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

import { laneAdvice, mergeParts, queueKey } from '../src/utils/systemParts.js'

// The System tab's one table (operator 2026-09-23: "combine the two sections
// into a single table"). What is pinned here is the JOIN, because its failure
// is silent and is precisely the thing the merge exists to fix: a lane that
// stops matching its roster part does not throw — the table grows a SECOND row
// for the same worker, one with controls and one without.

const PART = {
  key: 'celery:default,download,import,thumbnail',
  kind: 'celery',
  name: 'Worker',
  state: 'ok',
  detail: 'Worker is running',
  // The roster SORTS a celery part's queues into its key.
  queues: ['default', 'download', 'import', 'thumbnail'],
}

const LANE = {
  name: 'worker',
  display_name: 'Worker',
  // The lane table lists them in the order the role reads them, which is NOT
  // sorted. If the join ever compares these two lists directly rather than as
  // sets, this fixture is what catches it.
  queues: ['default', 'import', 'thumbnail', 'download'],
  slots_cap: 4,
  ceiling: 8,
  live: { present: true, replicas: 1, pool: 2, active: 0 },
  pending: 0,
}

const POSTGRES = {
  key: 'postgres', kind: 'datastore', name: 'PostgreSQL',
  state: 'ok', detail: 'answering', latency_ms: 2.5,
}

describe('queueKey', () => {
  it('does not care what order either side lists its queues in', () => {
    expect(queueKey(LANE.queues)).toBe(queueKey(PART.queues))
  })

  it('survives a part that has no queues at all', () => {
    // A datastore, and also the stale `Worker ()` row a previous deployment
    // left in the roster with an empty queue set. Neither must match a lane.
    expect(queueKey(undefined)).toBe('')
    expect(queueKey([])).toBe('')
  })
})

describe('mergeParts', () => {
  it('gives a worker ONE row, carrying its controls', () => {
    const rows = mergeParts([PART, POSTGRES], [LANE])

    expect(rows).toHaveLength(2)
    const worker = rows.find((r) => r.name === 'Worker')
    expect(worker.lane).toBe(LANE)
    expect(rows.filter((r) => r.name === 'Worker')).toHaveLength(1)
  })

  it('leaves a datastore without a lane rather than guessing one', () => {
    const pg = mergeParts([PART, POSTGRES], [LANE]).find((r) => r.key === 'postgres')
    expect(pg.lane).toBeUndefined()
  })

  it('still lists a lane the roster has never seen', () => {
    // Parts are learned as they appear; the lane table is known up front. The
    // lane an operator most needs to find — an optional one, never started —
    // is exactly the one with no roster entry.
    const ml = {
      ...LANE, name: 'ml', display_name: 'ML tagging', queues: ['ml'],
      slots_cap: 0, optional: true,
      live: { present: false, replicas: 0, pool: null, active: 0 },
    }
    const rows = mergeParts([POSTGRES], [ml])

    const row = rows.find((r) => r.name === 'ML tagging')
    expect(row.lane).toBe(ml)
    expect(row.kindLabel).toBe('optional lane')
  })

  it('does not call a lane capped at zero broken', () => {
    // The roster only knows a heartbeat age, so it goes on saying "is running"
    // for a lane the operator deliberately dialled to nothing. The lane knows
    // the difference; reporting the operator's own choice as a fault is how an
    // indicator stops being read.
    const off = { ...LANE, slots_cap: 0 }
    const row = mergeParts([PART], [off])[0]

    expect(row.detail).toBe('off — cap is zero')
  })

  it('puts the broken thing first, whatever it is', () => {
    const down = { ...POSTGRES, state: 'down', detail: 'not answering' }
    const rows = mergeParts([PART, down], [LANE])

    expect(rows[0].name).toBe('PostgreSQL')
  })

  it('otherwise puts the rows you can act on first', () => {
    const rows = mergeParts([POSTGRES, PART], [LANE])

    expect(rows.map((r) => r.name)).toEqual(['Worker', 'PostgreSQL'])
  })

  it('reports a wedged lane, and only through the reporter it was given', () => {
    // `laneStuckFor` is passed in rather than imported, so this file does not
    // re-test the store's rule — it tests that the merge asks.
    const asked = []
    const rows = mergeParts([PART], [LANE], (lane) => {
      asked.push(lane.name)
      return '40 minutes'
    })

    expect(asked).toEqual(['worker'])
    expect(rows[0].stuckFor).toBe('40 minutes')
    // The roster still owns a matched row's state — `stuckFor` is a note
    // beside it, not a verdict that overrides the heartbeat.
    expect(rows[0].state).toBe('ok')
  })

  it('handles an empty everything without inventing rows', () => {
    expect(mergeParts([], [])).toEqual([])
    expect(mergeParts(undefined, undefined)).toEqual([])
  })
})


// The nudge. Operator, 2026-09-23: *"there needs to be something that tells
// you user to bump those numbers to improve processing rate or they'd never
// know the controls exist."*
//
// The caps ship at one of each, so on a busy instance the SHIPPED
// CONFIGURATION is the bottleneck. What is pinned here is that it fires only
// when raising the cap would actually help — a notice on a lane that is
// keeping up, or one already at the machine's limit, is a notice people learn
// to scroll past, and at that point it is worse than not having it.

describe('laneAdvice', () => {
  const busyAtCap = {
    slots_cap: 1, ceiling: 7, pending: 4060,
    live: { present: true, pool: 1, active: 1 },
  }

  it('speaks when the cap is the limiting factor', () => {
    const advice = laneAdvice(busyAtCap)
    expect(advice).toContain('4,060 waiting')
    expect(advice).toContain('Raise the cap')
    // The headroom, so it is an instruction rather than a complaint.
    expect(advice).toContain('7')
  })

  it('says something different about a lane that is switched off', () => {
    const advice = laneAdvice({ ...busyAtCap, slots_cap: 0 })
    expect(advice).toContain('this lane is off')
  })

  it('stays quiet when the lane is keeping up', () => {
    expect(laneAdvice({ ...busyAtCap, pending: 2 })).toBeNull()
  })

  it('stays quiet when the cap is not the thing holding it back', () => {
    // Four allowed, two running — the sizing pass has room it has not taken,
    // so the queue is not the cap's fault.
    expect(laneAdvice({
      ...busyAtCap, slots_cap: 4, live: { present: true, pool: 2, active: 2 },
    })).toBeNull()
  })

  it('stays quiet at the machine ceiling, where the advice is untakeable', () => {
    // The one case where saying "raise the cap" would send someone to a
    // control that will refuse them.
    expect(laneAdvice({ ...busyAtCap, ceiling: 1 })).toBeNull()
  })

  it('stays quiet about a lane that is not answering', () => {
    // An unswept read is not a verdict: nothing replied, so "all workers
    // busy" is a claim nobody made.
    expect(laneAdvice({
      ...busyAtCap, live: { present: false, pool: null, active: 0 },
    })).toBeNull()
  })

  it('stays quiet when the backlog is unknown rather than reading it as huge', () => {
    expect(laneAdvice({ ...busyAtCap, pending: null })).toBeNull()
  })

  it('says nothing about a row that is not a lane at all', () => {
    expect(laneAdvice(undefined)).toBeNull()
  })
})