/**
 * The surface a platform trading client must expose. TradovateClient grew this
 * shape organically; TopstepXClient implements the same one so the scheduler,
 * reporter, state route and resolver can drive either platform without caring
 * which is behind the map entry.
 *
 * Contract ids are `number` on Tradovate and `string` on TopstepX (e.g.
 * "CON.F.US.ENQ.Z25") and DXTrade (the symbol, e.g. "BTC/USD") — everything
 * that compares them only ever compares within one client, so the union is
 * safe.
 */

import type { FirmPlatform, FirmStats } from './master-protocol';

export interface PlatformAccount {
    id: number;
    name: string;
    active: boolean;
}

/** How the batch's leg would size on a candidate instrument (see planLegSize):
 *  null when it can't be sized there. */
export interface PickContext {
    targetHoldHours: number;
    evaluate(contract: PlatformContract): { notional: number; holdHours: number; cost: number } | null;
}

export interface PlatformContract {
    id: number | string;
    name: string;
    tickSize: number;
    /** Dollars per 1.0 of price per engine contract. Absent = the CME
     *  product's POINT_VALUES entry (futures). */
    pointValue?: number;
    /** Commission as % of notional per side, where the firm charges that way. */
    commissionPct?: number;
    /** Notional of one engine contract at the current mid — present where the
     *  platform prices positions, which is what enables notional sizing. */
    stepNotional?: number;
    /** σ of log returns per √hour, from recent candles. */
    volatilityPerHour?: number;
    /** (ask − bid) / mid when the contract was picked. */
    spreadFraction?: number;
    /** Largest order the broker takes, in engine contracts. */
    maxContracts?: number;
    /** Smallest order the broker takes, in engine contracts. */
    minContracts?: number;
    /** Margin posted per dollar of notional (0.2 = 5:1 leverage), where the
     *  broker says — caps a position at available funds ÷ this. */
    marginRate?: number;
}

export interface PlatformClient {
    accountList: PlatformAccount[];
    /** realizedPnL is today's. pendingRoll (Tradovate): the broker still shows
     *  the ended day's record and today's share of it can't be told apart —
     *  the account waits for the broker to roll it. equity: balance plus open
     *  P&L, where the platform reports it; availableFunds: what margin can
     *  still draw on, where the platform reports it. */
    accountCashBalances: { [accountId: number]: { amount: number; realizedPnL: number; pendingRoll?: boolean; equity?: number; availableFunds?: number } };
    positions: {
        [accountId: number]: {
            contractId: number | string;
            netPos: number;
            netPrice: number;
            timestamp: Date;
        };
    };

    daysTraded: { [accountId: number]: number };
    dailyPnL: { [accountId: number]: { date: string; pnl: number }[] };
    fullDailyPnL: { [accountId: number]: { date: string; pnl: number }[] };
    lastFundDates: { [accountId: number]: string | null };
    fundTransactions: { [accountId: number]: { date: string; amount: number }[] };
    priorProfit: { [accountId: number]: number };
    autoLiqThresholds: { [accountId: number]: number };
    /** Share of a position's notional a stop may fill past its price — the
     *  part of the daily-loss reserve that grows with size (dllReserve).
     *  Only where this platform's stops are measured to fill closer than
     *  DLL_SLIPPAGE_FRACTION, the default. */
    stopSlippageFraction?: number;

    fetchDaysComplete: boolean;
    syncComplete: boolean;
    /** Epoch ms of the last sync that came back good (0 = never). */
    lastSyncAt: number;
    /** When that good sync started reading: everything it reported is at
     *  least this recent (a sequential pass can read an account long before
     *  it ends). */
    lastSyncStartedAt?: number;
    /** Whether the broker still shows a working order on the account. */
    hasWorkingOrders?(accountId: number): boolean;
    lastFetchErrors: Record<string, string>;
    lastFetchRaw: Record<string, string>;
    recentEntityEvents: { entityType: string; eventType: string; entity: unknown; ts: number }[];
    products: { id: number; name: string }[];

