/**
 * Shape loaded records + metrics output into tool results. Pure.
 *
 * Every numeric field here comes from @/lib/metrics. Tool results also
 * carry a `display` block of preformatted strings so the model never has
 * to format or round money itself.
 */
import {
  computeSiteSpend,
  computeSiteProjection,
  resolveSiteStartDate,
  parseDurationMonths,
  computeFuelLogStatuses,
  computeFuelCost,
  resolveFuelPrice,
  type EmployeeRateMap,
  type FuelPriceLike,
  type SiteStatus,
  type VehicleAttention,
} from "@/lib/metrics";
import type { PnGItemLike } from "@/lib/partition-fixed-costs";
import { describeLimitMismatch } from "@/lib/fuel-variance";
import type { AttendanceGroups } from "@/lib/attendance";
import type { SupplierBalanceRow } from "@/lib/metrics/supplier-balance";
import type { InboxColumnCount } from "@/lib/dn-pipeline/board";
import type { RainOutlookData } from "@/lib/weather/load";
import { formatNumber } from "@/lib/utils";
import { RAIN_STOP_MM, RAIN_WATCH_MM, RAIN_WATCH_PROBABILITY_PCT } from "@/lib/weather/outlook";

/** ZAR, no decimals, thin-space thousands. */
export function formatMoney(n: number): string {
  const neg = n < 0;
  const abs = Math.abs(Math.round(n));
  const grouped = abs.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " ");
  return `${neg ? "-" : ""}R ${grouped}`;
}

export interface SiteFinancialsInput {
  site: {
    id: string;
    name?: string;
    project_code?: string;
    duration?: string;
    contract_value?: number;
    job_start_date?: string;
  };
  fixedCosts: PnGItemLike[];
  timesheets: { employee: string; hours_worked?: number; date_logged?: string }[];
  employeeRates: EmployeeRateMap;
  purchaseOrders: { total_value?: number; created?: string }[];
  fuelLogs: { litres?: number; date_logged?: string }[];
  income: { gross_amount?: number; paid_on?: string; period_end?: string }[];
  /** Recorded diesel price changes. Omit to cost every litre at RATE_PER_LITRE. */
  fuelPrices?: FuelPriceLike[];
  now?: Date;
}

export interface SiteFinancialsResult {
  site: string;
  projectCode: string;
  contractValue: number;
  totalSpent: number;
  breakdown: {
    overheadsMonthly: number;
    overheadsOneOff: number;
    payroll: number;
    materials: number;
    fuel: number;
  };
  fuelLitres: number;
  startDate: string;
  startDateSource: string;
  projection: {
    durationMonths: number;
    elapsedMonths: number;
    percentElapsed: number;
    percentBurnt: number;
    remainingBudget: number;
    projectedTotal: number;
    projectedProfit: number;
    status: SiteStatus;
  };
  display: {
    contractValue: string;
    totalSpent: string;
    remainingBudget: string;
    projectedTotal: string;
    projectedProfit: string;
  };
}

export function formatSiteFinancials(
  input: SiteFinancialsInput,
): SiteFinancialsResult {
  const spend = computeSiteSpend({
    siteId: input.site.id,
    fixedCosts: input.fixedCosts,
    timesheets: input.timesheets,
    employeeRates: input.employeeRates,
    purchaseOrders: input.purchaseOrders,
    fuelLogs: input.fuelLogs,
    fuelPrices: input.fuelPrices,
  });

  const siteTimesheets = input.timesheets.filter(
    (t) => input.employeeRates.get(t.employee)?.site === input.site.id,
  );

  const start = resolveSiteStartDate({
    jobStartDate: input.site.job_start_date,
    fixedCosts: input.fixedCosts,
    timesheets: siteTimesheets,
    fuelLogs: input.fuelLogs,
    income: input.income,
    now: input.now,
  });

  const projection = computeSiteProjection({
    contractValue: input.site.contract_value ?? 0,
    totalSpent: spend.totalSpent,
    durationMonths: parseDurationMonths(input.site.duration),
    startDate: start.startDate,
    hasExplicitStart: start.source === "job_start_date",
    now: input.now,
  });

