import { describe, it, expect, vi, beforeEach } from 'vitest'

// Mock logger
vi.mock('@adonisjs/core/services/logger', () => ({
  default: { info: vi.fn(), debug: vi.fn(), warn: vi.fn(), error: vi.fn() },
}))

// Mock DeviceModel
vi.mock('../../../../app/models/device.js', () => ({
  default: {
    createOrUpdate: vi.fn().mockResolvedValue({}),
    findByDeviceId: vi.fn().mockResolvedValue(null),
    updateOne: vi.fn().mockResolvedValue({}),
  },
}))

// Mock CommandModel
vi.mock('../../../../app/models/command.js', () => ({
  default: {
    getCollection: vi.fn().mockReturnValue({
      find: vi.fn().mockReturnValue({ sort: vi.fn().mockReturnValue({ toArray: vi.fn().mockResolvedValue([]) }) }),
      countDocuments: vi.fn().mockResolvedValue(0),
    }),
    updateCommand: vi.fn().mockResolvedValue({}),
  },
}))

import { StateMachineManager, MachineStatus } from '../../../../app/services/cwmp/state_machine_manager.js'
import { Device } from '../../../../app/domain/device/device.js'
import { DeviceId } from '../../../../app/domain/device/device_id.js'
import { ResultStatus } from '../../../../app/services/cwmp/task_queue.js'
import CommandModel from '../../../../app/models/command.js'

function makeDevice(gpnStatus: string = 'unsupported'): Device {
  const device = new Device(new DeviceId('Sagemcom', 'F8B7FF', 'Livebox 4', 'LB4-TEST-001'))
  device.setDataModel('tr-181')
  device.setGpnStatus(gpnStatus as any)
  return device
}

describe('StateMachineManager — coverage', () => {
  let manager: StateMachineManager

  beforeEach(() => {
    vi.clearAllMocks()
    ;(StateMachineManager as any).instance = null
    manager = StateMachineManager.getInstance()
  })

  // --- Event routing ---

  it('routes BOOTSTRAP event to MainStateMachine', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-1', { events: ['0 BOOTSTRAP'] })
    expect(machine.status).toBe(MachineStatus.RUNNING)
    // MainStateMachine has getCurrentStateName
    expect(machine.stateMachine.getCurrentStateName()).toBeDefined()
  })

  it('routes CONNECTION_REQUEST to ImmediateCommandStateMachine', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-2', { events: ['6 CONNECTION REQUEST'] })
    expect(machine.status).toBe(MachineStatus.RUNNING)
    expect(machine.stateMachine.getCurrentStateName()).toBe('executing-commands')
  })

  it('routes PERIODIC to MainStateMachine', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-3', { events: ['2 PERIODIC'] })
    expect(machine.status).toBe(MachineStatus.RUNNING)
    expect(machine.stateMachine.getCurrentStateName()).toBe('idle')
  })

  it('forces MainStateMachine when NI commands exist', async () => {
    // Override the mock to return count > 0
    const collection = CommandModel.getCollection()
    vi.mocked(collection.countDocuments).mockResolvedValueOnce(3)
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-4', { events: ['6 CONNECTION REQUEST'] })
    // Should be MainStateMachine (idle) not ImmediateCommandStateMachine
    expect(machine.stateMachine.getCurrentStateName()).toBe('idle')
  })

  it('preempts ImmediateCommandStateMachine on BOOT event with same session', async () => {
    const device = makeDevice()
    // First: create ImmediateCommandStateMachine
    const machine1 = await manager.startStateMachine(device, 'sess-5', { events: ['6 CONNECTION REQUEST'] })
    expect(machine1.stateMachine.getCurrentStateName()).toBe('executing-commands')

    // Second: BOOT event arrives on same session (same TCP connection, new Inform)
    const machine2 = await manager.startStateMachine(device, 'sess-5', { events: ['1 BOOT'] })
    // Should have preempted to MainStateMachine (same machine instance, new state machine inside)
    // Since gpnStatus=unsupported, it starts and goes directly to critical-reads
    const stateName = machine2.stateMachine.getCurrentStateName()
    expect(stateName === 'idle' || stateName === 'critical-reads').toBe(true)
  })

