/**
 * Task H5 – Flächenberechnung Polygon (m²) + measure-area Tool.
 *
 * polygonArea: Shoelace-Formel (Absolutwert, CW/CCW egal),
 * formatArea: Einheiten-Formatierung analog formatDistance,
 * measureAreaTool: Klick-Sequenz, Live-Fläche im Status, ENTER
 * committet ab 3 Punkten, cancel setzt zurück.
 */
import { describe, it, expect, vi, beforeEach } from 'vitest';
import { polygonArea } from '../src/tools/modification/geometry';
import { formatArea } from '../src/utils/format';
import { measureAreaTool } from '../src/plugins/builtin/core-measure';
import type { CADElement } from '../src/types/cad.types';

describe('H5: polygonArea (Shoelace)', () => {
  it('Rechteck 100×50 = 5000 Welt-Einheiten²', () => {
    const pts = [
      { x: 0, y: 0 }, { x: 100, y: 0 },
      { x: 100, y: 50 }, { x: 0, y: 50 },
    ];
    expect(polygonArea(pts)).toBeCloseTo(5000, 6);
  });

  it('Dreieck 100×50/2 = 2500', () => {
    const pts = [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 0, y: 50 }];
    expect(polygonArea(pts)).toBeCloseTo(2500, 6);
  });

  it('Uhrzeigersinn und gegen Uhrzeigersinn ergeben denselben Absolutwert', () => {
    const ccw = [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 100 }, { x: 0, y: 100 }];
    const cw = [...ccw].reverse();
    expect(polygonArea(cw)).toBeCloseTo(polygonArea(ccw), 6);
    expect(polygonArea(cw)).toBeCloseTo(10000, 6);
  });

  it('weniger als 3 Punkte → 0; kollineare Punkte → 0', () => {
    expect(polygonArea([{ x: 0, y: 0 }, { x: 1, y: 1 }])).toBe(0);
    expect(polygonArea([{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 200, y: 0 }])).toBe(0);
  });
});

describe('H5: formatArea', () => {
  it('mm: 5000 → "5000 mm²" (scaleFactor 1)', () => {
    expect(formatArea(5000, 'mm', 1)).toBe('5000 mm²');
  });

  it('cm: 5000mm² → "50.0 cm²"', () => {
    expect(formatArea(5000, 'cm', 1)).toBe('50.0 cm²');
  });

  it('m: 5000000mm² → "5.00 m²"', () => {
    expect(formatArea(5000000, 'm', 1)).toBe('5.00 m²');
  });

  it('Flächen skalieren QUADRATISCH: 5 WE² bei scaleFactor 1000 = 5000000 mm²', () => {
    // 1 Welt-Einheit = 1000mm → 1 WE² = 1.000.000 mm²
    expect(formatArea(5, 'mm', 1000)).toBe('5000000 mm²');
  });
});

describe('H5: measureAreaTool', () => {
  // Module-State areaPts leakt zwischen Tests — vor jedem Test resetten:
  beforeEach(() => {
    measureAreaTool.handlers.cancel?.({ setStatus: () => {} } as never);
  });
  function fireSeq(events: Array<{ type: 'down' | 'move' | 'key' | 'cancel'; x?: number; y?: number; key?: string }>, options: Record<string, unknown> = {}) {
    const statuses: string[] = [];
    const ctx: any = {
      options,
      setStatus: (m: string) => statuses.push(m),
      setPreview: (_el: CADElement | null) => {},
      doc: null,
    };
    for (const ev of events) {
      if (ev.type === 'down') measureAreaTool.handlers.down!({ world: { x: ev.x!, y: ev.y! } } as never, ctx);
      if (ev.type === 'move') measureAreaTool.handlers.move!({ world: { x: ev.x!, y: ev.y! } } as never, ctx);
      if (ev.type === 'key' && ev.key) measureAreaTool.handlers.key?.({ key: ev.key } as never, ctx);
      if (ev.type === 'cancel') measureAreaTool.handlers.cancel?.(ctx);
    }
    return statuses;
  }

  it('erster Klick startet Messung, Status fordert weitere Punkte', () => {
    const s = fireSeq([{ type: 'down', x: 0, y: 0 }]);
    expect(s[0]).toContain('Fläche');
    expect(s[s.length - 1]).toContain('klicken');
  });

  it('Live-Fläche im Status ab 3 Punkten bei move', () => {
    const s = fireSeq([
      { type: 'down', x: 0, y: 0 },
      { type: 'down', x: 100, y: 0 },
      { type: 'down', x: 100, y: 50 },
      { type: 'move', x: 0, y: 50 },
    ]);
    expect(s.some((m) => m.includes('5000'))).toBe(true);
    expect(s[s.length - 1]).toContain('mm²');
  });

  it('ENTER committet ab 3 Punkten mit Endfläche im Status', () => {
    const s = fireSeq([
      { type: 'down', x: 0, y: 0 },
      { type: 'down', x: 100, y: 0 },
      { type: 'down', x: 100, y: 100 },
      { type: 'key', key: 'Enter' },
    ]);
    // Dreieck (0,0),(100,0),(100,100): Shoelace = 1/2 · 100 · 100 = 5000
    expect(s[s.length - 1]).toContain('5000');
    expect(s[s.length - 1]).toContain('3 Punkte');
  });

  it('ENTER mit weniger als 3 Punkten committet NICHT (Status erklärt)', () => {
    const s = fireSeq([
      { type: 'down', x: 0, y: 0 },
      { type: 'down', x: 100, y: 0 },
      { type: 'key', key: 'Enter' },
    ]);
    expect(s[s.length - 1]).toContain('3');
  });

  it('cancel setzt Messung zurück', () => {
    const s = fireSeq([
      { type: 'down', x: 0, y: 0 },
      { type: 'down', x: 50, y: 50 },
      { type: 'cancel' },
      { type: 'down', x: 0, y: 0 },
    ]);
    // Nach cancel startet eine frische Messung (kein altes Polygon)
    expect(s[s.length - 1]).toContain('klicken');
  });

  it('Manifest: id measure-area, tags basic, ribbonTab canvas', () => {
    expect(measureAreaTool.manifest.id).toBe('measure-area');
    expect(measureAreaTool.manifest.ribbonTab).toBe('canvas');
    expect((measureAreaTool.manifest.tags ?? [])).toContain('basic');
  });
});