/**
 * End-to-end smoke test for the Job/Scheduler backbone.
 *
 * Exercises a real DB via setupTestDatabase + a real SchedulerService + a real
 * JobManager wired through the standard mock @application factory (DbService
 * and CacheService come from the unified mock; SchedulerService and JobManager
 * are added in beforeAll). Verifies enqueue → running → progress → completed
 * as well as in-flight cancel and idempotencyKey reuse.
 *
 * Restart-recovery scenarios (abandon / retry / singleton) live in the
 * integration test, not here.
 */

import { application } from '@application'
import { jobService } from '@data/services/JobService'
import { JobManager } from '@main/core/job/JobManager'
import type { JobHandler } from '@main/core/job/types'
import { JOB_PROGRESS_KEY_PREFIX, JOB_STATE_KEY_PREFIX } from '@main/core/job/types'
import { BaseService } from '@main/core/lifecycle/BaseService'
import { SchedulerService } from '@main/core/scheduler/SchedulerService'
import { setupTestDatabase } from '@test-helpers/db'
import { MockMainCacheServiceExport, MockMainCacheServiceUtils } from '@test-mocks/main/CacheService'
import { MockMainDbServiceExport } from '@test-mocks/main/DbService'
import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from 'vitest'

import { drainTrailingDispatch as drainHelper } from './_helpers'

vi.mock('@application', async () => {
  const mod = await import('@test-mocks/main/application')
  return mod.mockApplicationFactory()
})

interface EchoInput {
  message: string
  /** Optional sleep before resolving, used to give cancel() time to abort mid-flight. */
  sleepMs?: number
}

interface EchoOutput {
  echoed: string
}

interface StubbornInput {
  /** Sleep duration; set longer than `cancelTimeoutMs` to force the timeout path. */
  sleepMs: number
}

let scheduler: SchedulerService
let jobManager: JobManager

// PowerService stub: JobManager acquires a sleep-prevention hold per attempt and
// releases it in the finally. Shared spies let the end-to-end test assert acquire/release.
const sleepHoldDispose = vi.fn()
const mockPowerService = {
  preventSleep: vi.fn(() => ({ dispose: sleepHoldDispose }))
}

function makeEchoHandler(): JobHandler<EchoInput> {
  return {
    recovery: 'abandon',
    cancelTimeoutMs: 2000,
    defaultConcurrency: 2,
    async execute(ctx) {
      ctx.reportProgress(25, { stage: 'starting' })
      const delay = ctx.input.sleepMs ?? 30
      await new Promise<void>((resolve, reject) => {
        if (ctx.signal.aborted) {
          reject(new Error('AbortError'))
          return
        }
        const t = setTimeout(() => resolve(), delay)
        ctx.signal.addEventListener(
          'abort',
          () => {
            clearTimeout(t)
            reject(new Error('AbortError'))
          },
          { once: true }
        )
      })
      ctx.reportProgress(100, { stage: 'done' })
      return { echoed: `echo: ${ctx.input.message}` } satisfies EchoOutput
    }
  }
}

/**
 * Handler that intentionally IGNORES `ctx.signal` until after the grace window,
 * forcing `cancel()` down its force-finalize-on-timeout branch. After the grace
 * window it honors the abort and throws, so the late settlement finalizes as
 * cancelled (matching a real handler that eventually reacts) rather than
 * clobbering the row back to completed.
 */
function makeStubbornHandler(): JobHandler<StubbornInput> {
  return {
    recovery: 'abandon',
    cancelTimeoutMs: 200,
    defaultConcurrency: 2,
    async execute(ctx) {
      await new Promise<void>((resolve) => setTimeout(resolve, ctx.input.sleepMs))
      if (ctx.signal.aborted) throw new Error('AbortError (late)')
      return { done: true }
    }
  }
}

/** Read JobManager's private executor-settlement promise for a job (test-only). */
function inFlightExecutedOf(id: string): Promise<void> | undefined {
  return (jobManager as unknown as { inFlightExecuted: Map<string, Promise<void>> }).inFlightExecuted.get(id)
}

