import { and, eq, inArray, isNull, sql } from 'drizzle-orm';

import { db } from '@/lib/db';
import { interests, interestTags } from '@/lib/db/schema/interests';
import { clients } from '@/lib/db/schema/clients';
import { berths } from '@/lib/db/schema/berths';
import { tags } from '@/lib/db/schema/system';
import { createAuditLog } from '@/lib/audit';
import { NotFoundError, ConflictError } from '@/lib/errors';
import { emitToRoom } from '@/lib/socket/server';
import { buildListQuery } from '@/lib/db/query-builder';
import { diffEntity } from '@/lib/entity-diff';
import { softDelete, restore, withTransaction } from '@/lib/db/utils';
import type {
  CreateInterestInput,
  UpdateInterestInput,
  ChangeStageInput,
  ListInterestsInput,
} from '@/lib/validators/interests';

// ─── Types ────────────────────────────────────────────────────────────────────

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

// ─── BR-011: Auto-promote leadCategory ───────────────────────────────────────

async function resolveLeadCategory(
  clientId: string,
  leadCategory: string | undefined | null,
): Promise<string | undefined> {
  if (leadCategory && leadCategory !== 'general_interest') {
    return leadCategory;
  }

  const client = await db.query.clients.findFirst({
    where: eq(clients.id, clientId),
  });

  if (client && (client.yachtLengthFt || client.yachtLengthM)) {
    return 'specific_qualified';
  }

  return leadCategory ?? undefined;
}

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

export async function listInterests(portId: string, query: ListInterestsInput) {
  const {
    page,
    limit,
    sort,
    order,
    search,
    includeArchived,
    clientId,
    berthId,
    pipelineStage,
    leadCategory,
    eoiStatus,
    tagIds,
  } = query;

  const filters = [];

  if (clientId) {
    filters.push(eq(interests.clientId, clientId));
  }
  if (berthId) {
    filters.push(eq(interests.berthId, berthId));
  }
  if (pipelineStage && pipelineStage.length > 0) {
    filters.push(inArray(interests.pipelineStage, pipelineStage));
  }
  if (leadCategory) {
    filters.push(eq(interests.leadCategory, leadCategory));
  }
  if (eoiStatus) {
    filters.push(eq(interests.eoiStatus, eoiStatus));
  }
  if (tagIds && tagIds.length > 0) {
    const interestsWithTags = await db
      .selectDistinct({ interestId: interestTags.interestId })
      .from(interestTags)
      .where(inArray(interestTags.tagId, tagIds));
    const matchingIds = interestsWithTags.map((r) => r.interestId);
    if (matchingIds.length > 0) {
      filters.push(inArray(interests.id, matchingIds));
    } else {
      return { data: [], total: 0 };
    }
  }

  const sortColumn = (() => {
    switch (sort) {
      case 'pipelineStage': return interests.pipelineStage;
      case 'leadCategory': return interests.leadCategory;
      case 'createdAt': return interests.createdAt;
      default: return interests.updatedAt;
    }
  })();

  const result = await buildListQuery({
    table: interests,
    portIdColumn: interests.portId,
    portId,
    idColumn: interests.id,
    updatedAtColumn: interests.updatedAt,
    filters,
    sort: { column: sortColumn, direction: order },
    page,
    pageSize: limit,
    searchColumns: [],
    searchTerm: search,
    includeArchived,
    archivedAtColumn: interests.archivedAt,
  });

  // Join client names and berth mooring numbers
  const interestIds = (result.data as Array<{ id: string; clientId: string; berthId: string | null }>).map((i) => i.id);
  const clientIds = [...new Set((result.data as Array<{ clientId: string }>).map((i) => i.clientId))];
  const berthIds = [...new Set(
    (result.data as Array<{ berthId: string | null }>)
      .map((i) => i.berthId)
      .filter(Boolean) as string[]
  )];

  let clientsMap: Record<string, string> = {};
  let berthsMap: Record<string, string> = {};
  let tagsByInterestId: Record<string, Array<{ id: string; name: string; color: string }>> = {};

  if (clientIds.length > 0) {
    const clientRows = await db
      .select({ id: clients.id, fullName: clients.fullName })
      .from(clients)
      .where(inArray(clients.id, clientIds));
    clientsMap = Object.fromEntries(clientRows.map((c) => [c.id, c.fullName]));
  }

  if (berthIds.length > 0) {
    const berthRows = await db
      .select({ id: berths.id, mooringNumber: berths.mooringNumber })
      .from(berths)
      .where(inArray(berths.id, berthIds));
    berthsMap = Object.fromEntries(berthRows.map((b) => [b.id, b.mooringNumber]));
  }

