/**
 * Tests for canvas controls (pan, zoom, rotate, reset, fit)
 * Tests viewport store and control functions
 */

import { describe, it, expect, beforeEach, vi } from 'vitest';
import { get } from 'svelte/store';
import { viewport, isViewportDefault, isZoomMin, isZoomMax } from '$lib/stores/viewport';
import { panTo, panBy } from '$lib/canvas/controls/pan';
import { zoomTo, zoomBy, zoomIn, zoomOut } from '$lib/canvas/controls/zoom';
import {
  rotateTo,
  rotateBy,
  rotateClockwise,
  rotateCounterClockwise,
  resetRotation,
  rotateTo90,
  rotateTo180,
  rotateTo270,
} from '$lib/canvas/controls/rotate';
import { resetCamera, resetPan, resetZoom } from '$lib/canvas/controls/reset';

describe('Viewport Store', () => {
  beforeEach(() => {
    // Reset viewport to default state before each test
    viewport.reset();
  });

  describe('Initialization', () => {
    it('starts with default values', () => {
      const state = get(viewport);
      expect(state).toEqual({
        x: 0,
        y: 0,
        zoom: 1.0,
        rotation: 0,
      });
    });

    it('isViewportDefault is true at initialization', () => {
      expect(get(isViewportDefault)).toBe(true);
    });

    it('provides viewport bounds', () => {
      const bounds = viewport.getBounds();
      expect(bounds).toEqual({
        minZoom: 0.1,
        maxZoom: 5.0,
        minRotation: 0,
        maxRotation: 360,
      });
    });
  });

  describe('Pan Operations', () => {
    it('sets pan position', () => {
      viewport.setPan(100, 200);
      const state = get(viewport);
      expect(state.x).toBe(100);
      expect(state.y).toBe(200);
    });

    it('pans by delta', () => {
      viewport.setPan(50, 50);
      viewport.panBy(25, 30);
      const state = get(viewport);
      expect(state.x).toBe(75);
      expect(state.y).toBe(80);
    });

    it('allows negative pan values', () => {
      viewport.setPan(-100, -200);
      const state = get(viewport);
      expect(state.x).toBe(-100);
      expect(state.y).toBe(-200);
    });

    it('handles large pan values', () => {
      viewport.setPan(100000, 100000);
      const state = get(viewport);
      expect(state.x).toBe(100000);
      expect(state.y).toBe(100000);
    });
  });

  describe('Zoom Operations', () => {
    it('sets zoom level', () => {
      viewport.setZoom(2.0);
      const state = get(viewport);
      expect(state.zoom).toBe(2.0);
    });

    it('clamps zoom to minimum', () => {
      viewport.setZoom(0.05);
      const state = get(viewport);
      expect(state.zoom).toBe(0.1);
    });

    it('clamps zoom to maximum', () => {
      viewport.setZoom(10.0);
      const state = get(viewport);
      expect(state.zoom).toBe(5.0);
    });

    it('zooms by factor', () => {
      viewport.setZoom(1.0);
      viewport.zoomBy(2.0);
      const state = get(viewport);
      expect(state.zoom).toBe(2.0);
    });

    it('zooms to center point', () => {
      viewport.setZoom(1.0, 100, 100);
      const state = get(viewport);
      expect(state.zoom).toBe(1.0);
      // Position should remain at center
    });

    it('isZoomMin reflects minimum zoom', () => {
      viewport.setZoom(0.1);
      expect(get(isZoomMin)).toBe(true);

      viewport.setZoom(1.0);
      expect(get(isZoomMin)).toBe(false);
    });

    it('isZoomMax reflects maximum zoom', () => {
      viewport.setZoom(5.0);
      expect(get(isZoomMax)).toBe(true);

      viewport.setZoom(1.0);
      expect(get(isZoomMax)).toBe(false);
    });
  });

  describe('Rotation Operations', () => {
    it('sets rotation', () => {
      viewport.setRotation(45);
      const state = get(viewport);
      expect(state.rotation).toBe(45);
    });

    it('normalizes rotation to 0-360', () => {
      viewport.setRotation(450);
      expect(get(viewport).rotation).toBe(90);