// Local thin alias so existing call sites stay short — implementation lives
// in __tests__/_helpers.ts and is shared with the integration suite.
async function drainTrailingDispatch(): Promise<void> {
  return drainHelper(jobManager)
}

describe('JobManager smoke (dummy.echo)', () => {
  setupTestDatabase()

  beforeAll(async () => {
    BaseService.resetInstances()
    scheduler = new SchedulerService()
    jobManager = new JobManager()

    const dbSvc = MockMainDbServiceExport.dbService
    const cacheSvc = MockMainCacheServiceExport.cacheService

    ;(application.get as ReturnType<typeof vi.fn>).mockImplementation((name: string) => {
      switch (name) {
        case 'DbService':
          return dbSvc
        case 'CacheService':
          return cacheSvc
        case 'SchedulerService':
          return scheduler
        case 'JobManager':
          return jobManager
        case 'PowerService':
          return mockPowerService
      }
      throw new Error(`Unexpected application.get('${name}')`)
    })

    await scheduler._doInit()
    await jobManager._doInit()
    jobManager.registerHandler('dummy.echo' as never, makeEchoHandler() as JobHandler)
    jobManager.registerHandler('dummy.stubborn' as never, makeStubbornHandler() as JobHandler)

    // `onAllReady` now schedules startup recovery via a setTimeout and returns
    // synchronously (the framework runs `_doAllReady` fire-and-forget). Skip
    // the 60s quiet window via fake timers, then await `_recoveryDone` — set
    // inside the timer callback — to wait for the deferred flow to finish.
    // `toFake` must pair setTimeout with clearTimeout, otherwise the timer
    // queue keeps a dangling entry.
    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] })
    void jobManager._doAllReady()
    await vi.advanceTimersByTimeAsync(60_000)
    await (jobManager as unknown as { _recoveryDone?: Promise<void> })._recoveryDone
    vi.useRealTimers()
  })

  afterAll(async () => {
    // Surface shutdown errors rather than swallowing them — a regression in
    // `_doStop` (e.g. cancel-timeout misclassified, dangling promise) should
    // fail the suite, not hide behind a silent catch.
    await jobManager._doStop()
    await scheduler._doStop()
    BaseService.resetInstances()
  })

  afterEach(async () => {
    await drainTrailingDispatch()
    MockMainCacheServiceUtils.resetMocks()
    // Reset the sleep-prevention spies so each test asserts its own acquire/release counts.
    mockPowerService.preventSleep.mockClear()
    sleepHoldDispose.mockClear()
  })

  it('runs a job end-to-end (pending → running → completed)', async () => {
    const handle = jobManager.enqueue('dummy.echo' as never, { message: 'hello' } as never)
    expect(handle.snapshot.status).toBe('pending')

    const settled = await handle.finished
    expect(settled.status).toBe('completed')
    expect(settled.output).toEqual({ echoed: 'echo: hello' })
    expect(settled.attempt).toBe(0)
    expect(settled.startedAt).not.toBeNull()
    expect(settled.finishedAt).not.toBeNull()
    expect(settled.error).toBeNull()

    // The hold is released in the task's finally, which runs after finalizeJob resolves
    // handle.finished — drain so that trailing continuation has executed before asserting.
    await drainTrailingDispatch()

