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}${path.includes("?") ? "&" : "?"}per_page=${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() {
        const 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) }
        )

        const showSubmittedAssignments = plasmoid.configuration.showSubmittedAssignments

        announcementsModel.clear()
        assignmentsModel.clear()

        let importantCount = {announcements: 0, assignments: 0}

        for (let course of courses) {
            callApi(`/announcements?context_codes[]=course_${course[0]}`, 10, announcements => {
                announcements.forEach(announcement => {
                    const info = {
                        type: "announcement",
                        activityId: announcement.id,
                        course: course[1],
                        title: announcement.title,
                        url: announcement.html_url,
                        important: plasmoid.configuration.importantAnnouncements.includes(announcement.id.toString()),
                    }

                    if (info.important) {
                        announcementsModel.insert(importantCount.announcements++, info) // place above unimportant ones
                    } else {
                        announcementsModel.append(info)
                    }
                })
            })

            callApi(`/courses/${course[0]}/assignments`, 10, assignments => {
                assignments.forEach(assignment => {
                    const info = {
                        type: "assignment",
                        activityId: assignment.id,
                        course: course[1],
                        title: assignment.name,
                        dueAt: assignment.due_at,
                        submitted: assignment.has_submitted_submissions,
                        url: assignment.html_url,
                        important: plasmoid.configuration.importantAssignments.includes(assignment.id.toString()),
                    }

                    if (!info.submitted || showSubmittedAssignments) {
                        if (info.important) {
                            assignmentsModel.insert(importantCount.assignments++, info)
                        } else {
                            assignmentsModel.append(info)
                        }
                    }
                })
            })
        }
    }

    Timer {
        interval: plasmoid.configuration.refreshInterval * 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 {
                type: "announcement"
                course: "CS101"
                title: "Title"
                url: "https://xkcd.com"
                important: true
                activityId: 0
            }
        }

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

            ListView {
                id: announcementsListView
                Layout.fillWidth: true
                spacing: PlasmaCore.Units.smallSpacing
                delegate: ActivityView {}
                model: announcementsModel
            }
        }

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

        ListModel {
            id: assignmentsModel
            ListElement {
                type: "assignment"
                course: "EE210"
                title: "Title"
                dueAt: "2022-04-10T15:59:59Z"
                submitted: true
                url: "https://xkcd.com"
                important: true
                activityId: 1
            }
        }

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

            ListView {
                id: assignmentsListView
                Layout.fillWidth: true
                spacing: PlasmaCore.Units.gridUnit
                delegate: ActivityView {}
                model: assignmentsModel
            }
        }

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