      viewport.setRotation(-90);
      expect(get(viewport).rotation).toBe(270);
    });

    it('rotates by delta', () => {
      viewport.setRotation(45);
      viewport.rotateBy(15);
      expect(get(viewport).rotation).toBe(60);
    });

    it('handles negative rotation delta', () => {
      viewport.setRotation(45);
      viewport.rotateBy(-15);
      expect(get(viewport).rotation).toBe(30);
    });

    it('wraps rotation around 360', () => {
      viewport.setRotation(350);
      viewport.rotateBy(20);
      expect(get(viewport).rotation).toBe(10);
    });
  });

  describe('Reset Operations', () => {
    it('resets viewport to default', () => {
      viewport.setPan(100, 100);
      viewport.setZoom(2.0);
      viewport.setRotation(45);

      viewport.reset();

      const state = get(viewport);
      expect(state).toEqual({
        x: 0,
        y: 0,
        zoom: 1.0,
        rotation: 0,
      });
    });

    it('reset makes isViewportDefault true', () => {
      viewport.setPan(100, 100);
      expect(get(isViewportDefault)).toBe(false);

      viewport.reset();
      expect(get(isViewportDefault)).toBe(true);
    });
  });

  describe('Fit to Screen', () => {
    it('fits content to screen with default padding', () => {
      viewport.fitToScreen(800, 600, 1024, 768);

      const state = get(viewport);
      expect(state.zoom).toBeGreaterThan(0);
      expect(state.rotation).toBe(0); // Rotation reset when fitting
    });

    it('fits content with custom padding', () => {
      viewport.fitToScreen(800, 600, 1024, 768, 100);

      const state = get(viewport);
      expect(state.zoom).toBeGreaterThan(0);
    });

    it('handles oversized content', () => {
      viewport.fitToScreen(2000, 1500, 1024, 768);

      const state = get(viewport);
      expect(state.zoom).toBeLessThan(1.0);
    });

    it('handles undersized content', () => {
      viewport.fitToScreen(100, 100, 1024, 768);

      const state = get(viewport);
      expect(state.zoom).toBeGreaterThan(1.0);
    });

    it('respects maximum zoom when fitting', () => {
      // Very small content that would zoom beyond max
      viewport.fitToScreen(10, 10, 1024, 768);

      const state = get(viewport);
      expect(state.zoom).toBeLessThanOrEqual(5.0);
    });
  });

  describe('Load State', () => {
    it('loads partial state', () => {
      viewport.loadState({ x: 100, y: 200 });

      const state = get(viewport);
      expect(state.x).toBe(100);
      expect(state.y).toBe(200);
      expect(state.zoom).toBe(1.0); // Unchanged
      expect(state.rotation).toBe(0); // Unchanged
    });

    it('loads complete state', () => {
      viewport.loadState({
        x: 100,
        y: 200,
        zoom: 2.5,
        rotation: 90,
      });

      const state = get(viewport);
      expect(state).toEqual({
        x: 100,
        y: 200,
        zoom: 2.5,
        rotation: 90,
      });
    });

    it('clamps loaded zoom to bounds', () => {
      viewport.loadState({ zoom: 10.0 });
      expect(get(viewport).zoom).toBe(5.0);

      viewport.loadState({ zoom: 0.01 });
      expect(get(viewport).zoom).toBe(0.1);
    });

    it('normalizes loaded rotation', () => {
      viewport.loadState({ rotation: 450 });
      expect(get(viewport).rotation).toBe(90);

      viewport.loadState({ rotation: -45 });
      expect(get(viewport).rotation).toBe(315);
    });
  });

  describe('State Subscription', () => {
    it('notifies subscribers on pan changes', () => {
      const subscriber = vi.fn();
      const unsubscribe = viewport.subscribe(subscriber);

      viewport.setPan(100, 100);

      expect(subscriber).toHaveBeenCalled();
      unsubscribe();
    });

    it('notifies subscribers on zoom changes', () => {
      const subscriber = vi.fn();
      const unsubscribe = viewport.subscribe(subscriber);

      viewport.setZoom(2.0);

      expect(subscriber).toHaveBeenCalled();
      unsubscribe();
    });

