import { describe, expect, it } from 'vitest';
import type { Coordinate } from './meters';
import { disabledReasonOf, handlesForSegment, intervalRangeHandles, reservesForSegment } from './selection';
import type { ConstraintKind, EditHandle, HandleManifest, SemanticAnchor } from './types';

function handle(handleId: string, kind: ConstraintKind, anchor: SemanticAnchor, editable = true): EditHandle {
  return {
    handleId,
    kind,
    anchor,
    position: [116.397, 39.908],
    axisAzimuth: 90,
    value: { current: 0, min: -5, max: 5, unit: 'meter' },
    affects: [],
    editable,
    ...(editable ? {} : { disabledReason: '该道路全部位于路口保留区，请进入 JunctionTools 编辑。' }),
  };
}

const roadInterval = (roadId: string): SemanticAnchor => ({
  type: 'road-interval',
  roadId,
  startStation: 0.15,
  endStation: 0.85,
  side: 'left',
});

// Two segments, plus a junction handle the main map must never render.
const manifest: HandleManifest = {
  schema: 'road-edit-handles/v1',
  revisionId: 'rev-0001',
  previewSeq: 0,
  handles: [
    handle('h:edge:a', 'road-edge-offset', roadInterval('road:way/1:forward')),
    handle('h:sidewalk:a', 'road-sidewalk-width', roadInterval('road:way/1:forward')),
    handle('h:edge:b', 'road-edge-offset', roadInterval('road:way/2:forward')),
    handle('h:blocked:a', 'road-lane-divider', roadInterval('road:way/1:forward'), false),
    handle('h:approach', 'junction-approach-width', { type: 'junction-approach', nodeId: '9', segmentId: 'seg:1' }),
    handle('h:corner', 'junction-corner-radius', {
      type: 'junction-corner',
      nodeId: '9',
      incomingRoadId: 'seg:1',
      outgoingRoadId: 'seg:2',
    }),
  ],
  reserves: [
    { nodeId: '9', roadId: 'seg:1', fromStation: 0, toStation: 0.15 },
    { nodeId: '10', roadId: 'seg:1', fromStation: 0.85, toStation: 1 },
    { nodeId: '11', roadId: 'seg:2', fromStation: 0, toStation: 0.3 },
  ],
};

const segmentOf = (roadId: string) =>
  ({ 'road:way/1:forward': 'seg:1', 'road:way/2:forward': 'seg:2' })[roadId] ?? undefined;

describe('handlesForSegment', () => {
  it('keeps only the selected segment', () => {
    expect(handlesForSegment(manifest, 'seg:1', segmentOf).map((item) => item.handleId)).toEqual([
      'h:edge:a',
      'h:sidewalk:a',
      'h:blocked:a',
    ]);
    expect(handlesForSegment(manifest, 'seg:2', segmentOf).map((item) => item.handleId)).toEqual(['h:edge:b']);
  });

  it('never renders junction kinds on the main map', () => {
    // Reserve interiors belong to JunctionTools; offering a second way to edit
    // them here is exactly the ownership split design.md forbids.
    const kinds = handlesForSegment(manifest, 'seg:1', segmentOf).map((item) => item.kind);
    expect(kinds).not.toContain('junction-approach-width');
    expect(kinds).not.toContain('junction-corner-radius');
  });

  it('keeps disabled handles so the boundary stays explainable', () => {
    const blocked = handlesForSegment(manifest, 'seg:1', segmentOf).find((item) => !item.editable);
    expect(blocked?.handleId).toBe('h:blocked:a');
  });

  it('returns nothing without a manifest or a selection', () => {
    expect(handlesForSegment(null, 'seg:1', segmentOf)).toEqual([]);
    expect(handlesForSegment(manifest, null, segmentOf)).toEqual([]);
  });

  it('drops handles whose road no longer resolves to a segment', () => {
    expect(handlesForSegment(manifest, 'seg:1', () => undefined)).toEqual([]);
  });
});

describe('reservesForSegment', () => {
  it('returns only that segment’s reserves', () => {
    expect(reservesForSegment(manifest, 'seg:1').map((item) => item.nodeId)).toEqual(['9', '10']);
    expect(reservesForSegment(manifest, 'seg:2').map((item) => item.nodeId)).toEqual(['11']);
  });

