import {
  constrainCropperValue,
  getCoverScale,
  getCropArea,
  getCropperBounds,
  zoomCropperValueAtPoint,
} from "@workspace/cropper"
import { describe, expect, it } from "vitest"

const viewport = { height: 300, width: 300 }
const landscape = { height: 500, width: 1000 }

describe("cropper geometry", () => {
  it("fits an image so the viewport is always covered", () => {
    expect(getCoverScale(viewport, landscape)).toBe(0.6)
    expect(getCropperBounds(viewport, landscape, 1)).toEqual({
      maxX: 150,
      maxY: 0,
    })
  })

  it("constrains zoom and translation to the covered image", () => {
    expect(
      constrainCropperValue(
        { x: 5000, y: -500, zoom: 10 },
        { image: landscape, maxZoom: 4, minZoom: 1, viewport }
      )
    ).toEqual({ x: 1050, y: -450, zoom: 4 })
  })

  it("preserves an initial translation until dimensions are available", () => {
    expect(
      constrainCropperValue(
        { x: 40, y: -20, zoom: 2 },
        { image: { height: 0, width: 0 }, viewport }
      )
    ).toEqual({ x: 40, y: -20, zoom: 2 })
  })

  it("returns a source-pixel crop rectangle", () => {
    expect(getCropArea({ x: 0, y: 0, zoom: 1 }, viewport, landscape)).toEqual({
      height: 500,
      width: 500,
      x: 250,
      y: 0,
    })

    expect(getCropArea({ x: 150, y: 0, zoom: 1 }, viewport, landscape)).toEqual(
      {
        height: 500,
        width: 500,
        x: 0,
        y: 0,
      }
    )
  })

  it("keeps the source point beneath the zoom origin stationary", () => {
    expect(
      zoomCropperValueAtPoint(
        { x: 0, y: 0, zoom: 1 },
        2,
        { x: 100, y: 0 },
        { image: landscape, viewport }
      )
    ).toEqual({ x: -100, y: 0, zoom: 2 })
  })
})