    it('notifies subscribers on rotation changes', () => {
      const subscriber = vi.fn();
      const unsubscribe = viewport.subscribe(subscriber);

      viewport.setRotation(45);

      expect(subscriber).toHaveBeenCalled();
      unsubscribe();
    });
  });
});

describe('Pan Controls', () => {
  beforeEach(() => {
    viewport.reset();
  });

  describe('Programmatic Pan', () => {
    it('panTo sets absolute position', () => {
      panTo(100, 200);

      const state = get(viewport);
      expect(state.x).toBe(100);
      expect(state.y).toBe(200);
    });

    it('panBy moves relative to current position', () => {
      panTo(50, 50);
      panBy(25, 30);

      const state = get(viewport);
      expect(state.x).toBe(75);
      expect(state.y).toBe(80);
    });

    it('panBy with negative deltas', () => {
      panTo(100, 100);
      panBy(-50, -50);

      const state = get(viewport);
      expect(state.x).toBe(50);
      expect(state.y).toBe(50);
    });
  });
});

describe('Zoom Controls', () => {
  beforeEach(() => {
    viewport.reset();
  });

  describe('Programmatic Zoom', () => {
    it('zoomTo sets absolute zoom level', () => {
      zoomTo(2.5);

      expect(get(viewport).zoom).toBe(2.5);
    });

    it('zoomBy multiplies current zoom', () => {
      zoomTo(2.0);
      zoomBy(1.5);

      expect(get(viewport).zoom).toBe(3.0);
    });

    it('zoomIn increases zoom', () => {
      const initialZoom = get(viewport).zoom;
      zoomIn();

      expect(get(viewport).zoom).toBeGreaterThan(initialZoom);
    });

    it('zoomOut decreases zoom', () => {
      zoomTo(2.0);
      const initialZoom = get(viewport).zoom;
      zoomOut();

      expect(get(viewport).zoom).toBeLessThan(initialZoom);
    });

    it('zoomIn respects maximum zoom', () => {
      zoomTo(4.9);
      zoomIn();

      expect(get(viewport).zoom).toBeLessThanOrEqual(5.0);
    });

    it('zoomOut respects minimum zoom', () => {
      zoomTo(0.15);
      zoomOut();

      expect(get(viewport).zoom).toBeGreaterThanOrEqual(0.1);
    });
  });
});

describe('Rotate Controls', () => {
  beforeEach(() => {
    viewport.reset();
  });

  describe('Programmatic Rotation', () => {
    it('rotateTo sets absolute rotation', () => {
      rotateTo(90);

      expect(get(viewport).rotation).toBe(90);
    });

    it('rotateBy adds to current rotation', () => {
      rotateTo(45);
      rotateBy(15);

      expect(get(viewport).rotation).toBe(60);
    });

    it('rotateClockwise rotates by step', () => {
      rotateClockwise();

      // Default step is 15 degrees
      expect(get(viewport).rotation).toBe(15);
    });

    it('rotateCounterClockwise rotates by negative step', () => {
      rotateTo(30);
      rotateCounterClockwise();

      // Default step is 15 degrees
      expect(get(viewport).rotation).toBe(15);
    });

    it('resetRotation sets to 0', () => {
      rotateTo(90);
      resetRotation();

      expect(get(viewport).rotation).toBe(0);
    });

    it('rotateTo90 sets to 90 degrees', () => {
      rotateTo90();

      expect(get(viewport).rotation).toBe(90);
    });

    it('rotateTo180 sets to 180 degrees', () => {
      rotateTo180();

      expect(get(viewport).rotation).toBe(180);
    });

    it('rotateTo270 sets to 270 degrees', () => {
      rotateTo270();

      expect(get(viewport).rotation).toBe(270);
    });
  });
});

describe('Reset Controls', () => {
  beforeEach(() => {
    // Set non-default values
    viewport.setPan(100, 200);
    viewport.setZoom(2.5);
    viewport.setRotation(90);
  });

  describe('Selective Reset', () => {
    it('resetPan only resets position', () => {
      resetPan();

      const state = get(viewport);
      expect(state.x).toBe(0);
      expect(state.y).toBe(0);
      expect(state.zoom).toBe(2.5); // Unchanged
      expect(state.rotation).toBe(90); // Unchanged
    });

