import type { IncidentRecord } from '../data/types';
import type { RngStream } from '../core/SeededRNG';

// The Incident Report (design §3.3). At last drinks the venue asks the player to
// write up the night, and the player may lie. This module builds that form and
// encodes what was filed. The cross-night audit that CATCHES the lies is Phase 4;
// everything here exists to leave that audit something it can read.
//
// Nothing in this file scores anything. There is no honesty meter, no chime for
// telling the truth, and no line of prose that tells the player they did well or
// badly (§4.3). The lie is cheap tonight and that is the whole joke.
//
// ---- STORAGE ENCODING — read before touching fileReport ----
// IncidentRecord is a frozen contract type {clockMin, kind, patronId?, detail},
// so a filed row carries its machine payload inside `detail`:
//
//   detail = `${account}` + REPORT_MARKER + JSON.stringify(FiledPayload)
//
// The account the player chose comes FIRST and verbatim, so a debug dump of
// pastReports still reads like a report. Everything Phase 4 needs — which option
// was picked, whether it was true, and the truth-log line the account replaced —
// is JSON after the marker. The marker is newline-prefixed and no authored
// account contains a newline, so it cannot collide with prose.
//
// Parse with parseFiledAccount(). Do not hand-roll a regex over this: it returns
// undefined for a raw truth-log row, which matters because GameState.pastReports
// already holds unfiled NightState.incidents rows from Phase 2.

export interface ReportOption {
  id: string;
  /** the written account, first person, bouncer-report register */
  text: string;
  truthful: boolean;
}

export interface ReportQuestion {
  incident: IncidentRecord;
  prompt: string;
  options: ReportOption[];
}

export interface FiledAnswer {
  incident: IncidentRecord;
  chosen: ReportOption;
}

/** What parseFiledAccount recovers from a filed row. */
export interface FiledAccount {
  /** the prose the player filed */
  account: string;
  optionId: string;
  /** false = the player filed a flattering version of this incident */
  truthful: boolean;
  /** the incident's own `detail` from the truth log, before the account replaced it */
  truthLog: string;
}

export const REPORT_TUNING = {
  /** Three questions is twenty seconds. A fourth turns the bit into homework. */
  maxQuestions: 3,

  // How worth-asking-about each incident kind is. Kinds are open strings written
  // by three different scenes (DoorScene verdicts + 'kayden', NightScene
  // 'deferred', FloorDemoScene's five), so this is a lookup, not a union.
  //
  // Zero means "never ask": a clean admit is not a story, and a night is mostly
  // clean admits. Ties are broken by an rng jitter below 1, so a weight is a
  // band, never a fixed running order.
  // A weight is a band, and it has to price FREQUENCY as well as interest. The
  // form takes the top three of the night, so a kind that fires twenty-six
  // times at weight 6 IS the form — three near-identical questions and every
  // rare, loaded thing crowded out. Rule of thumb: once-a-night and awkward
  // scores high, many-times-a-night scores 0-2 however interesting it feels.
  interest: {
    deferred: 10, // a breach the audit already found — the awkward one
    jointPocketed: 9, // the one question you really don't want asked
    baggiePocketed: 9, // ...and the one they ask when the lights are on
    barServeBreach: 8, // a pour into someone who could not find the glass
    djTip: 8, // money changed hands at the booth and the booth took it
    tabMisreturned: 8, // somebody went home with another person's bank card
    ejection: 8,
    firstAid: 7,
    fainter: 7,
    maggotUnhandled: 7,
    fight: 6,
    kayden: 6, // his mistake, your signature
    cutOff: 5,
    barCutOff: 5, // the bar's own refusal — same call, other side of the counter
    stallBusted: 5,
    jointIgnored: 5,
    rackDropped: 4,
    tabUnclaimed: 4,
    patDown: 4, // both door and floor log this kind; one bank covers both
    phoneConfiscated: 4,
    baggieBinned: 3,
    jointBinned: 3,
    carpetStorm: 3,
    radioOrder: 3, // you did not do it; you said who would
    radioedIn: 6, // the glassie's whole shift: you saw it and could only say so
    deny: 3,
    vomit: 2,
    slip: 2,
    floorScore: 2,
    sobrietyTest: 2,
    barWater: 2,
    djRequest: 2,
    // High-frequency or no-story. Zero means never asked; a night is mostly
    // these, and a form full of them is a form nobody reads.
    barServe: 1, // ~26 a night on a bar shift. Pouring a beer is not a story.
    djDrop: 1,
    tabClosed: 1,
    lostProperty: 1,
    glassieRun: 1,
    waterServed: 1,
    mopped: 0,
    wetFloorSign: 0,
    phoneAsked: 0,
    phoneAllowed: 0,
    barShift: 0, // holding the taps is a shift, not an incident
    djShift: 0,
    carpet: 0,
    carpetEntrance: 0,
    lightsOn: 0,
    admit: 0,
    wait: 0,
  } as Record<string, number>,

