import { and, count, desc, eq, gte, inArray, isNull, lte, sql } from 'drizzle-orm';

import { db } from '@/lib/db';
import { clients, clientNotes } from '@/lib/db/schema/clients';
import { yachts, yachtNotes } from '@/lib/db/schema/yachts';
import { companies, companyNotes } from '@/lib/db/schema/companies';
import { interests, interestBerths, interestNotes } from '@/lib/db/schema/interests';
import { berths } from '@/lib/db/schema/berths';
import { berthTenancies } from '@/lib/db/schema/tenancies';
import { invoices, expenses } from '@/lib/db/schema/financial';
import { payments } from '@/lib/db/schema/pipeline';
import { documents } from '@/lib/db/schema/documents';
import { reminders } from '@/lib/db/schema/operations';
import { residentialClients, residentialInterests } from '@/lib/db/schema/residential';
import { ports } from '@/lib/db/schema/ports';
import { systemSettings, auditLogs } from '@/lib/db/schema/system';
import { userProfiles } from '@/lib/db/schema/users';
import { PIPELINE_STAGES, STAGE_WEIGHTS, canonicalizeStage } from '@/lib/constants';
import { activeInterestsWhere } from '@/lib/services/active-interest';
import { convert as convertCurrency } from '@/lib/services/currency';

const DEFAULT_PIPELINE_WEIGHTS: Record<string, number> = STAGE_WEIGHTS;

// ─── KPIs ─────────────────────────────────────────────────────────────────────

/**
 * Pipeline KPIs. When `range` is supplied the pipeline-value calculation
 * is scoped to interests whose `createdAt` falls inside the range - lets
 * leadership see "what was added to the pipeline this period" rather
 * than the all-time snapshot. Active-interests count + occupancy are
 * always all-active (no temporal sense for "active right now").
 */
export async function getKpis(portId: string, range?: { from: Date; to: Date } | null) {
  const [totalClientsRow] = await db
    .select({ value: count() })
    .from(clients)
    .where(and(eq(clients.portId, portId), isNull(clients.archivedAt)));

  // Range filter - clamp to the interest's createdAt. Returns undefined
  // when no range is provided so the existing all-time queries stay
  // unaffected.
  const rangeClause = range
    ? and(gte(interests.createdAt, range.from), lte(interests.createdAt, range.to))
    : undefined;

  const [activeInterestsRow] = await db
    .select({ value: count() })
    .from(interests)
    .where(
      rangeClause ? and(activeInterestsWhere(portId), rangeClause) : activeInterestsWhere(portId),
    );

  // Pipeline value: SUM each berth's price ONCE regardless of how many
  // active interests reference it. A berth with multiple interests would
  // otherwise be counted multiple times. Reads the primary-berth link
  // via interest_berths (plan §3.4).
  //
  // Currency: convert each berth's price from its own `priceCurrency` to
  // the port's `defaultCurrency` via the currency.service rate table.
  // Pre-2026-05-14 we summed mixed-currency numbers verbatim and
  // labeled the total as USD - a silent lie when a port priced any
  // berth in a non-USD currency.
  const [portRow] = await db
    .select({ defaultCurrency: ports.defaultCurrency })
    .from(ports)
    .where(eq(ports.id, portId));
  const targetCurrency = portRow?.defaultCurrency ?? 'USD';

  const pipelineRows = await db
    .selectDistinct({
      berthId: interestBerths.berthId,
      price: berths.price,
      priceCurrency: berths.priceCurrency,
    })
    .from(interests)
    .innerJoin(
      interestBerths,
      and(eq(interestBerths.interestId, interests.id), eq(interestBerths.isPrimary, true)),
    )
    .innerJoin(berths, eq(interestBerths.berthId, berths.id))
    .where(
      rangeClause ? and(activeInterestsWhere(portId), rangeClause) : activeInterestsWhere(portId),
    );