  it('returns nothing without a manifest or a selection', () => {
    expect(reservesForSegment(null, 'seg:1')).toEqual([]);
    expect(reservesForSegment(manifest, null)).toEqual([]);
  });
});

describe('intervalRangeHandles', () => {
  // Heads due north, about 1112 m long.
  const centerline: Coordinate[] = [
    [116.397, 39.9],
    [116.397, 39.91],
  ];
  const reserves = manifest.reserves;
  const parent = handle('h:edge:a', 'road-edge-offset', roadInterval('road:way/1:forward'));

  it('produces one handle per end of the affected interval', () => {
    const ends = intervalRangeHandles(parent, centerline, reserves, 'seg:1');
    expect(ends.map((item) => item.end)).toEqual(['start', 'end']);
    expect(ends.map((item) => item.station)).toEqual([0.15, 0.85]);
  });

  it('derives ids from the parent so the pair stays traceable', () => {
    const ends = intervalRangeHandles(parent, centerline, reserves, 'seg:1');
    expect(ends.map((item) => item.handleId)).toEqual(['h:edge:a:range:start', 'h:edge:a:range:end']);
    expect(ends.every((item) => item.parentHandleId === 'h:edge:a')).toBe(true);
  });

  it('carries the reserve-free window, not the whole road', () => {
    const [start] = intervalRangeHandles(parent, centerline, reserves, 'seg:1');
    // The two reserves on seg:1 leave 0.15..0.85, which is exactly the interval
    // the solver anchored — a range drag may shrink it but never grow past this.
    expect(start.window).toEqual({ minStation: 0.15, maxStation: 0.85 });
  });

  it('places the ends apart, along the road', () => {
    const [start, end] = intervalRangeHandles(parent, centerline, reserves, 'seg:1');
    expect(start.position[1]).toBeLessThan(end.position[1]);
    expect(start.position[0]).toBeCloseTo(116.397, 6);
    // Drag axis is the road direction, which is due north here.
    expect(start.tangentAzimuth).toBeCloseTo(0, 3);
    expect(start.roadLengthMeters).toBeCloseTo(end.roadLengthMeters, 6);
    expect(start.roadLengthMeters).toBeGreaterThan(1000);
  });

  it('offers nothing for a handle that cannot be dragged', () => {
    const blocked = handle('h:blocked', 'road-edge-offset', roadInterval('road:way/1:forward'), false);
    expect(intervalRangeHandles(blocked, centerline, reserves, 'seg:1')).toEqual([]);
  });

  it('offers nothing for a junction anchor', () => {
    const approach = handle('h:approach', 'junction-approach-width', {
      type: 'junction-approach',
      nodeId: '9',
      segmentId: 'seg:1',
    });
    expect(intervalRangeHandles(approach, centerline, reserves, 'seg:1')).toEqual([]);
  });

  it('offers nothing for a road with no length', () => {
    expect(intervalRangeHandles(parent, [[116.397, 39.9]], reserves, 'seg:1')).toEqual([]);
    expect(
      intervalRangeHandles(
        parent,
        [
          [116.397, 39.9],
          [116.397, 39.9],
        ],
        reserves,
        'seg:1',
      ),
    ).toEqual([]);
  });
});

describe('disabledReasonOf', () => {
  it('says nothing for an editable handle', () => {
    expect(disabledReasonOf(handle('h', 'road-edge-offset', roadInterval('road:way/1:forward')))).toBeUndefined();
  });

  it('passes the server reason through', () => {
    const blocked = handle('h', 'road-edge-offset', roadInterval('road:way/1:forward'), false);
    expect(disabledReasonOf(blocked)).toContain('JunctionTools');
  });

  it('always gives some reason, even when the server omitted one', () => {
    const blocked = { ...handle('h', 'road-edge-offset', roadInterval('road:way/1:forward'), false) };
    delete blocked.disabledReason;
    expect(disabledReasonOf(blocked)).toContain('路口保留区');
  });
});