// ── Phase advance gates (EVENTS_PLAN.md Phase 5) ───────────────────────────
//
// The runner's half of this is in `eventRunner.test.js`, where a gate holds a
// phase and lets it go. This file is the other half — the two things that only
// exist because an operator has to READ them:
//
//   • `phrase()`, which renders a condition tree in the CONDITION BUILDER's own
//     words. § Observability's claim is that `gte` says "is at least" on the
//     diagnosis panel because it says "is at least" in the rule editor. That is
//     a claim about two files agreeing, so it is tested against the grammar's
//     own labels rather than against a string this file wrote down.
//   • `observe()`, whose whole reason for existing is that a firing between two
//     ticks is not observable from either of them — and whose near-miss branch
//     is the more valuable of its two outcomes on the night.
//
// **`describe()` is tested for what it does NOT say as much as what it does.**
// An `after` gate is never stalled, however long it was authored to wait: a
// phase waiting out six hours it was told to wait is working, and health that
// said otherwise would train an operator to ignore it.
//
// Point the DB at a closed port before requiring anything.
process.env.DB_HOST = '127.0.0.1'
process.env.DB_PORT = '59999'

const { test, beforeEach, afterEach, after } = require('node:test')
const assert = require('node:assert/strict')

const gates = require('../src/events/gates')
const conditions = require('../src/engagement/conditions')
const gatesDb = require('../src/model/events/eventPhaseGates.db')
const logDb = require('../src/model/events/eventRunLog.db')
const db = require('../src/utils/db')

after(() => db.close())

const T0 = new Date('2026-09-02T20:31:04Z')

// ── phrase(): the words are the grammar's, not this file's ─────────────────

test('every operator renders with the label the condition grammar declares', () => {
  // Not a table of expected strings: that would be a second copy of the labels,
  // and the point of rendering server-side is that there is only one.
  for (const [cmp, operator] of Object.entries(conditions.OPERATORS)) {
    const leaf =
      operator.arity === 0
        ? { variable: 'region', cmp }
        : operator.arity === 'list'
          ? { variable: 'region', cmp, value: ['Yew', 'Britain'] }
          : { variable: 'region', cmp, value: 'Yew' }
    const rendered = gates.phrase(leaf)
    assert.ok(rendered.startsWith(`region ${operator.label}`), `${cmp} should read as "${operator.label}"`)
  }
})

test('a tree reads as a sentence, and only brackets where the reading changes', () => {
  assert.equal(gates.phrase({ variable: 'region', cmp: 'eq', value: 'Yew' }), 'region is "Yew"')
  assert.equal(
    gates.phrase({ op: 'and', nodes: [{ variable: 'region', cmp: 'eq', value: 'Yew' }, { variable: 'level', cmp: 'gte', value: 3 }] }),
    'region is "Yew" and level is at least 3',
    'a flat and is a sentence, not a nest of brackets',
  )
  assert.equal(
    gates.phrase({
      op: 'or',
      nodes: [
        { op: 'and', nodes: [{ variable: 'a', cmp: 'present' }, { variable: 'b', cmp: 'in', value: ['x', 'y'] }] },
        { variable: 'c', cmp: 'absent' },
      ],
    }),
    '(a is present and b is one of "x", "y") or c is absent',
  )
  assert.equal(gates.phrase({ op: 'not', nodes: [{ variable: 'region', cmp: 'eq', value: 'Yew' }] }), 'not (region is "Yew")')
})

test('no conditions renders as nothing, not as "always true"', () => {
  // The caller says "on any firing of this trigger"; a clause claiming
  // everything is true is one more thing to read past.
  assert.equal(gates.phrase(null), null)
  assert.equal(gates.phrase({ variable: 'x', cmp: 'nonsense', value: 1 }), null)
})

test('variablesIn names each variable once, in the order the tree names them', () => {
  const tree = {
    op: 'and',
    nodes: [
      { variable: 'region', cmp: 'eq', value: 'Yew' },
      { op: 'or', nodes: [{ variable: 'level', cmp: 'gte', value: 3 }, { variable: 'region', cmp: 'ne', value: 'Britain' }] },
    ],
  }
  assert.deepEqual(gates.variablesIn(tree), ['region', 'level'])
  assert.deepEqual(gates.variablesIn(null), [])
})

