commit d7711ba95fc445e4935919bdb0e3cedb3d9b3873
Author: didier amyot <didier.amyot@gmail.com>
Date:   Thu Oct 19 11:48:30 2023 -0400

    implemented homework

diff --git a/.gitignore b/.gitignore
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,131 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
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+
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+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
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+
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+
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+
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+
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+.pnp.*.idea
+.idea
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/src/buttonclient.ts b/src/buttonclient.ts
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index 0000000..754806b
--- /dev/null
+++ b/src/buttonclient.ts
@@ -0,0 +1,52 @@
+import { LiftRequest} from "./shared.ts";
+
+class ButtonClient{
+
+    private readonly host: string;
+
+    constructor(host: string) {
+        this.host = host;
+    }
+
+    private async sendPost(url: string, payload: unknown): Promise<Response>{
+        return  await fetch(url, {
+            method: "POST",
+            headers: {
+                "Content-Type": "application/json",
+            },
+            body: JSON.stringify(payload),
+        });
+    }
+
+    async listLiftRequests(): Promise<LiftRequest[]> {
+        const resp = await fetch(`${this.host}/api/v1/lift-requests`);
+        const ret = await resp.json();
+        return ret as LiftRequest[] ;
+    }
+
+    async createLiftRequest(direction: string, level: number): Promise<boolean> {
+        const payload = {
+            direction: direction,
+            level: level,
+        }
+        const resp = await this.sendPost(`${this.host}/api/v1/lift-requests`, payload);
+        return 199 < resp.status && resp.status < 300;
+    }
+
+}
+
+async function experiment(): Promise<void>{
+    const client = new ButtonClient("http://localhost:3000");
+    console.log(await client.listLiftRequests());
+    console.log(await client.createLiftRequest("UP", -1))
+    console.log(await client.createLiftRequest("UP", -1))
+    console.log(await client.listLiftRequests());
+    console.log(await client.createLiftRequest("UP", 10))
+    console.log(await client.createLiftRequest("UP", 10))
+    console.log(await client.listLiftRequests());
+
+
+}
+
+
+await experiment()
\ No newline at end of file
diff --git a/src/liftclient.ts b/src/liftclient.ts
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--- /dev/null
+++ b/src/liftclient.ts
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+import {Lift, LiftFilterCriteron, SmallLiftRepresentation} from "./shared.ts";
+import {h} from "https://esm.sh/stable/preact@10.8.1/denonext/preact.mjs";
+
+class LiftClient{
+
+    private readonly host: string;
+
+    constructor(host: string) {
+        this.host = host;
+    }
+
+    async listElevators(): Promise<SmallLiftRepresentation[]> {
+        const resp = await fetch(`${this.host}/api/v1/lifts`);
+        const ret = await resp.json();
+        return ret.lifts as SmallLiftRepresentation[] ;
+    }
+
+    async filterLifts(criteron: LiftFilterCriteron):  Promise<SmallLiftRepresentation[]> {
+        const searchParams =  new URLSearchParams(criteron);
+        const resp = await fetch(`${this.host}/api/v1/lifts?${searchParams}`);
+        const ret = await resp.json();
+        return ret.lifts as SmallLiftRepresentation[];
+    }
+
+    async getLiftById(id: number): Promise<Lift | null> {
+        const resp = await fetch(`${this.host}/api/v1/lifts/${id}`);
+        if(resp.status === 404){
+            return null;
+        }
+        return (await resp.json()) as Lift;
+    }
+