  /**
   * Weight for a kind nobody listed. Deliberately askable: a lane that adds an
   * incident kind should find it turning up in the form, not silently missing.
   */
  defaultInterest: 2,
};

/** Separates the filed account from its machine payload inside `detail`. */
export const REPORT_MARKER = '\n[report:v1]';

interface FiledPayload {
  optionId: string;
  truthful: boolean;
  truthLog: string;
}

interface AccountBank {
  prompt: string;
  options: readonly ReportOption[];
}

// The register: clipped, passive where a real report hedges, faintly defensive.
// The joke is SPECIFICITY vs MUSH — the truthful option names what actually
// happened and who did it; the flattering ones are plausible deniability, the
// account a tired adult would actually write and could actually defend, never a
// cartoon denial that nothing occurred (a lie you can't say out loud isn't a
// choice, it's a button).
//
// §4.3: no account may pronounce a VERDICT on the player's night. "It was
// wrong", "they had a point", "I had decided before they finished" all tell the
// player which choice was right, which is the one thing this game does not do.
// A truthful account states the fact and stops. The reader supplies the wince.
const BANKS: Record<string, AccountBank> = {
  deferred: {
    prompt: 'Flagged on the nightly audit. Your account?',
    options: [
      { id: 'deferred.true', text: 'I let them in. That was my call at the desk and my name is on the sheet.', truthful: true },
      { id: 'deferred.soft1', text: 'Patron presented as compliant at the point of entry. Lighting at the rope is what it is.', truthful: false },
      { id: 'deferred.soft2', text: 'Entry was authorised on the information available at the desk at that time.', truthful: false },
    ],
  },
  ejection: {
    prompt: 'A patron was removed from the premises. Your account?',
    options: [
      { id: 'ejection.true', text: 'I walked them out. They did not want to go and I did not give them the option.', truthful: true },
      { id: 'ejection.soft1', text: 'Patron elected to leave and was accompanied to the exit as a courtesy.', truthful: false },
      { id: 'ejection.soft2', text: 'An escort was offered and accepted. No more than a guiding hand was required.', truthful: false },
    ],
  },
  maggotUnhandled: {
    prompt: 'A patron was left a while in a poor state. Your account?',
    options: [
      { id: 'maggot.true', text: 'I saw them and I was on the door. Nobody got to them for a good while.', truthful: true },
      { id: 'maggot.soft1', text: 'Patron was monitored at intervals from the floor. Water was made available.', truthful: false },
      { id: 'maggot.soft2', text: 'Patron was seated and stable. No intervention was assessed as necessary at that point.', truthful: false },
    ],
  },
  jointPocketed: {
    prompt: 'Contraband was located in the smoking area. Where is it now?',
    options: [
      { id: 'jointP.true', text: 'On me. I took possession and I still have possession. That is the account.', truthful: true },
      { id: 'jointP.soft1', text: 'Item was destroyed on the spot in view of the patron.', truthful: false },
      { id: 'jointP.soft2', text: 'Item was placed in the amnesty bin per procedure. The bin was emptied by close.', truthful: false },
    ],
  },
  jointBinned: {
    prompt: 'Contraband was located in the smoking area. Your account?',
    options: [
      { id: 'jointB.true', text: 'Confiscated and binned in front of them. The yard went quiet for a bit.', truthful: true },
      { id: 'jointB.soft1', text: 'Patron surrendered the item voluntarily and thanked security for the chat.', truthful: false },
      { id: 'jointB.soft2', text: 'Item was assessed as herbal cigarettes. Binned as general litter.', truthful: false },
    ],
  },
  jointIgnored: {
    prompt: 'A smell was reported near the smoking area. Your account?',
    options: [
      { id: 'jointI.true', text: 'I smelled it, I saw it, and I decided the fence line was more interesting.', truthful: true },
      { id: 'jointI.soft1', text: 'Area was patrolled at the time stated. Nothing of note was observed.', truthful: false },
      { id: 'jointI.soft2', text: 'Smell was traced to the kebab shop exhaust across the road.', truthful: false },
    ],
  },
  // ---- the floor's own paperwork (bar, booth, carpet, close) ----------------