  return {
    site: input.site.name ?? "",
    projectCode: input.site.project_code ?? "",
    contractValue: input.site.contract_value ?? 0,
    totalSpent: spend.totalSpent,
    breakdown: {
      overheadsMonthly: spend.fixedSum,
      overheadsOneOff: spend.oneOffSum,
      payroll: spend.payrollBurn,
      materials: spend.materialSum,
      fuel: spend.fuelBurn,
    },
    fuelLitres: spend.fuelLitres,
    startDate: start.startDate,
    startDateSource: start.source,
    projection: {
      durationMonths: projection.months,
      elapsedMonths: projection.elapsedMonths,
      percentElapsed: projection.elapsedPct,
      percentBurnt: projection.burnPct,
      remainingBudget: projection.remaining,
      projectedTotal: projection.projectedTotal,
      projectedProfit: projection.projectedProfit,
      status: projection.status,
    },
    display: {
      contractValue: formatMoney(input.site.contract_value ?? 0),
      totalSpent: formatMoney(spend.totalSpent),
      remainingBudget: formatMoney(projection.remaining),
      projectedTotal: formatMoney(projection.projectedTotal),
      projectedProfit: formatMoney(projection.projectedProfit),
    },
  };
}

export interface AttentionResult {
  /** Vehicles with real fuel alerts or warnings. */
  totalFlagged: number;
  /** Vehicles whose fuel limit is in the wrong unit (config to fix). */
  limitProblems: number;
  vehicles: {
    vehicle: string;
    projectCode: string;
    qrCodeId: string;
    site: string;
    alerts: number;
    warnings: number;
    lastFlagged: string | null;
    dismissed: boolean;
    /** Plain-language wrong-unit explanation, or null. */
    limitProblem: string | null;
  }[];
}

export function formatAttentionList(
  items: VehicleAttention[],
  siteNames: Map<string, string>,
  opts: { includeDismissed?: boolean },
): AttentionResult {
  const visible = opts.includeDismissed
    ? items
    : items.filter((i) => !i.acknowledged);

  const vehicles = visible
    .slice()
    .sort((a, b) => {
      if (b.alert !== a.alert) return b.alert - a.alert;
      return b.warn - a.warn;
    })
    .map((i) => ({
      vehicle: i.description,
      projectCode: i.projectCode,
      qrCodeId: i.qrCodeId,
      site: siteNames.get(i.siteId) ?? i.siteId,
      alerts: i.alert,
      warnings: i.warn,
      lastFlagged: i.maxFlaggedDate,
      dismissed: i.acknowledged,
      limitProblem: i.limitMismatch ? describeLimitMismatch(i.limitMismatch) : null,
    }));

  return {
    totalFlagged: vehicles.filter((v) => v.alerts + v.warnings > 0).length,
    limitProblems: vehicles.filter((v) => v.limitProblem).length,
    vehicles,
  };
}
export interface TopWorkersResult {
  scope: string;
  workers: {
    worker: string;
    position: string;
    site: string;
    hours: number;
    cost: number;
    ratePerHour: number;
    display: { cost: string };
  }[];
}

/**
 * Roll up hours and cost per worker. The data already exists — this is
 * `computeSiteSpend(...).payrollByEmployee` joined to an employee
 * record — but no tool exposed it before.
 */
export function formatTopWorkers(
  employees: {
    id: string;
    name?: string;
    rate_per_hour?: number;
    site?: string;
    position?: string;
  }[],
  timesheets: { employee: string; hours_worked?: number }[],
  siteNames: Map<string, string>,
  opts: { siteId?: string; limit?: number },
): TopWorkersResult {
  const byId = new Map(employees.map((e) => [e.id, e]));
  const acc = new Map<string, number>();

  for (const t of timesheets) {
    const emp = byId.get(t.employee);
    if (!emp) continue;
    if (opts.siteId && emp.site !== opts.siteId) continue;
    acc.set(t.employee, (acc.get(t.employee) ?? 0) + (t.hours_worked ?? 0));
  }

  const workers = Array.from(acc.entries())
    .filter(([, hours]) => hours > 0)
    .map(([id, hours]) => {
      const e = byId.get(id)!;
      const rate = e.rate_per_hour ?? 0;
      const cost = hours * rate;
      return {
        worker: e.name ?? "(unnamed)",
        position: e.position ?? "",
        site: siteNames.get(e.site ?? "") ?? e.site ?? "",
        hours,
        cost,
        ratePerHour: rate,
        display: { cost: formatMoney(cost) },
      };
    })
    .sort((a, b) => b.hours - a.hours)
    .slice(0, opts.limit ?? 10);