+    private async sendPost(url: string, payload: unknown): Promise<Response>{
+        return  await fetch(url, {
+            method: "POST",
+            headers: {
+                "Content-Type": "application/json",
+            },
+            body: JSON.stringify(payload),
+        });
+    }
+
+    async moveLift(liftId: number, newLevel: number): Promise<boolean> {
+        const payload = {
+            type: 'lift-move',
+            level: newLevel,
+        }
+        const resp = await this.sendPost(`${this.host}/api/v1/lifts/${liftId}`, payload);
+        return 199 < resp.status && resp.status < 300;
+    }
+
+    async openLiftDoor(liftId: number): Promise<boolean> {
+        const lift = await this.getLiftById(liftId);
+        if(lift == null){
+            return false;
+        }
+        const payload = {
+            type: 'door-open',
+            level: lift.level,
+        }
+        const resp = await this.sendPost(`${this.host}/api/v1/lifts/${liftId}`, payload);
+        return 199 < resp.status && resp.status < 300;
+    }
+
+    async setDestination(liftId: number, newDestination: number): Promise<boolean> {
+        const payload = {
+            type: 'add-destination',
+            destination: newDestination,
+        }
+        const resp = await this.sendPost(`${this.host}/api/v1/lifts/${liftId}`, payload);
+        return 199 < resp.status && resp.status < 300;
+    }
+}
+
+async function experiment(): Promise<void>{
+    const client = new LiftClient("http://localhost:3000");
+    console.log(await client.getLiftById(2));
+    console.log(await client.setDestination(2, -1))
+    console.log(await client.setDestination(2, 11))
+    console.log(await client.setDestination(2, 16))
+    console.log(await client.setDestination(2, 14))
+    console.log(await client.setDestination(2, -1))
+
+
+    console.log(await client.getLiftById(2));
+    console.log(await client.openLiftDoor(2))
+    console.log(await client.getLiftById(2));
+}
+
+
+await experiment()
\ No newline at end of file
diff --git a/src/liftserver.ts b/src/liftserver.ts
new file mode 100644
index 0000000..0e489b9
--- /dev/null
+++ b/src/liftserver.ts
@@ -0,0 +1,299 @@
+// @deno-types="npm:@types/express@4.17.20"
+import express, {Response, Request} from "npm:express@4.18.2";
+import bodyParser from "npm:body-parser@1.20.2";
+import {Lift, LiftFilterCriteron, LiftRequest, SmallLiftRepresentation} from "./shared.ts";
+import c from "https://esm.sh/v132/@babel/runtime@7.22.15/denonext/helpers/getPrototypeOf.js";
+
+const app = express()
+app.use(bodyParser.json());
+
+const port = 3000;
+
+type LiftSearchRequestParams = {
+    floor?: string,
+    min_floor?: string,
+    max_floor?: string,
+    direction?: string,
+}
+
+type LiftAction = {
+    type: string,
+    level?: number,
+    destination?: number,
+}
+
+class ButtonService{
+    private readonly liftRequests : LiftRequest[] = [];
+
+    getLiftRequests(): LiftRequest[]{
+        return this.liftRequests;
+    }
+
+    addLiftRequest(liftRequest: LiftRequest): boolean{
+        for(const lr of this.liftRequests){
+            if(lr.level === liftRequest.level && lr.direction === liftRequest.direction){
+                return false;
+            }
+        }
+        this.liftRequests.push(liftRequest);
+        return true;
+    }
+}
+
+class LiftService {
+
+    private readonly lifts: Lift[];
+
+    constructor(lifts: Lift[]) {
+        this.lifts = lifts;
+    }
+
+    getAllLifts(): Lift[] {
+        return this.lifts;
+    }
+
+    private computeDirection(lift: Lift): string{
+        if(lift.destinations.length === 0){
+            return "IDLE";
+        }
+        const nextDestination = lift.destinations[0];
+        if(nextDestination === lift.level){
+            return lift.direction;
+        }
+        if(nextDestination > lift.level){
+            return "UP";
+        }