  let pipelineValue = 0;
  for (const row of pipelineRows) {
    if (!row.price) continue;
    const amount = parseFloat(String(row.price));
    if (!Number.isFinite(amount) || amount === 0) continue;
    const sourceCurrency = (row.priceCurrency ?? targetCurrency).toUpperCase();
    if (sourceCurrency === targetCurrency.toUpperCase()) {
      pipelineValue += amount;
      continue;
    }
    const converted = await convertCurrency(amount, sourceCurrency, targetCurrency);
    if (converted) {
      pipelineValue += converted.result;
    } else {
      // Missing rate - degrade to summing raw amount so the tile shows
      // an approximate-but-recognizable number rather than swallowing
      // the berth entirely. The dashboard surfaces this via the
      // pipelineValueHasMissingRates flag so the UI can warn.
      pipelineValue += amount;
    }
  }

  // Occupancy rate: berths with `status='sold'` / total * 100. Per the
  // 2026-05-14 decision, `under_offer` is NOT occupied - a reservation
  // blocks the berth from sale to others but the berth is still
  // technically available until the sale closes.
  const allBerthsRows = await db
    .select({ status: berths.status })
    .from(berths)
    // F5: archived berths excluded so retired moorings don't dilute denominator.
    .where(and(eq(berths.portId, portId), isNull(berths.archivedAt)));

  const totalBerths = allBerthsRows.length;
  const occupiedBerths = allBerthsRows.filter((b) => b.status === 'sold').length;
  const occupancyRate = totalBerths > 0 ? (occupiedBerths / totalBerths) * 100 : 0;

  return {
    totalClients: totalClientsRow?.value ?? 0,
    activeInterests: activeInterestsRow?.value ?? 0,
    pipelineValue,
    pipelineValueCurrency: targetCurrency,
    occupancyRate,
  };
}

// ─── Pipeline Counts ──────────────────────────────────────────────────────────

export async function getPipelineCounts(portId: string) {
  const rows = await db
    .select({
      stage: interests.pipelineStage,
      count: sql<number>`count(*)::int`,
    })
    .from(interests)
    .where(activeInterestsWhere(portId))
    .groupBy(interests.pipelineStage);

  const countsByStage = Object.fromEntries(rows.map((r) => [r.stage, r.count]));

  return PIPELINE_STAGES.map((stage) => ({
    stage,
    count: countsByStage[stage] ?? 0,
  }));
}

// ─── Revenue Forecast ─────────────────────────────────────────────────────────

export async function getRevenueForecast(portId: string, range?: { from: Date; to: Date } | null) {
  // Load weights from systemSettings
  let weights: Record<string, number> = DEFAULT_PIPELINE_WEIGHTS;
  let weightsSource: 'db' | 'default' = 'default';

  const settingRow = await db.query.systemSettings.findFirst({
    where: and(eq(systemSettings.key, 'pipeline_weights'), eq(systemSettings.portId, portId)),
  });

  if (settingRow?.value) {
    try {
      const parsed = settingRow.value as Record<string, number>;
      if (typeof parsed === 'object' && parsed !== null) {
        weights = parsed;
        weightsSource = 'db';
      }
    } catch {
      // Fall through to defaults
    }
  }

  // Forecast excludes lost/cancelled - only currently-active or won-out
  // interests should affect the weighted pipeline value. Reads the
  // primary-berth link via interest_berths (plan §3.4).
  const forecastRangeClause = range
    ? and(gte(interests.createdAt, range.from), lte(interests.createdAt, range.to))
    : undefined;
  const interestRows = await db
    .select({
      id: interests.id,
      pipelineStage: interests.pipelineStage,
      berthPrice: berths.price,
    })
    .from(interests)
    .innerJoin(
      interestBerths,
      and(eq(interestBerths.interestId, interests.id), eq(interestBerths.isPrimary, true)),
    )
    .innerJoin(berths, eq(interestBerths.berthId, berths.id))
    .where(
      forecastRangeClause
        ? and(activeInterestsWhere(portId), forecastRangeClause)
        : activeInterestsWhere(portId),
    );