    fetchDaysTraded(onlyAccountIds?: number[]): Promise<{ failedAccounts: number }>;
    /**
     * Whether the account's history can be planned on. False until this
     * client has loaded it (right after a restart, a client rebuild, a wipe,
     * or for an account that just appeared), and on Tradovate while a balance
     * change the history can't explain — a payout between reports — waits
     * for a Cash History. The missing rows and withdrawals would otherwise
     * read as a fresh stage-1 cycle, so such an account must not trade.
     */
    historyReady(accountId: number): boolean;
    /** historyReady() as it stands, for a reader that must not change it: no
     *  new hold, no baseline moved. Only where historyReady() has side effects
     *  (Tradovate's balance-drift check); elsewhere historyReady() is the read. */
    peekHistoryReady?(accountId: number): boolean;
    /** Dollars of balance the account's books don't explain yet, or null when
     *  they do. Only where balances arrive live but fund events are booked
     *  later (TopstepX: the hub, then the next sync); the engine holds the
     *  account until they're booked, or a payout plans as lost profit. */
    unbookedBalanceChange?(accountId: number): number | null;
    /** What the broker says about the account beyond active (DXTrade: its
     *  accountStatus and registration time, epoch ms or NaN). */
    brokerAccountMeta?(accountId: number): { status: string; registrationTime: number } | undefined;
    /**
     * The account's closed balance at the firm's last daily reset — what a
     * hard daily loss limit is measured from. Only platforms that know the
     * firm's own day implement it (DXTrade: 22:00 UTC); the rest leave it out
     * and the engine falls back to the session's realized P&L. null = the
     * platform knows it but can't tell yet (history not fetched): hold the
     * account rather than size a stop on a guess.
     */
    dayStartBalance?(accountId: number): number | null;
    /**
     * The equity the account may not fall below today, where the platform
     * states its daily-loss floor itself and moves it with the day's
     * transfers (Vest: reset balance × (1 − rate), lowered by a payout). The
     * engine's room is then what's left of the stage's limit (widened by
     * dayGainForRoom), never more than balance − floor (floorRoom), so a
     * same-day payout that lowers the floor frees room to trade again. null =
     * the platform has one but it isn't known yet (hold); undefined = none
     * here (the engine falls back to dayStartBalance / realized P&L).
     */
    dailyLossFloor?(accountId: number): number | null | undefined;
    /**
     * With dailyLossFloor: how much of the day's gain a leg starting now, its
     * take-profit `leg` away and its room `limit` before any gain, may add to
     * its daily-loss room (floorRoom's `gain`) — the gain still in the account
     * since the day's base, no more than keeps the leg all but sure to close
     * before the platform's daily reset (resetClearStop).
     */
    dayGainForRoom?(accountId: number, o: { leg: number; limit: number }): number;
    /** Payouts made since the firm's last daily reset — what picks the stage
     *  of an account type whose stages reset each day. */
    sameDayClaims?(accountId: number): number;
    /** Each payout taken from the account, by the day it counts on — one
     *  entry per payout, where a fund row can hold several (Vest books a
     *  whole day's claims as one); undefined until the platform's own record
     *  of them has been read. Without it, each negative fund row is one, on
     *  its date. */
    payoutDays?(accountId: number): string[] | undefined;
    /** Request a payout of `amount` from the account to the login's own main
     *  account, where the platform takes one by API (Vest's Claim Profit).
     *  Resolves once the platform accepted it and the books were updated;
     *  rejects with the platform's reason otherwise. */
    claimProfit?(accountId: number, amount: number): Promise<{ claimed: number; received: number | null }>;
    /** A claim this client made that no good sync has read past yet: the
     *  balance on hand may not show it, so no claim may be judged on it. */
    claimPending?(accountId: number): boolean;
    /** Drop the account's history from memory (the wipe routes), so it reads
     *  unloaded until the next fetch rebuilds it. */
    forgetHistory(accountId: number, accountName: string): void;
    /** The contract a product trades as. A platform that chooses between
     *  instruments (DXTrade's symbol map) ranks them with `pick` when given —
     *  how a leg would size on each — and platforms that don't, ignore it. */
    findFrontMonthContract(productName: string, pick?: PickContext): Promise<PlatformContract | null>;
    fetchInstrumentFees(symbols: string[]): Promise<{ [symbol: string]: number }>;

    sendOrder(
        accountId: number,
        contractSymbol: string,
        quantity: number,
        action: 'Buy' | 'Sell',
        orderType: 'Market' | 'Limit',
        price?: number
    ): Promise<Record<string, unknown>>;

    placeOrderNoWait(
        accountId: number,
        contractSymbol: string,
        quantity: number,
        action: 'Buy' | 'Sell',
        orderType: 'Market' | 'Limit',
        price?: number
    ): Promise<{ orderId?: number }>;

    placeOcoExit(
        accountId: number,
        contractSymbol: string,
        quantity: number,
        exitAction: 'Buy' | 'Sell',
        limitPrice: number,
        stopPrice: number,
    ): Promise<{ orderId?: number }>;

    disconnect(): void;
    onFill(orderId: number, callback: (fill: Record<string, unknown>) => void): void;
    health(): ClientHealth;
}

