/**
 * @type {string | null}
 */
var fromStation = null
/**
 * @type {string | null}
 */
var toStation = null
/**
 * @type {Date | null}
 */
var departureDate = null
var transitKind = {
    ice: true,
    ic: true,
    re: true,
    rb: true,
    s: true,
    bus: true,
    ferry: true,
    u: true,
    tram: true,
}

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

var itineraries = null

function goToStation(stationId) {
    var url = new URL(window.location.href)
    if (!fromStation) {
        url.searchParams.set('from', stationId)
    }
    else if (!toStation) {
        url.searchParams.set('to', stationId)
    }
    // 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 suggestions = knownStations.slice()

    suggestions.forEach(function (suggestion, index) {
        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(JSON.stringify(suggestion))
            }
            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 || suggestion.address
            stationNameP.classList.add('pri', 'stationName')

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

            // trainCompanyP.textContent = suggestion.company
            // trainCompanyP.classList.add('thi')
        }, 0)
    })

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

var fetchAbortController = new AbortController()
function reloadSuggestions() {
	var stationNameInput = document.getElementById('stationName')
	var stationName = searchNormalize(stationNameInput.value.trim())

	var locationsUrl = new URL('https://v6.db.transport.rest/locations')
	locationsUrl.searchParams.set('query', stationName)
	locationsUrl.searchParams.set('limit', '25')
	locationsUrl.searchParams.set('fuzzy', 'true')
	locationsUrl.searchParams.set('stops', 'true')
	locationsUrl.searchParams.set('addresses', 'true')
	locationsUrl.searchParams.set('poi', 'true')

	fetchAbortController.abort()
	fetchAbortController = new AbortController()
	fetch(locationsUrl.toString(), { signal: fetchAbortController.signal })
		.then(function (response) {
			return response.json()
		})
		.then(function (data) {
			if (data) {
				knownStations = Object.values(data)
				rebuildSuggestions()
			}
		})
}

/**
 * @typedef DbJourney
 * @prop {'journey'} type
 * @prop {(DbTrip & DbArrDep & {tripId: string})[]} legs
 * @prop {string} refreshToken
 * @prop {DbRemark[]} remarks
 */

/**
 * @param {{journeys: DbJourney[]}} data
 */
function onItineraries(data) {
    var contentDiv = document.getElementById('content-div')
    if (!contentDiv) {
        contentDiv = document.createElement('div')
        document.body.insertBefore(contentDiv, document.querySelector('footer'))
        contentDiv.classList.add('content')
        contentDiv.id = 'content-div'
    }

    while (contentDiv.childNodes.length > 0) {
        contentDiv.childNodes[contentDiv.childNodes.length - 1].remove()
    }

    for (var i = 0; i < data.journeys.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.journeys[i].legs.forEach(function (train, idx) {
            var last = idx === data.journeys[i].legs.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.plannedDeparture)
                departureTimePre.textContent = departure.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })

                var departureHeading = document.createElement('h3')
                trainDiv.appendChild(departureHeading)
                departureHeading.classList.add('departure', 'station')
                if (train.origin.type === 'stop' || train.origin.type === 'station') {
                    var departureLink = document.createElement('a')
                    departureHeading.appendChild(departureLink)
                    departureLink.textContent = train.origin.name
                    departureLink.classList.add('no-custom-a', 'items')
                    var departureUrl = new URL('/view-station.html', window.location.origin)
                    departureUrl.searchParams.set('stationId', train.origin.id)
                    departureLink.href = departureUrl.toString()
                }
                else {
                    var departureSpan = document.createElement('span')
                    departureHeading.append(departureSpan)
                    departureSpan.innerText = train.origin.name || train.origin.address
                }
                
                if (train.departurePlatform || train.plannedDeparturePlatform) {
                    var departurePlatformP = document.createElement('p')
                    trainDiv.append(departurePlatformP)
                    departurePlatformP.classList.add('sec', 'departure', 'platform')
                    if (train.departurePlatform && train.departurePlatform != train.plannedDeparturePlatform) {
                        departurePlatformP.classList.add('changed')
                    }
                    departurePlatformP.textContent = `${train.departurePlatform || train.plannedDeparturePlatform}`
                }
            }

