import QtQuick 2.15
import QtQuick.Layouts 1.15
import QtQuick.Controls 2.15

import org.kde.plasma.plasmoid 2.0
import org.kde.plasma.core 2.0 as PlasmaCore
import org.kde.plasma.components 2.0 as PlasmaComponents
import org.kde.plasma.components 3.0 as PlasmaComponents3
import org.kde.plasma.extras 2.0 as PlasmaExtras

Item {
    width: PlasmaCore.Units.gridUnit * 20
    height: PlasmaCore.Units.gridUnit * 40
    clip: true

    readonly property string canvasUrl: plasmoid.configuration.canvasUrl
    readonly property string apiEndpoint: `${canvasUrl.replace(/\/$/, "")}/api/v1`
    readonly property string oauth2Token: plasmoid.configuration.oauth2Token
    readonly property string authHeader: `Bearer ${oauth2Token}`

    function callApi(path, amount, callback) {
        let xhr = new XMLHttpRequest()
        xhr.open("GET", `${apiEndpoint}${path}` + (amount ? `?per_page=${amount}` : ""))
        xhr.setRequestHeader("Authorization", authHeader)
        xhr.onload = () => {
            if (xhr.status == 200) {
                try {
                    let json = JSON.parse(xhr.responseText)
                    if (callback) { callback(json) }
                } catch (e) {
                    if (e instanceof SyntaxError) {
                        console.error(`Cannot parse response for ${path} as JSON:\n${xhr.responseText}`)
                    } else { throw e }
                }
            } else {
                console.error(`XHR failed when retrieving ${path} (status ${xhr.status}):\n${xhr.responseText}`)
            }
        }
        xhr.send()
    }

    function syncCanvas() {
        let courses = plasmoid.configuration.courses.split("\n").map(
            // each line in the "courses" config consists of
            // a numeric course id, a space, and a course code
            line => { return line.split(" ", 2) }
        )
        announcementsModel.clear()
        for (let course of courses) {
            callApi(`/courses/${course[0]}/activity_stream`, 10, activityStream => {
                // Get activity stream for each course
                for (let activity of activityStream) {
                    if (activity.type == "Announcement") {
                        announcementsModel.append({
                            course: course[1],
                            title: activity.title,
                            url: activity.html_url
                        })
                    }
                }
            })
        }
    }

    Timer {
        interval: 60 * 1000
        running: true;
        repeat: true;
        onTriggered: syncCanvas();
    }

    ColumnLayout {
        id: main
        anchors.fill: parent

        PlasmaExtras.Heading {
            level: 1
            text: "Kanvas"
        }

        PlasmaExtras.Heading {
            level: 2
            text: "Announcements"
        }

        ListModel {
            id: announcementsModel
            ListElement {
                course: "CS101"
                title: "Title of the announcement"
                url: "https://xkcd.com"
            }
        }

        ScrollView {
            implicitHeight: PlasmaCore.Units.gridUnit * 20
            Layout.margins: PlasmaCore.Units.smallSpacing
            Layout.fillWidth: true
            Layout.fillHeight: true

            ScrollBar.horizontal.policy: ScrollBar.AlwaysOff

            ListView {
                Layout.fillWidth: true
                delegate: AnnouncementView {}
                model: announcementsModel
            }
        }

        PlasmaComponents3.Button {
            icon.name: "view-refresh"
            text: i18n("Refresh")
            onClicked: syncCanvas()
        }
    }
}