/**
 * interest_berths junction helpers.
 *
 * The junction is the source of truth for which berths an interest is
 * linked to. Callers should resolve "the berth for this deal" through
 * `getPrimaryBerth(interestId)` rather than reading the legacy
 * `interests.berth_id` column (slated for removal once every caller
 * is migrated - see plan §3.4).
 *
 * Role-flag semantics (see plan §1):
 *   - is_primary           : at most one row per interest. Templates,
 *                            forms, and "the berth for this deal"
 *                            UIs resolve through this row.
 *   - is_specific_interest : the berth shows as "Under Offer" on the
 *                            public map. False = legal/EOI-only link.
 *   - is_in_eoi_bundle     : covered by the interest's EOI signature.
 */

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

import { db } from '@/lib/db';
import { interestBerths, interests, type InterestBerth } from '@/lib/db/schema/interests';
import { berths } from '@/lib/db/schema/berths';
import { CodedError, NotFoundError } from '@/lib/errors';
import type { AuditMeta } from '@/lib/audit';

type DbOrTx = typeof db | Parameters<Parameters<typeof db.transaction>[0]>[0];

// ─── Reads ──────────────────────────────────────────────────────────────────

export interface PrimaryBerthRef {
  berthId: string;
  mooringNumber: string | null;
  isInEoiBundle: boolean;
  isSpecificInterest: boolean;
}

/**
 * The primary berth for an interest, if any. Resolves the row marked
 * `is_primary=true`; falls back to the most recently added berth row
 * when no row is flagged primary (defensive — the unique partial index
 * guarantees ≤1 primary, but reads should never throw on data drift).
 */
export async function getPrimaryBerth(interestId: string): Promise<PrimaryBerthRef | null> {
  const rows = await db
    .select({
      berthId: interestBerths.berthId,
      isPrimary: interestBerths.isPrimary,
      isSpecificInterest: interestBerths.isSpecificInterest,
      isInEoiBundle: interestBerths.isInEoiBundle,
      addedAt: interestBerths.addedAt,
      mooringNumber: berths.mooringNumber,
    })
    .from(interestBerths)
    .innerJoin(berths, eq(berths.id, interestBerths.berthId))
    .where(eq(interestBerths.interestId, interestId))
    .orderBy(desc(interestBerths.isPrimary), desc(interestBerths.addedAt));
  const first = rows[0];
  if (!first) return null;
  return {
    berthId: first.berthId,
    mooringNumber: first.mooringNumber,
    isInEoiBundle: first.isInEoiBundle,
    isSpecificInterest: first.isSpecificInterest,
  };
}

/**
 * Map { interestId → primary berth ref } for a batch of interest ids.
 * One round-trip; preferred for list pages over a per-row helper.
 */
export async function getPrimaryBerthsForInterests(
  interestIds: string[],
): Promise<Map<string, PrimaryBerthRef>> {
  if (interestIds.length === 0) return new Map();
  const rows = await db
    .select({
      interestId: interestBerths.interestId,
      berthId: interestBerths.berthId,
      isPrimary: interestBerths.isPrimary,
      isSpecificInterest: interestBerths.isSpecificInterest,
      isInEoiBundle: interestBerths.isInEoiBundle,
      addedAt: interestBerths.addedAt,
      mooringNumber: berths.mooringNumber,
    })
    .from(interestBerths)
    .innerJoin(berths, eq(berths.id, interestBerths.berthId))
    .where(inArray(interestBerths.interestId, interestIds))
    .orderBy(desc(interestBerths.isPrimary), desc(interestBerths.addedAt));

  const out = new Map<string, PrimaryBerthRef>();
  for (const r of rows) {
    if (out.has(r.interestId)) continue;
    out.set(r.interestId, {
      berthId: r.berthId,
      mooringNumber: r.mooringNumber,
      isInEoiBundle: r.isInEoiBundle,
      isSpecificInterest: r.isSpecificInterest,
    });
  }
  return out;
}

/** Berth metadata surfaced alongside each junction row by {@link listBerthsForInterest}. */
export interface InterestBerthWithDetails extends InterestBerth {
  mooringNumber: string | null;
  area: string | null;
  status: string;
  lengthFt: string | null;
  widthFt: string | null;
  draftFt: string | null;
}