            var trainP = document.createElement('p')
            trainDiv.appendChild(trainP)
            trainP.classList.add('pri', 'train')
            if (!train.walking) {
                var trainLink = document.createElement('a')
                trainP.appendChild(trainLink)
                trainLink.innerText = train.line.name
                trainLink.classList.add('no-custom-a', 'items')
                if (train.line.product) {
                    if (train.line.productName === 'STB' && train.line.name.startsWith('STB U')) {
                        train.line.product = 'subway'
                    }
                    trainLink.classList.add('product-' + train.line.product)
                }
                var trainUrl = new URL('/view-train.html', window.location.origin)
                trainUrl.searchParams.set('tripId', train.tripId)
                trainUrl.searchParams.set('startId', train.origin.id)
                trainUrl.searchParams.set('stopId', train.destination.id)
                trainLink.href = trainUrl.toString()
                trainP.appendChild(document.createTextNode(' '))
                if (train.line.operator) {
                    var trainCompany = document.createElement('span')
                    trainP.appendChild(trainCompany)
                    trainCompany.textContent = '(' + train.line.operator.name + ')'
                    trainCompany.classList.add('company')
                }
            }
            else {
                var walkingSpan = document.createElement('span')
                trainP.append(walkingSpan)
                walkingSpan.classList.add('walking')
                walkingSpan.innerText = `Walking (${train.distance} m)`
            }

            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.plannedArrival)
            arrivalTimePre.textContent = arrival.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })

            var arrivalHeading = document.createElement('h3')
            trainDiv.appendChild(arrivalHeading)
            arrivalHeading.classList.add('arrival', 'station')
            if (train.destination.type === 'stop' || train.destination.type === 'station') {
                var arrivalLink = document.createElement('a')
                arrivalHeading.appendChild(arrivalLink)
                arrivalLink.textContent = train.destination.name
                arrivalLink.classList.add('no-custom-a', 'items')
                var arrivalUrl = new URL('/view-station.html', window.location.origin)
                arrivalUrl.searchParams.set('stationId', train.destination.id)
                arrivalLink.href = arrivalUrl.toString()
            }
            else {
                var arrivalSpan = document.createElement('span')
                arrivalHeading.append(arrivalSpan)
                arrivalSpan.innerText = train.destination.name || train.destination.address
            }
                
            if (train.arrivalPlatform || train.plannedArrivalPlatform) {
                var arrivalPlatformP = document.createElement('p')
                trainDiv.append(arrivalPlatformP)
                arrivalPlatformP.classList.add('sec', 'arrival', 'platform')
                if (train.arrivalPlatform && train.arrivalPlatform != train.plannedArrivalPlatform) {
                    arrivalPlatformP.classList.add('changed')
                }
                arrivalPlatformP.textContent = `${train.arrivalPlatform || train.plannedArrivalPlatform}`
            }

            if (!last) {
                var nextTrain = data.journeys[i].legs[idx + 1]
                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(nextTrain.plannedDeparture)
                departureTimePre.textContent = departure.toLocaleTimeString([], { 'hour': '2-digit', 'minute': '2-digit' })
                
                if (nextTrain.departurePlatform || nextTrain.plannedDeparturePlatform) {
                    var departurePlatformP = document.createElement('p')
                    trainDiv.append(departurePlatformP)
                    departurePlatformP.classList.add('sec', 'next-departure', 'platform')
                    if (nextTrain.departurePlatform && nextTrain.departurePlatform != nextTrain.plannedDeparturePlatform) {
                        departurePlatformP.classList.add('changed')
                    }
                    departurePlatformP.textContent = `${nextTrain.departurePlatform || nextTrain.plannedDeparturePlatform}`
                }
            }
        })
    }
}

