<template>
    <div class="chart-wrap">
        <div class="chart-title">Top countries</div>

        <div v-if="series.length" class="chart-outer">
            <div class="chart-scroll" :style="{ height: scrollHeight }">
                <apexchart
                    type="bar"
                    :height="chartHeight"
                    :options="chartOptions"
                    :series="chartSeries"
                />
            </div>
            <div class="chart-footer">
                <span class="total-count">{{ totalCountries }}</span>
                <span class="total-label">total countries</span>
            </div>
        </div>

        <div v-else class="chart-empty">No country data available</div>
    </div>
</template>

<script setup lang="ts">
import { computed } from 'vue'
import type { Flight } from '@/Types/types'

const props = defineProps<{
    flights: Flight[]
    upcomingFlights: Flight[]
}>()

const MAX_VISIBLE = 12
const BAR_HEIGHT = 32

function countCountries(flights: Flight[]): Map<string, number> {
    const counts = new Map<string, number>()
    flights.forEach(f => {
        const depCountry = f.departure_airport?.region?.country?.name ?? null
        const arrCountry = f.arrival_airport?.region?.country?.name ?? null
        if (depCountry) counts.set(depCountry, (counts.get(depCountry) ?? 0) + 1)
        if (arrCountry && arrCountry !== depCountry) {
            counts.set(arrCountry, (counts.get(arrCountry) ?? 0) + 1)
        }
    })
    return counts
}

const series = computed(() => {
    const past = countCountries(props.flights)
    const upcoming = countCountries(props.upcomingFlights)

    const allCountries = new Set([...past.keys(), ...upcoming.keys()])

    return [...allCountries]
        .map(name => ({
            name,
            past: past.get(name) ?? 0,
            upcoming: upcoming.get(name) ?? 0,
        }))
        .sort((a, b) => (b.past + b.upcoming) - (a.past + a.upcoming))
})

const totalCountries = computed(() => series.value.length)

const chartHeight = computed(() => series.value.length * BAR_HEIGHT + 40)

const scrollHeight = computed(() => {
    const visible = Math.min(series.value.length, MAX_VISIBLE)
    return `${visible * BAR_HEIGHT + 40}px`
})

const chartSeries = computed(() => [
    {
        name: 'Flights',
        data: series.value.map(s => s.past),
    },
    {
        name: 'Upcoming',
        data: series.value.map(s => s.upcoming),
    },
])

const chartOptions = computed(() => ({
    chart: {
        type: 'bar',
        background: 'transparent',
        fontFamily: 'inherit',
        toolbar: { show: false },
        animations: { enabled: false },
        stacked: true,
    },
    theme: { mode: 'dark' },
    plotOptions: {
        bar: {
            horizontal: true,
            barHeight: '60%',
            borderRadius: 3,
            borderRadiusWhenStacked: 'last',
        },
    },
    colors: ['#4da6ff', '#ffc107'],
    dataLabels: {
        enabled: false,
    },
    xaxis: {
        categories: series.value.map(s => s.name),
        labels: { show: false },
        axisBorder: { show: false },
        axisTicks: { show: false },
    },
    yaxis: {
        labels: {
            style: {
                colors: '#778899',
                fontSize: '12px',
            },
        },
    },
    grid: {
        show: false,
    },
    legend: {
        show: true,
        position: 'top',
        horizontalAlign: 'right',
        labels: { colors: '#778899' },
        markers: { width: 8, height: 8, radius: 2 },
        itemMargin: { horizontal: 8 },
    },
    tooltip: {
        theme: 'dark',
        shared: true,
        intersect: false,
        y: {
            formatter: (val: number) => `${val} flights`,
        },
    },
    states: {
        hover: { filter: { type: 'lighten', value: 0.1 } },
    },
}))
</script>

<style scoped>
.chart-wrap {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.chart-title {
    font-size: 13px;
    font-weight: 500;
    color: #556677;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.chart-outer {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.chart-scroll {
    overflow-y: auto;
    overflow-x: hidden;
    scrollbar-width: thin;
    scrollbar-color: #334455 transparent;
}

.chart-scroll::-webkit-scrollbar {
    width: 4px;
}

.chart-scroll::-webkit-scrollbar-track {
    background: transparent;
}

.chart-scroll::-webkit-scrollbar-thumb {
    background: #334455;
    border-radius: 2px;
}

.chart-footer {
    display: flex;
    align-items: baseline;
    gap: 6px;
    padding-left: 4px;
}

.total-count {
    font-size: 28px;
    font-weight: 600;
    color: #e0e6f0;
    line-height: 1;
}

.total-label {
    font-size: 13px;
    color: #556677;
}

.chart-empty {
    height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    color: #445566;
}
</style>
