'use strict';

const test = require('node:test');
const assert = require('node:assert/strict');

const DashboardApi = require('../../src/specificClass.js');

// Build a source node with an optional registered-child Map. `children` is an
// array of source nodes; each is wrapped in the { child, position, softwareType }
// entry shape that childRegistrationUtils.registeredChildren uses at runtime.
function makeNode(id, softwareType, children = [], positionVsParent = 'downstream') {
  const map = new Map();
  for (const c of children) {
    map.set(c.config.general.id, {
      child: c,
      softwareType: c.config.functionality.softwareType,
      position: c.config.functionality.positionVsParent || 'downstream',
    });
  }
  return {
    config: {
      general: { id, name: id },
      functionality: { softwareType, positionVsParent },
    },
    childRegistrationUtils: { registeredChildren: map },
  };
}

test('recurses a 3-level tree from a single wired root', () => {
  const api = new DashboardApi({});
  // dashboardapi(root) -> machineGroup(child) -> machine(grandchild)
  const grandchild = makeNode('rm-1', 'machine');
  const child = makeNode('mgc-1', 'machineGroupControl', [grandchild]);
  const root = makeNode('ps-1', 'pumpingStation', [child], 'atequipment');

  const dashboards = api.generateDashboardsForGraph(root);
  const ids = dashboards.map((d) => d.nodeId);

  assert.deepEqual(ids, ['ps-1', 'mgc-1', 'rm-1'], 'pre-order: root, child, grandchild');
  assert.equal(dashboards[0].nodeId, 'ps-1', 'root composed first');
});

test('each parent links only to its own direct children (per-level links)', () => {
  const api = new DashboardApi({});
  const grandchild = makeNode('rm-1', 'machine');
  const child = makeNode('mgc-1', 'machineGroupControl', [grandchild]);
  const root = makeNode('ps-1', 'pumpingStation', [child], 'atequipment');

  const dashboards = api.generateDashboardsForGraph(root);
  const byId = Object.fromEntries(dashboards.map((d) => [d.nodeId, d.dashboard]));

  assert.equal(byId['ps-1'].links.length, 1, 'root links to its one direct child');
  assert.equal(byId['ps-1'].links[0].title, 'mgc-1');
  assert.equal(byId['mgc-1'].links.length, 1, 'child links to its one grandchild');
  assert.equal(byId['mgc-1'].links[0].title, 'rm-1');
  assert.ok(!byId['rm-1'].links || byId['rm-1'].links.length === 0, 'leaf has no child links');
});

test('cycle protection: a node reachable twice is composed once', () => {
  const api = new DashboardApi({});
  const a = makeNode('a', 'pumpingStation', [], 'atequipment');
  const b = makeNode('b', 'machineGroupControl');
  // wire a -> b and b -> a (cycle)
  a.childRegistrationUtils.registeredChildren.set('b', { child: b, softwareType: 'machineGroupControl', position: 'downstream' });
  b.childRegistrationUtils.registeredChildren.set('a', { child: a, softwareType: 'pumpingStation', position: 'downstream' });

  const dashboards = api.generateDashboardsForGraph(a);
  const ids = dashboards.map((d) => d.nodeId).sort();
  assert.deepEqual(ids, ['a', 'b'], 'each node composed exactly once despite the cycle');
});

test('diamond topology: shared descendant composed once', () => {
  const api = new DashboardApi({});
  const shared = makeNode('shared', 'machine');
  const left = makeNode('left', 'machineGroupControl', [shared]);
  const right = makeNode('right', 'machineGroupControl', [shared]);
  const root = makeNode('root', 'pumpingStation', [left, right], 'atequipment');

  const dashboards = api.generateDashboardsForGraph(root);
  const sharedCount = dashboards.filter((d) => d.nodeId === 'shared').length;
  assert.equal(sharedCount, 1, 'shared grandchild gets a single dashboard');
});

test('subtreeIdsFor recurses the full subtree (great-grandchildren included)', () => {
  const api = new DashboardApi({});
  const ggc = makeNode('ggc-1', 'measurement');
  const gc = makeNode('gc-1', 'machine', [ggc]);
  const child = makeNode('child-1', 'machineGroupControl', [gc]);

  const ids = api.subtreeIdsFor('dApi-1', child);
  assert.ok(ids.has('dApi-1') && ids.has('child-1') && ids.has('gc-1') && ids.has('ggc-1'));
  assert.equal(ids.size, 4, 'dashboardAPI + child + grandchild + great-grandchild');
});

test('includeChildren:false composes only the root (no recursion)', () => {
  const api = new DashboardApi({});
  const grandchild = makeNode('rm-1', 'machine');
  const child = makeNode('mgc-1', 'machineGroupControl', [grandchild]);
  const root = makeNode('ps-1', 'pumpingStation', [child], 'atequipment');

  const dashboards = api.generateDashboardsForGraph(root, { includeChildren: false });
  assert.equal(dashboards.length, 1);
  assert.equal(dashboards[0].nodeId, 'ps-1');
});