/**
 * @jest-environment node
 */

import { eventMcpToolUsage, EVENT_MCP_TOOL_USAGE } from './build'
import type { McpToolName } from './build'

describe('MCP Telemetry Events', () => {
  it('should generate correct telemetry events for single tool', () => {
    const usages = [
      {
        featureName: 'mcp/get_errors' as McpToolName,
        invocationCount: 5,
      },
    ]

    const events = eventMcpToolUsage(usages)

    expect(events).toHaveLength(1)
    expect(events[0]).toEqual({
      eventName: EVENT_MCP_TOOL_USAGE,
      payload: {
        toolName: 'mcp/get_errors',
        invocationCount: 5,
      },
    })
  })

  it('should generate correct telemetry events for multiple tools', () => {
    const usages = [
      {
        featureName: 'mcp/get_errors' as McpToolName,
        invocationCount: 3,
      },
      {
        featureName: 'mcp/get_logs' as McpToolName,
        invocationCount: 1,
      },
      {
        featureName: 'mcp/get_page_metadata' as McpToolName,
        invocationCount: 7,
      },
    ]

    const events = eventMcpToolUsage(usages)

    expect(events).toHaveLength(3)

    expect(events[0]).toEqual({
      eventName: EVENT_MCP_TOOL_USAGE,
      payload: {
        toolName: 'mcp/get_errors',
        invocationCount: 3,
      },
    })

    expect(events[1]).toEqual({
      eventName: EVENT_MCP_TOOL_USAGE,
      payload: {
        toolName: 'mcp/get_logs',
        invocationCount: 1,
      },
    })

    expect(events[2]).toEqual({
      eventName: EVENT_MCP_TOOL_USAGE,
      payload: {
        toolName: 'mcp/get_page_metadata',
        invocationCount: 7,
      },
    })
  })

  it('should handle all MCP tool types', () => {
    const allTools: McpToolName[] = [
      'mcp/get_errors',
      'mcp/get_logs',
      'mcp/get_page_metadata',
      'mcp/get_project_metadata',
      'mcp/get_server_action_by_id',
    ]

    const usages = allTools.map((tool, index) => ({
      featureName: tool,
      invocationCount: index + 1,
    }))

    const events = eventMcpToolUsage(usages)

    expect(events).toHaveLength(5)

    events.forEach((event, index) => {
      expect(event.eventName).toBe(EVENT_MCP_TOOL_USAGE)
      expect(event.payload.toolName).toBe(allTools[index])
      expect(event.payload.invocationCount).toBe(index + 1)
    })
  })

  it('should handle empty usage array', () => {
    const events = eventMcpToolUsage([])
    expect(events).toEqual([])
  })

  it('should use correct event name constant', () => {
    expect(EVENT_MCP_TOOL_USAGE).toBe('NEXT_MCP_TOOL_USAGE')
  })

  it('should transform featureName to toolName in payload', () => {
    const usages = [
      {
        featureName: 'mcp/get_project_metadata' as McpToolName,
        invocationCount: 2,
      },
    ]

    const events = eventMcpToolUsage(usages)

    // Verify the input has 'featureName' but output has 'toolName'
    expect(usages[0]).toHaveProperty('featureName')
    expect(events[0].payload).toHaveProperty('toolName')
    expect(events[0].payload).not.toHaveProperty('featureName')
  })
})