import { describe, it, expect } from 'vitest'
import { addStack } from './transforms'

describe('addStack', () => {
  it('passes through non-objects unchanged', () => {
    expect(addStack(undefined)).toBe(undefined)
    expect(addStack(null)).toBe(null)
    expect(addStack(42)).toBe(42)
  })

  it('marks every existing series with stack:"total"', () => {
    const out = addStack({
      title: { text: 'x' },
      series: [{ type: 'bar' }, { type: 'bar' }],
    }) as { series: { type: string; stack: string }[]; title: { text: string } }
    expect(out.series).toHaveLength(2)
    expect(out.series[0]).toMatchObject({ type: 'bar', stack: 'total' })
    expect(out.series[1]).toMatchObject({ type: 'bar', stack: 'total' })
    expect(out.title).toEqual({ text: 'x' })
  })

  it('emits a broadcast template when there are no existing series (data-fusion widgets)', () => {
    const out = addStack({}) as { series: { stack: string }[] }
    expect(out.series).toEqual([{ stack: 'total' }])
  })

  it('emits a broadcast template when series is missing entirely', () => {
    const out = addStack({ tooltip: {} }) as {
      series: { stack: string }[]
      tooltip: object
    }
    expect(out.series).toEqual([{ stack: 'total' }])
    expect(out.tooltip).toBeDefined()
  })

  it('preserves non-object series entries (defensive)', () => {
    const out = addStack({ series: ['weird', { type: 'bar' }] }) as {
      series: unknown[]
    }
    expect(out.series[0]).toBe('weird')
    expect(out.series[1]).toMatchObject({ type: 'bar', stack: 'total' })
  })
})