  // --- continue() ---

  it('continue() calls handleResponse on state machine', async () => {
    const device = makeDevice()
    await manager.startStateMachine(device, 'sess-6', { events: ['0 BOOTSTRAP'] })
    // continue sends empty POST handling
    const response = await manager.continue('sess-6')
    // Should have produced a GPV (critical reads since gpn=unsupported)
    expect(response).toContain('GetParameterValues')
  })

  it('continue() treats empty body as task failure when lastTaskId is set', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-7', { events: ['0 BOOTSTRAP'] })
    // Manually set lastTaskId to simulate in-flight task
    machine.lastTaskId = 'fake-task-id'
    // Add a fake task to the queue so failTask doesn't error
    manager.getTaskQueue().addCWMPTask(device.deviceId, 'get_parameter_values', [])

    const response = await manager.continue('sess-7')
    // Should have treated as failure and advanced the state machine
    expect(machine.lastTaskId).toBeUndefined()
  })

  it('continue() returns empty for unknown session', async () => {
    const response = await manager.continue('unknown-session')
    expect(response).toBe('')
  })

  // --- handleCWMPResponse() ---

  it('handleCWMPResponse() correlates response with lastTaskId and executes callback', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-8', { events: ['0 BOOTSTRAP'] })

    // Start state machine (sends GPV)
    await manager.continue('sess-8')

    // Manually set lastTaskId
    const taskId = 'test-task-123'
    machine.lastTaskId = taskId
    const callbackFn = vi.fn().mockResolvedValue('')
    manager.getTaskQueue()['taskCallbacks'].set(taskId, callbackFn)
    manager.getTaskQueue()['tasks'].set(taskId, { id: taskId, deviceId: device.deviceId, type: 'get_parameter_values', payload: [], status: 'SENT' as any, createdAt: new Date() })

    // Send success response
    await manager.handleCWMPResponse('sess-8', true, { ParameterList: { ParameterValueStruct: [] } })

    // Callback should have been invoked
    expect(callbackFn).toHaveBeenCalled()
    expect(machine.lastTaskId).toBeUndefined()
  })

  it('handleCWMPResponse() returns empty for unknown session', async () => {
    const response = await manager.handleCWMPResponse('no-such-session', true, {})
    expect(response).toBe('')
  })

  // --- Session helpers ---

  it('hasSession returns false for unknown session', () => {
    expect(manager.hasSession('nonexistent')).toBe(false)
  })

  it('hasSession returns true for registered session', async () => {
    const device = makeDevice()
    await manager.startStateMachine(device, 'sess-9', { events: ['0 BOOTSTRAP'] })
    expect(manager.hasSession('sess-9')).toBe(true)
  })

  it('ensureSessionForRemote rebinds session correctly', async () => {
    const device = makeDevice()
    await manager.startStateMachine(device, 'sess-10', { events: ['0 BOOTSTRAP'] })
    manager.bindRemoteToDevice('remote-1', device.deviceId)

    const result = manager.ensureSessionForRemote('remote-1', 'sess-10-new')
    expect(result).toBe(true)
    expect(manager.hasSession('sess-10-new')).toBe(true)
    expect(manager.hasSession('sess-10')).toBe(false)
  })

  it('ensureSessionForRemote returns false for unknown remote', () => {
    expect(manager.ensureSessionForRemote('unknown-remote', 'sess')).toBe(false)
  })

  // --- Cleanup ---

  it('cleanupCompletedMachines removes old completed machines', async () => {
    const device = makeDevice()
    const machine = await manager.startStateMachine(device, 'sess-11', { events: ['0 BOOTSTRAP'] })
    // Force complete and set old completion date
    ;(machine as any).status = MachineStatus.COMPLETED
    ;(machine as any).completedAt = new Date(Date.now() - 2 * 60 * 60 * 1000) // 2h ago

    // Verify machine exists in internal map before cleanup
    const machinesMap = (manager as any).machines as Map<string, any>
    expect(machinesMap.has(machine.id)).toBe(true)

    manager.cleanupCompletedMachines(1)

    // Machine should be removed from internal map
    expect(machinesMap.has(machine.id)).toBe(false)
  })
})