  baggiePocketed: {
    prompt: 'Contraband was recovered from the floor after close. Where is it now?',
    options: [
      { id: 'baggieP.true', text: 'In my pocket. I picked it up off the floor and I kept it. That is where it is.', truthful: true },
      { id: 'baggieP.soft1', text: 'Item was disposed of during the close-down sweep. No patron was present to caution.', truthful: false },
      { id: 'baggieP.soft2', text: 'Item was bagged and left for the licensee per the amnesty procedure.', truthful: false },
    ],
  },
  baggieBinned: {
    prompt: 'Contraband was recovered from the floor after close. Your account?',
    options: [
      { id: 'baggieB.true', text: 'Found it on the floor at lights-on and put it straight in the amnesty bin.', truthful: true },
      { id: 'baggieB.soft1', text: 'A small quantity of unidentified material was disposed of as general waste.', truthful: false },
      { id: 'baggieB.soft2', text: 'Nothing of note was recovered. The sweep was routine and unremarkable.', truthful: false },
    ],
  },
  barServeBreach: {
    prompt: 'Service was provided to a patron in an advanced state. Your account?',
    options: [
      { id: 'barSB.true', text: 'I poured it and I handed it over. It took them three goes to find the glass.', truthful: true },
      { id: 'barSB.soft1', text: 'Patron presented as coherent at the point of service. Assessment was made at the bar.', truthful: false },
      { id: 'barSB.soft2', text: 'Beverage was supplied to a member of the same group and not to the patron named.', truthful: false },
    ],
  },
  // Added 2026-07-22: these kinds were being asked about with the generic
  // "an entry was made in the log" line. The report is where the game's moral
  // weight actually lands (design §4.3), so the loaded ones need to be asked
  // about BY NAME — a form that shrugs at a pocketed find is not a test.