/** All berth links for a single interest, ordered with primary first. */
export async function listBerthsForInterest(
  interestId: string,
): Promise<Array<InterestBerthWithDetails>> {
  return db
    .select({
      id: interestBerths.id,
      interestId: interestBerths.interestId,
      berthId: interestBerths.berthId,
      isPrimary: interestBerths.isPrimary,
      isSpecificInterest: interestBerths.isSpecificInterest,
      isInEoiBundle: interestBerths.isInEoiBundle,
      eoiBypassReason: interestBerths.eoiBypassReason,
      eoiBypassedBy: interestBerths.eoiBypassedBy,
      eoiBypassedAt: interestBerths.eoiBypassedAt,
      addedBy: interestBerths.addedBy,
      addedAt: interestBerths.addedAt,
      notes: interestBerths.notes,
      mooringNumber: berths.mooringNumber,
      area: berths.area,
      status: berths.status,
      lengthFt: berths.lengthFt,
      widthFt: berths.widthFt,
      draftFt: berths.draftFt,
    })
    .from(interestBerths)
    .innerJoin(berths, eq(berths.id, interestBerths.berthId))
    .where(eq(interestBerths.interestId, interestId))
    .orderBy(desc(interestBerths.isPrimary), desc(interestBerths.addedAt));
}

/** All interest links for a single berth (used by the recommender + admin UI). */
export async function listInterestsForBerth(berthId: string): Promise<Array<InterestBerth>> {
  return db
    .select()
    .from(interestBerths)
    .where(eq(interestBerths.berthId, berthId))
    .orderBy(desc(interestBerths.addedAt));
}

// ─── Writes ─────────────────────────────────────────────────────────────────

interface AddOrUpdateOpts {
  isPrimary?: boolean;
  isSpecificInterest?: boolean;
  isInEoiBundle?: boolean;
  addedBy?: string;
  notes?: string;
  /**
   * EOI bypass fields. Set `eoiBypassReason` to a non-empty string to record
   * that the berth's own EOI is waived (the parent interest's primary EOI
   * covers it), or to `null` to clear the bypass and re-require it.
   * `eoiBypassedBy` should be the acting user id; the timestamp is stamped
   * server-side.
   */
  eoiBypassReason?: string | null;
  eoiBypassedBy?: string | null;
}

/**
 * Idempotently link a berth to an interest. If the row already exists,
 * provided flags are merged; otherwise a fresh row is inserted.
 *
 * When `isPrimary=true` is requested, the previous primary (if any) is
 * demoted in the same transaction so the unique partial index is never
 * violated.
 */
export async function upsertInterestBerth(
  interestId: string,
  berthId: string,
  opts: AddOrUpdateOpts = {},
): Promise<InterestBerth> {
  return db.transaction(async (tx) => {
    return upsertInterestBerthTx(tx, interestId, berthId, opts);
  });
}

/**
 * Transaction-bound variant of {@link upsertInterestBerth}. Use this when the
 * junction write must roll back together with another write (e.g. inserting
 * the parent interest row in the same transaction).
 */
export async function upsertInterestBerthTx(
  tx: DbOrTx,
  interestId: string,
  berthId: string,
  opts: AddOrUpdateOpts = {},
): Promise<InterestBerth> {
  // Cross-port guard. The junction is silently multi-port-shaped (it has
  // no port_id of its own — it inherits via the FKs) so a caller wiring
  // an interest from one port to a berth from another would corrupt the
  // recommender + public-berth aggregates with phantom rows. We assert
  // both rows live in the same port BEFORE inserting; if either side is
  // missing, the FK constraint will surface that on insert.
  const sides = await tx
    .select({
      interestPortId: interests.portId,
      berthPortId: berths.portId,
    })
    .from(interests)
    .innerJoin(berths, eq(berths.id, berthId))
    .where(eq(interests.id, interestId))
    .limit(1);
  const side = sides[0];
  if (side && side.interestPortId !== side.berthPortId) {
    throw new CodedError('CROSS_PORT_LINK_REJECTED', {
      internalMessage: `interest ${interestId} (port ${side.interestPortId}) ↔ berth ${berthId} (port ${side.berthPortId})`,
    });
  }