+        return "DOWN";
+    }
+
+    private isBetween(x: number, min_: number, max_: number): boolean{
+        return min_ < x && x < max_;
+    }
+
+    private addDestination(destinations: number[], currentLevel: number, newDestination: number){
+        if(destinations.length === 0){
+            return [newDestination];
+        }
+        if(destinations.includes(newDestination)){
+            return destinations;
+        }
+
+        const firstDestination = destinations[0];
+        if(this.isBetween(newDestination, currentLevel, firstDestination)){
+            return [newDestination].concat(destinations);
+
+        }
+        for(let i = 0; i < destinations.length - 1; i++){
+            const first = destinations[i];
+            const second = destinations[i + 1];
+            if(this.isBetween(newDestination, first, second)){
+                const firstPart = destinations.slice(0, i + 1);
+                const secondPart = destinations.slice(i + 1);
+                return firstPart.concat([newDestination]).concat(secondPart);
+            }
+        }
+        return destinations.concat([newDestination]);
+
+    }
+
+    processAddDestination(liftId: number, level: number): boolean {
+        const lift = this.getElevatorById(liftId);
+        if(!lift){
+            return false;
+        }
+        lift.destinations = this.addDestination(lift.destinations, lift.level, level);
+        lift.direction = this.computeDirection(lift);
+        return true;
+    }
+
+    processDoorOpen(liftId: number, level: number): boolean {
+        const lift = this.getElevatorById(liftId);
+        if(!lift){
+            return false;
+        }
+        lift.destinations = this.removeFromArray(lift.destinations, level);
+        lift.direction = this.computeDirection(lift);
+        return true;
+    }
+    removeFromArray(lst: number[], toRemove: number): number[] {
+        const ret: number[] = [];
+        for(const e of lst){
+            if(e !== toRemove){
+                ret.push(e);
+            }
+        }
+        return ret
+    }
+
+    processLiftMovement(liftId: number, level: number): boolean {
+        const lift = this.getElevatorById(liftId);
+        if(!lift){
+            return false;
+        }
+        lift.level = level;
+        return true;
+    }
+
+    private matches(lift: Lift, liftFilterCriteria: LiftFilterCriteron) {
+        if (liftFilterCriteria.floor !== undefined && lift.level != liftFilterCriteria.floor) {
+            return false;
+        }
+
+        if (liftFilterCriteria.min_floor !== undefined && lift.level < liftFilterCriteria.min_floor) {
+            return false;
+        }
+
+        if (liftFilterCriteria.max_floor !== undefined && lift.level > liftFilterCriteria.max_floor) {
+            return false;
+        }
+
+        if (liftFilterCriteria.direction !== undefined && lift.direction !== liftFilterCriteria.direction) {
+            return false;
+        }
+
+        return true;
+    }
+
+    getAllListsMatching(liftFilterCriteria: LiftFilterCriteron): Lift[] {
+        const ret: Lift[] = [];
+        for (const lift of this.lifts) {
+            if (this.matches(lift, liftFilterCriteria)) {
+                ret.push(lift);
+            }
+        }
+        return ret;
+    }
+
+    getElevatorById(id: number): Lift | null {
+        for (const lift of this.lifts) {
+            if (lift.id === id) {
+                return lift;
+            }
+        }
+        return null;
+    }
+}
+
+
+function createLiftService(): LiftService {
+    const defaultLifts: Lift[] = [
+        {id: 1, level: 12, direction: 'IDLE', destinations: []},
+        {id: 2, level: -1, direction: 'IDLE', destinations: []},
+        {id: 3, level: 5, direction: 'IDLE', destinations: []},
+        {id: 4, level: 17, direction: 'IDLE', destinations: []},
+    ];
+    return new LiftService(defaultLifts);
