import type { MapViewport } from '@/domain/poi'
import { describe, expect, it } from 'vitest'
import { isSignificantViewportChange } from '@/services/map'

const current: MapViewport = { longitude: 113.935, latitude: 22.748, scale: 13 }

function shifted(delta: Partial<MapViewport>): MapViewport {
  return {
    longitude: current.longitude + (delta.longitude ?? 0),
    latitude: current.latitude + (delta.latitude ?? 0),
    scale: current.scale + (delta.scale ?? 0),
  }
}

describe('isSignificantViewportChange', () => {
  it('丢弃地图回传中心点的量化噪声', () => {
    expect(isSignificantViewportChange(current, shifted({}))).toBe(false)
    expect(isSignificantViewportChange(current, shifted({ longitude: 1e-6 }))).toBe(false)
    expect(isSignificantViewportChange(current, shifted({ latitude: -1e-6 }))).toBe(false)
    expect(isSignificantViewportChange(current, shifted({ scale: 0.001 }))).toBe(false)
  })

  it('接受真实拖动与缩放', () => {
    expect(isSignificantViewportChange(current, shifted({ longitude: 0.01 }))).toBe(true)
    expect(isSignificantViewportChange(current, shifted({ latitude: -0.01 }))).toBe(true)
    expect(isSignificantViewportChange(current, shifted({ scale: 1 }))).toBe(true)
  })

  it('单个维度超阈值就算变化', () => {
    const next = shifted({ longitude: 1e-6, latitude: 1e-6, scale: 2 })
    expect(isSignificantViewportChange(current, next)).toBe(true)
  })
})