  if (opts.isPrimary === true) {
    await tx
      .update(interestBerths)
      .set({ isPrimary: false })
      .where(and(eq(interestBerths.interestId, interestId), eq(interestBerths.isPrimary, true)));
  }
  const setForUpdate: Partial<InterestBerth> = {};
  if (opts.isPrimary !== undefined) setForUpdate.isPrimary = opts.isPrimary;
  if (opts.isSpecificInterest !== undefined)
    setForUpdate.isSpecificInterest = opts.isSpecificInterest;
  if (opts.isInEoiBundle !== undefined) setForUpdate.isInEoiBundle = opts.isInEoiBundle;
  if (opts.addedBy !== undefined) setForUpdate.addedBy = opts.addedBy;
  if (opts.notes !== undefined) setForUpdate.notes = opts.notes;
  // Bypass fields move as a unit — either we set all three to record a bypass
  // or clear all three. Touching the reason field decides which.
  if (opts.eoiBypassReason !== undefined) {
    if (opts.eoiBypassReason && opts.eoiBypassReason.trim().length > 0) {
      setForUpdate.eoiBypassReason = opts.eoiBypassReason;
      setForUpdate.eoiBypassedBy = opts.eoiBypassedBy ?? null;
      setForUpdate.eoiBypassedAt = new Date();
    } else {
      setForUpdate.eoiBypassReason = null;
      setForUpdate.eoiBypassedBy = null;
      setForUpdate.eoiBypassedAt = null;
    }
  }

  const [row] = await tx
    .insert(interestBerths)
    .values({
      interestId,
      berthId,
      isPrimary: opts.isPrimary ?? false,
      isSpecificInterest: opts.isSpecificInterest ?? true,
      isInEoiBundle: opts.isInEoiBundle ?? false,
      addedBy: opts.addedBy,
      notes: opts.notes,
      eoiBypassReason: setForUpdate.eoiBypassReason ?? null,
      eoiBypassedBy: setForUpdate.eoiBypassedBy ?? null,
      eoiBypassedAt: setForUpdate.eoiBypassedAt ?? null,
    })
    .onConflictDoUpdate({
      target: [interestBerths.interestId, interestBerths.berthId],
      set: setForUpdate,
    })
    .returning();
  return row!;
}

/** Promote a single berth to primary for the interest. Demotes any prior primary. */
export async function setPrimaryBerth(interestId: string, berthId: string): Promise<void> {
  await upsertInterestBerth(interestId, berthId, { isPrimary: true });
}

/** Remove a berth from an interest.
 *
 * `portId` is required for cross-port defense — `upsertInterestBerth`
 * and `setPrimaryBerth` both verify the interest + berth share the
 * caller's port before mutation, but the original `removeInterestBerth`
 * issued a delete keyed only by (interestId, berthId), so a future
 * caller that omitted its own port check could delete a junction row
 * across tenants. This now mirrors the cross-check used by upsert.
 */
export async function removeInterestBerth(
  interestId: string,
  berthId: string,
  portId: string,
  meta?: AuditMeta,
): Promise<void> {
  // Verify both the interest and the berth belong to the caller's
  // port before issuing the delete. A tenant boundary breach would
  // otherwise be a single misrouted call away.
  const [interestRow, berthRow] = await Promise.all([
    db.query.interests.findFirst({
      where: and(eq(interests.id, interestId), eq(interests.portId, portId)),
    }),
    db.query.berths.findFirst({
      where: and(eq(berths.id, berthId), eq(berths.portId, portId)),
    }),
  ]);
  if (!interestRow || !berthRow) {
    throw new NotFoundError('interest or berth');
  }
  await db
    .delete(interestBerths)
    .where(and(eq(interestBerths.interestId, interestId), eq(interestBerths.berthId, berthId)));

  // G-C4: fire the berth_unlinked berth-rule. Default mode is 'off' so this
  // is a silent no-op unless an admin opted in via system_settings.berth_rules.
  // Dynamic import avoids a static cycle: berth-rules-engine imports this file
  // (getPrimaryBerth). meta is optional so older callers that haven't been
  // threaded through can still call this without triggering the rule.
  if (meta) {
    const { evaluateRule } = await import('@/lib/services/berth-rules-engine');
    void evaluateRule('berth_unlinked', interestId, portId, meta);
  }
}