/**
 * Liveness snapshot of one client — what /api/health shows, what the registry
 * supervisor judges, and the numbers to read before restarting a broken box.
 * Timestamps are epoch ms, 0 = never. Never carries tokens or credentials.
 */
export interface ClientHealth {
    platform: FirmPlatform;
    /** Holding a session token right now. */
    authenticated: boolean;
    /** Tradovate: socket readyState name; TopstepX: hub state; DXTrade: 'rest'
     *  or its push socket's state. 'none' = no transport. */
    transport: string;
    syncComplete: boolean;
    lastSyncAt: number;
    lastLoginAt: number;
    lastLoginError: string | null;
    consecutiveLoginFailures: number;
    /** When the next reconnect/login attempt fires (0 = none scheduled). */
    nextReconnectAt: number;
    tokenExpiresAt: number;
    /** Last frame from the broker's realtime channel (socket or hub). */
    lastInboundAt: number;
    /** Requests still waiting on a broker answer (acks, fills). */
    pendingRequests: number;
    /** When the in-flight sync started (0 = none in flight). */
    syncInFlightSince: number;
    /** When the in-flight daily P&L report fetch started (0 = none in flight). */
    daysFetchInFlightSince: number;
}

/** A sync older than this means positions and balances can't be traded on. */
export const SYNC_STALE_MS = 5 * 60 * 1000;

/** The one readiness rule shared by the scheduler, the supervisor and /api/health:
 *  synced, and synced recently. */
export function isClientReady(client: PlatformClient, now = Date.now()): boolean {
    return client.syncComplete && client.lastSyncAt > 0 && now - client.lastSyncAt < SYNC_STALE_MS;
}

// ── Account status, as the master's ledger reads it ──────────────────────────
//
// Pure, so scripts/check-account-status.mjs can load this file. The reporter
// is the only caller: the scheduler, the dashboards and the trading decisions
// keep their own copies of the dead test for now.

/** FirmStats.statusVersion: this build sends the status fields. The master
 *  reads a firm without it as an older build — unknown, never dead. */
export const REPORT_STATUS_VERSION = 1 as const;

export type ReportedAccount = NonNullable<FirmStats['accounts']>[number];
export type AccountReportStatus = NonNullable<ReportedAccount['status']>;

export interface AccountStatusInput {
    /** The cash balance; null or undefined while the platform has none. */
    cash: number | null | undefined;
    /** Auto-liquidation floor; 0 = none known. */
    floor: number;
    active: boolean;
    historyReady: boolean;
    /** Why the platform has the account inactive, where it can say. */
    inactiveReason?: string;
    /** Why a dead account is dead, where the platform can say. */
    deadReason?: string;
}

/** The dead test the reporter has always applied: a floor (0 = none, negative
 *  = a reconstructed TopstepX MLL) the cash is at or below. It read a missing
 *  balance as 0, so pass `cash ?? 0` for the old answer. */
export function legacyDead(cashOrZero: number, floor: number): boolean {
    return floor !== 0 && cashOrZero <= floor;
}

/**
 * The account's status, first match wins:
 *   1. no balance → unknown (cash_missing) — never dead, never 0;
 *   2. the legacy dead test → dead;
 *   3. history not loaded → history_pending;
 *   4. inactive → locked: the firm stopped it trading (DLL, liquidate-only,
 *      canTrade=false, CLOSE_ONLY — a pass lock looks the same);
 *   5. live.
 * So with a balance, 'dead' is exactly legacyDead(cash, floor).
 */
export function accountStatus(input: AccountStatusInput): { status: AccountReportStatus; reason?: string } {
    const { cash, floor } = input;
    if (cash === null || cash === undefined) return { status: 'unknown', reason: 'cash_missing' };
    if (legacyDead(cash, floor)) return input.deadReason ? { status: 'dead', reason: input.deadReason } : { status: 'dead' };
    if (!input.historyReady) return { status: 'history_pending' };
    if (!input.active) return { status: 'locked', reason: input.inactiveReason || 'inactive' };
    return { status: 'live' };
}

export interface BrokerFacts {
    brokerStatus?: string;
    inactiveReason?: string;
    deadReason?: string;
    registeredAt?: number;
}