  if (interestIds.length > 0) {
    const tagRows = await db
      .select({
        interestId: interestTags.interestId,
        id: tags.id,
        name: tags.name,
        color: tags.color,
      })
      .from(interestTags)
      .innerJoin(tags, eq(interestTags.tagId, tags.id))
      .where(inArray(interestTags.interestId, interestIds));

    for (const row of tagRows) {
      if (!tagsByInterestId[row.interestId]) tagsByInterestId[row.interestId] = [];
      tagsByInterestId[row.interestId]!.push({ id: row.id, name: row.name, color: row.color });
    }
  }

  const data = (result.data as Array<Record<string, unknown>>).map((i) => ({
    ...i,
    clientName: clientsMap[i.clientId as string] ?? null,
    berthMooringNumber: i.berthId ? (berthsMap[i.berthId as string] ?? null) : null,
    tags: tagsByInterestId[i.id as string] ?? [],
  }));

  return { data, total: result.total };
}

// ─── Get by ID ────────────────────────────────────────────────────────────────

export async function getInterestById(id: string, portId: string) {
  const interest = await db.query.interests.findFirst({
    where: eq(interests.id, id),
  });

  if (!interest || interest.portId !== portId) {
    throw new NotFoundError('Interest');
  }

  const [clientRow] = await db
    .select({ fullName: clients.fullName })
    .from(clients)
    .where(eq(clients.id, interest.clientId));

  let berthMooringNumber: string | null = null;
  if (interest.berthId) {
    const [berthRow] = await db
      .select({ mooringNumber: berths.mooringNumber })
      .from(berths)
      .where(eq(berths.id, interest.berthId));
    berthMooringNumber = berthRow?.mooringNumber ?? null;
  }

  const tagRows = await db
    .select({ id: tags.id, name: tags.name, color: tags.color })
    .from(interestTags)
    .innerJoin(tags, eq(interestTags.tagId, tags.id))
    .where(eq(interestTags.interestId, id));

  return {
    ...interest,
    clientName: clientRow?.fullName ?? null,
    berthMooringNumber,
    tags: tagRows,
  };
}

// ─── Create ───────────────────────────────────────────────────────────────────

export async function createInterest(
  portId: string,
  data: CreateInterestInput,
  meta: AuditMeta,
) {
  const { tagIds, ...interestData } = data;

  // BR-011: auto-promote leadCategory
  const resolvedLeadCategory = await resolveLeadCategory(
    data.clientId,
    data.leadCategory,
  );

  const result = await withTransaction(async (tx) => {
    const [interest] = await tx
      .insert(interests)
      .values({
        portId,
        ...interestData,
        leadCategory: resolvedLeadCategory,
      })
      .returning();

    if (tagIds && tagIds.length > 0) {
      await tx.insert(interestTags).values(
        tagIds.map((tagId) => ({ interestId: interest!.id, tagId })),
      );
    }

    return interest!;
  });

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'create',
    entityType: 'interest',
    entityId: result.id,
    newValue: { clientId: result.clientId, pipelineStage: result.pipelineStage },
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'interest:created', { interestId: result.id, clientId: result.clientId, berthId: result.berthId ?? null, source: result.source ?? '' });

  void import('@/lib/services/webhook-dispatch').then(({ dispatchWebhookEvent }) =>
    dispatchWebhookEvent(portId, 'interest:created', { interestId: result.id, clientId: result.clientId }),
  );

  return result;
}

// ─── Update ───────────────────────────────────────────────────────────────────

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

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

  // BR-011: auto-promote leadCategory if provided
  let resolvedLeadCategory = data.leadCategory;
  if ('leadCategory' in data) {
    resolvedLeadCategory = await resolveLeadCategory(
      existing.clientId,
      data.leadCategory,
    ) as typeof data.leadCategory;
  }

  const updateData = { ...data, leadCategory: resolvedLeadCategory };
  const { diff } = diffEntity(
    existing as Record<string, unknown>,
    updateData as Record<string, unknown>,
  );

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

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

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

  return updated!;
}

// ─── Change Stage ─────────────────────────────────────────────────────────────

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

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

  const oldStage = existing.pipelineStage;

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

  // BR-133: Auto-populate milestones based on stage
  const milestoneUpdates: Record<string, unknown> = {};
  if (data.pipelineStage === 'signed_eoi_nda') milestoneUpdates.dateEoiSigned = new Date();
  if (data.pipelineStage === 'contract') milestoneUpdates.dateContractSigned = new Date();
  if (data.pipelineStage === 'deposit_10pct') milestoneUpdates.dateDepositReceived = new Date();
  if (Object.keys(milestoneUpdates).length > 0) {
    await db.update(interests).set({ ...milestoneUpdates, updatedAt: new Date() }).where(eq(interests.id, id));
  }

