import { GRADUATION_DB_ID, GRADUATION_ACTIVITY_ID, GRADUATION_DB_PARAMS_MAP } from "./config.js";
import { loadFromDatabase, addEntryToDatabaseActivity } from "./database.js"

const LEVEL_NAMES = ["Beginner", "Entdecker"];

class GraduationChange {
	constructor(date, id, name, change, reason, coach, json) {
		this.date = date;
		this.id = id;
		this.name = name;
		this.change = change;
		this.reason = reason;
		this.coach = coach;
		this.json = json;
	}

	static newGreenPointChange(student, reason, coach) {
		return new GraduationChange(
			new Date(),
			student.id, student.name,
			"Grün", reason, coach, ""
		);
	}

	static newOrangePointChange(student, reason, coach) {
		return new GraduationChange(
			new Date(),
			student.id, student.name,
			"Orange", reason, coach, ""
		);
	}

	static newRedPointChange(student, reason, coach) {
		return new GraduationChange(
			new Date(),
			student.id, student.name,
			"Rot", reason, coach, ""
		);
	}
}

class Graduation {
	constructor(student, green, orange, red, level, stickers, observed, changes) {
		this.student = student;
		this.green = green;
		this.orange = orange;
		this.red = red;
		this.level = level;
		this.stickers = stickers;
		this.observed = observed;
		this.changes = changes;

		student.graduation = this;
	}

	static from(student, changes) {
		let green = 0;
		let orange = 0;
		let red = 0;
		let level = 1;
		let observed = false;
		let stickers = [];
		for (const change of changes) {
			switch (change.change) {
			case "Grün":
				green++;
				break;
			case "Orange":
				orange++;
				break;
			case "Rot":
				red++;
				break;
			case "Gespräch":
				orange = 0;
				break;
			case "Änderung":
				let ctx = JSON.parse(change.json)
				switch (ctx.type) {
				case "ObservationStart":
					observed = true;
					break;
				default:
					alert(`Unexpected ctx type: ${ctx.type}`);
				}
				break;
			default:
				alert(`Unexpected change: ${change}`);
			}
		}
		return new Graduation(student, green, orange, red, level, stickers, observed, changes);
	}

	addChange(change) {
		// TODO(muhq): Implement incremental addition
		let changes = this.changes;
		changes.push(change);
		// This updates the student.graduation reference as well
		Graduation.from(this.student, changes);
	}

	/**
	 * Request observation
	 */
	async requestObservation() {
		// TODO(muhq): Implement observation mark
		this.observed = true;
	}

	/**
	 * Return if the student is in observation.
	 */
	isObserved() {
		return this.observed;
	}

	/**
	 * Return the URI of the icon representing the graduation level.
	 */
	getIcon() {
		return "";
	}

	/**
	 * Return the name of the current graduation level.
	 * @return {String} The name of the current level.
	 */
	getLevelName() {
		return LEVEL_NAMES[this.level - 1];
	}
}

async function fetchGraduationChanges(student) {
	let params = {};
	// The id is enough
	params[GRADUATION_DB_PARAMS_MAP["id"]] = student.id;

	const data = await loadFromDatabase(GRADUATION_DB_ID, params);

	let changes = [];
	for (const e of data) {
		const gradChange = new GraduationChange(e.date, e.id, e.change, e.reason, e.coach, e.json);
		changes.push(gradChange);
	}
	return changes;
}

async function fetchGraduation(student) {
	const changes = await fetchGraduationChanges(student);
	return Graduation.from(student, changes);
}

async function submitGraduationChange(student, change) {
	let params = {};
	student.graduation.addChange(change);
	for (const key in GRADUATION_DB_PARAMS_MAP) {
		params[GRADUATION_DB_PARAMS_MAP[key]] = change[key];
	}

	addEntryToDatabaseActivity(GRADUATION_ACTIVITY_ID, params);
}

export {
	LEVEL_NAMES,
	GraduationChange,
	Graduation,
	fetchGraduation,
	fetchGraduationChanges,
	submitGraduationChange
};