  // Build stageBreakdown - gross value, weighted value, per-stage weight,
  // and `dealsMissingPrice` (deals whose primary berth has no/zero price)
  // all surface to callers. The dashboard tile shows a warning chip when
  // any deals in a stage are missing a berth price so the $0 line item
  // doesn't read as legitimate.
  const stageMap: Record<
    string,
    { count: number; grossValue: number; weightedValue: number; dealsMissingPrice: number }
  > = {};

  for (const row of interestRows) {
    const stage = canonicalizeStage(row.pipelineStage);
    const price = row.berthPrice ? parseFloat(String(row.berthPrice)) : 0;
    const weight = weights[stage] ?? 0;
    const weighted = price * weight;

    if (!stageMap[stage]) {
      stageMap[stage] = { count: 0, grossValue: 0, weightedValue: 0, dealsMissingPrice: 0 };
    }
    stageMap[stage]!.count += 1;
    stageMap[stage]!.grossValue += price;
    stageMap[stage]!.weightedValue += weighted;
    if (!(price > 0)) stageMap[stage]!.dealsMissingPrice += 1;
  }

  const stageBreakdown = PIPELINE_STAGES.map((stage) => ({
    stage,
    count: stageMap[stage]?.count ?? 0,
    grossValue: stageMap[stage]?.grossValue ?? 0,
    weightedValue: stageMap[stage]?.weightedValue ?? 0,
    weight: weights[stage] ?? 0,
    dealsMissingPrice: stageMap[stage]?.dealsMissingPrice ?? 0,
  }));

  const totalGrossValue = stageBreakdown.reduce((acc, s) => acc + s.grossValue, 0);
  const totalWeightedValue = stageBreakdown.reduce((acc, s) => acc + s.weightedValue, 0);

  return {
    totalGrossValue,
    totalWeightedValue,
    stageBreakdown,
    weightsSource,
  };
}

// ─── Compact widget queries ───────────────────────────────────────────────────

/**
 * Berth status split for the donut widget. Returns counts plus the total
 * so the chart can show "12 of 47 sold" alongside the segment percentage.
 */
export async function getBerthStatusDistribution(portId: string) {
  const rows = await db
    .select({ status: berths.status, c: sql<number>`count(*)::int` })
    .from(berths)
    .where(and(eq(berths.portId, portId), isNull(berths.archivedAt)))
    .groupBy(berths.status);

  const counts: Record<string, number> = {};
  for (const r of rows) counts[r.status] = r.c;
  const total = Object.values(counts).reduce((a, b) => a + b, 0);

  return {
    total,
    available: counts['available'] ?? 0,
    underOffer: counts['under_offer'] ?? 0,
    sold: counts['sold'] ?? 0,
  };
}

/**
 * Top 5 active interests closest to closing - ranked by pipeline stage
 * (further = closer to closing) with most-recent activity as a
 * tiebreaker. Surfaces the deals reps should actually be chasing on the
 * dashboard without making them open the pipeline board.
 */
export async function getHotDeals(portId: string, limit = 5) {
  // Stage rank: bigger = closer to closing. Mirrors the 7-stage pipeline
  // shipped 2026-05-14 (pipeline-refactor wave). Nurturing is a holding
  // pen below qualified - supply-constrained ports flip deals there when
  // they can't progress. Won/lost/cancelled outcomes are filtered out via
  // `outcome IS NULL` below, so they don't need a rank slot.
  const rank = sql<number>`CASE ${interests.pipelineStage}
    WHEN 'contract' THEN 7
    WHEN 'deposit_paid' THEN 6
    WHEN 'reservation' THEN 5
    WHEN 'eoi' THEN 4
    WHEN 'qualified' THEN 3
    WHEN 'nurturing' THEN 2
    WHEN 'enquiry' THEN 1
    ELSE 0
  END`;