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'update',
    entityType: 'interest',
    entityId: id,
    oldValue: { pipelineStage: oldStage },
    newValue: { pipelineStage: data.pipelineStage, reason: data.reason },
    metadata: { type: 'stage_change', reason: data.reason },
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'interest:stageChanged', {
    interestId: id,
    oldStage: oldStage ?? '',
    newStage: data.pipelineStage,
    clientName: '',
    berthNumber: '',
  });

  void import('@/lib/services/webhook-dispatch').then(({ dispatchWebhookEvent }) =>
    dispatchWebhookEvent(portId, 'interest:stageChanged', {
      interestId: id,
      oldStage: oldStage ?? null,
      newStage: data.pipelineStage,
    }),
  );

  // Fire-and-forget notification to the acting user
  void import('@/lib/services/notifications.service').then(({ createNotification }) =>
    createNotification({
      portId,
      userId: meta.userId,
      type: 'interest_stage_changed',
      title: `Interest moved to ${data.pipelineStage}`,
      description: `Interest ${id} stage changed from ${oldStage ?? 'unknown'} to ${data.pipelineStage}`,
      link: `/interests/${id}`,
      entityType: 'interest',
      entityId: id,
      dedupeKey: `interest:${id}:stage:${data.pipelineStage}`,
      cooldownMs: 300_000,
    }),
  );

  return updated!;
}

// ─── Archive / Restore ────────────────────────────────────────────────────────

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

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

  // BR-014: Block archive if pending EOI/contract
  if (existing.eoiStatus === 'waiting_for_signatures' || existing.contractStatus === 'pending') {
    throw new ConflictError('Cannot archive interest with pending documents. Cancel documents first.');
  }

  await softDelete(interests, interests.id, id);

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

  emitToRoom(`port:${portId}`, 'interest:archived', { interestId: id });
}

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

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

  await restore(interests, interests.id, id);

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

  emitToRoom(`port:${portId}`, 'interest:updated', { interestId: id, changedFields: [] });
}

// ─── Set Tags ─────────────────────────────────────────────────────────────────

export async function setInterestTags(
  id: string,
  portId: string,
  tagIds: string[],
  meta: AuditMeta,
) {
  const existing = await db.query.interests.findFirst({
    where: eq(interests.id, id),
  });

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

  await db.delete(interestTags).where(eq(interestTags.interestId, id));

  if (tagIds.length > 0) {
    await db
      .insert(interestTags)
      .values(tagIds.map((tagId) => ({ interestId: id, tagId })));
  }

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'update',
    entityType: 'interest',
    entityId: id,
    metadata: { type: 'tags_updated', tagIds },
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'interest:updated', { interestId: id, changedFields: ['tags'] });

  return { interestId: id, tagIds };
}

// ─── Link / Unlink Berth ──────────────────────────────────────────────────────

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

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

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

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'update',
    entityType: 'interest',
    entityId: id,
    oldValue: { berthId: existing.berthId },
    newValue: { berthId },
    metadata: { type: 'berth_linked' },
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'interest:berthLinked', { interestId: id, berthId });

  void import('@/lib/services/webhook-dispatch').then(({ dispatchWebhookEvent }) =>
    dispatchWebhookEvent(portId, 'interest:berthLinked', { interestId: id, berthId }),
  );

  return updated!;
}

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

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

  const oldBerthId = existing.berthId;

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

  void createAuditLog({
    userId: meta.userId,
    portId,
    action: 'update',
    entityType: 'interest',
    entityId: id,
    oldValue: { berthId: oldBerthId },
    newValue: { berthId: null },
    metadata: { type: 'berth_unlinked' },
    ipAddress: meta.ipAddress,
    userAgent: meta.userAgent,
  });

  emitToRoom(`port:${portId}`, 'interest:berthUnlinked', { interestId: id, berthId: oldBerthId ?? '' });

  return updated!;
}

// ─── Stage Counts (for board) ────────────────────────────────────────────────

export async function getInterestStageCounts(portId: string) {
  const rows = await db.select({ stage: interests.pipelineStage, count: sql<number>`count(*)::int` })
    .from(interests)
    .where(and(eq(interests.portId, portId), isNull(interests.archivedAt)))
    .groupBy(interests.pipelineStage);
  return Object.fromEntries(rows.map(r => [r.stage, r.count]));
}