import { and, eq, ilike, or, sql } from 'drizzle-orm';
import { db } from '@/lib/db';
import { yachts, yachtOwnershipHistory, clients } from '@/lib/db/schema';
import type { Yacht } from '@/lib/db/schema/yachts';
import { companies } from '@/lib/db/schema/companies';
import { createAuditLog } from '@/lib/audit';
import { NotFoundError, ValidationError } from '@/lib/errors';
import { emitToRoom } from '@/lib/socket/server';
import { diffEntity } from '@/lib/entity-diff';
import { buildListQuery } from '@/lib/db/query-builder';
import { withTransaction } from '@/lib/db/utils';
import type { z } from 'zod';
import type {
  createYachtSchema,
  UpdateYachtInput,
  TransferOwnershipInput,
  ListYachtsInput,
} from '@/lib/validators/yachts';

type CreateYachtInput = z.input<typeof createYachtSchema>;

interface AuditMeta {
  userId: string;
  portId: string;
  ipAddress: string;
  userAgent: string;
}

async function assertOwnerExists(
  portId: string,
  owner: { type: 'client' | 'company'; id: string },
  tx: typeof db,
): Promise<void> {
  if (owner.type === 'client') {
    const client = await tx.query.clients.findFirst({
      where: and(eq(clients.id, owner.id), eq(clients.portId, portId)),
    });
    if (!client) throw new ValidationError('owner not found');
  } else {
    const company = await tx.query.companies.findFirst({
      where: and(eq(companies.id, owner.id), eq(companies.portId, portId)),
    });
    if (!company) throw new ValidationError('owner not found');
  }
}

export async function createYacht(portId: string, data: CreateYachtInput, meta: AuditMeta) {
  return await withTransaction(async (tx) => {
    await assertOwnerExists(portId, data.owner, tx);

    const [yacht] = await tx
      .insert(yachts)
      .values({
        portId,
        name: data.name,
        hullNumber: data.hullNumber ?? null,
        registration: data.registration ?? null,
        flag: data.flag ?? null,
        yearBuilt: data.yearBuilt ?? null,
        builder: data.builder ?? null,
        model: data.model ?? null,
        hullMaterial: data.hullMaterial ?? null,
        lengthFt: data.lengthFt ?? null,
        widthFt: data.widthFt ?? null,
        draftFt: data.draftFt ?? null,
        lengthM: data.lengthM ?? null,
        widthM: data.widthM ?? null,
        draftM: data.draftM ?? null,
        currentOwnerType: data.owner.type,
        currentOwnerId: data.owner.id,
        status: data.status ?? 'active',
        notes: data.notes ?? null,
      })
      .returning();

    await tx.insert(yachtOwnershipHistory).values({
      yachtId: yacht!.id,
      ownerType: data.owner.type,
      ownerId: data.owner.id,
      startDate: new Date(),
      endDate: null,
      createdBy: meta.userId,
    });

    void createAuditLog({
      userId: meta.userId,
      portId,
      action: 'create',
      entityType: 'yacht',
      entityId: yacht!.id,
      newValue: { name: yacht!.name, owner: data.owner },
      ipAddress: meta.ipAddress,
      userAgent: meta.userAgent,
    });

    emitToRoom(`port:${portId}`, 'yacht:created', { yachtId: yacht!.id });

    return yacht!;
  });
}

export async function getYachtById(id: string, portId: string) {
  const yacht = await db.query.yachts.findFirst({
    where: and(eq(yachts.id, id), eq(yachts.portId, portId)),
  });
  if (!yacht) throw new NotFoundError('Yacht');
  return yacht;
}

export async function updateYacht(
  id: string,
  portId: string,
  data: UpdateYachtInput,
  meta: AuditMeta,
) {
  // Defense-in-depth: owner changes must go through /transfer, not PATCH.
  const dataRecord = data as Record<string, unknown>;
  if (
    Object.prototype.hasOwnProperty.call(dataRecord, 'currentOwnerType') ||
    Object.prototype.hasOwnProperty.call(dataRecord, 'currentOwnerId')
  ) {
    throw new ValidationError('use /transfer to change ownership');
  }

  const existing = await db.query.yachts.findFirst({
    where: eq(yachts.id, id),
  });

  if (!existing || existing.portId !== portId) {
    throw new NotFoundError('Yacht');
  }

  const { diff } = diffEntity(
    existing as unknown as Record<string, unknown>,
    data as Record<string, unknown>,
  );

  const [updated] = await db
    .update(yachts)
    .set({ ...data, updatedAt: new Date() })
    .where(and(eq(yachts.id, id), eq(yachts.portId, portId)))
    .returning();

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'update',
    entityType: 'yacht',
    entityId: id,
    oldValue: diff as Record<string, unknown>,
    newValue: data as Record<string, unknown>,
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'yacht:updated', {
    yachtId: id,
    changedFields: Object.keys(diff),
  });

  return updated!;
}

export async function archiveYacht(id: string, portId: string, meta: AuditMeta) {
  const existing = await db.query.yachts.findFirst({
    where: eq(yachts.id, id),
  });

  if (!existing || existing.portId !== portId) {
    throw new NotFoundError('Yacht');
  }