+}
+
+function toSmallRepresentation(lifts: Lift[]): SmallLiftRepresentation[] {
+    const ret: SmallLiftRepresentation[] = [];
+    for (const lift of lifts) {
+        ret.push({id: lift.id, level: lift.level});
+    }
+    return ret;
+
+}
+
+const liftService = createLiftService();
+
+const buttonService = new ButtonService();
+
+function send404(res: Response): void {
+    res.status(404);
+    res.send({});
+}
+
+function send400(res: Response): void {
+    res.status(400);
+    res.send({});
+}
+
+app.get('/api/v1/lifts', (req: Request, res: Response): void => {
+    const query = req.query as LiftSearchRequestParams;
+    const criterion = liftSearchRequestParamsToLiftFilterCriteria(query);
+    const ret = liftService.getAllListsMatching(criterion);
+    res.send({lifts: toSmallRepresentation(ret)})
+});
+
+app.get('/api/v1/lifts/:id', (req: Request<{ id: string }>, res: Response): void => {
+    const id = req.params.id;
+    const ret = liftService.getElevatorById(parseInt(id));
+    if (ret == null) {
+        return send404(res);
+    }
+    res.send(ret)
+});
+
+app.post('/api/v1/lifts/:id', (req: Request<{ id: string }>, res: Response): void => {
+    const id = parseInt(req.params.id);
+    const ret = liftService.getElevatorById(id);
+    if (ret == null) {
+        return send404(res);
+    }
+    const action = req.body as LiftAction | null;
+    if(!action || !isValidAction(action)){
+        return send400(res)
+    }
+    if(action.type === 'lift-move'){
+        liftService.processLiftMovement(id, action.level!);
+    }
+    if(action.type === 'door-open'){
+        liftService.processDoorOpen(id, action.level!);
+    }
+    if(action.type === 'add-destination'){
+        liftService.processAddDestination(id, action.destination!);
+    }
+
+    res.send(ret)
+});
+
+app.get('/api/v1/lift-requests',  (req: Request, res: Response): void => {
+    res.send(buttonService.getLiftRequests());
+});
+
+app.post('/api/v1/lift-requests',  (req: Request, res: Response): void => {
+    const changed = buttonService.addLiftRequest(req.body as LiftRequest);
+    res.send({changed: changed});
+});
+
+app.listen(port, () => {
+    console.log(`Example app listening on port ${port}`)
+})
+
+function liftSearchRequestParamsToLiftFilterCriteria(query: LiftSearchRequestParams): LiftFilterCriteron {
+    const ret: LiftFilterCriteron = {};
+    if (query.direction !== undefined) {
+        ret.direction = query.direction;
+    }
+    if (query.floor !== undefined) {
+        ret.floor = parseInt(query.floor);
+    }
+    if (query.max_floor !== undefined) {
+        ret.max_floor = parseInt(query.max_floor);
+    }
+    if (query.min_floor !== undefined) {
+        ret.min_floor = parseInt(query.min_floor);
+    }
+    return ret;
+}
+
+function isLevel(x: any): boolean{
+    const allLevels = [
+        -2, -1, 1, 2, 3, 4, 5,
+        6, 7, 8, 9, 10, 11, 12,
+        13, 14, 15, 16, 17, 18];
+    return allLevels.includes(x);
+}
+
+function isValidAction(action?: LiftAction): boolean {
+    if(!action){
+        return false;
+    }
+    if(action.type === "lift-move" || action.type === "door-open" ){
+        return isLevel(action.level);
+    }
+    if(action.type === "add-destination" ){
+        return isLevel(action.destination);
+    }
+    return false;
+}
diff --git a/src/shared.ts b/src/shared.ts
new file mode 100644
index 0000000..77f7493
--- /dev/null
+++ b/src/shared.ts
@@ -0,0 +1,24 @@
+export type Lift = {
+    id: number,
+    level: number,
+    direction: string,
+    destinations: number[]
+}
+
+export type SmallLiftRepresentation = {
+    id: number,
+    level: number,
+}
+
+export type LiftFilterCriteron = {
+    floor?: number,
+    min_floor?: number,
+    max_floor?: number,
+    direction?: string,
+}
+
+
+export type LiftRequest = {
+    direction: string,
+    level: number,
+}
\ No newline at end of file