/**
 * @type {string | null}
 */
var fromStation = null
/**
 * @type {string | null}
 */
var toStation = null
/**
 * @type {Date | null}
 */
var departureDate = null

/**
 * @type {{ name: string, stoppedAtBy: string[] }[]}
 */
var knownStations = []

function goToStation(station) {
    var url = new URL(window.location.href)
    if (!fromStation) {
        url.searchParams.set('from', station)
    }
    else if (!toStation) {
        url.searchParams.set('to', station)
    }
    // url.searchParams.set('date', new Date().toISOString())
    window.location.href = url.toString()
}

function setDepartureDate(departureDate) {
    var url = new URL(window.location.href)
    url.searchParams.set('departureDate', departureDate.toISOString())
    window.location.href = url.toString()
}

function searchNormalize(str) {
    return str
        .toLowerCase()
        .replaceAll('ă', 'a')
        .replaceAll('â', 'a')
        .replaceAll('î', 'i')
        .replaceAll('ș', 's')
        .replaceAll('ț', 't')
}

var focusedElement = null

var _rebuildDebounce = null
var _rebuildRequested = false
function rebuildSuggestions() {
    if (_rebuildDebounce !== null) {
        _rebuildRequested = true
        return
    }

    _rebuildRequested = false
    _rebuildDebounce = 123

    var suggestionsArea = document.getElementById('suggestionsArea')
    while (suggestionsArea.childNodes.length > 0) {
        suggestionsArea.childNodes[0].remove()
    }

    var stationNameInput = document.getElementById('stationName')
    var stationName = searchNormalize(stationNameInput.value.trim())

    var suggestions = []
    if (!stationName) {
        suggestions = knownStations.slice()
    }
    else {
        for (var i = 0; i < knownStations.length; i++) {
            if (!searchNormalize(knownStations[i].name).includes(stationName)) {
                continue
            }
            suggestions.push(knownStations[i])
        }
        suggestions.sort((s1, s2) => {
            var s1n = searchNormalize(s1.name);
            var s2n = searchNormalize(s2.name);

            if (s1n.indexOf(stationName) != s2n.indexOf(stationName)) {
                return s1n.indexOf(stationName) - s2n.indexOf(stationName);
            }

            if (s1.stoppedAtBy.length != s2.stoppedAtBy.length) {
                return s2.stoppedAtBy.length - s1.stoppedAtBy.length;
            }

            return s1.name.localeCompare(s2.name);
        })
    }

    var foundInput = false
    suggestions.forEach(function (suggestion, index) {
        if (stationName == searchNormalize(suggestion.name)) {
            foundInput = true
        }
        var suggestionLi = document.createElement('li')
        suggestionsArea.appendChild(suggestionLi)

        setTimeout(function () {
            suggestionLi.classList.add('items')
            suggestionLi.tabIndex = index + 1
            suggestionLi.style.padding = '2px 0'

            function onAction(e) {
                goToStation(suggestion.name)
            }
            suggestionLi.addEventListener('click', onAction)
            suggestionLi.addEventListener('keypress', function (e) {
                if (e.key == 'Enter') {
                    onAction(e)
                }
            })
            suggestionLi.addEventListener('focus', function (e) {
                focusedElement = suggestionLi
            })

            var stationNameP = document.createElement('p')
            suggestionLi.appendChild(stationNameP)

            stationNameP.textContent = suggestion.name
            stationNameP.classList.add('pri', 'stationName')

            // var trainCompanyP = document.createElement('p')
            // suggestionLi.appendChild(trainCompanyP)