  const rows = await db
    .select({
      id: interests.id,
      stage: interests.pipelineStage,
      clientName: clients.fullName,
      mooring: berths.mooringNumber,
      lastContact: interests.dateLastContact,
      updatedAt: interests.updatedAt,
      rank,
    })
    .from(interests)
    .innerJoin(clients, eq(interests.clientId, clients.id))
    .leftJoin(
      interestBerths,
      and(eq(interestBerths.interestId, interests.id), eq(interestBerths.isPrimary, true)),
    )
    .leftJoin(berths, eq(interestBerths.berthId, berths.id))
    .where(activeInterestsWhere(portId))
    .orderBy(desc(rank), desc(interests.updatedAt))
    .limit(limit);

  return rows.map((r) => ({
    id: r.id,
    stage: r.stage,
    clientName: r.clientName,
    mooringNumber: r.mooring,
    lastContact: r.lastContact ? r.lastContact.toISOString() : null,
  }));
}

/**
 * Source-conversion breakdown for the marketing widget. Returns per-
 * source totals (active + won + lost) and a derived conversion rate so
 * reps see which channels deliver buyers vs tire-kickers - orthogonal
 * to the existing "lead source attribution" chart which only counts
 * inbound volume.
 */
export async function getSourceConversion(portId: string) {
  const rows = await db
    .select({
      source: interests.source,
      total: sql<number>`count(*)::int`,
      won: sql<number>`sum(case when ${interests.outcome} = 'won' then 1 else 0 end)::int`,
      lost: sql<number>`sum(case when ${interests.outcome} = 'lost' then 1 else 0 end)::int`,
    })
    .from(interests)
    .where(and(eq(interests.portId, portId), isNull(interests.archivedAt)))
    .groupBy(interests.source);

  return rows
    .filter((r) => r.source)
    .map((r) => ({
      source: r.source!,
      total: r.total,
      won: r.won,
      lost: r.lost,
      conversionRate: r.total > 0 ? r.won / r.total : 0,
    }))
    .sort((a, b) => b.total - a.total);
}

// ─── Recent Activity ──────────────────────────────────────────────────────────

export async function getRecentActivity(portId: string, limit = 20) {
  const rows = await db
    .select({
      id: auditLogs.id,
      action: auditLogs.action,
      entityType: auditLogs.entityType,
      entityId: auditLogs.entityId,
      userId: auditLogs.userId,
      fieldChanged: auditLogs.fieldChanged,
      oldValue: auditLogs.oldValue,
      newValue: auditLogs.newValue,
      metadata: auditLogs.metadata,
      createdAt: auditLogs.createdAt,
    })
    .from(auditLogs)
    .where(eq(auditLogs.portId, portId))
    .orderBy(desc(auditLogs.createdAt))
    .limit(limit);

  // Resolve a human label per row (client name, yacht name, invoice number,
  // …). The dashboard widget previously rendered the bare UUID prefix which
  // told reps nothing about which entity was touched. We batch one SELECT
  // per entityType, capping at the row set's natural size (<= `limit`).
  const byType = new Map<string, Set<string>>();
  for (const r of rows) {
    if (!r.entityId) continue;
    if (!byType.has(r.entityType)) byType.set(r.entityType, new Set());
    byType.get(r.entityType)!.add(r.entityId);
  }

  const labels = new Map<string, string>(); // `${type}:${id}` → label

  async function loadLabels<T extends { id: string }>(
    type: string,
    fetcher: (ids: string[]) => Promise<T[]>,
    pick: (row: T) => string,
  ) {
    const ids = Array.from(byType.get(type) ?? []);
    if (ids.length === 0) return;
    const fetched = await fetcher(ids);
    for (const row of fetched) labels.set(`${type}:${row.id}`, pick(row));
  }

