp;'
            else html += ch
        }
        return html
    }

    /**
     *
     * @param {type} tasks to execute
     * @param {type} onCompleted callback
     * @param {type} onProgress callback
     * @param {type} onError callback
     * @param {type} notifyMillis
     * @param {type} delay
     * @returns undefined
     *
     * task : { run : fn, message: string, iterations: fn }
     */
    static executeTasks(tasks, onCompleted, onProgress, onError, notifyMillis, delay) {
        notifyMillis = notifyMillis || 100
        delay = delay || 10

        var postTask = function(i, j) {
            var task = tasks[i]
            var iterations = task.iterations ? task.iterations() : 1
            var message = task.message
            if (iterations > 1) {
                message += ' (' + j + ' / ' + iterations + ')'
            }

            if (onProgress) {
                var taskPerc = 100.0 / tasks.length
                var percentage = Math.round((i + j / iterations) * taskPerc)

                onProgress({ progress: percentage, message: message })
            }

            setTimeout(function() {
                var t0 = Date.now()
                do {
                    try {
                        task.run(j++)
                    } catch (ex) {
                        if (onError) onError(ex)
                        return
                    }
                } while (j < iterations && Date.now() - t0 < notifyMillis)

                if (j < iterations) {
                    postTask(i, j)
                } else {
                    i++
                    if (i < tasks.length) {
                        postTask(i, 0)
                    } else if (onCompleted) {
                        if (onProgress) {
                            onProgress({ progress: 100, message: 'Completed.' })
                            setTimeout(onCompleted, 100)
                        } else {
                            onCompleted()
                        }
                    }
                }
            }, delay)
        }

        postTask(0, 0)
    }
}

export { WebUtils }