/**
 * Gauge Update Behavior Tests
 * Tests for how gauge responds to prop updates (renderChart vs initChart paths)
 */

describe('Gauge Update Behavior', () => {
  describe('renderChart Path (no full reinit)', () => {
    /**
     * Simulates the shouldRenderChart logic - returns true when props should be handled
     * by renderChart instead of initChart (avoiding gauge reset)
     */
    const shouldUseRenderChart = (prev: any, curr: any): { shouldRender: boolean; changes: string[] } => {
      const changes: string[] = [];
      
      // Value changes go through renderChart
      if (prev.value !== curr.value) {
        changes.push('valueChanged');
      }
      
      // Pointer props (except hide) go through renderChart
      const pointerPropsToCheck = ['type', 'color', 'length', 'width', 'strokeWidth', 'strokeColor'];
      pointerPropsToCheck.forEach(prop => {
        if (prev.pointer?.[prop] !== curr.pointer?.[prop]) {
          changes.push(`pointer.${prop}Changed`);
        }
      });
      
      // Multi-pointer value and prop changes go through renderChart
      if (Array.isArray(prev.pointers) && Array.isArray(curr.pointers)) {
        const valuesChanged = curr.pointers.some((p: any, i: number) => 
          p.value !== prev.pointers[i]?.value
        );
        if (valuesChanged) {
          changes.push('multiPointerValuesChanged');
        }
        
        const propsChanged = curr.pointers.some((p: any, i: number) => {
          const prevP = prev.pointers[i];
          if (!prevP) return false;
          return p.type !== prevP.type || p.color !== prevP.color;
        });
        if (propsChanged) {
          changes.push('multiPointerPropsChanged');
        }
      }
      
      return { shouldRender: changes.length > 0, changes };
    };

    it('should use renderChart for value changes', () => {
      const prev = { value: 50 };
      const curr = { value: 75 };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('valueChanged');
    });

    it('should use renderChart for pointer type changes', () => {
      const prev = { pointer: { type: 'needle' } };
      const curr = { pointer: { type: 'blob' } };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('pointer.typeChanged');
    });

    it('should use renderChart for pointer color changes', () => {
      const prev = { pointer: { color: '#464A4F' } };
      const curr = { pointer: { color: '#ff0000' } };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('pointer.colorChanged');
    });

    it('should use renderChart for pointer length changes', () => {
      const prev = { pointer: { length: 0.8 } };
      const curr = { pointer: { length: 0.6 } };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('pointer.lengthChanged');
    });

    it('should use renderChart for multi-pointer value changes', () => {
      const prev = { pointers: [{ value: 30 }, { value: 60 }] };
      const curr = { pointers: [{ value: 40 }, { value: 70 }] };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('multiPointerValuesChanged');
    });

    it('should use renderChart for multi-pointer prop changes', () => {
      const prev = { pointers: [{ value: 30, type: 'needle' }] };
      const curr = { pointers: [{ value: 30, type: 'blob' }] };
      const { shouldRender, changes } = shouldUseRenderChart(prev, curr);
      expect(shouldRender).toBe(true);
      expect(changes).toContain('multiPointerPropsChanged');
    });
  });

  describe('Animation Flag Preservation', () => {
    it('should preserve animation progress when using renderChart path', () => {
      // Simulates that renderChart doesn't reset animation flags
      const initialAnimationTriggered = { current: true };
      const animationInProgress = { current: false };
      
      // After renderChart (not initChart), flags should be preserved
      // initChart would reset these to false
      expect(initialAnimationTriggered.current).toBe(true);
    });

    it('should allow animation to continue from current position', () => {
      const lastRenderedProgress = 0.6;
      const targetProgress = 0.8;
      
      // Animation should interpolate from current to target
      const animationStartPercent = lastRenderedProgress;
      expect(animationStartPercent).toBe(0.6);
      expect(targetProgress - animationStartPercent).toBeCloseTo(0.2);
    });
  });

  describe('Slider Real-time Updates', () => {
    it('should detect value change immediately', () => {
      const prevValue = 50 as number;
      const currValue = 51 as number; // Small change from slider drag
      const valueChanged = prevValue !== currValue;
      expect(valueChanged).toBe(true);
    });

    it('should not require full reinit for slider updates', () => {
      const prev = { value: 50 as number, pointer: { type: 'needle' as string } };
      const curr = { value: 51 as number, pointer: { type: 'needle' as string } };
      
      // Only value changed, pointer is same
      const onlyValueChanged = prev.value !== curr.value && 
        prev.pointer.type === curr.pointer.type;
      expect(onlyValueChanged).toBe(true);
    });
  });
});