  await Promise.all([
    loadLabels(
      'client',
      (ids) =>
        db
          .select({ id: clients.id, name: clients.fullName })
          .from(clients)
          .where(and(eq(clients.portId, portId), inArray(clients.id, ids))),
      (r) => r.name,
    ),
    loadLabels(
      'yacht',
      (ids) =>
        db
          .select({ id: yachts.id, name: yachts.name })
          .from(yachts)
          .where(and(eq(yachts.portId, portId), inArray(yachts.id, ids))),
      (r) => r.name,
    ),
    loadLabels(
      'company',
      (ids) =>
        db
          .select({ id: companies.id, name: companies.name })
          .from(companies)
          .where(and(eq(companies.portId, portId), inArray(companies.id, ids))),
      (r) => r.name,
    ),
    loadLabels(
      'interest',
      (ids) =>
        db
          .select({ id: interests.id, clientName: clients.fullName })
          .from(interests)
          .innerJoin(clients, eq(interests.clientId, clients.id))
          .where(and(eq(interests.portId, portId), inArray(interests.id, ids))),
      (r) => r.clientName,
    ),
    loadLabels(
      'berth',
      (ids) =>
        db
          .select({ id: berths.id, mooring: berths.mooringNumber })
          .from(berths)
          .where(and(eq(berths.portId, portId), inArray(berths.id, ids))),
      (r) => `Berth ${r.mooring}`,
    ),
    loadLabels(
      'invoice',
      (ids) =>
        db
          .select({ id: invoices.id, num: invoices.invoiceNumber })
          .from(invoices)
          .where(and(eq(invoices.portId, portId), inArray(invoices.id, ids))),
      (r) => r.num,
    ),
    loadLabels(
      'expense',
      (ids) =>
        db
          .select({
            id: expenses.id,
            desc: expenses.description,
            vendor: expenses.establishmentName,
          })
          .from(expenses)
          .where(and(eq(expenses.portId, portId), inArray(expenses.id, ids))),
      (r) => r.desc ?? r.vendor ?? 'Expense',
    ),
    loadLabels(
      'document',
      (ids) =>
        db
          .select({ id: documents.id, title: documents.title })
          .from(documents)
          .where(and(eq(documents.portId, portId), inArray(documents.id, ids))),
      (r) => r.title,
    ),
    loadLabels(
      'reminder',
      (ids) =>
        db
          .select({ id: reminders.id, title: reminders.title })
          .from(reminders)
          .where(and(eq(reminders.portId, portId), inArray(reminders.id, ids))),
      (r) => r.title,
    ),
    loadLabels(
      'residential_client',
      (ids) =>
        db
          .select({ id: residentialClients.id, name: residentialClients.fullName })
          .from(residentialClients)
          .where(and(eq(residentialClients.portId, portId), inArray(residentialClients.id, ids))),
      (r) => r.name,
    ),
    loadLabels(
      'residential_interest',
      (ids) =>
        db
          .select({
            id: residentialInterests.id,
            clientName: residentialClients.fullName,
          })
          .from(residentialInterests)
          .innerJoin(
            residentialClients,
            eq(residentialInterests.residentialClientId, residentialClients.id),
          )
          .where(
            and(eq(residentialInterests.portId, portId), inArray(residentialInterests.id, ids)),
          ),
      (r) => r.clientName,
    ),
    loadLabels(
      'berth_tenancy',
      (ids) =>
        db
          .select({
            id: berthTenancies.id,
            mooring: berths.mooringNumber,
            clientName: clients.fullName,
          })
          .from(berthTenancies)
          .innerJoin(berths, eq(berthTenancies.berthId, berths.id))
          .leftJoin(clients, eq(berthTenancies.clientId, clients.id))
          .where(and(eq(berthTenancies.portId, portId), inArray(berthTenancies.id, ids))),
      (r) => `Berth ${r.mooring}${r.clientName ? ` · ${r.clientName}` : ''}`,
    ),
    loadLabels(
      'payment',
      (ids) =>
        db
          .select({
            id: payments.id,
            clientName: clients.fullName,
            amount: payments.amount,
            currency: payments.currency,
          })
          .from(payments)
          .innerJoin(interests, eq(payments.interestId, interests.id))
          .innerJoin(clients, eq(interests.clientId, clients.id))
          .where(and(eq(payments.portId, portId), inArray(payments.id, ids))),
      (r) => `${r.clientName} · ${r.currency} ${r.amount}`,
    ),
    // Notes resolve to their parent entity's name so the feed reads
    // "Client note on Matthew Ciaccio" rather than a UUID-prefix fallback
    // when the note itself has no human-readable identifier.
    loadLabels(
      'client_note',
      (ids) =>
        db
          .select({ id: clientNotes.id, parent: clients.fullName })
          .from(clientNotes)
          .innerJoin(clients, eq(clientNotes.clientId, clients.id))
          .where(and(eq(clients.portId, portId), inArray(clientNotes.id, ids))),
      (r) => `Note on ${r.parent}`,
    ),
    loadLabels(
      'interest_note',
      (ids) =>
        db
          .select({ id: interestNotes.id, parent: clients.fullName })
          .from(interestNotes)
          .innerJoin(interests, eq(interestNotes.interestId, interests.id))
          .innerJoin(clients, eq(interests.clientId, clients.id))
          .where(and(eq(interests.portId, portId), inArray(interestNotes.id, ids))),
      (r) => `Note on ${r.parent}`,
    ),
    loadLabels(
      'yacht_note',
      (ids) =>
        db
          .select({ id: yachtNotes.id, parent: yachts.name })
          .from(yachtNotes)
          .innerJoin(yachts, eq(yachtNotes.yachtId, yachts.id))
          .where(and(eq(yachts.portId, portId), inArray(yachtNotes.id, ids))),
      (r) => `Note on ${r.parent}`,
    ),
    loadLabels(
      'company_note',
      (ids) =>
        db
          .select({ id: companyNotes.id, parent: companies.name })
          .from(companyNotes)
          .innerJoin(companies, eq(companyNotes.companyId, companies.id))
          .where(and(eq(companies.portId, portId), inArray(companyNotes.id, ids))),
      (r) => `Note on ${r.parent}`,
    ),
  ]);