    it('resetZoom only resets zoom', () => {
      resetZoom();

      const state = get(viewport);
      expect(state.x).toBe(100); // Unchanged
      expect(state.y).toBe(200); // Unchanged
      expect(state.zoom).toBe(1.0);
      expect(state.rotation).toBe(90); // Unchanged
    });

    it('resetRotation (from reset controls) only resets rotation', () => {
      resetRotation();

      const state = get(viewport);
      expect(state.x).toBe(100); // Unchanged
      expect(state.y).toBe(200); // Unchanged
      expect(state.zoom).toBe(2.5); // Unchanged
      expect(state.rotation).toBe(0);
    });

    it('resetCamera resets everything', () => {
      resetCamera();

      const state = get(viewport);
      expect(state).toEqual({
        x: 0,
        y: 0,
        zoom: 1.0,
        rotation: 0,
      });
    });
  });
});

describe('Viewport State Serialization', () => {
  beforeEach(() => {
    viewport.reset();
  });

  it('serializes viewport state to JSON', async () => {
    const { serializeViewportState } = await import('$lib/stores/viewport');

    viewport.setPan(100, 200);
    viewport.setZoom(2.0);
    viewport.setRotation(45);

    const state = get(viewport);
    const serialized = serializeViewportState(state);

    expect(serialized).toBe(JSON.stringify({ x: 100, y: 200, zoom: 2, rotation: 45 }));
  });

  it('deserializes viewport state from JSON', async () => {
    const { deserializeViewportState } = await import('$lib/stores/viewport');

    const json = JSON.stringify({ x: 100, y: 200, zoom: 2.5, rotation: 90 });
    const state = deserializeViewportState(json);

    expect(state).toEqual({
      x: 100,
      y: 200,
      zoom: 2.5,
      rotation: 90,
    });
  });

  it('handles invalid JSON gracefully', async () => {
    const { deserializeViewportState } = await import('$lib/stores/viewport');

    const state = deserializeViewportState('invalid json');

    // Should return default state
    expect(state).toEqual({
      x: 0,
      y: 0,
      zoom: 1.0,
      rotation: 0,
    });
  });

  it('validates deserialized values', async () => {
    const { deserializeViewportState } = await import('$lib/stores/viewport');

    const json = JSON.stringify({ x: 100, y: 200, zoom: 10.0, rotation: 450 });
    const state = deserializeViewportState(json);

    // Zoom should be clamped to max
    expect(state.zoom).toBe(5.0);

    // Rotation should be normalized to 0-360
    expect(state.rotation).toBe(90);
  });

  it('handles missing fields in JSON', async () => {
    const { deserializeViewportState } = await import('$lib/stores/viewport');

    const json = JSON.stringify({ x: 100 });
    const state = deserializeViewportState(json);

    expect(state.x).toBe(100);
    expect(state.y).toBe(0); // Default
    expect(state.zoom).toBe(1.0); // Default
    expect(state.rotation).toBe(0); // Default
  });
});

describe('Integration Tests', () => {
  beforeEach(() => {
    viewport.reset();
  });

  it('complex viewport manipulation sequence', () => {
    // Pan
    viewport.setPan(100, 100);

    // Zoom
    viewport.setZoom(2.0);

    // Rotate
    viewport.setRotation(45);

    // Pan by delta
    viewport.panBy(50, 50);

    const state = get(viewport);
    expect(state.x).toBe(150);
    expect(state.y).toBe(150);
    expect(state.zoom).toBe(2.0);
    expect(state.rotation).toBe(45);
  });

  it('reset after complex manipulation', () => {
    viewport.setPan(100, 100);
    viewport.setZoom(3.0);
    viewport.setRotation(180);

    viewport.reset();

    expect(get(isViewportDefault)).toBe(true);
  });

  it('multiple zoom operations maintain center', () => {
    viewport.setZoom(2.0, 500, 500);
    viewport.setZoom(1.5, 500, 500);

    // Position should adjust to keep point at 500,500 centered
    const state = get(viewport);
    expect(state.zoom).toBe(1.5);
  });
});