import type { DynamicToolUIPart, ToolUIPart, UIMessage } from 'ai'
import { describe, expect, it } from 'vitest'

import {
  getParallelApprovalIdsToReject,
  isManualApprovalRequested,
  prepareMessagesForAPI,
} from './message-utils'
import { createAssistantMessageWithUpdateNotebookTool } from './test-fixtures'

const makeApprovalPart = (id: string, isAutomatic = false): DynamicToolUIPart =>
  ({
    type: 'dynamic-tool',
    toolName: 'test_tool',
    toolCallId: id,
    state: 'approval-requested',
    input: {},
    approval: { id, ...(isAutomatic ? { isAutomatic: true } : {}) },
  }) as DynamicToolUIPart

const makeResultPart = (id: string): DynamicToolUIPart => ({
  type: 'dynamic-tool',
  toolName: 'test_tool',
  toolCallId: id,
  state: 'output-available',
  input: {},
  output: {},
})

describe('isManualApprovalRequested', () => {
  it('returns true for a human approval-requested tool part', () => {
    expect(isManualApprovalRequested(makeApprovalPart('a1'))).toBe(true)
  })

  it('returns false for an automatic approval', () => {
    expect(isManualApprovalRequested(makeApprovalPart('a1', true))).toBe(false)
  })

  it('returns false for a tool result part', () => {
    expect(isManualApprovalRequested(makeResultPart('r1'))).toBe(false)
  })

  it('returns false for a content part with no state or approval', () => {
    expect(isManualApprovalRequested({ type: 'text', text: 'hello' })).toBe(false)
  })
})

describe('getParallelApprovalIdsToReject', () => {
  it('returns [] for empty messages', () => {
    expect(getParallelApprovalIdsToReject([])).toEqual([])
  })

  it('returns [] when there are no assistant messages', () => {
    const messages: UIMessage[] = [{ id: '1', role: 'user', parts: [] }]
    expect(getParallelApprovalIdsToReject(messages)).toEqual([])
  })

  it('returns [] when last assistant message has no pending approvals', () => {
    const messages: UIMessage[] = [{ id: '1', role: 'assistant', parts: [makeResultPart('r1')] }]
    expect(getParallelApprovalIdsToReject(messages)).toEqual([])
  })

  it('returns [] when there is only one pending approval', () => {
    const messages: UIMessage[] = [{ id: '1', role: 'assistant', parts: [makeApprovalPart('a1')] }]
    expect(getParallelApprovalIdsToReject(messages)).toEqual([])
  })

  it('returns all but the first id when there are multiple pending approvals', () => {
    const messages: UIMessage[] = [
      {
        id: '1',
        role: 'assistant',
        parts: [makeApprovalPart('a1'), makeApprovalPart('a2'), makeApprovalPart('a3')],
      },
    ]
    expect(getParallelApprovalIdsToReject(messages)).toEqual(['a2', 'a3'])
  })

  it('only inspects the last assistant message', () => {
    const messages: UIMessage[] = [
      {
        id: '1',
        role: 'assistant',
        parts: [makeApprovalPart('old1'), makeApprovalPart('old2')],
      },
      { id: '2', role: 'user', parts: [] },
      { id: '3', role: 'assistant', parts: [makeApprovalPart('new1')] },
    ]
    expect(getParallelApprovalIdsToReject(messages)).toEqual([])
  })

  it('ignores non-approval tool parts', () => {
    const messages: UIMessage[] = [
      {
        id: '1',
        role: 'assistant',
        parts: [makeResultPart('r1'), makeApprovalPart('a1'), makeApprovalPart('a2')],
      },
    ]
    expect(getParallelApprovalIdsToReject(messages)).toEqual(['a2'])
  })

  it('ignores automatic approvals when picking extras to reject', () => {
    const messages: UIMessage[] = [
      {
        id: '1',
        role: 'assistant',
        parts: [
          makeApprovalPart('auto', true),
          makeApprovalPart('manual-1'),
          makeApprovalPart('manual-2'),
        ],
      },
    ]
    expect(getParallelApprovalIdsToReject(messages)).toEqual(['manual-2'])
  })
})

describe('prepareMessagesForAPI', () => {
  it('should limit messages to last 7 entries', () => {
    const messages: UIMessage[] = Array.from({ length: 10 }, (_, i) => ({
      id: `msg-${i}`,
      role: 'user',
      parts: [{ type: 'text', text: `Message ${i}` }],
    }))

