import { GTK_ALIGN_CENTER, GTK_ALIGN_FILL } from '../constants.js'

const mpris = await Service.import("mpris")
const players = mpris.bind("players")

const FALLBACK_ICON = "audio-x-generic-symbolic"
const PLAY_ICON = "media-playback-start-symbolic"
const PAUSE_ICON = "media-playback-pause-symbolic"
const PREV_ICON = "media-skip-backward-symbolic"
const NEXT_ICON = "media-skip-forward-symbolic"

/** @param {number} length */
function lengthStr(length) {
    const min = Math.floor(length / 60)
    const sec = Math.floor(length % 60)
    const sec0 = sec < 10 ? "0" : ""
    return `${min}:${sec0}${sec}`
}

/** @param {import('types/service/mpris').MprisPlayer} player */
function Player(player) {
    const artists = player.bind("track_artists").transform(a => a.join(", "))

    const playPause = Widget.Button({
        className: "play-pause",
        onClicked: () => player.playPause(),
        visible: player.bind("can_play"),
        child: Widget.Icon({
            icon: player.bind("play_back_status").transform(s => {
                switch (s) {
                    case "Playing": return PAUSE_ICON
                    case "Paused":
                    case "Stopped": return PLAY_ICON
                }
            }),
        }),
    })

    const prev = Widget.Button({
        onClicked: () => player.previous(),
        visible: player.bind("can_go_prev"),
        child: Widget.Icon(PREV_ICON),
    })

    const next = Widget.Button({
        onClicked: () => player.next(),
        visible: player.bind("can_go_next"),
        child: Widget.Icon(NEXT_ICON),
    })

    const positionSlider = Widget.Slider({
        className: "position",
        drawValue: false,
        onChange: ({ value }) => player.position = value * player.length,
        visible: player.bind("length").as(l => l > 0),
        setup: self => {
            function update() {
                const value = player.position / player.length
                self.value = value > 0 ? value : 0
            }
            self.hook(player, update)
            self.hook(player, update, "position")
            self.poll(1000, update)
        },
    })

    const positionLabel = Widget.Label({
        className: "position",
        hpack: "start",
        setup: self => {
            const update = (_, time) => {
                self.label = lengthStr(time || player.position)
                self.visible = player.length > 0
            }

            self.hook(player, update, "position")
            self.poll(1000, update)
        },
    })

    const lengthLabel = Widget.Label({
        className: "length",
        hpack: "end",
        visible: player.bind("length").transform(l => l > 0),
        label: player.bind("length").transform(lengthStr),
    })

    return Widget.Overlay({
        className: "player",
        child: Widget.Box({
            className: "bg-img",
            vpack: "start",
            css: player.bind("cover_path").transform(p => `background-image: url('${p}');`),
        }),
        overlays: [
            Widget.Box({
                className: "bg-cover"
            }),
            Widget.Box({
                className: "overlay",
                vertical: true,
                halign: GTK_ALIGN_CENTER,
                children: [
                    Widget.Box({
                        className: "info",
                        vertical: true,
                        children: [
                            Widget.Label({ className: "title", label: player.bind("track_title") }),
                            Widget.Label({ className: "album", label: player.bind("track_album") }),
                            Widget.Label({ className: "artist", label: artists }),
                        ],
                    }),
                    Widget.Box({
                        vexpand: true,
                    }),
                    Widget.CenterBox({
                        className: "controls",
                        startWidget: positionLabel,
                        centerWidget: Widget.Box({
                            halign: GTK_ALIGN_CENTER,
                            spacing: 20,
                            children: [
                                prev,
                                playPause,
                                next,
                            ],
                        }),
                        endWidget: lengthLabel,
                    }),
                    positionSlider,
                ],
            })
        ],
    })
}

function MediaContent() {
    const currentIdx = Variable(0);
    const currentPlayer = Utils.merge([currentIdx.bind(), players], (currentIdx, players) => {
        const idx = Math.min(currentIdx, players.length - 1);
        return players[idx];
    })

    return Widget.Box({
        children: currentPlayer.as(p => [Player(p)]),
    })
}

export function Media(monitor = 0) {
    return Widget.Window({
        monitor,
        visible: false,
        exclusivity: "normal",
        className: "media",
        margins: [10, 10, 0, 10],
        name: `media${monitor}`,
        anchor: ["left", "top"],
        child: MediaContent(),
    })
}