  /**
   * The glassie's whole shift, in one question. You saw it, you had no standing
   * to touch it, you said so on the radio — and then it was somebody else's
   * call whether anything happened. The truthful option is the only one that
   * admits nobody came.
   */
  radioedIn: {
    prompt: 'An issue was called in over the radio rather than actioned. Your account?',
    options: [
      { id: 'radio.true', text: 'I called it in. I am not authorised to touch it. I do not know if anyone went.', truthful: true },
      { id: 'radio.soft1', text: 'Escalated to floor staff in line with procedure and handed over cleanly.', truthful: false },
      { id: 'radio.soft2', text: 'Reported and monitored until resolved. No further intervention was required.', truthful: false },
    ],
  },
  fainter: {
    prompt: 'A patron became unresponsive on the floor. Your account?',
    options: [
      { id: 'faint.true', text: 'Someone went down. I got to them and did what I could remember of a first-aid course.', truthful: true },
      { id: 'faint.soft1', text: 'Patron was assisted promptly and recovered without incident.', truthful: false },
      { id: 'faint.soft2', text: 'A brief episode was observed. Patron declined assistance and left with friends.', truthful: false },
    ],
  },
  fight: {
    prompt: 'A physical altercation developed between patrons. Your account?',
    options: [
      { id: 'fight.true', text: 'Two blokes squared up over nothing at all and I was not close enough, fast enough, or both.', truthful: true },
      { id: 'fight.soft1', text: 'A verbal disagreement was de-escalated by staff before physical contact occurred.', truthful: false },
      { id: 'fight.soft2', text: 'Patrons were separated immediately and both parties left the premises calmly.', truthful: false },
    ],
  },
  rackDropped: {
    prompt: 'Glassware was broken in the service area. Your account?',
    options: [
      { id: 'rack.true', text: 'I had the rack too high and I took the corner too fast. That one is mine.', truthful: true },
      { id: 'rack.soft1', text: 'A rack was destabilised by patron contact in a congested area.', truthful: false },
      { id: 'rack.soft2', text: 'Breakage occurred during routine collection. Area was made safe immediately.', truthful: false },
    ],
  },
  /** You swept cash off the floor at close and it did not go in the till. */
  floorScore: {
    prompt: 'Currency was recovered from the floor after close. Your account?',
    options: [
      { id: 'score.true', text: 'I picked it up off the floor and it went in my pocket. It was on the floor.', truthful: true },
      { id: 'score.soft1', text: 'Recovered currency was logged and placed with lost property for the standard period.', truthful: false },
      { id: 'score.soft2', text: 'Loose change was collected during the close-down sweep and returned to the till.', truthful: false },
    ],
  },
  vomit: {
    prompt: 'A biological spill occurred on the floor. Your account?',
    options: [
      { id: 'vom.true', text: 'Someone redecorated the dance floor and I dealt with it in that order: sign, then mop.', truthful: true },
      { id: 'vom.soft1', text: 'A spill was identified, signed and cleaned within minutes of occurring.', truthful: false },
      { id: 'vom.soft2', text: 'Minor spillage attended to as part of routine floor maintenance.', truthful: false },
    ],
  },
  slip: {
    prompt: 'A patron lost their footing on the floor. Your account?',
    options: [
      { id: 'slip.true', text: 'They went over near a puddle that was not signed yet. It was not signed because of me.', truthful: true },
      { id: 'slip.soft1', text: 'Patron slipped in a signed and cordoned area despite clear warning signage.', truthful: false },
      { id: 'slip.soft2', text: 'A patron stumbled. No hazard was present and no injury was reported.', truthful: false },
    ],
  },
  barCutOff: {
    prompt: 'A patron was refused service at the bar. Your account?',
    options: [
      { id: 'barCO.true', text: 'I cut them off from behind the taps. They took it about as well as you would think.', truthful: true },
      { id: 'barCO.soft1', text: 'Service was concluded under RSA and a water was offered in its place.', truthful: false },
      { id: 'barCO.soft2', text: 'Patron was approaching the limit and elected to stop of their own accord.', truthful: false },
    ],
  },
  djTip: {
    prompt: 'A gratuity was offered at the DJ booth. Your account?',
    options: [
      { id: 'djTip.true', text: 'They put cash on the glass, I took it, and then I played what they asked for.', truthful: true },
      { id: 'djTip.soft1', text: 'A request was received at the booth and accommodated within the existing set.', truthful: false },
      { id: 'djTip.soft2', text: 'Any monies offered went to the staff tin behind the bar at the end of the shift.', truthful: false },
    ],
  },
  tabMisreturned: {
    prompt: 'A card was returned to the wrong patron. Your account?',
    options: [
      { id: 'tabM.true', text: 'I handed back the wrong card. They were out the door before anyone checked it.', truthful: true },
      { id: 'tabM.soft1', text: 'Card was released to a patron who identified it as theirs at the counter.', truthful: false },
      { id: 'tabM.soft2', text: 'All cards held behind the bar were reconciled against tabs before close.', truthful: false },
    ],
  },
  tabUnclaimed: {
    prompt: 'A card was left behind the bar overnight. Your account?',
    options: [
      { id: 'tabU.true', text: 'They gave up waiting and left without it. It is still in the jar.', truthful: true },
      { id: 'tabU.soft1', text: 'Patron was paged at the bar and did not present. Card retained per procedure.', truthful: false },
      { id: 'tabU.soft2', text: 'Card was retained at the patron’s own request pending their return.', truthful: false },
    ],
  },
  carpetStorm: {
    prompt: 'A patron left the holding area before being seen. Your account?',
    options: [
      { id: 'carpetS.true', text: 'I left them standing on the carpet and they got sick of it and went home.', truthful: true },
      { id: 'carpetS.soft1', text: 'Patron declined to wait for assessment and departed the queue voluntarily.', truthful: false },
      { id: 'carpetS.soft2', text: 'Holding area was managed to capacity. Departure was the patron’s own decision.', truthful: false },
    ],
  },
  radioOrder: {
    prompt: 'An instruction was issued to floor staff over the radio. Your account?',
    options: [
      { id: 'radio.true', text: 'I called it in and somebody else walked over and dealt with it.', truthful: true },
      { id: 'radio.soft1', text: 'The matter was delegated and supervised to completion from the door.', truthful: false },
      { id: 'radio.soft2', text: 'Response was coordinated across the team in line with the run sheet.', truthful: false },
    ],
  },
  // Plain words only. The fainter is not a bit (docs/GAME_DESIGN §4.3 tone guard),
  // so even the flattering accounts stay flat rather than funny.
  firstAid: {
    prompt: 'First aid was administered on the floor. Your account?',
    options: [
      { id: 'aid.true', text: 'They went down, I put them on their side, and they were walked out to a taxi.', truthful: true },
      { id: 'aid.soft1', text: 'Patron was assisted to the exit and monitored until transport arrived.', truthful: false },
      { id: 'aid.soft2', text: 'Patron was briefly unwell, recovered without intervention, and left unaided.', truthful: false },
    ],
  },
  phoneConfiscated: {
    prompt: 'A patron’s phone was held by staff. Your account?',
    options: [
      { id: 'phoneC.true', text: 'I took their phone off them and it sat behind the bar until close.', truthful: true },
      { id: 'phoneC.soft1', text: 'Device was surrendered voluntarily and returned in full at the end of the night.', truthful: false },
      { id: 'phoneC.soft2', text: 'Patron was asked to stop filming and complied. No property was held.', truthful: false },
    ],
  },

