const VolumeMap = {
    isOn: false,
    size: 320,
    positions: new Map(),
    toggle() {
        VolumeMap.isOn = !VolumeMap.isOn
    },
    onremove() {
        VolumeMap.positions.clear()
    },
    getDot(username) {
        if(VolumeMap.positions.has(username)) {
            return VolumeMap.positions.get(username)
        }
        return [VolumeMap.size / 2, VolumeMap.size / 2]
    },
    moveNotify({layerX, layerY}) {
        wire({kind: 'volumeMapMove', value: [layerX, layerY]})
    },
    moveDot({detail: {source, value}}) {
        VolumeMap.positions.set(source, value)
        const [x0, y0] = VolumeMap.getDot(State.username);
        for(const video of document.querySelectorAll('video:not(.self')) {
            const [x1, y1] = VolumeMap.getDot(video.username)
            const dist1 = Math.sqrt(Math.pow(x1 - x0, 2) + Math.pow(y1 - y0, 2))
            const dist2 = VolumeMap.size / Math.pow(dist1, 1.5) - 0.2
            const dist3  = Math.max(Math.min(dist2, 1), 0)
            video.style.opacity = dist3
            video.volume = dist3
            video.muted = !dist3  // iPhone does not allow graded volume
        }
    },
    view() {
        const style = {
            'z-index': '999',
            'background-color': 'rgba(65, 105, 225, 0.8)',
            'font-family': 'monospace',
            'position': 'fixed',
            'height': VolumeMap.size + 'px',
            'width': VolumeMap.size + 'px',
        }
        return m('svg', {onclick: VolumeMap.moveNotify, style},
            m('style', 'text { pointer-events: none }'),
            State.online.map(username => {
                const [x, y] = VolumeMap.getDot(username)
                return m('text', {x, y, fill: 'white'}, `・${username}`)
            })
        )
    },
}
addEventListener('volumeMapMove', VolumeMap.moveDot)