// ── describe(): what the panel shows ───────────────────────────────────────

const gateRow = (over = {}) => ({
  id: 1,
  run_id: 1,
  phase: 'boss',
  kind: 'on',
  after_seconds: null,
  trigger_id: 'uo.champ.boss_up',
  conditions: { variable: 'region', cmp: 'eq', value: 'Yew' },
  needed: 1,
  tally: 0,
  entered_at: T0,
  due_at: null,
  last_event: null,
  last_event_at: null,
  satisfied_at: null,
  satisfied_by: null,
  ...over,
})

test('the panel answers "why didn\'t phase 3 start?" with the tally, the clock and the clause', () => {
  const at = new Date(T0.getTime() + 28 * 60_000)
  const described = gates.describe(gateRow(), at)
  assert.equal(described.phase, 'boss')
  assert.equal(described.waitingOn, 'uo.champ.boss_up')
  assert.equal(described.where, 'region is "Yew"')
  assert.equal(described.seen, 0)
  assert.equal(described.needed, 1)
  assert.equal(described.elapsedSeconds, 28 * 60)
  assert.equal(described.satisfied, false)
  assert.equal(described.stalled, false, '28 minutes is not yet a stall')
})

test('a satisfied gate stops its clock at the moment it was satisfied', () => {
  // Live, `elapsedSeconds` answers "how long has this phase been waiting";
  // afterwards it answers "how long did it wait", and those are the same number
  // only while it is still waiting. The walk found it disagreeing with
  // `phase.advanced`'s own `waitedSeconds` by the age of the open screen.
  const gate = gateRow({ satisfied_at: new Date(T0.getTime() + 121_000), satisfied_by: 'forced' })
  const muchLater = new Date(T0.getTime() + 3 * 3600_000)
  assert.equal(gates.describe(gate, muchLater).elapsedSeconds, 121)
  // And an open one still measures to now.
  assert.equal(gates.describe(gateRow(), new Date(T0.getTime() + 300_000)).elapsedSeconds, 300)
})

test('an `after` gate is never stalled, however long it was told to wait', () => {
  const gate = gateRow({
    kind: 'after',
    trigger_id: null,
    conditions: null,
    after_seconds: 6 * 3600,
    due_at: new Date(T0.getTime() + 6 * 3600_000),
  })
  const described = gates.describe(gate, new Date(T0.getTime() + gates.STALL_MS * 4))
  assert.equal(described.stalled, false)
  assert.equal(described.after, 6 * 3600)
  assert.equal(described.waitingOn, undefined, 'and it carries none of the `on` fields')
})

test('an `on` gate is stalled once it has waited past the threshold, and never once satisfied', () => {
  const late = new Date(T0.getTime() + gates.STALL_MS + 1000)
  assert.equal(gates.describe(gateRow(), late).stalled, true)
  assert.equal(gates.describe(gateRow({ satisfied_at: T0, satisfied_by: 'condition' }), late).stalled, false)
})

// ── observe(): the emit path ───────────────────────────────────────────────

let store

function installStubs() {
  store = { gates: [], log: [] }
  gatesDb.openForTrigger = async (triggerId) => store.gates.filter((g) => g.trigger_id === triggerId && !g.satisfied_at)
  gatesDb.count = async (id, { lastEvent, now }) => {
    const g = store.gates.find((x) => x.id === id)
    if (!g || g.satisfied_at) return { counted: false, satisfied: false }
    g.tally += 1
    g.last_event = lastEvent
    g.last_event_at = now
    if (g.tally >= g.needed) g.satisfied_at = now
    return { counted: true, satisfied: Boolean(g.satisfied_at), tally: g.tally }
  }
  gatesDb.noteNearMiss = async (id, { lastEvent, now }) => {
    const g = store.gates.find((x) => x.id === id)
    if (!g) return false
    g.last_event = lastEvent
    g.last_event_at = now
    return true
  }
  logDb.write = async (line) => {
    store.log.push(line)
    return true
  }
}