  kayden: {
    prompt: 'A ruling was made at the rope while you were inside. Your account?',
    options: [
      { id: 'kayden.true', text: 'I was on the floor. Kayden made that call and I heard about it after.', truthful: true },
      { id: 'kayden.soft1', text: 'Door was covered under my direction while I attended a matter inside.', truthful: false },
      { id: 'kayden.soft2', text: 'Ruling was consistent with the brief given to the second on the door.', truthful: false },
    ],
  },
  cutOff: {
    prompt: 'A patron was refused further service. Your account?',
    options: [
      { id: 'cutOff.true', text: 'I cut them off. They were filthy about it and they said so at length.', truthful: true },
      { id: 'cutOff.soft1', text: 'Service was concluded in line with RSA. Patron was cooperative throughout.', truthful: false },
      { id: 'cutOff.soft2', text: 'A water was provided and the matter was resolved at the bar without escalation.', truthful: false },
    ],
  },
  stallBusted: {
    prompt: 'Two patrons were found in one cubicle. Your account?',
    options: [
      { id: 'stall.true', text: 'I banged on the door until it opened. Both were spoken to and both were embarrassed.', truthful: true },
      { id: 'stall.soft1', text: 'Cubicle was checked as part of a routine sweep. Occupants dispersed on request.', truthful: false },
      { id: 'stall.soft2', text: 'One patron was assisting another who was unwell. Nothing further was observed.', truthful: false },
    ],
  },
  patDown: {
    prompt: 'A patron was searched. Your account?',
    options: [
      { id: 'patDown.true', text: 'I searched them on a hunch and the whole queue watched me do it.', truthful: true },
      { id: 'patDown.soft1', text: 'Search was conducted with consent as part of a routine entry check.', truthful: false },
      { id: 'patDown.soft2', text: 'Pockets and bag were checked in line with venue policy. Patron was thanked.', truthful: false },
    ],
  },
  deny: {
    prompt: 'Entry was refused. Your account?',
    options: [
      { id: 'deny.true', text: 'I knocked them back for the reason I had at the time. They copped it at the rope.', truthful: true },
      { id: 'deny.soft1', text: 'Entry was declined under the dress code as advised by management on the night.', truthful: false },
      { id: 'deny.soft2', text: 'Patron did not meet conditions of entry. Advised of same, politely, at the rope.', truthful: false },
    ],
  },
  sobrietyTest: {
    prompt: 'A patron was assessed at the desk. Your account?',
    options: [
      { id: 'sobriety.true', text: 'I tested them at the desk myself. It took a minute and I called it there.', truthful: true },
      { id: 'sobriety.soft1', text: 'A brief assessment was carried out at the desk and the result recorded.', truthful: false },
    ],
  },
};