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(7)
    expect(result[0].parts[0]).toEqual({ type: 'text', text: 'Message 3' })
    expect(result[6].parts[0]).toEqual({ type: 'text', text: 'Message 9' })
  })

  it('should remove results property from assistant messages', () => {
    const messages = [
      {
        id: 'msg-1',
        role: 'assistant',
        parts: [{ type: 'text', text: 'Response' }],
        results: { data: 'some data' },
      },
    ] as Array<UIMessage & { results?: unknown }>

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(1)
    expect(result[0]).not.toHaveProperty('results')
    expect(result[0].parts[0]).toEqual({ type: 'text', text: 'Response' })
  })

  it('should preserve messages without results', () => {
    const messages: UIMessage[] = [
      {
        id: 'msg-1',
        role: 'user',
        parts: [{ type: 'text', text: 'Question' }],
      },
      {
        id: 'msg-2',
        role: 'assistant',
        parts: [{ type: 'text', text: 'Answer' }],
      },
    ]

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(2)
    expect(result[0]).toEqual(messages[0])
    expect(result[1]).toEqual(messages[1])
  })

  it('should handle empty array', () => {
    const messages: UIMessage[] = []

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(0)
    expect(result).toEqual([])
  })

  it('should handle array with fewer than 7 messages', () => {
    const messages: UIMessage[] = [
      { id: 'msg-1', role: 'user', parts: [{ type: 'text', text: 'Message 1' }] },
      { id: 'msg-2', role: 'assistant', parts: [{ type: 'text', text: 'Message 2' }] },
      { id: 'msg-3', role: 'user', parts: [{ type: 'text', text: 'Message 3' }] },
    ]

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(3)
    expect(result).toEqual(messages)
  })

  it('should handle array with exactly 7 messages', () => {
    const messages: UIMessage[] = Array.from({ length: 7 }, (_, i) => ({
      id: `msg-${i}`,
      role: i % 2 === 0 ? 'user' : 'assistant',
      parts: [{ type: 'text', text: `Message ${i}` }],
    }))

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(7)
    expect(result).toEqual(messages)
  })

  it('should only remove results from assistant messages, not user messages', () => {
    const messages = [
      {
        id: 'msg-1',
        role: 'user',
        parts: [{ type: 'text', text: 'Question' }],
        results: { data: 'user data' },
      },
      {
        id: 'msg-2',
        role: 'assistant',
        parts: [{ type: 'text', text: 'Answer' }],
        results: { data: 'assistant data' },
      },
    ] as Array<UIMessage & { results?: unknown }>

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(2)
    // User message keeps results (not removed by the function)
    expect((result[0] as any).results).toEqual({ data: 'user data' })
    // Assistant message has results removed
    expect(result[1]).not.toHaveProperty('results')
  })

  it('should handle mixed messages with and without results', () => {
    const messages = [
      {
        id: 'msg-1',
        role: 'assistant',
        parts: [{ type: 'text', text: 'First' }],
        results: { data: 'data1' },
      },
      {
        id: 'msg-2',
        role: 'user',
        parts: [{ type: 'text', text: 'Second' }],
      },
      {
        id: 'msg-3',
        role: 'assistant',
        parts: [{ type: 'text', text: 'Third' }],
      },
      {
        id: 'msg-4',
        role: 'assistant',
        parts: [{ type: 'text', text: 'Fourth' }],
        results: { data: 'data2' },
      },
    ] as Array<UIMessage & { results?: unknown }>

    const result = prepareMessagesForAPI(messages)

    expect(result).toHaveLength(4)
    expect(result[0]).not.toHaveProperty('results')
    expect(result[1]).toEqual(messages[1])
    expect(result[2]).toEqual(messages[2])
    expect(result[3]).not.toHaveProperty('results')
  })

  it('strips update_notebook previous_content before re-uploading to the API', () => {
    const messages = [createAssistantMessageWithUpdateNotebookTool()]

    const result = prepareMessagesForAPI(messages)

    expect((result[0].parts[0] as ToolUIPart).output).toEqual({
      id: 'notebook-1',
      name: 'Signup funnel',
    })
  })

  it('does not mutate the original message parts when stripping previous_content', () => {
    const messages = [createAssistantMessageWithUpdateNotebookTool()]
    const originalParts = messages[0].parts

    prepareMessagesForAPI(messages)

    expect(messages[0].parts).toBe(originalParts)
    expect((originalParts[0] as ToolUIPart).output).toHaveProperty('previous_content')
  })

  it('leaves an update_notebook output without previous_content unchanged', () => {
    const messages = [
      createAssistantMessageWithUpdateNotebookTool({ id: 'notebook-1', name: 'Signup funnel' }),
    ]

    const result = prepareMessagesForAPI(messages)

    expect((result[0].parts[0] as ToolUIPart).output).toEqual({
      id: 'notebook-1',
      name: 'Signup funnel',
    })
  })
})