import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
import { setActivePinia, createPinia } from 'pinia'
import { laneStuckFor, useSystemActivityStore } from '../src/stores/systemActivity.js'

// Milestone 422 step 4. Covers the store half of the worker-lane dial — the
// part that decides what the card can tell the operator.
//
// What is protected here since 2026-09-23: pressing the dial must not wait on
// a broker round trip. Operator: *"when the number is changed the change
// should be queued so that it isn't blocking of the webui or the system
// itself. we shouldn't have to wait for the validation live."* The endpoint
// answers once the cap is STORED, so the store patches its row from that
// reply and lets the 15s poll bring the live columns — it used to refetch,
// and GET /api/system/workers costs a celery inspect on an eleven-second
// budget.
//
// And still: a REFUSED value (400) is a failure and must reach the operator
// as one. A control that silently does nothing is worse than one that
// refuses out loud.

function stubFetch(handler) {
  globalThis.fetch = vi.fn(async (url, init) => {
    const { status, body } = handler(url, init)
    return {
      ok: status >= 200 && status < 300,
      status,
      statusText: String(status),
      text: async () => (body == null ? '' : JSON.stringify(body)),
    }
  })
}

const LANES_BODY = {
  lanes: [
    {
      name: 'worker', display_name: 'Worker',
      queues: ['default', 'import', 'thumbnail', 'download'],
      slots_cap: 1, ceiling: 8, enabled: true, memory_bound: false,
      live: { present: true, replicas: 1, pool: 1, active: 0, reserved: 3 },
      queue_depth: 5, pending: 8,
    },
    {
      name: 'ml', display_name: 'ML tagging', queues: ['ml'],
      slots_cap: 0, ceiling: 2, enabled: false, memory_bound: true,
      live: { present: false, replicas: 0, pool: null, active: 0, reserved: 0 },
      queue_depth: null, pending: null,
    },
  ],
  fetched_at: '2026-09-22T12:00:00Z',
}

describe('worker lanes store', () => {
  beforeEach(() => setActivePinia(createPinia()))
  afterEach(() => vi.restoreAllMocks())

  it('loads the lanes', async () => {
    stubFetch(() => ({ status: 200, body: LANES_BODY }))
    const s = useSystemActivityStore()
    await s.loadLanes()
    expect(s.lanes.lanes.map((l) => l.name)).toEqual(['worker', 'ml'])
  })

  it('a load failure records the error rather than throwing at the caller', async () => {
    // The System tab polls this every 15s. An unhandled rejection per tick
    // would drown the console and stop the other pollers in the same
    // function.
    stubFetch(() => ({ status: 500, body: { error: 'boom' } }))
    const s = useSystemActivityStore()
    await expect(s.loadLanes()).resolves.toBeUndefined()
    expect(s.lastError).toBeTruthy()
  })

  it('setLane posts only the fields it was given', async () => {
    // One field: the cap. How many workers are running is a measurement the
    // sizing pass owns, so there is nothing else for the UI to send.
    const calls = []
    stubFetch((url, init) => {
      calls.push({ url, init })
      if (init?.method === 'POST') {
        return { status: 200, body: { name: 'worker', slots_cap: 2, queued: true } }
      }
      return { status: 200, body: LANES_BODY }
    })
    const s = useSystemActivityStore()
    await s.setLane('worker', { slots_cap: 2 })

    const post = calls.find((c) => c.init?.method === 'POST')
    expect(post.url).toContain('/api/system/workers/worker')
    expect(JSON.parse(post.init.body)).toEqual({ slots_cap: 2 })
  })

  it('setLane does not refetch — that refetch is what blocked the press', async () => {
    // It refetched until 2026-09-23, so that the card showed server truth
    // rather than a local guess. The cost was the operator's: GET
    // /api/system/workers runs a celery inspect, so every press of `+` sat
    // with the stepper disabled through a broker round trip the press did not
    // need.
    let gets = 0
    stubFetch((url, init) => {
      if (init?.method === 'POST') {
        return { status: 200, body: { slots_cap: 2, ceiling: 8, enabled: true } }
      }
      gets += 1
      return { status: 200, body: LANES_BODY }
    })
    const s = useSystemActivityStore()
    await s.loadLanes()
    gets = 0
    await s.setLane('worker', { slots_cap: 2 })

    expect(gets).toBe(0)
  })

  it('patches the row from the reply, so the new number shows at once', async () => {
    stubFetch((url, init) => {
      if (init?.method === 'POST') {
        return {
          status: 200,
          body: { name: 'worker', slots_cap: 2, ceiling: 8, enabled: true, queued: true },
        }
      }
      return { status: 200, body: LANES_BODY }
    })
    const s = useSystemActivityStore()
    await s.loadLanes()
    await s.setLane('worker', { slots_cap: 2 })