const originals = [
  [gatesDb, { ...gatesDb }],
  [logDb, { ...logDb }],
]
beforeEach(installStubs)
afterEach(() => {
  for (const [mod, fns] of originals) Object.assign(mod, fns)
})

const emit = (data, triggerId = 'uo.champ.boss_up') =>
  gates.observe({ triggerId, occurredAt: T0.toISOString(), subject: 'champ:yew', data })

test('a matching firing counts, and a near miss is recorded without counting', async () => {
  store.gates.push(gateRow({ needed: 2 }))

  await emit({ region: 'Britain', level: 4 })
  assert.equal(store.gates[0].tally, 0)
  assert.equal(store.gates[0].last_event.matched, false)

  await emit({ region: 'Yew', level: 4 })
  assert.equal(store.gates[0].tally, 1)
  assert.equal(store.gates[0].satisfied_at, null)

  await emit({ region: 'Yew', level: 1 })
  assert.equal(store.gates[0].tally, 2)
  assert.ok(store.gates[0].satisfied_at)
})

test('only the variables the condition names are recorded, never the payload', async () => {
  // The row is read back onto an admin screen, and a copy of a whole game
  // event's data is a second copy of exactly the content `engagement_sends` is
  // careful not to keep.
  store.gates.push(gateRow())
  await emit({ region: 'Yew', playerName: 'Dupre', houseLocation: '1423,1712', level: 4 })

  assert.deepEqual(store.gates[0].last_event.variables, { region: 'Yew' })
  const line = store.log.find((l) => l.kind === 'condition.evaluated')
  assert.deepEqual(line.detail.variables, { region: 'Yew' })
  assert.equal(JSON.stringify(store.log).includes('Dupre'), false)
  assert.equal(JSON.stringify(store.gates).includes('1423,1712'), false)
})

test('both outcomes are logged, with the tally the row actually holds', async () => {
  store.gates.push(gateRow({ needed: 2 }))
  await emit({ region: 'Britain' })
  await emit({ region: 'Yew' })

  const lines = store.log.filter((l) => l.kind === 'condition.evaluated')
  assert.equal(lines.length, 2)
  assert.deepEqual(lines.map((l) => l.detail.matched), [false, true])
  assert.deepEqual(lines.map((l) => l.detail.seen), [0, 1])
  assert.deepEqual(lines.map((l) => l.detail.satisfied), [false, false])
})

test('a gate with no `where` counts every firing of its trigger', async () => {
  store.gates.push(gateRow({ conditions: null }))
  await emit({ anything: true })
  assert.equal(store.gates[0].tally, 1)
  assert.deepEqual(store.gates[0].last_event.variables, {}, 'and there are no named variables to record')
})

test('a firing of another trigger touches nothing', async () => {
  store.gates.push(gateRow())
  const summary = await emit({ region: 'Yew' }, 'uo.champ.started')
  assert.equal(summary.gates, 0)
  assert.equal(store.gates[0].tally, 0)
  assert.equal(store.log.length, 0)
})

test('observe never rejects, however badly the database is behaving', async () => {
  // It is called from inside a game-event handler by way of `ctx.events.emit`,
  // exactly as `engine.dispatch` is. A database problem of core's must not
  // become a module's control flow at three in the morning.
  gatesDb.openForTrigger = async () => {
    throw new Error('pool exhausted')
  }
  const summary = await emit({ region: 'Yew' })
  assert.deepEqual(summary, { gates: 0, counted: 0, satisfied: 0 })
})