  return {
    scope: opts.siteId
      ? siteNames.get(opts.siteId) ?? opts.siteId
      : "all sites",
    workers,
  };
}

export interface FuelLogResult {
  vehicle: string;
  qrCodeId: string;
  projectCode: string;
  fuelLimit: string;
  fillUpCount: number;
  totalLitres: number;
  totalSpend: number;
  flagged: number;
  fillUps: {
    date: string;
    litres: number;
    odoReading: number;
    variancePct: number | null;
    status: string;
    cost: number;
    display: { cost: string };
  }[];
  display: { totalSpend: string };
}

/**
 * Per-fill variance for one vehicle, reusing the same pass the dashboard
 * uses so per-fill status matches `/dashboard/fuel/<id>`.
 */
export function formatFuelLog(
  vehicle: {
    id: string;
    description?: string;
    qr_code_id?: string;
    project_code?: string;
    fuel_limits?: string;
  },
  logs: {
    id: string;
    vehicle: string;
    date_logged?: string;
    odo_reading?: number;
    litres?: number;
  }[],
  opts: { limit?: number; fuelPrices?: FuelPriceLike[] },
): FuelLogResult {
  const fuelPrices = opts.fuelPrices ?? [];
  // computeFuelLogStatuses takes a vehicles array; pass one-element.
  const statuses = new Map(
    computeFuelLogStatuses({ vehicles: [vehicle], fuelLogs: logs }).map(
      (s) => [s.logId, s],
    ),
  );

  const totalLitres = logs.reduce((s, l) => s + (l.litres ?? 0), 0);
  const totalSpend = computeFuelCost(logs, fuelPrices);
  const flagged = Array.from(statuses.values()).filter(
    (s) => s.status === "warn" || s.status === "alert",
  ).length;

  const fillUps = logs
    .slice()
    .sort((a, b) => (a.date_logged ?? "") < (b.date_logged ?? "") ? 1 : -1)
    .slice(0, opts.limit ?? 20)
    .map((l) => {
      const st = statuses.get(l.id);
      const cost = (l.litres ?? 0) * resolveFuelPrice(l.date_logged, fuelPrices);
      return {
        date: l.date_logged ?? "",
        litres: l.litres ?? 0,
        odoReading: l.odo_reading ?? 0,
        variancePct: st?.variance ?? null,
        status: st?.status ?? "no-limit",
        cost,
        display: { cost: formatMoney(cost) },
      };
    });

  return {
    vehicle: vehicle.description ?? "",
    qrCodeId: vehicle.qr_code_id ?? "",
    projectCode: vehicle.project_code ?? "",
    fuelLimit: vehicle.fuel_limits ?? "",
    fillUpCount: logs.length,
    totalLitres,
    totalSpend,
    flagged,
    fillUps,
    display: { totalSpend: formatMoney(totalSpend) },
  };
}

/** "07:42" in Johannesburg. */
function saTime(iso: string): string {
  return new Intl.DateTimeFormat("en-ZA", {
    timeZone: "Africa/Johannesburg",
    hour: "2-digit",
    minute: "2-digit",
    hour12: false,
  }).format(new Date(iso));
}

/** "2026-09-23" in Johannesburg. */
function saDate(iso: string): string {
  return new Intl.DateTimeFormat("en-CA", { timeZone: "Africa/Johannesburg" }).format(new Date(iso));
}

export interface AttendanceResult {
  scope: string;
  counts: { onSiteNow: number; clockedOutToday: number; notArrivedToday: number; needsAttention: number };
  onSiteNow: { worker: string; site: string; since: string }[];
  clockedOutToday: { worker: string; site: string; at: string }[];
  notArrivedToday: { worker: string; site: string; lastSeen: string }[];
  needsAttention: { worker: string; site: string; clockedInOn: string; at: string }[];
  /** True when a list was cut to `limit`; counts are always complete. */
  truncated: boolean;
  href: string;
}