    const worker = s.lanes.lanes.find((l) => l.name === 'worker')
    expect(worker.slots_cap).toBe(2)
  })

  it('does not invent the live columns the reply cannot know', async () => {
    // The reply is decided from the stored cap and the machine's ceiling
    // alone — it never asked a worker anything. Pool, active and pending are
    // MEASUREMENTS, and the poll a few seconds later is what carries them.
    // Zeroing or guessing them here would make the table lie in the direction
    // that reads as "the lane stopped".
    stubFetch((url, init) => {
      if (init?.method === 'POST') {
        return { status: 200, body: { slots_cap: 2, ceiling: 8, enabled: true } }
      }
      return { status: 200, body: LANES_BODY }
    })
    const s = useSystemActivityStore()
    await s.loadLanes()
    const before = { ...s.lanes.lanes[0].live }
    await s.setLane('worker', { slots_cap: 2 })

    expect(s.lanes.lanes[0].live).toEqual(before)
    expect(s.lanes.lanes[0].pending).toBe(8)
  })

  it('survives a reply arriving for a lane it has not loaded yet', async () => {
    // First paint, or a lane added by a newer build. Patching must not be the
    // thing that throws inside the click handler.
    stubFetch(() => ({ status: 200, body: { slots_cap: 2 } }))
    const s = useSystemActivityStore()
    await expect(s.setLane('worker', { slots_cap: 2 })).resolves.toBeTruthy()
  })

  it('a refused value throws so the card can show the reason', async () => {
    // Deliberately NOT swallowed. The detail is written to be read by a person
    // ("above what this container can hold"), and a control that silently does
    // nothing is worse than one that refuses out loud.
    stubFetch((url, init) => {
      if (init?.method === 'POST') {
        return {
          status: 400,
          body: { error: 'refused', detail: 'cap 10000 is above what this container can hold (2 for ML tagging)' },
        }
      }
      return { status: 200, body: LANES_BODY }
    })
    const s = useSystemActivityStore()
    // Assert the REASON is reachable, not merely that it threw. `toThrow()`
    // alone passes whether the card can read the sentence or not — which is
    // how the first version of the card shipped reading `e.detail` (always
    // undefined) and would have shown the operator the bare word "refused".
    const err = await s.setLane('ml', { slots_cap: 10000 }).catch((e) => e)
    expect(err.status).toBe(400)
    expect(err.body.detail).toContain('container can hold')
  })
})

// --- the long-running-task warning (step 7) ----------------------------------
//
// The operator asked for "a task runs for x concurrent time" to TRIGGER
// growth. It became a warning: extra slots do not make a running task finish
// sooner. What is pinned here is the AND — a warning that fires on half its
// condition is one people learn to ignore, and at that point it is worse than
// not having it.

describe('laneStuckFor', () => {
  const lane = (over = {}) => ({
    oldest_running_minutes: 40,
    live: { present: true, pool: 4, active: 4 },
    ...over,
  })

  it('warns when every slot is busy and the oldest task is old', () => {
    expect(laneStuckFor(lane())).toBe('40 minutes')
  })

  it('says nothing when the lane has a free slot', () => {
    expect(laneStuckFor(lane({ live: { present: true, pool: 4, active: 3 } })))
      .toBeNull()
  })

  it('says nothing for a saturated lane whose tasks are young', () => {
    expect(laneStuckFor(lane({ oldest_running_minutes: 2 }))).toBeNull()
  })

  it('says nothing when nothing is running', () => {
    expect(laneStuckFor(lane({ oldest_running_minutes: null }))).toBeNull()
  })

  it('says nothing about a lane that is not answering', () => {
    // Unknown is not busy. A lane nothing answered for has no live reading to
    // call saturated, and asserting one would be a verdict from an unswept
    // read — the same distinction `present` exists for everywhere else here.
    expect(laneStuckFor(lane({ live: { present: false, pool: null, active: 0 } })))
      .toBeNull()
  })

  it('says nothing when the pool is zero', () => {
    // A lane with no workers is not "fully busy at zero" — it is off.
    expect(laneStuckFor(lane({ live: { present: true, pool: 0, active: 0 } })))
      .toBeNull()
  })

  it('switches to hours once minutes stop being readable', () => {
    expect(laneStuckFor(lane({ oldest_running_minutes: 195 }))).toBe('3 hours')
  })
})