import { parseBacklinks, syncBacklinks, getBacklinksForNote, getOutgoingLinksForNote } from '@/lib/backlinks'

// Mock prisma before importing backlinks module
jest.mock('@/lib/prisma', () => ({
  prisma: {
    backlink: {
      deleteMany: jest.fn(),
      createMany: jest.fn(),
      findMany: jest.fn(),
    },
    note: {
      findMany: jest.fn(),
    },
  },
}))

import { prisma } from '@/lib/prisma'

describe('backlinks.ts', () => {
  beforeEach(() => {
    jest.clearAllMocks()
  })

  describe('parseBacklinks', () => {
    it('extracts single wiki-link', () => {
      const content = 'This is about [[Docker Commands]]'
      const result = parseBacklinks(content)
      expect(result).toEqual(['Docker Commands'])
    })

    it('extracts multiple wiki-links', () => {
      const content = 'See [[Docker Commands]] and [[Git Commands]] for reference'
      const result = parseBacklinks(content)
      expect(result).toContain('Docker Commands')
      expect(result).toContain('Git Commands')
    })

    it('extracts wiki-links with extra whitespace', () => {
      const content = 'Check [[  Docker Commands  ]] for details'
      const result = parseBacklinks(content)
      expect(result).toEqual(['Docker Commands'])
    })

    it('returns empty array when no wiki-links', () => {
      const content = 'This is a plain note without any links'
      const result = parseBacklinks(content)
      expect(result).toEqual([])
    })

    it('handles wiki-links at start of content', () => {
      const content = '[[First Note]] is the beginning'
      const result = parseBacklinks(content)
      expect(result).toEqual(['First Note'])
    })

    it('handles wiki-links at end of content', () => {
      const content = 'The solution is [[Last Note]]'
      const result = parseBacklinks(content)
      expect(result).toEqual(['Last Note'])
    })

    it('deduplicates repeated wiki-links', () => {
      const content = 'See [[Docker Commands]] and again [[Docker Commands]]'
      const result = parseBacklinks(content)
      expect(result).toEqual(['Docker Commands'])
    })

    it('handles nested brackets gracefully', () => {
      const content = 'Check [[This]] and [[That]]'
      const result = parseBacklinks(content)
      expect(result).toHaveLength(2)
    })
  })

  describe('syncBacklinks', () => {
    it('deletes existing backlinks before creating new ones', async () => {
      ;(prisma.backlink.deleteMany as jest.Mock).mockResolvedValue({ count: 2 })
      ;(prisma.note.findMany as jest.Mock).mockResolvedValue([])
      ;(prisma.backlink.createMany as jest.Mock).mockResolvedValue({ count: 0 })

      await syncBacklinks('note-1', 'No links here')

      expect(prisma.backlink.deleteMany).toHaveBeenCalledWith({
        where: { sourceNoteId: 'note-1' },
      })
    })

    it('creates backlinks for valid linked notes', async () => {
      ;(prisma.backlink.deleteMany as jest.Mock).mockResolvedValue({ count: 0 })
      ;(prisma.note.findMany as jest.Mock).mockResolvedValue([
        { id: 'note-2', title: 'Docker Commands' },
        { id: 'note-3', title: 'Git Commands' },
      ])
      ;(prisma.backlink.createMany as jest.Mock).mockResolvedValue({ count: 2 })

      await syncBacklinks('note-1', 'See [[Docker Commands]] and [[Git Commands]]')

      expect(prisma.backlink.createMany).toHaveBeenCalledWith({
        data: [
          { sourceNoteId: 'note-1', targetNoteId: 'note-2' },
          { sourceNoteId: 'note-1', targetNoteId: 'note-3' },
        ],
      })
    })

    it('does not create backlink to self', async () => {
      ;(prisma.backlink.deleteMany as jest.Mock).mockResolvedValue({ count: 0 })
      ;(prisma.note.findMany as jest.Mock).mockResolvedValue([
        { id: 'note-1', title: 'Docker Commands' },
      ])
      ;(prisma.backlink.createMany as jest.Mock).mockResolvedValue({ count: 0 })

      await syncBacklinks('note-1', 'This is [[Docker Commands]]')