            // trainCompanyP.textContent = suggestion.company
            // trainCompanyP.classList.add('thi')
        }, 0)
    })
    if (!foundInput && stationName) {
        var suggestionLi = document.createElement('li')
        suggestionsArea.appendChild(suggestionLi)

        suggestionLi.classList.add('items')
        suggestionLi.tabIndex = suggestions.length + 2
        suggestionLi.style.padding = '2px 0'

        function onAction(e) {
            goToStation(stationNameInput.value.trim())
        }
        suggestionLi.addEventListener('click', onAction)
        suggestionLi.addEventListener('keypress', function (e) {
            if (e.key == 'Enter') {
                onAction(e)
            }
        })
        suggestionLi.addEventListener('focus', function (e) {
            focusedElement = suggestionLi
        })

        var stationNameP = document.createElement('p')
        suggestionLi.appendChild(stationNameP)

        stationNameP.textContent = stationNameInput.value.trim()
        stationNameP.classList.add('pri', 'stationName')
    }

    setTimeout(function () {
        _rebuildDebounce = null
        if (_rebuildRequested) {
            rebuildSuggestions()
        }
    }, 500)
}

/**
 * @typedef ItineraryTrain
 * @property {string} from
 * @property {string} to
 * @property {string[]} intermediateStops
 * @property {string} departureDate
 * @property {string} arrivalDate
 * @property {number} km
 * @property {string} operator
 * @property {string} trainRank
 * @property {string} trainNumber
 */
/**
 * @typedef Itinerary
 * @property {ItineraryTrain[]} trains
 */
/**
 * @param {Itinerary[]} data
 */
function onItineraries(data) {
    var contentDiv = document.createElement('div')
    document.body.insertBefore(contentDiv, document.querySelector('footer'))
    contentDiv.classList.add('content')

    for (var i = 0; i < data.length; i++) {
        var itineraryDiv = document.createElement('div')
        contentDiv.appendChild(itineraryDiv)

        var heading = document.createElement('h4')
        itineraryDiv.appendChild(heading)
        heading.textContent = `Itinerary ${i + 1}`

        var trainsDiv = document.createElement('div')
        itineraryDiv.appendChild(trainsDiv)
        trainsDiv.classList.add('itinerary-trains')

        data[i].trains.forEach(function (train, idx) {
            var last = idx === data[i].trains.length - 1

            var trainDiv = document.createElement('div')
            trainsDiv.appendChild(trainDiv)
            trainDiv.classList.add('itinerary-train')

            if (idx === 0) {
                var departureTimeP = document.createElement('p')
                trainDiv.appendChild(departureTimeP)
                departureTimeP.classList.add('sec', 'departure', 'time')
                var departureTimePre = document.createElement('pre')
                departureTimeP.appendChild(departureTimePre)
                var departure = new Date(train.departureDate)
                departureTimePre.textContent = departure.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })

                var departureHeading = document.createElement('h3')
                trainDiv.appendChild(departureHeading)
                departureHeading.classList.add('departure', 'station')
                var departureLink = document.createElement('a')
                departureHeading.appendChild(departureLink)
                departureLink.textContent = train.from
                departureLink.classList.add('no-custom-a', 'items')
                var departureUrl = new URL('/view-station.html', window.location.origin)
                departureUrl.searchParams.set('station', train.from)
                departureLink.href = departureUrl.toString()
            }

            var trainP = document.createElement('p')
            trainDiv.appendChild(trainP)
            trainP.classList.add('pri', 'train')
            var trainLink = document.createElement('a')
            trainP.appendChild(trainLink)
            trainIdSpan(train.trainRank, train.trainNumber, trainLink)
            trainLink.classList.add('no-custom-a', 'items')
            var trainUrl = new URL('/view-train.html', window.location.origin)
            trainUrl.searchParams.set('train', train.trainNumber)
            trainLink.href = trainUrl.toString()
            trainP.appendChild(document.createTextNode(' '))
            var trainCompany = document.createElement('span')
            trainP.appendChild(trainCompany)
            trainCompany.textContent = '(' + train.operator + ')'
            trainCompany.classList.add('company')

            var arrivalTimeP = document.createElement('p')
            trainDiv.appendChild(arrivalTimeP)
            arrivalTimeP.classList.add('sec', 'arrival', 'time')
            var arrivalTimePre = document.createElement('pre')
            arrivalTimeP.appendChild(arrivalTimePre)
            var arrival = new Date(train.arrivalDate)
            arrivalTimePre.textContent = arrival.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })

            var arrivalHeading = document.createElement('h3')
            trainDiv.appendChild(arrivalHeading)
            arrivalHeading.classList.add('arrival', 'station')
            var arrivalLink = document.createElement('a')
            arrivalHeading.appendChild(arrivalLink)
            arrivalLink.textContent = train.to
            arrivalLink.classList.add('no-custom-a', 'items')
            var arrivalUrl = new URL('/view-station.html', window.location.origin)
            arrivalUrl.searchParams.set('station', train.from)
            arrivalLink.href = arrivalUrl.toString()

            if (!last) {
                var nextDepartureTimeP = document.createElement('p')
                trainDiv.appendChild(nextDepartureTimeP)
                nextDepartureTimeP.classList.add('sec', 'next-departure', 'time')
                var departureTimePre = document.createElement('pre')
                nextDepartureTimeP.appendChild(departureTimePre)
                var departure = new Date(data[i].trains[idx + 1].departureDate)
                departureTimePre.textContent = departure.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })
            }
        })
    }
}

function lsk() {
    document.getElementById('stationName').focus()
}

function csk() {
    if (focusedElement == null) {
        return
    }

    if (focusedElement.id === 'stationName') {
        goToTrain(document.activeElement.value.trim())
    }
    else {
        focusedElement.click()
    }
}

window.addEventListener('load', function (e) {
    var sp = new URL(window.location.href).searchParams
    fromStation = sp.get('from')
    toStation = sp.get('to')
    var departureDateStr = sp.get('departureDate')
    if (departureDateStr) {
        departureDate = new Date(departureDateStr)
    }

    var titleH1 = document.querySelector("header > h1")
    if (!fromStation) {
        titleH1.textContent = 'Find Route - From'
    }
    else if (!toStation) {
        titleH1.textContent = 'Find Route - To'
    }
    else if (!departureDate) {
        titleH1.textContent = 'Find Route - Departure Date'
    }
    else {
        titleH1.textContent = `${fromStation} - ${toStation}`
    }

    var footer = document.querySelector('footer')

    if (!fromStation || !toStation) {
        // Build station selection UI
        var stationNameH4 = document.createElement('h4')
        document.body.insertBefore(stationNameH4, footer)
        var stationNameLabel = document.createElement('label')
        stationNameH4.appendChild(stationNameLabel)
        stationNameLabel.htmlFor = 'stationName'
        stationNameLabel.textContent = 'Station Name'

        var stationNameInput = document.createElement('input')
        document.body.insertBefore(stationNameInput, footer)
        stationNameInput.type = 'search'
        stationNameInput.classList.add('items')
        stationNameInput.name = 'stationName'
        stationNameInput.id = 'stationName'

        var suggestionsH4 = document.createElement('h4')
        document.body.insertBefore(suggestionsH4, footer)
        suggestionsH4.textContent = 'Suggestions'

        var contentDiv = document.createElement('div')
        document.body.insertBefore(contentDiv, footer)
        contentDiv.classList.add('content')
        var suggestionsUl = document.createElement('ul')
        contentDiv.appendChild(suggestionsUl)
        suggestionsUl.id = 'suggestionsArea'

        document.querySelector('.csk').textContent = 'Search'

        var stationName = document.getElementById('stationName')
        stationName.addEventListener('input', function (e) {
            rebuildSuggestions()
        })
        stationName.addEventListener('focus', function (e) {
            focusedElement = stationName
            document.getElementsByClassName('lsk')[0].textContent = ''
            document.getElementsByClassName('csk')[0].textContent = 'Search'
        })
        stationName.addEventListener('blur', function (e) {
            document.getElementsByClassName('lsk')[0].textContent = 'Search'
            document.getElementsByClassName('csk')[0].textContent = 'Select'
        })
        stationName.addEventListener('keypress', function (e) {
            if (e.key == 'Enter') {
                goToStation(stationName.value.trim())
            }
        })

