import { prepareFlightRouterStateForRequest } from './flight-data-helpers'
import {
  PrefetchHint,
  type FlightRouterState,
} from '../shared/lib/app-router-types'

describe('prepareFlightRouterStateForRequest', () => {
  describe('HMR refresh handling', () => {
    it('should preserve complete state for HMR refresh requests', () => {
      const flightRouterState: FlightRouterState = [
        '__PAGE__?{"sensitive":"data"}',
        {},
        ['/some/url', ''],
        'refetch',
        PrefetchHint.IsRootLayout | 1,
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState, true)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded).toEqual(flightRouterState)
    })
  })

  describe('__PAGE__ segment handling', () => {
    it('should strip search params from __PAGE__ segments', () => {
      const flightRouterState: FlightRouterState = [
        '__PAGE__?{"param":"value","foo":"bar"}',
        {},
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[0]).toBe('__PAGE__')
    })

    it('should preserve non-page segments', () => {
      const flightRouterState: FlightRouterState = ['regular-segment', {}]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[0]).toBe('regular-segment')
    })

    it('should preserve dynamic segments', () => {
      const dynamicSegment: [string, string, 'd', null] = [
        'slug',
        'test-value',
        'd',
        null,
      ]
      const flightRouterState: FlightRouterState = [dynamicSegment, {}]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[0]).toEqual(dynamicSegment)
    })
  })

  describe('URL stripping', () => {
    it('should always set URL (index 2) to null', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        ['/sensitive/url/path', ''],
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[2]).toBeUndefined()
    })
  })

  describe('refresh marker handling', () => {
    it('should preserve "refetch" marker', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        ['/url', ''],
        'refetch',
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[3]).toBe('refetch')
    })

    it('should preserve "inside-shared-layout" marker', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        ['/url', ''],
        'inside-shared-layout',
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[3]).toBe('inside-shared-layout')
    })

    it('should strip "refresh" state (client-only)', () => {
      const flightRouterState: FlightRouterState = ['segment', {}, ['/url', '']]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[2]).toBeUndefined()
    })

    it('should strip null refresh marker', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        ['/url', ''],
        null,
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[3]).toBeUndefined()
    })
  })

  describe('optional fields preservation', () => {
    it('should preserve prefetchHints with IsRootLayout', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        null,
        null,
        PrefetchHint.IsRootLayout,
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[4]).toBe(PrefetchHint.IsRootLayout)
    })

    it('should preserve prefetchHints with SegmentHasLoadingBoundary', () => {
      const flightRouterState: FlightRouterState = [
        'segment',
        {},
        null,
        null,
        PrefetchHint.SegmentHasLoadingBoundary,
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[4]).toBe(PrefetchHint.SegmentHasLoadingBoundary)
    })

    it('should handle minimal FlightRouterState (only segment and parallelRoutes)', () => {
      const flightRouterState: FlightRouterState = ['segment', {}]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded).toEqual(['segment', {}])
    })
  })

  describe('recursive processing of parallel routes', () => {
    it('should recursively process nested parallel routes', () => {
      const flightRouterState: FlightRouterState = [
        'parent',
        {
          children: ['__PAGE__?{"nested":"param"}', {}, ['/nested/url', '']],
          modal: ['modal-segment', {}, ['/modal/url', ''], 'refetch'],
        },
        ['/parent/url', ''],
        'inside-shared-layout',
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded).toEqual([
        'parent',
        {
          children: [
            '__PAGE__', // search params stripped
            {},
            // URL stripped
            // 'refresh' marker stripped
          ],
          modal: [
            'modal-segment',
            {},
            null, // URL stripped
            'refetch', // server marker preserved
          ],
        },
        null, // URL stripped
        'inside-shared-layout', // server marker preserved
      ])
    })

    it('should handle deeply nested parallel routes', () => {
      const flightRouterState: FlightRouterState = [
        'root',
        {
          children: [
            'level1',
            {
              children: [
                '__PAGE__?{"deep":"nesting"}',
                {},
                ['/deep/url', ''],
                'refetch',
              ],
            },
          ],
        },
      ]

      const result = prepareFlightRouterStateForRequest(flightRouterState)
      const decoded = JSON.parse(decodeURIComponent(result))

      expect(decoded[1].children[1].children[0]).toBe('__PAGE__')
      expect(decoded[1].children[1].children[2]).toBeNull()
      expect(decoded[1].children[1].children[3]).toBe('refetch')
    })
  })

  describe('real-world scenarios', () => {
    it('should handle complex FlightRouterState with all features', () => {
      const complexState: FlightRouterState = [
        '__PAGE__?{"userId":"123"}',
        {
          children: [
            'dashboard',
            {
              modal: [
                '__PAGE__?{"modalParam":"data"}',
                {},
                ['/modal/path', ''],
                null,
                PrefetchHint.SegmentHasLoadingBoundary,
              ],
            },
            ['/dashboard/url', ''],
            'refetch',
            PrefetchHint.IsRootLayout | PrefetchHint.SegmentHasLoadingBoundary,
          ],
          sidebar: [
            ['slug', 'user-123', 'd', null],
            {},
            ['/sidebar/url', ''],
            null,
          ],
        },
        ['/main/url', ''],
        'inside-shared-layout',
        PrefetchHint.IsRootLayout | PrefetchHint.SegmentHasLoadingBoundary,
      ]

      const result = prepareFlightRouterStateForRequest(complexState)
      const decoded = JSON.parse(decodeURIComponent(result))

      // Root level checks
      expect(decoded[0]).toBe('__PAGE__') // search params stripped
      expect(decoded[2]).toBeNull() // URL stripped
      expect(decoded[3]).toBe('inside-shared-layout') // server marker preserved
      expect(decoded[4]).toBe(
        PrefetchHint.IsRootLayout | PrefetchHint.SegmentHasLoadingBoundary
      ) // prefetchHints preserved

      // Children route checks
      const childrenRoute = decoded[1].children
      expect(childrenRoute[2]).toBeNull() // URL stripped
      expect(childrenRoute[3]).toBe('refetch') // server marker preserved
      expect(childrenRoute[4]).toBe(
        PrefetchHint.IsRootLayout | PrefetchHint.SegmentHasLoadingBoundary
      ) // prefetchHints preserved

      // Modal route checks
      const modalRoute = childrenRoute[1].modal
      expect(modalRoute[0]).toBe('__PAGE__') // search params stripped
      expect(modalRoute[2]).toBeNull() // URL stripped
      expect(modalRoute[3]).toBeNull() // 'refresh' marker stripped
      expect(modalRoute[4]).toBe(PrefetchHint.SegmentHasLoadingBoundary) // prefetchHints preserved

      // Sidebar route (dynamic segment) checks
      const sidebarRoute = decoded[1].sidebar
      expect(sidebarRoute[0]).toEqual(['slug', 'user-123', 'd', null]) // dynamic segment preserved
      expect(sidebarRoute[2]).toBeUndefined() // URL stripped
      expect(sidebarRoute[3]).toBeUndefined() // null marker stripped
    })
  })
})