      // Should not create a backlink to itself
      expect(prisma.backlink.createMany).not.toHaveBeenCalled()
    })

    it('handles case-insensitive title matching', async () => {
      ;(prisma.backlink.deleteMany as jest.Mock).mockResolvedValue({ count: 0 })
      ;(prisma.note.findMany as jest.Mock).mockResolvedValue([
        { id: 'note-2', title: 'Docker Commands' },
      ])
      ;(prisma.backlink.createMany as jest.Mock).mockResolvedValue({ count: 1 })

      await syncBacklinks('note-1', 'See [[docker commands]]')

      expect(prisma.backlink.createMany).toHaveBeenCalled()
    })

    it('does nothing when no wiki-links in content', async () => {
      ;(prisma.backlink.deleteMany as jest.Mock).mockResolvedValue({ count: 2 })
      ;(prisma.note.findMany as jest.Mock).mockResolvedValue([])

      await syncBacklinks('note-1', 'Plain content without links')

      expect(prisma.backlink.createMany).not.toHaveBeenCalled()
    })
  })

  describe('getBacklinksForNote', () => {
    it('returns backlinks with source note info', async () => {
      const mockBacklinks = [
        {
          id: 'bl-1',
          sourceNoteId: 'note-2',
          targetNoteId: 'note-1',
          createdAt: new Date('2024-01-01'),
          sourceNote: { id: 'note-2', title: 'Related Note', type: 'command' },
        },
      ]
      ;(prisma.backlink.findMany as jest.Mock).mockResolvedValue(mockBacklinks)

      const result = await getBacklinksForNote('note-1')

      expect(result).toHaveLength(1)
      expect(result[0].sourceNote.title).toBe('Related Note')
      expect(result[0].sourceNote.type).toBe('command')
    })

    it('returns empty array when no backlinks', async () => {
      ;(prisma.backlink.findMany as jest.Mock).mockResolvedValue([])

      const result = await getBacklinksForNote('note-1')

      expect(result).toEqual([])
    })

    it('converts Date to ISO string', async () => {
      const mockBacklinks = [
        {
          id: 'bl-1',
          sourceNoteId: 'note-2',
          targetNoteId: 'note-1',
          createdAt: new Date('2024-01-01T12:00:00Z'),
          sourceNote: { id: 'note-2', title: 'Related Note', type: 'command' },
        },
      ]
      ;(prisma.backlink.findMany as jest.Mock).mockResolvedValue(mockBacklinks)

      const result = await getBacklinksForNote('note-1')

      expect(result[0].createdAt).toBe('2024-01-01T12:00:00.000Z')
    })
  })

  describe('getOutgoingLinksForNote', () => {
    it('returns outgoing links with target note info', async () => {
      const mockBacklinks = [
        {
          id: 'bl-1',
          sourceNoteId: 'note-1',
          targetNoteId: 'note-2',
          createdAt: new Date('2024-01-01'),
          targetNote: { id: 'note-2', title: 'Linked Note', type: 'snippet' },
        },
      ]
      ;(prisma.backlink.findMany as jest.Mock).mockResolvedValue(mockBacklinks)

      const result = await getOutgoingLinksForNote('note-1')

      expect(result).toHaveLength(1)
      expect(result[0].sourceNote.title).toBe('Linked Note')
      expect(result[0].sourceNote.type).toBe('snippet')
    })

    it('returns empty array when no outgoing links', async () => {
      ;(prisma.backlink.findMany as jest.Mock).mockResolvedValue([])

      const result = await getOutgoingLinksForNote('note-1')

      expect(result).toEqual([])
    })
  })
})