        fetch('https://scraper.infotren.dcdev.ro/v3/stations')
            .then(function (response) {
                return response.json()
            })
            .then(function (response) {
                knownStations = response
                knownStations = knownStations.filter((s) => ![fromStation, toStation].includes(s.name))
                knownStations.sort(function(a, b) { return b.stoppedAtBy.length - a.stoppedAtBy.length })
            })
            .then(function () {
                rebuildSuggestions()
            })
    }
    else if (!departureDate) {
        var departureDateH4 = document.createElement('h4')
        document.body.insertBefore(departureDateH4, footer)
        departureDateH4.textContent = 'Departure Date'

        var contentDiv = document.createElement('div')
        document.body.insertBefore(contentDiv, footer)
        contentDiv.classList.add('content')
        var departureDateUl = document.createElement('ul')
        contentDiv.appendChild(departureDateUl)
        departureDateUl.id = 'suggestionsArea'

        for (var i = 0, departureOption = new Date(); i < 30; i++, departureOption.setDate(departureOption.getDate() + 1)) {
            var suggestionLi = document.createElement('li')
            departureDateUl.appendChild(suggestionLi)
            suggestionLi.classList.add('items')
            suggestionLi.tabIndex = i + 10
            // Capture
            ;(function () {
                var d = new Date(departureOption.getTime())
                function onAction() {
                    setDepartureDate(d)
                }
                suggestionLi.addEventListener('click', onAction)
                suggestionLi.addEventListener('keypress', function (e) {
                    if (e.key == 'Enter') {
                        onAction(e)
                    }
                })
                suggestionLi.addEventListener('focus', function (e) {
                    focusedElement = suggestionLi
                })
            })()
            var innerP = document.createElement('p')
            suggestionLi.appendChild(innerP)
            innerP.classList.add('pri')
            var innerPre = document.createElement('pre')
            innerP.appendChild(innerPre)
            innerPre.textContent = `${departureOption.getDate().toString().padStart(2, '0')}.${(departureOption.getMonth() + 1).toString().padStart(2, '0')}.${departureOption.getFullYear().toString().padStart(4, '0')}`
        }

        document.querySelector('.csk').textContent = 'Select'
    }
    else {
        var contentDiv = document.createElement('div')
        document.body.insertBefore(contentDiv, footer)
        contentDiv.classList.add('content')
        contentDiv.style.display = 'flex'
        contentDiv.style.flexDirection = 'column'
        contentDiv.style.alignItems = 'center'
        contentDiv.style.justifyContent = 'center'

        var loadingP = document.createElement('p')
        contentDiv.appendChild(loadingP)
        loadingP.classList.add('pri')
        loadingP.textContent = 'Loading data...'


        var url = new URL('https://scraper.infotren.dcdev.ro/v3/itineraries')
        url.searchParams.set('from', fromStation)
        url.searchParams.set('to', toStation)
        url.searchParams.set('date', departureDate.toISOString())
        fetch(url.toString())
            .then(function (response) {
                return response.json()
            })
            .then(function (data) {
                contentDiv.remove()
                onItineraries(data)
            })
            .catch(function (e) {
                loadingP.textContent = 'An error has occured'

                var errorP = document.createElement('p')
                contentDiv.appendChild(errorP)
                errorP.classList.add('sec')
                errorP.textContent = e.toString()

                var retryLink = document.createElement('a')
                contentDiv.appendChild(retryLink)
                retryLink.classList.add('items')
                retryLink.textContent = 'Retry'
                retryLink.href = ''
            })
    }

    document.querySelectorAll('.lsk').forEach(function (lskElem) {
        lskElem.addEventListener('click', function (e) {
            lsk()
        })
    })
    document.querySelectorAll('.csk').forEach(function (cskElem) {
        cskElem.addEventListener('click', function (e) {
            csk()
        })
    })
    document.body.addEventListener('keydown', function (e) {
        if (e.key == 'SoftLeft') {
            lsk()
        }
        else if (e.key == 'Enter') {
            csk()
        }
    })
})