import { describe, expect, it } from 'vitest';
import { buildGeometry, insetPolygon, signedArea } from '../src/lib/geometry';
import type { Point, Room } from '../src/lib/types';

const rectangle = (last = 3000): Room => ({
  id: 'r1',
  name: 'Room',
  direction: 0,
  walls: [4000, 3000, 4000, last].map((length, index) => ({
    id: `w${index}`,
    length,
    turn: 90,
    doors: [],
  })),
});

function roomFromPoints(vertices: Point[]): Room {
  const headings = vertices.map((point, index) => {
    const next = vertices[(index + 1) % vertices.length];
    return (Math.atan2(next.y - point.y, next.x - point.x) * 180) / Math.PI;
  });
  return {
    id: 'shape',
    name: 'Shape',
    direction: 0,
    walls: vertices.map((point, index) => {
      const next = vertices[(index + 1) % vertices.length];
      const turn = ((headings[(index + 1) % headings.length] - headings[index] + 540) % 360) - 180;
      return {
        id: `w${index}`,
        length: Math.hypot(next.x - point.x, next.y - point.y),
        turn,
        doors: [],
      };
    }),
  };
}

describe('measured room geometry', () => {
  it('closes a rectangle and ignores the unused final turn', () => {
    const room = rectangle();
    room.walls[3].turn = 0;
    const result = buildGeometry(room, 5);
    expect(result.valid).toBe(true);
    expect(result.vertices).toHaveLength(4);
    expect(result.area).toBeCloseTo(12_000_000);
    expect(result.perimeter).toBeCloseTo(14_000);
    expect(result.finalLengthError).toBeCloseTo(0);
    expect(result.finalAngleError).toBeCloseTo(0);
  });

  it('predicts the next closing length and signed turn for an unfinished room', () => {
    const room = rectangle();
    room.walls.pop();
    const result = buildGeometry(room, 5);
    expect(result.closed).toBe(false);
    expect(result.valid).toBe(false);
    expect(result.vertices).toHaveLength(4);
    expect(result.closingLength).toBeCloseTo(3000);
    expect(result.closingTurn).toBeCloseTo(90);
  });

  it('reports the measured final wall mismatch, accepting only residuals inside tolerance', () => {
    const result = buildGeometry(rectangle(3003), 5);
    expect(result.valid).toBe(true);
    expect(result.gap).toBeCloseTo(3);
    expect(result.finalLengthError).toBeCloseTo(3);
    expect(result.edges[3].length).toBeCloseTo(3000);
    expect(
      result.issues.some(
        (issue) => issue.severity === 'warning' && issue.message.includes('remeasure'),
      ),
    ).toBe(true);
    expect(buildGeometry(rectangle(3020), 5).valid).toBe(false);
    expect(buildGeometry(rectangle(3020), 1e308).closed).toBe(false);
    expect(buildGeometry(rectangle(), 51).valid).toBe(false);
  });

  it('reports direction mismatch rather than assigning the residual to a bowed wall', () => {
    const room = rectangle();
    room.walls[2].turn = 88;
    const result = buildGeometry(room, 5);
    expect(result.valid).toBe(false);
    expect(Math.abs(result.finalAngleError)).toBeCloseTo(2);
    expect(result.gap).toBeGreaterThan(100);
  });

  it('supports a concave fireplace and a slanted outer wall', () => {
    const room = roomFromPoints([
      { x: 0, y: 0 },
      { x: 5000, y: 0 },
      { x: 5000, y: 4000 },
      { x: 3000, y: 4000 },
      { x: 3000, y: 3400 },
      { x: 2000, y: 3400 },
      { x: 2000, y: 4000 },
      { x: 0, y: 3500 },
    ]);
    const result = buildGeometry(room, 0.1);
    expect(result.valid).toBe(true);
    expect(result.vertices).toHaveLength(8);
    expect(result.area).toBeCloseTo(18_900_000);
    const inset = insetPolygon(result.vertices, 10);
    expect(inset).toHaveLength(1);
    expect(Math.abs(signedArea(inset[0]))).toBeLessThan(result.area);
  });

  it('rejects crossing outlines, invalid lengths and impossible turns', () => {
    const crossed = roomFromPoints([
      { x: 0, y: 0 },
      { x: 4000, y: 0 },
      { x: 0, y: 3000 },
      { x: 4000, y: 3000 },
    ]);
    expect(buildGeometry(crossed, 5).issues.some((issue) => issue.message.includes('cross'))).toBe(
      true,
    );
    const room = rectangle();
    room.walls[0].length = -1;
    room.walls[1].turn = 180;
    expect(buildGeometry(room, 5).valid).toBe(false);
    room.walls[0].length = 1e308;
    expect(Number.isFinite(buildGeometry(room, 5).area)).toBe(true);
  });

  it('validates door boundaries and overlapping openings', () => {
    const room = rectangle();
    room.walls[0].doors = [
      { id: 'd1', offset: 300, width: 900 },
      { id: 'd2', offset: 1000, width: 900 },
    ];
    expect(buildGeometry(room, 5).issues.some((issue) => issue.message.includes('overlap'))).toBe(
      true,
    );
    room.walls[0].doors = [{ id: 'd1', offset: 3500, width: 900 }];
    expect(buildGeometry(room, 5).valid).toBe(false);
    room.walls[0].doors = [{ id: 'd1', offset: 0, width: 900 }];
    expect(buildGeometry(room, 5).valid).toBe(true);
  });

  it('insets clockwise and anticlockwise rectangles and detects an erased room', () => {
    const vertices = buildGeometry(rectangle(), 5).vertices;
    for (const points of [vertices, [...vertices].reverse()]) {
      const inset = insetPolygon(points, 10);
      expect(inset).toHaveLength(1);
      expect(Math.abs(signedArea(inset[0]))).toBeCloseTo(3980 * 2980);
    }
    expect(insetPolygon(vertices, 1600)).toEqual([]);
    expect(insetPolygon(vertices, 1e308)).toEqual([]);
  });

  it('returns separate floor regions when a narrow connecting passage disappears', () => {
    const inset = insetPolygon(
      [
        { x: 0, y: 0 },
        { x: 2000, y: 0 },
        { x: 2000, y: 900 },
        { x: 3000, y: 900 },
        { x: 3000, y: 0 },
        { x: 5000, y: 0 },
        { x: 5000, y: 2000 },
        { x: 3000, y: 2000 },
        { x: 3000, y: 1100 },
        { x: 2000, y: 1100 },
        { x: 2000, y: 2000 },
        { x: 0, y: 2000 },
      ],
      150,
    );
    expect(inset).toHaveLength(2);
    expect(inset.every((polygon) => signedArea(polygon) > 0)).toBe(true);
  });
});