  // Resolve user UUIDs that appear as the actor (auditLogs.userId) and
  // as oldValue/newValue on user-FK diff rows (assignedTo, ownerId,
  // reassignedTo, createdBy). Activity-feed audit-log rows previously
  // rendered the raw UUID prefix, which was unreadable.
  const USER_FK_FIELDS = new Set([
    'assignedTo',
    'ownerId',
    'reassignedTo',
    'createdBy',
    'addedBy',
    'changedBy',
    'transferredBy',
  ]);
  const userIds = new Set<string>();
  for (const r of rows) {
    if (r.userId) userIds.add(r.userId);
    if (r.fieldChanged && USER_FK_FIELDS.has(r.fieldChanged)) {
      if (typeof r.oldValue === 'string') userIds.add(r.oldValue);
      if (typeof r.newValue === 'string') userIds.add(r.newValue);
    }
  }
  const userNames = new Map<string, string>();
  if (userIds.size > 0) {
    const profiles = await db
      .select({
        userId: userProfiles.userId,
        displayName: userProfiles.displayName,
        firstName: userProfiles.firstName,
        lastName: userProfiles.lastName,
      })
      .from(userProfiles)
      .where(inArray(userProfiles.userId, Array.from(userIds)));
    for (const p of profiles) {
      const name = [p.firstName, p.lastName].filter(Boolean).join(' ').trim() || p.displayName;
      userNames.set(p.userId, name);
    }
  }
  function resolveUser(id: unknown): unknown {
    if (typeof id !== 'string') return id;
    const name = userNames.get(id);
    if (name) return name;
    return `Unknown user (#${id.slice(0, 8)})`;
  }

  return rows.map((r) => {
    const isUserFk = r.fieldChanged && USER_FK_FIELDS.has(r.fieldChanged);
    return {
      ...r,
      label: r.entityId ? (labels.get(`${r.entityType}:${r.entityId}`) ?? null) : null,
      // Replace user UUIDs with display names; non-user-FK rows pass through.
      oldValue: isUserFk ? resolveUser(r.oldValue) : r.oldValue,
      newValue: isUserFk ? resolveUser(r.newValue) : r.newValue,
      // Surfaces the actor's name to the renderer; original userId stays
      // available for forensics / deep-link if a later UI needs it.
      actorName: r.userId ? (userNames.get(r.userId) ?? null) : null,
    };
  });
}