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')
    var fromJson = JSON.parse(fromStation || 'null')
    toStation = sp.get('to')
    var toJson = JSON.parse(toStation || 'null')
    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 = `${fromJson.name || fromJson.address} - ${toJson.name || toJson.address}`
    }

    var transitKindJson = JSON.parse(sp.get('transitKind'))
    if (transitKindJson) {
        transitKind = transitKindJson
    }

    var footer = document.querySelector('footer')

    if (!fromStation || !toStation) {
        // Build station selection UI
        document.body.insertBefore(
            h4(
                label('Station Name').att$('for', 'stationName'),
            ),
            footer,
        )
        // 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'

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

        document.body.insertBefore(h4('Suggestions'), footer)
        // 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) {
            reloadSuggestions()
        })
        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())
            }
        })
    }
    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 = -1, departureOption = (function () { var d = new Date(); d.setDate(d.getDate() - 1); return d })(); 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
                })
                if (i === 0) {
                    suggestionLi.focus()
                }
            })()
            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')}`
            if (i === 0) {
                innerPre.textContent += ' (today)'
            }
        }

        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://v6.db.transport.rest/journeys')
        if (fromJson.type === 'stop' || fromJson.type === 'station') {
            url.searchParams.set('from', fromJson.id)
        }
        else {
            if (fromJson.type === 'location') {
                delete fromJson.id
            }
            Object.keys(fromJson).forEach(function (key) {
                url.searchParams.set(`from.${key}`, fromJson[key])
            })
        }
        if (toJson.type === 'stop' || toJson.type === 'station') {
            url.searchParams.set('to', toJson.id)
        }
        else {
            if (toJson.type === 'location') {
                delete toJson.id
            }
            Object.keys(toJson).forEach(function (key) {
                url.searchParams.set(`to.${key}`, toJson[key])
            })
        }
        url.searchParams.set('departure', departureDate.toISOString())
        url.searchParams.set('results', '20')
        url.searchParams.set('stopovers', 'true')
        url.searchParams.set('nationalExpress', transitKind.ice)
        url.searchParams.set('national', transitKind.ic)
        url.searchParams.set('regionalExpress', transitKind.re)
        url.searchParams.set('regional', transitKind.rb)
        url.searchParams.set('suburban', transitKind.s)
        url.searchParams.set('bus', transitKind.bus)
        url.searchParams.set('ferry', transitKind.ferry)
        url.searchParams.set('subway', transitKind.u)
        url.searchParams.set('tram', transitKind.tram)

        if (window.localStorage) {
            this.localStorage.setItem('recent/route', JSON.stringify({
                $addDate: new Date().toISOString(),
                from: fromJson.name || fromJson.address,
                to: toJson.name || toJson.address,
                queryParams: new URL(window.location.href).search,
            }))
        }

        fetch(url.toString())
            .then(function (response) {
                return response.json()
            })
            .then(function (data) {
                contentDiv.remove()
                onItineraries(data)
                itineraries = data
                function fetchMore() {
                    console.debug(`Got ${itineraries.journeys.length} journeys, fetching more`)
                    var moreUrl = new URL(url.toString())
                    moreUrl.searchParams.delete('departure')
                    moreUrl.searchParams.set('laterThan', itineraries.laterRef)
                    fetch(moreUrl.toString())
                        .then(function (result) {
                            return result.json()
                        })
                        .then(function (data) {
                            if (data.journeys) {
                                itineraries.journeys = itineraries.journeys.concat(data.journeys)
                                itineraries.laterRef = data.laterRef
                                onItineraries(itineraries)
                                
                                if (itineraries.laterRef) {
                                    var lastJourney = itineraries.journeys[itineraries.journeys.length - 1]
                                    var lastLeg = lastJourney.legs[lastJourney.legs.length - 1]
                                    var departureDate = new Date(lastLeg.plannedDeparture)
                                    if (departureDate.getTime() - Date.now() < 86400000) {
                                        setTimeout(fetchMore, 500)
                                    }
                                }
                            }
                        })
                }
                fetchMore()
            })
            .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()
        }
    })
})