    // JobManager acquired exactly one sleep-prevention hold for the single attempt and
    // released it on completion. Reason is `job:<type>:<id>` — id is dynamic, match prefix.
    expect(mockPowerService.preventSleep).toHaveBeenCalledTimes(1)
    expect(mockPowerService.preventSleep).toHaveBeenCalledWith(expect.stringMatching(/^job:dummy\.echo:/))
    expect(sleepHoldDispose).toHaveBeenCalledTimes(1)
  })

  it('publishes state + progress through CacheService', async () => {
    const setShared = MockMainCacheServiceExport.cacheService.setShared

    const handle = jobManager.enqueue('dummy.echo' as never, { message: 'progress' } as never)
    await handle.finished

    const stateKey = `${JOB_STATE_KEY_PREFIX}${handle.id}`
    const progressKey = `${JOB_PROGRESS_KEY_PREFIX}${handle.id}`

    const calls = setShared.mock.calls.map((c) => c[0])
    expect(calls).toContain(stateKey)
    expect(calls).toContain(progressKey)

    const progressCalls = setShared.mock.calls.filter((c) => c[0] === progressKey)
    expect(progressCalls.length).toBeGreaterThanOrEqual(2)
    expect(progressCalls[0][1]).toMatchObject({ progress: 25 })
    expect(progressCalls.at(-1)?.[1]).toMatchObject({ progress: 100 })
  })

  it('cancels an in-flight job (handler observes abort → outcome cancelled)', async () => {
    const handle = jobManager.enqueue('dummy.echo' as never, { message: 'long', sleepMs: 500 } as never)
    // Wait for dispatch tx to fully commit before launching the next write.
    await drainTrailingDispatch()
    // Give the handler time to actually enter its abortable await.
    await new Promise((r) => setTimeout(r, 50))

    const result = await jobManager.cancel(handle.id, 'user requested')
    expect(result).toEqual({ outcome: 'cancelled' })

    const settled = await handle.finished
    expect(settled.status).toBe('cancelled')
    expect(settled.cancelRequested).toBe(true)
    expect(settled.error).toMatchObject({
      code: 'JOB_CANCELLED',
      retryable: false,
      message: expect.stringContaining('user requested')
    })

    await drainTrailingDispatch()
    // A cancelled (non-completed) job must still release its hold via the task finally.
    expect(sleepHoldDispose).toHaveBeenCalledTimes(1)
  })

  it('reports timed-out when the handler ignores the abort past cancelTimeoutMs', async () => {
    const handle = jobManager.enqueue('dummy.stubborn' as never, { sleepMs: 600 } as never)
    await drainTrailingDispatch()
    // Give the handler time to enter its (un-abortable) sleep before cancelling.
    await new Promise((r) => setTimeout(r, 50))
    // Capture the executor settlement so we can await the late handler return and
    // not leak a trailing task into the next test.
    const executed = inFlightExecutedOf(handle.id)

    const result = await jobManager.cancel(handle.id, 'stubborn cancel')
    expect(result).toEqual({ outcome: 'timed-out' })

    const settled = await handle.finished
    expect(settled.status).toBe('cancelled')

    await executed
    await drainTrailingDispatch()
    // Even on the force-timeout terminal the hold is released once the late handler settles.
    expect(sleepHoldDispose).toHaveBeenCalledTimes(1)
  }, 10_000)

  it('reports cancelled for a not-in-flight delayed job', async () => {
    const handle = jobManager.enqueue(
      'dummy.echo' as never,
      { message: 'later' } as never,
      {
        scheduledAt: Date.now() + 60_000
      } as never
    )
    expect(handle.snapshot.status).toBe('delayed')

    const result = await jobManager.cancel(handle.id)
    expect(result).toEqual({ outcome: 'cancelled' })

    const row = jobService.getById(handle.id)
    expect(row?.status).toBe('cancelled')
  })

  it('reports not-cancellable for an already-terminal job', async () => {
    const handle = jobManager.enqueue('dummy.echo' as never, { message: 'done' } as never)
    const settled = await handle.finished
    expect(settled.status).toBe('completed')
    await drainTrailingDispatch()

    const result = await jobManager.cancel(handle.id)
    expect(result).toEqual({ outcome: 'not-cancellable' })
  })