/**
 * The broker's own words for an account, per platform. Tradovate's list
 * entries carry closed/archived/restricted, and an inactive one there is
 * liquidate-only (a DLL lockout and a pass look alike). TopstepX's active is
 * canTrade. DXTrade's accountStatus decides both — CLOSE_ONLY inactive, the
 * terminal ones dead (dxtrade-class.ts DEAD_STATUSES) — and FULL_TRADING is
 * the normal case, so it isn't repeated. Each field is left out when there is
 * nothing to say.
 */
export function brokerFacts(
    platform: FirmPlatform,
    account: { active: boolean; closed?: unknown; archived?: unknown; restricted?: unknown },
    meta?: { status: string; registrationTime: number },
): BrokerFacts {
    if (platform === 'tradovate') {
        const flags = (['closed', 'archived', 'restricted'] as const).filter((k) => account[k] === true);
        return { inactiveReason: 'liquidate_only', ...(flags.length > 0 ? { brokerStatus: flags.join(',') } : {}) };
    }
    if (platform === 'topstepx') {
        return { inactiveReason: 'cannot_trade', ...(account.active ? {} : { brokerStatus: 'canTrade:false' }) };
    }
    if (platform === 'vest') {
        // Vest's capital account status is a number; 2 is the live one
        // (vest-helpers VEST_STATUS_ACTIVE). A breached account leaves the
        // active list, so no status here reads as terminal.
        const status = meta?.status;
        return {
            inactiveReason: status ? `status:${status}` : 'inactive',
            ...(status && status !== '2' ? { brokerStatus: `status:${status}` } : {}),
            ...(meta && validTime(meta.registrationTime) ? { registeredAt: meta.registrationTime } : {}),
        };
    }
    const status = meta?.status || undefined;
    return {
        inactiveReason: status === 'CLOSE_ONLY' ? 'close_only' : status ? `status:${status}` : 'inactive',
        ...(status ? { deadReason: `terminal:${status}` } : {}),
        ...(status && status !== 'FULL_TRADING' ? { brokerStatus: status } : {}),
        ...(meta && validTime(meta.registrationTime) ? { registeredAt: meta.registrationTime } : {}),
    };
}

export interface AccountReportInput extends AccountStatusInput, BrokerFacts {
    /** The account's resolved catalog type; null or undefined = unassigned. */
    accountTypeId: string | null | undefined;
    /** The account's fund rows; undefined until its fund history has loaded. */
    fundTransactions: { date: string; amount: number }[] | undefined;
}

const CT_DATE = new Intl.DateTimeFormat('en-CA', { timeZone: 'America/Chicago', year: 'numeric', month: '2-digit', day: '2-digit' });
const cents = (n: number) => Math.round(n * 100) / 100;
/** Epoch ms a Date can hold — formatting anything else throws. */
const validTime = (ms: number | undefined): ms is number => ms !== undefined && Number.isFinite(ms) && Math.abs(ms) <= 8.64e15;

/**
 * When the account opened, as far as the broker shows: its earliest positive
 * fund row's date (YYYY-MM-DD), or for a DXTrade account with none its
 * registration date, in Chicago. Undefined until the fund history has loaded
 * (`fundTransactions` undefined) and when neither says. The report's
 * firstFundDate. The resolver's evidence for an account's rules date reads
 * the fund rows through here (registeredAt undefined) but takes the
 * registration instant itself, not its day (lib/kept-rules.ts openingEvidence).
 */
export function firstFundDate(
    fundTransactions: { date: string; amount: number }[] | undefined,
    registeredAt: number | undefined,
): string | undefined {
    if (!fundTransactions) return undefined;
    const positive = fundTransactions.filter((f) => f.amount > 0);
    if (positive.length > 0) return positive.reduce((min, f) => (f.date < min ? f.date : min), positive[0].date).slice(0, 10);
    return validTime(registeredAt) ? CT_DATE.format(new Date(registeredAt)) : undefined;
}

/**
 * The status fields one accounts[] entry adds. Every one is left out when it
 * is null or at its default — 2000 accounts must stay well under the master
 * socket's 1 MB frame. firstFundDate: see the function of that name;
 * positiveFunds counts the positive fund rows, and both wait for the fund
 * history.
 */
export function accountStatusFields(input: AccountReportInput): Omit<ReportedAccount, 'name' | 'size' | 'payoutable' | 'withdrawals'> {
    const { status, reason } = accountStatus(input);
    const positive = input.fundTransactions?.filter((f) => f.amount > 0);
    const firstFund = firstFundDate(input.fundTransactions, input.registeredAt);
    return {
        status,
        ...(reason ? { reason } : {}),
        ...(typeof input.cash === 'number' && Number.isFinite(input.cash) ? { balance: cents(input.cash) } : {}),
        ...(Number.isFinite(input.floor) && input.floor !== 0 ? { floor: cents(input.floor) } : {}),
        ...(input.accountTypeId ? { accountTypeId: input.accountTypeId } : {}),
        ...(firstFund ? { firstFundDate: firstFund } : {}),
        ...(positive ? { positiveFunds: positive.length } : {}),
        ...(input.brokerStatus ? { brokerStatus: input.brokerStatus } : {}),
    };
}