// For kinds this file has never heard of. Vague on purpose — the player is
// signing something they did not read, which is the correct amount of realism.
const DEFAULT_BANK: AccountBank = {
  prompt: 'An entry was made in the log. Your account?',
  options: [
    { id: 'other.true', text: 'It went in the log at the time and the log has it about right.', truthful: true },
    { id: 'other.soft1', text: 'Logged for completeness. Nothing arising required action on the night.', truthful: false },
  ],
};

// Load-time, like dressCode's card check: a question with two truthful options
// or a duplicate id is a form the Phase 4 audit cannot read, and finding that out
// at 3 AM in a summary screen is finding it out too late.
for (const [key, bank] of Object.entries({ ...BANKS, _default: DEFAULT_BANK })) {
  if (bank.options.length < 2) {
    throw new Error(`incidentReport: bank '${key}' offers no choice`);
  }
  if (bank.options.filter((o) => o.truthful).length !== 1) {
    throw new Error(`incidentReport: bank '${key}' must have exactly one truthful account`);
  }
  if (new Set(bank.options.map((o) => o.id)).size !== bank.options.length) {
    throw new Error(`incidentReport: bank '${key}' has duplicate option ids`);
  }
}

// Own-property lookups only. `kind` is an open string, so a kind that happens to
// name an Object.prototype member ('toString', 'constructor', 'valueOf') would
// otherwise resolve to an inherited function: `interestOf` would return a
// Function, `fn > 0` is false, and the incident would vanish from the form — the
// exact silent-drop this module's defaultInterest exists to prevent.
const own = <T>(table: Record<string, T>, key: string): T | undefined =>
  Object.prototype.hasOwnProperty.call(table, key) ? table[key] : undefined;

const interestOf = (incident: IncidentRecord): number =>
  own(REPORT_TUNING.interest, incident.kind) ?? REPORT_TUNING.defaultInterest;

/** Fisher-Yates, so the truthful account is not always the top button. */
function shuffled(options: readonly ReportOption[], rng: RngStream): ReportOption[] {
  const out = [...options];
  for (let i = out.length - 1; i > 0; i--) {
    const j = rng.int(0, i);
    const a = out[i]!;
    const b = out[j]!;
    out[i] = b;
    out[j] = a;
  }
  return out;
}

export function buildReport(
  incidents: readonly IncidentRecord[],
  rng: RngStream,
): ReportQuestion[] {
  const scored = incidents
    // Already-filed rows are skipped rather than trusted: pastReports holds both
    // shapes, and asking the player to file an account of an account is a loop.
    .filter((i) => interestOf(i) > 0 && parseFiledAccount(i) === undefined)
    .map((incident) => ({ incident, score: interestOf(incident) + rng.next() }));