  it('reuses an existing handle when idempotencyKey matches a non-terminal job', async () => {
    const key = `idem-${Date.now()}-${Math.random().toString(36).slice(2)}`
    const first = jobManager.enqueue(
      'dummy.echo' as never,
      { message: 'unique', sleepMs: 500 } as never,
      { idempotencyKey: key } as never
    )
    await drainTrailingDispatch()
    const second = jobManager.enqueue(
      'dummy.echo' as never,
      { message: 'unique', sleepMs: 500 } as never,
      { idempotencyKey: key } as never
    )

    expect(second.id).toBe(first.id)

    await drainTrailingDispatch()
    await new Promise((r) => setTimeout(r, 50))
    await jobManager.cancel(first.id)
    await first.finished
  })

  it('GETs jobs through JobService after enqueue', async () => {
    const handle = jobManager.enqueue('dummy.echo' as never, { message: 'listed' } as never)
    await handle.finished
    await drainTrailingDispatch()

    const row = jobService.getById(handle.id)
    expect(row).not.toBeNull()
    expect(row?.type).toBe('dummy.echo')
    expect(row?.status).toBe('completed')

    const all = jobService.list({ type: 'dummy.echo' })
    expect(all.some((r) => r.id === handle.id)).toBe(true)
  })

  // Regression: the per-queue concurrency gate must count only `running` jobs,
  // not pending+delayed+running. Enqueueing more jobs than the concurrency cap
  // into a single queue previously deadlocked — once pending+running reached the
  // cap, the gate blocked every claim and no further job was ever dispatched.
  it('drains a single queue when jobs exceed concurrency (regression: pending-count deadlock)', async () => {
    // makeEchoHandler caps concurrency at 2; 6 jobs share the default queue.
    const handles = await Promise.all(
      Array.from({ length: 6 }, (_, i) =>
        jobManager.enqueue('dummy.echo' as never, { message: `m${i}`, sleepMs: 20 } as never)
      )
    )
    const settled = await Promise.all(handles.map((h) => h.finished))
    expect(settled.map((s) => s.status)).toEqual(Array(6).fill('completed'))
  }, 10_000)

  // Regression for #16291 (defense-in-depth): spawnExecute must refuse to run a
  // handler for a jobId already executing in THIS process, guarding any stray
  // re-dispatch path (not just startup recovery) from double-running a job.
  it('refuses to double-run a job already in-flight in this process', async () => {
    let executeCount = 0
    let releaseGate!: () => void
    const gate = new Promise<void>((resolve) => {
      releaseGate = resolve
    })
    const gateHandler: JobHandler<EchoInput> = {
      recovery: 'retry',
      cancelTimeoutMs: 1000,
      defaultConcurrency: 1,
      async execute(ctx) {
        executeCount++
        await new Promise<void>((resolve, reject) => {
          if (ctx.signal.aborted) return reject(new Error('AbortError'))
          const onAbort = () => reject(new Error('AbortError'))
          ctx.signal.addEventListener('abort', onAbort, { once: true })
          void gate.then(() => {
            ctx.signal.removeEventListener('abort', onAbort)
            resolve()
          })
        })
        return { echoed: `echo: ${ctx.input.message}` } satisfies EchoOutput
      }
    }
    jobManager.registerHandler('dummy.inflight.guard' as never, gateHandler as JobHandler)

    const handle = jobManager.enqueue('dummy.inflight.guard' as never, { message: 'once' } as never)
    await drainTrailingDispatch()
    expect(executeCount).toBe(1)

    const row = jobService.getById(handle.id)
    const firstExecuted = inFlightExecutedOf(handle.id)

    // Simulate a stray re-dispatch invoking spawnExecute for an id already
    // executing in this process.
    ;(jobManager as unknown as { spawnExecute: (r: unknown) => void }).spawnExecute(row)

    // Guard prevented a second execution and did not clobber the in-flight marker.
    expect(executeCount).toBe(1)
    expect(inFlightExecutedOf(handle.id)).toBe(firstExecuted)

    releaseGate()
    const settled = await handle.finished
    expect(settled.status).toBe('completed')
    expect(executeCount).toBe(1)
  })
})
