import {expect, test} from "@jest/globals";

import {Graph} from "./Graph-demo.js";


test("Graph: constructor:", ()=>{
    const g = new Graph();
    g.addEdge(1, 2);
    g.addEdge(1, 3);
    g.addEdge(2, 3);
    g.addEdge(2, 4);
    const txt = g.toString();
    const expected = `1 → [2, 3]
2 → [1, 3, 4]
3 → [1, 2]
4 → [2]`;
    expect(txt).toBe(expected);
    const vertices = [1, 2, 3, 4];
    const action = (v) => expect(vertices).toContain(v);
    g.forEachVertices(action);
});

test("Graph: iterate all edges:", ()=>{
    const g = new Graph();
    g.addEdge(1, 2);
    g.addEdge(3, 1);
    g.addEdge(2, 3);
    g.addEdge(2, 4);
    const edges = [
        "1-2", "1-3", "2-3", "2-4"
    ];
    const action = (a, b) => {
        const [s,e] = a < b ? [a,b] : [b,a];
        const edge = `${s}-${e}`;
        expect(edges).toContain(edge)
    };
    g.forEachEdges(action);
});

test("Graph: Don't add floating point number to vertex set:", ()=>{
    const g = new Graph();
    try {
        g.addVertex(1.2);
    }catch (e) {
        expect(e.message).toBe('Argument 1.2 is not a valid vertex');
        expect(e.constructor).toBe(TypeError);
    }
});

test("Graph: Don't add string to vertex set:", ()=>{
    const g = new Graph();
    try {
        g.addVertex("add");
    }catch (e) {
        expect(e.message).toBe('Argument add is not a valid vertex');
        expect(e.constructor).toBe(TypeError);
    }
});


test("Graph: iterates over vertices:", ()=>{
    const g = new Graph();
    g.addEdge(1, 2);
    g.addEdge(1, 3);
    g.addEdge(2, 3);
    g.addEdge(2, 4);
    const vertices = [];
    for(const v of g.vertices()) {
        vertices.push(v);
    }
    vertices.sort();
    const expected = [1, 2, 3, 4];
    expect(vertices).toEqual(expected);

});

test("Graph: iterates over neighbor of a vertex:", ()=>{
    const g = new Graph();
    g.addEdge(1, 2);
    g.addEdge(1, 3);
    g.addEdge(2, 3);
    g.addEdge(2, 4);
    g.addEdge(4, 1);
    const vertices = [];
    for(const v of g.adjacentOf(1)) {
        vertices.push(v);
    }
    vertices.sort();
    const expected = [2, 3, 4];
    expect(vertices).toEqual(expected);

});

test("Graph: merge existing attributes:", ()=>{
    const g = new Graph();
    g.addVertex(1);
    const undef = g.getAttribute(1);
    expect(undef).toBe(undefined);
    const firstA = {'a':1, 'b':2};
    g.mergeAttribute(1, firstA);
    const getFirstA = g.getAttribute(1);
    expect(getFirstA.get('a')).toBe( firstA['a'] );
    expect(getFirstA.get('b')).toBe( firstA['b'] );
    const secondA = {'b': 3, 'c': 5};
    g.mergeAttribute(1,secondA);
    const getSecondA = g.getAttribute(1);
    expect(getSecondA.get('a')).toBe(firstA['a']); // same thing
    expect(getSecondA.get('b')).toBe(secondA['b']);
    expect(getSecondA.get('c')).toBe(secondA['c']);

});

test("Graph: don't merge attributes if given vertex not in graph:", ()=>{
    const g = new Graph();
    g.addVertex(1);
    try {
        g.mergeAttribute(2, {'a':1, 'b':2});
    }catch (e) {
        expect(e.message).toBe('Graph does not include vertex 2');
        expect(e.constructor).toBe(Error);
    }
});

test("Graph: don't merge bad attribute:", ()=>{
    const g = new Graph();
    g.addVertex(1);
    try {
        g.mergeAttribute(1, null);
    }catch (e) {
        expect(e.message).toBe('Bad attribute');
        expect(e.constructor).toBe(Error);
    }
});