/**
 * Today's attendance from groupAttendance (the On-site page's grouping),
 * optionally narrowed to one site. Counts are the full list lengths;
 * each list is capped so a big roster does not flood the answer.
 */
export function formatAttendance(
  g: AttendanceGroups,
  opts: { siteId?: string; scope?: string; limit?: number } = {},
): AttendanceResult {
  const limit = opts.limit ?? 30;
  const keep = <T extends { siteId: string }>(rows: T[]) =>
    opts.siteId ? rows.filter((r) => r.siteId === opts.siteId) : rows;
  const onSite = keep(g.onSite);
  const out = keep(g.clockedOutToday);
  const notArrived = keep(g.notArrivedToday);
  const attention = keep(g.needsAttention);
  return {
    scope: opts.scope ?? "all sites",
    counts: {
      onSiteNow: onSite.length,
      clockedOutToday: out.length,
      notArrivedToday: notArrived.length,
      needsAttention: attention.length,
    },
    onSiteNow: onSite.slice(0, limit).map((r) => ({ worker: r.employeeName, site: r.siteName, since: saTime(r.clockedInAt) })),
    clockedOutToday: out.slice(0, limit).map((r) => ({ worker: r.employeeName, site: r.siteName, at: saTime(r.clockedOutAt) })),
    notArrivedToday: notArrived.slice(0, limit).map((r) => ({ worker: r.employeeName, site: r.siteName, lastSeen: saDate(r.lastSeenAt) })),
    needsAttention: attention.slice(0, limit).map((r) => ({
      worker: r.employeeName,
      site: r.siteName,
      clockedInOn: saDate(r.clockedInAt),
      at: saTime(r.clockedInAt),
    })),
    truncated: [onSite, out, notArrived, attention].some((l) => l.length > limit),
    href: opts.siteId ? `/dashboard/workforce/on-site?site=${opts.siteId}` : "/dashboard/workforce/on-site",
  };
}

export interface SupplierBalancesResult {
  scope: string;
  supplierCount: number;
  showing: number;
  /** Set when a period was asked for: the window and what was received in it. */
  period?: { label: string; from: string | null; to: string | null };
  totals: { display: { ordered: string; delivered: string; outstanding: string; receivedInPeriod?: string } };
  suppliers: {
    supplier: string;
    purchaseOrders: number;
    unresolvedDeliveryNotes: number;
    display: { ordered: string; delivered: string; outstanding: string; receivedInPeriod?: string };
    href: string;
  }[];
}

/**
 * Supplier balances (computeSupplierBalances), optionally narrowed by a
 * name fragment. Totals are summed here so the model never adds rows.
 */
export function formatSupplierBalances(
  rows: SupplierBalanceRow[],
  opts: {
    supplier?: string;
    limit?: number;
    /** Value received per supplier id in the period; rows with none are dropped. */
    period?: { label: string; from: string | null; to: string | null; received: Map<string, number> };
  } = {},
): SupplierBalancesResult | { error: string } {
  const q = (opts.supplier ?? "").trim().toLowerCase();
  const byName = q ? rows.filter((r) => r.name.toLowerCase().includes(q)) : rows;
  const received = opts.period?.received;
  // With a period, "who do I pay" = suppliers with something received in
  // it, largest first.
  const matched = received
    ? byName
        .filter((r) => (received.get(r.id) ?? 0) > 0)
        .sort((a, b) => (received.get(b.id) ?? 0) - (received.get(a.id) ?? 0))
    : byName;
  if (q && matched.length === 0) {
    return {
      error: `No supplier matches "${opts.supplier}". Suppliers with the most outstanding: ${rows
        .slice(0, 8)
        .map((r) => r.name)
        .join(", ")}`,
    };
  }
  let ordered = 0;
  let delivered = 0;
  let outstanding = 0;
  let inPeriod = 0;
  for (const r of matched) {
    ordered += r.ordered;
    delivered += r.delivered;
    outstanding += r.outstanding;
    inPeriod += received?.get(r.id) ?? 0;
  }
  const limit = opts.limit ?? 25;
  return {
    scope: q ? `suppliers matching "${opts.supplier}"` : "all suppliers",
    ...(opts.period ? { period: { label: opts.period.label, from: opts.period.from, to: opts.period.to } } : {}),
    supplierCount: matched.length,
    showing: Math.min(limit, matched.length),
    totals: {
      display: {
        ordered: formatMoney(ordered),
        delivered: formatMoney(delivered),
        outstanding: formatMoney(outstanding),
        ...(received ? { receivedInPeriod: formatMoney(inPeriod) } : {}),
      },
    },
    suppliers: matched.slice(0, limit).map((r) => ({
      supplier: r.name,
      purchaseOrders: r.poCount,
      unresolvedDeliveryNotes: r.unresolvedCandidates,
      display: {
        ordered: formatMoney(r.ordered),
        delivered: formatMoney(r.delivered),
        outstanding: formatMoney(r.outstanding),
        ...(received ? { receivedInPeriod: formatMoney(received.get(r.id) ?? 0) } : {}),
      },
      href: `/dashboard/financial/suppliers/${r.id}`,
    })),
  };
}

