import BaseObservableMap from "./BaseObservableMap.js";

export default class ObservableMap extends BaseObservableMap {
    constructor(keyFn, initialValues) {
        super();
        this._keyFn = keyFn;
        this._values = new Map(initialValues);
    }

    update(key, params) {
        const value = this._values.get(key);
        if (value !== undefined) {
            // could be the same value, so it's already updated
            // but we don't assume this here
            this._values.set(key, value);
            this.emitUpdate(key, value, params);
            return true;
        }
        return false;   // or return existing value?
    }

    add(key, value) {
        if (!this._values.has(key)) {
            this._values.set(key, value);
            this.emitAdd(key, value);
            return true;
        }
        return false;   // or return existing value?
    }

    remove(key) {
        const value = this._values.get(key);
        if (value !== undefined) {
            this._values.delete(key);
            this.emitRemove(key, value);
            return true;
        } else {
            return false;
        }
    }

    reset() {
        this._values.clear();
        this.emitReset();
    }

    get(key) {
        return this._values.get(key);
    }

    get size() {
        return this._values.size;
    }

    [Symbol.iterator]() {
        return this._values.entries();
    }
}

//#ifdef TESTS
export function tests() {
    return {
        test_add(assert) {
            let fired = 0;
            const map = new ObservableMap();
            map.subscribe({
                onAdd(key, value) {
                    fired += 1;
                    assert.equal(key, 1);
                    assert.deepEqual(value, {value: 5}); 
                }
            });
            map.add(1, {value: 5});
            assert.equal(map.size, 1);
            assert.equal(fired, 1);
        },

        test_update(assert) {
            let fired = 0;
            const map = new ObservableMap();
            const value = {number: 5};
            map.add(1, value);
            map.subscribe({
                onUpdate(key, value, params) {
                    fired += 1;
                    assert.equal(key, 1);
                    assert.deepEqual(value, {number: 6}); 
                    assert.equal(params, "test");
                }
            });
            value.number = 6;
            map.update(1, "test");
            assert.equal(fired, 1);
        },

        test_update_unknown(assert) {
            let fired = 0;
            const map = new ObservableMap(v => v.id);
            map.subscribe({
                onUpdate() { fired += 1; }
            });
            const result = map.update(1);
            assert.equal(fired, 0);
            assert.equal(result, false);
        },

        test_remove(assert) {
            let fired = 0;
            const map = new ObservableMap();
            const value = {value: 5};
            map.add(1, value);
            map.subscribe({
                onRemove(key, value) {
                    fired += 1;
                    assert.equal(key, 1);
                    assert.deepEqual(value, {value: 5}); 
                }
            });
            map.remove(1);
            assert.equal(map.size, 0);
            assert.equal(fired, 1);
        },

        test_iterate(assert) {
            const results = [];
            const map = new ObservableMap();
            map.add(1, {number: 5});
            map.add(2, {number: 6});
            map.add(3, {number: 7});
            for (let e of map) {
                results.push(e);
            }
            assert.equal(results.length, 3);
            assert.equal(results.find(([key]) => key === 1)[1].number, 5);
            assert.equal(results.find(([key]) => key === 2)[1].number, 6);
            assert.equal(results.find(([key]) => key === 3)[1].number, 7);
        },
        test_size(assert) {
            const map = new ObservableMap();
            map.add(1, {number: 5});
            map.add(2, {number: 6});
            assert.equal(map.size, 2);
        },
    }
}
//#endif