  // NOTE: bypassing the shared `softDelete(...)` util: it sets the raw
  // column key `archived_at`, which Drizzle does not recognise (the JS
  // key is `archivedAt`) and therefore emits an empty SET clause. Until
  // the utility is fixed, do the update inline.
  await db
    .update(yachts)
    .set({ archivedAt: new Date() })
    .where(and(eq(yachts.id, id), eq(yachts.portId, portId)));

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'archive',
    entityType: 'yacht',
    entityId: id,
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'yacht:archived', { yachtId: id });
}

export async function transferOwnership(
  yachtId: string,
  portId: string,
  data: TransferOwnershipInput,
  meta: AuditMeta,
) {
  return await withTransaction(async (tx) => {
    const yacht = await tx.query.yachts.findFirst({
      where: and(eq(yachts.id, yachtId), eq(yachts.portId, portId)),
    });
    if (!yacht) throw new NotFoundError('Yacht');

    if (
      yacht.currentOwnerType === data.newOwner.type &&
      yacht.currentOwnerId === data.newOwner.id
    ) {
      throw new ValidationError('same owner — nothing to transfer');
    }

    await assertOwnerExists(portId, data.newOwner, tx);

    // Close the currently-active history row
    await tx
      .update(yachtOwnershipHistory)
      .set({ endDate: data.effectiveDate })
      .where(
        and(
          eq(yachtOwnershipHistory.yachtId, yachtId),
          sql`${yachtOwnershipHistory.endDate} IS NULL`,
        ),
      );

    // Open new row
    await tx.insert(yachtOwnershipHistory).values({
      yachtId,
      ownerType: data.newOwner.type,
      ownerId: data.newOwner.id,
      startDate: data.effectiveDate,
      endDate: null,
      transferReason: data.transferReason ?? null,
      transferNotes: data.transferNotes ?? null,
      createdBy: meta.userId,
    });

    // Update denormalized current-owner columns
    const [updated] = await tx
      .update(yachts)
      .set({
        currentOwnerType: data.newOwner.type,
        currentOwnerId: data.newOwner.id,
        updatedAt: new Date(),
      })
      .where(eq(yachts.id, yachtId))
      .returning();

    void createAuditLog({
      userId: meta.userId,
      portId,
      action: 'update',
      entityType: 'yacht',
      entityId: yachtId,
      newValue: { ownerTransferTo: data.newOwner, reason: data.transferReason },
      ipAddress: meta.ipAddress,
      userAgent: meta.userAgent,
    });

    emitToRoom(`port:${portId}`, 'yacht:ownership_transferred', {
      yachtId,
      newOwner: data.newOwner,
    });

    return updated!;
  });
}

// ─── List ─────────────────────────────────────────────────────────────────────

export async function listYachts(portId: string, query: ListYachtsInput) {
  const { page, limit, sort, order, search, includeArchived, ownerType, ownerId, status } = query;

  const filters = [];
  if (ownerType) filters.push(eq(yachts.currentOwnerType, ownerType));
  if (ownerId) filters.push(eq(yachts.currentOwnerId, ownerId));
  if (status) filters.push(eq(yachts.status, status));

  let sortColumn: typeof yachts.name | typeof yachts.createdAt | typeof yachts.updatedAt =
    yachts.updatedAt;
  if (sort === 'name') sortColumn = yachts.name;
  else if (sort === 'createdAt') sortColumn = yachts.createdAt;

  const result = await buildListQuery<Yacht>({
    table: yachts,
    portIdColumn: yachts.portId,
    portId,
    idColumn: yachts.id,
    updatedAtColumn: yachts.updatedAt,
    searchColumns: [yachts.name, yachts.hullNumber, yachts.registration],
    searchTerm: search,
    filters,
    sort: sort ? { column: sortColumn, direction: order } : undefined,
    page,
    pageSize: limit,
    includeArchived,
    archivedAtColumn: yachts.archivedAt,
  });

  return result;
}

// ─── List for owner ───────────────────────────────────────────────────────────

export async function listYachtsForOwner(
  portId: string,
  ownerType: 'client' | 'company',
  ownerId: string,
) {
  return await db.query.yachts.findMany({
    where: and(
      eq(yachts.portId, portId),
      eq(yachts.currentOwnerType, ownerType),
      eq(yachts.currentOwnerId, ownerId),
    ),
    orderBy: (t, { desc }) => [desc(t.updatedAt)],
  });
}

// ─── Ownership history ────────────────────────────────────────────────────────

export async function listOwnershipHistory(yachtId: string, portId: string) {
  // First scope-check the yacht (throws NotFoundError if cross-tenant)
  await getYachtById(yachtId, portId);
  return await db.query.yachtOwnershipHistory.findMany({
    where: eq(yachtOwnershipHistory.yachtId, yachtId),
    orderBy: (t, { desc }) => [desc(t.startDate)],
  });
}

// ─── Autocomplete ─────────────────────────────────────────────────────────────

export async function autocomplete(portId: string, q: string) {
  const pattern = `%${q}%`;
  return await db
    .select()
    .from(yachts)
    .where(
      and(
        eq(yachts.portId, portId),
        or(
          ilike(yachts.name, pattern),
          ilike(yachts.hullNumber, pattern),
          ilike(yachts.registration, pattern),
        ),
      ),
    )
    .limit(10);
}