export interface DnQueueCandidateLike {
  siteName: string;
  supplierId: string;
  supplierName: string;
  purchaseOrderId: string;
  purchaseOrderNumber: string;
  documentNumber: string;
  reason: string;
  unresolvedLineItems: number;
}

export interface DnQueueResult {
  inbox: { columns: InboxColumnCount[]; failedBatches: number; href: string };
  workQueue: {
    open: number;
    withoutSupplier: number;
    withoutPurchaseOrder: number;
    withUnmatchedLines: number;
    byReason: { reason: string; count: number }[];
    examples: { document: string; site: string; supplier: string; purchaseOrder: string; reason: string }[];
    href: string;
  };
}

/** Inbox board counts plus the open work-queue exceptions, display-ready. */
export function formatDnQueue(
  board: { columns: InboxColumnCount[]; failedBatches: number },
  candidates: DnQueueCandidateLike[],
  opts: { examples?: number } = {},
): DnQueueResult {
  const byReason = new Map<string, number>();
  for (const c of candidates) byReason.set(c.reason, (byReason.get(c.reason) ?? 0) + 1);
  return {
    inbox: { ...board, href: "/dashboard/financial/delivery-notes/inbox" },
    workQueue: {
      open: candidates.length,
      withoutSupplier: candidates.filter((c) => !c.supplierId).length,
      withoutPurchaseOrder: candidates.filter((c) => !c.purchaseOrderId).length,
      withUnmatchedLines: candidates.filter((c) => c.unresolvedLineItems > 0).length,
      byReason: [...byReason.entries()]
        .map(([reason, count]) => ({ reason, count }))
        .sort((a, b) => b.count - a.count),
      examples: candidates.slice(0, opts.examples ?? 10).map((c) => ({
        document: c.documentNumber || "(no number yet)",
        site: c.siteName,
        supplier: c.supplierName || "(no supplier)",
        purchaseOrder: c.purchaseOrderNumber || "(no PO)",
        reason: c.reason,
      })),
      href: "/dashboard/financial/delivery-notes/work-queue",
    },
  };
}

const SEVERITY_TEXT = { dry: "dry", watch: "watch", "likely-stop": "likely stop" } as const;

export interface RainOutlookResult {
  available: boolean;
  rule: string;
  sites: {
    site: string;
    projectCode: string;
    likelyStopDays: number;
    watchDays: number;
    display: { totalRain: string };
    days: { date: string; rain: string; chance: string; outlook: string }[];
    href: string;
  }[];
  sitesWithoutLocation: string[];
}

/** The Overview rain card's data (loadRainOutlook), display-ready. */
export function formatRainOutlook(data: RainOutlookData): RainOutlookResult {
  const mm = (n: number) => `${formatNumber(n, { maximumFractionDigits: 1 })} mm`;
  return {
    available: data.available,
    rule: `A day with ${RAIN_STOP_MM} mm or more is a likely stop for earthworks; ${RAIN_WATCH_MM} mm or more, or a ${RAIN_WATCH_PROBABILITY_PCT}% chance, is one to watch.`,
    sites: data.outlooks.map((o) => ({
      site: o.siteName,
      projectCode: o.projectCode,
      likelyStopDays: o.likelyStopDays,
      watchDays: o.watchDays,
      display: { totalRain: mm(o.totalMm) },
      days: o.days.map((d) => ({
        date: d.date,
        rain: mm(d.precipitationMm),
        chance: `${formatNumber(d.probabilityPct, { maximumFractionDigits: 0 })}%`,
        outlook: SEVERITY_TEXT[d.severity],
      })),
      href: `/dashboard/sites/${o.siteId}`,
    })),
    sitesWithoutLocation: data.sitesWithoutLocation,
  };
}