  // Jitter is < 1 and weights are integers, so shuffling never promotes a dull
  // incident over an interesting one — it only reorders within a band.
  scored.sort((a, b) => b.score - a.score);

  // One question per KIND first. Three slots is the whole form, and a night
  // with two radio calls in it was spending two of them on the same prompt,
  // word for word — which reads as a stuck machine, not an interrogation. Take
  // the best of each kind, then backfill from what is left if there is room.
  const bestOfEachKind: typeof scored = [];
  const leftovers: typeof scored = [];
  const seenKinds = new Set<string>();
  for (const row of scored) {
    if (seenKinds.has(row.incident.kind)) leftovers.push(row);
    else {
      seenKinds.add(row.incident.kind);
      bestOfEachKind.push(row);
    }
  }
  // Never padded: an uneventful night gets a short form, which is its own joke.
  const asked = [...bestOfEachKind, ...leftovers].slice(0, REPORT_TUNING.maxQuestions);

  // Filed in the order it happened, because that is how a report reads and how
  // Phase 4 will want to diff two nights against each other.
  asked.sort((a, b) => a.incident.clockMin - b.incident.clockMin);

  return asked.map(({ incident }) => {
    const bank = own(BANKS, incident.kind) ?? DEFAULT_BANK;
    return { incident, prompt: bank.prompt, options: shuffled(bank.options, rng) };
  });
}

/** The rows to push onto GameState.pastReports. See the encoding note up top. */
export function fileReport(answers: readonly FiledAnswer[]): IncidentRecord[] {
  return answers.map(({ incident, chosen }) => {
    const payload: FiledPayload = {
      optionId: chosen.id,
      truthful: chosen.truthful,
      truthLog: incident.detail,
    };
    const filed: IncidentRecord = {
      clockMin: incident.clockMin,
      kind: incident.kind,
      detail: `${chosen.text}${REPORT_MARKER}${JSON.stringify(payload)}`,
    };
    // Spread rather than assigning undefined: patronId is optional and a present
    // key holding undefined survives JSON round-trips as a different shape.
    return incident.patronId === undefined ? filed : { ...filed, patronId: incident.patronId };
  });
}

/** undefined for anything that is not a filed report row — including truth-log rows. */
export function parseFiledAccount(record: IncidentRecord): FiledAccount | undefined {
  const at = record.detail.indexOf(REPORT_MARKER);
  if (at < 0) return undefined;

  let parsed: unknown;
  try {
    parsed = JSON.parse(record.detail.slice(at + REPORT_MARKER.length));
  } catch {
    return undefined;
  }
  if (typeof parsed !== 'object' || parsed === null) return undefined;

  const { optionId, truthful, truthLog } = parsed as Partial<FiledPayload>;
  if (typeof optionId !== 'string' || typeof truthful !== 'boolean' || typeof truthLog !== 'string') {
    return undefined;
  }
  return { account: record.detail.slice(0, at), optionId, truthful, truthLog };
}

export function lieCount(answers: readonly FiledAnswer[]): number {
  return answers.filter((a) => !a.chosen.truthful).length;
}

/**
 * Design §3.3's "one taste" of the long-memory conscience: Kayden keeps his own
 * log, and it does not flatter anyone. If a PREVIOUS night's filed report
 * embellished a Kayden incident, this is what Dazza reads out the next morning.
 *
 * Phase 4 generalises this to a full cross-night audit with strikes attached;
 * for now it is one line, arriving one night late, which is the shape of the
 * mechanic in miniature.
 */
export function findKaydenContradiction(
  pastReports: readonly (readonly IncidentRecord[])[],
): string | undefined {
  for (let n = pastReports.length - 1; n >= 0; n--) {
    for (const record of pastReports[n] ?? []) {
      if (record.kind !== 'kayden') continue;
      const filed = parseFiledAccount(record);
      if (!filed || filed.truthful) continue;
      return `kayden wrote his version of ${record.patronId ?? 'that one'} up too. it does not match urs. he is very proud of the log`;
    }
  }
  return undefined;
}