import { GraduationChange, submitGraduationChange } from "./graduation-ENV.ts";
import { findDuplicateChanges } from "./graduation-common.ts";
import { fetchStudent, fetchStudents } from "./student-ENV.ts";
import { fetchCourses } from "./moodle-ENV.ts";
import { DB } from "./database-ENV.ts";
import { DATETIME_FMT } from "./utils-common.ts";

import JSZip from "jszip";
import FileSaver from "file-saver";

let outputNode;
function output(msg) {
	if (outputNode.style.display === "none") {
		outputNode.style.display = "block";
	}
	const line = document.createElement("div");
	line.innerHTML = msg;
	line.classList.add("admin-tools-output-line");
	outputNode.appendChild(line);
}

async function coachAssignmentImport() {
	const csv = document.getElementById("admin-tools-coach-import").value;
	const assignments = {};

	for (const line of csv.split("\n")) {
		const [studentName, ...coaches] = line.trim().split(";");
		if (studentName === "*") {
			const students = await fetchStudents();
			for (const student of students) {
				assignments[student.id] = coaches;
			}
		} else {
			const student = await fetchStudent(undefined, studentName);
			if (student === null) {
				output(`${studentName} nicht gefunden`);
				continue;
			}
			assignments[student.id] = coaches;
		}
	}

	const assignmentChange = GraduationChange.newCoachAssignmentChange(assignments);
	await submitGraduationChange(assignmentChange);
	output("Coach Zuweisung importiert");
}

async function updateActivities(course) {
	const promises = [];
	for (const activityName of ["Cockpit", "Klassenliste", "Coaching", "Admin-Tools"]) {
		const input = document.getElementById(`${activityName.toLowerCase()}-file-input`);
		if (input.value === "") continue;

		const activity = await course.getActivity(activityName);
		if (activity === null) {
			output(course.title + ": Skipping non existing: " + activityName);
			continue;
		}

		const text = input.files[0].text();
		promises.push(activity.update(await text));
	}
	return Promise.all(promises);
}

async function updateCourses() {
	output("loading courses ...");
	const courses = await fetchCourses("SOL Graduierung");
	output(`updating ${courses.length} courses ... `);
	const promises = [];
	for (const course of courses) {
		promises.push(updateActivities(course));
	}

	Promise.all(promises)
		.then(() => {
			output("Updating activities done.");
		})
		.catch((error) => {
			output("Updating activities failed: " + error);
		});
}

async function findDuplicates(course) {
	const dbActivity = await course.getActivity("Graduation");
	const db = new DB(dbActivity.id);
	const entries = await db.fetchEntries();
	const changes = entries.map((e) => GraduationChange.fromDBEntry(e));

	const duplicates = findDuplicateChanges(changes);

	if (duplicates.length !== 0) {
		let msg = `${course.title} Duplikate:<br>`;
		for (const d of duplicates) {
			const ids = d.map((e) => e.changeId);
			const c = d[0];
			msg += `- ${DATETIME_FMT.format(c.date)} ${c.coach} ${c.studentId} ${c.change} ${JSON.stringify(c.context)} ids: ${ids}<br>`;
		}
		output(msg + "\n");
	}

	return [course, duplicates];
}

async function findAllDuplicates() {
	output("loading courses ...");
	const courses = await fetchCourses("SOL Graduierung");
	output(`searching in ${courses.length} courses ... `);
	for (const course of courses) {
		findDuplicates(course);
	}
}

async function exportGraduations(course) {
	const dbActivity = await course.getActivity("Graduation");
	const db = new DB(dbActivity.id);
	const exportResponse = await db.exportEntries();
	return [course, await exportResponse.text()];
}

async function exportAllGraduations() {
	output("loading courses ...");
	const courses = await fetchCourses("SOL Graduierung");
	output(`exporting graduations of ${courses.length} courses ... `);
	const promises = [];
	for (const course of courses) {
		promises.push(exportGraduations(course));
	}
	const results = await Promise.all(promises);

	const zip = new JSZip();

	for (const [course, entries] of results) {
		zip.file(`${course.title}.csv`, entries);
	}

	zip.generateAsync({ type: "blob" }).then(function (content) {
		FileSaver.saveAs(content, "graduation-db-exports.zip");
	});
}

async function init() {
	outputNode = document.getElementById("admin-tools-output");
	output("Admin tools ready.");
	document
		.getElementById("admin-tools-coach-import-submit")
		.addEventListener("click", coachAssignmentImport);
	document.getElementById("activity-update-submit").addEventListener("click", updateCourses);
	document.getElementById("print-ids").addEventListener("click", async function () {
		const students = await fetchStudents();
		output(JSON.stringify(students.map((s) => s.id)));
	});
	document.getElementById("find-duplicates").addEventListener("click", findAllDuplicates);
	document.getElementById("export-graduation-dbs").addEventListener("click", exportAllGraduations);
}

if (document.readyState === "loading") {
	document.addEventListener("DOMContentLoaded", init);
} else {
	init();
}