/** The firm-level keys every FirmStats from this build adds. syncedAt only
 *  once the client has synced: the master trusts the statuses while it is
 *  recent (SYNC_STALE_MS). */
export function firmStatusFields(firmId: string, syncComplete: boolean, lastSyncAt: number): Pick<FirmStats, 'statusVersion' | 'firmId' | 'syncedAt'> {
    return {
        statusVersion: REPORT_STATUS_VERSION,
        firmId,
        ...(syncComplete && validTime(lastSyncAt) && lastSyncAt > 0 ? { syncedAt: new Date(lastSyncAt).toISOString() } : {}),
    };
}

/** FirmStats.keptRuleIds: the firm's kept rule set ids when this machine's
 *  catalog can be trusted to hold them (lib/firm-catalog.ts
 *  getKeptRuleIdsForFirm), else left out — the master then counts this
 *  machine as trading every account on the newest rules. */
export function keptRuleIdsField(keptRuleIds: string[] | null): Pick<FirmStats, 'keptRuleIds'> {
    return keptRuleIds ? { keptRuleIds } : {};
}

/**
 * FirmStats for a firm with no accounts to walk — no client yet, or an empty
 * broker list. accounts is [] only once synced: before that, a firm whose
 * accounts haven't arrived would read as every saved account erased. A synced
 * firm with none also says when it synced, so the master sees a fresh, empty
 * list rather than an unknown one.
 */
export function emptyFirmStats(
    firm: { id: string; name: string },
    client: { syncComplete: boolean; lastSyncAt: number } | undefined,
    keptRuleIds: string[] | null = null,
): FirmStats {
    const synced = client?.syncComplete === true;
    return {
        firm: firm.name, totalAccounts: 0, accountsTraded: 0, inTrade: 0,
        targetHit: 0, partial: 0, loss: 0, personalDll: 0, completed: 0,
        ...(synced ? { accounts: [] } : {}),
        accountTypes: [],
        ...firmStatusFields(firm.id, synced, client?.lastSyncAt ?? 0),
        ...keptRuleIdsField(keptRuleIds),
    };
}

/**
 * Thrown when a client KNOWS an order never reached the broker: no live
 * connection, the broker refused it, or it failed before anything was sent.
 * Anything ambiguous (a timeout waiting for an ack or a fill — it may still
 * have filled) must stay a plain Error. The scheduler un-counts a leg only for
 * this one, so a wrong "not placed" could let an account trade twice.
 */
export class OrderNotPlacedError extends Error {
    readonly orderNotPlaced = true;
    constructor(message: string) {
        super(message);
        this.name = 'OrderNotPlacedError';
    }
}

/** Duck-typed so it survives module duplication across route bundles. */
export function isOrderNotPlaced(err: unknown): boolean {
    return !!err && typeof err === 'object' && (err as { orderNotPlaced?: unknown }).orderNotPlaced === true;
}

/** An error's message without the rest of it. AxiosErrors carry the request
 *  config — Tradovate's login body (the password) and Bearer tokens — so they
 *  must never be logged whole. */
export function errorMessage(err: unknown): string {
    if (!err || typeof err !== 'object') return String(err);
    const e = err as { message?: unknown; code?: unknown; response?: { status?: unknown } };
    const status = typeof e.response?.status === 'number' ? ` (HTTP ${e.response.status})` : '';
    const code = typeof e.code === 'string' && !String(e.message ?? '').includes(e.code) ? ` [${e.code}]` : '';
    return `${typeof e.message === 'string' ? e.message : String(err)}${status}${code}`;
}

/** lastFetchErrors note for a Tradovate account whose Cash History is
 *  unavailable (passed accounts) and whose rows came from the Fills report —
 *  a fresh fetch, not a failure. */
export const FILLS_FALLBACK_NOTE = 'cash history unavailable (using fills fallback)';

/**
 * Can this account's daily P&L be trusted for a verdict the master keeps
 * for good (cycleCompletion 'today')? Not while a fetch run is in flight —
 * at startup Tradovate serves the DB cache before each account's fetch —
 * and not when the account's last fetch failed and left cached rows behind.
 */
export function historyFresh(client: PlatformClient, account: PlatformAccount): boolean {
    if (!client.fetchDaysComplete) return false;
    const error = client.lastFetchErrors?.[account.name];
    return !error || error === FILLS_FALLBACK_NOTE;
}