import { db, canAccessTrip } from '../db/database';
import { loadTagsByPlaceIds, loadParticipantsByAssignmentIds, formatAssignmentWithPlace } from './queryHelpers';
import { AssignmentRow, Day, DayNote } from '../types';

export function verifyTripAccess(tripId: string | number, userId: number) {
  return canAccessTrip(tripId, userId);
}

// ---------------------------------------------------------------------------
// Day assignment helpers
// ---------------------------------------------------------------------------

export function getAssignmentsForDay(dayId: number | string) {
  const assignments = db.prepare(`
    SELECT da.*, p.id as place_id, p.name as place_name, p.description as place_description,
      p.lat, p.lng, p.address, p.category_id, p.price, p.currency as place_currency,
      COALESCE(da.assignment_time, p.place_time) as place_time,
      COALESCE(da.assignment_end_time, p.end_time) as end_time,
      p.duration_minutes, p.notes as place_notes,
      p.image_url, p.transport_mode, p.google_place_id, p.website, p.phone,
      c.name as category_name, c.color as category_color, c.icon as category_icon
    FROM day_assignments da
    JOIN places p ON da.place_id = p.id
    LEFT JOIN categories c ON p.category_id = c.id
    WHERE da.day_id = ?
    ORDER BY da.order_index ASC, da.created_at ASC
  `).all(dayId) as AssignmentRow[];

  return assignments.map(a => {
    const tags = db.prepare(`
      SELECT t.* FROM tags t
      JOIN place_tags pt ON t.id = pt.tag_id
      WHERE pt.place_id = ?
    `).all(a.place_id);

    return {
      id: a.id,
      day_id: a.day_id,
      order_index: a.order_index,
      notes: a.notes,
      created_at: a.created_at,
      place: {
        id: a.place_id,
        name: a.place_name,
        description: a.place_description,
        lat: a.lat,
        lng: a.lng,
        address: a.address,
        category_id: a.category_id,
        price: a.price,
        currency: a.place_currency,
        place_time: a.place_time,
        end_time: a.end_time,
        duration_minutes: a.duration_minutes,
        notes: a.place_notes,
        image_url: a.image_url,
        transport_mode: a.transport_mode,
        google_place_id: a.google_place_id,
        website: a.website,
        phone: a.phone,
        category: a.category_id ? {
          id: a.category_id,
          name: a.category_name,
          color: a.category_color,
          icon: a.category_icon,
        } : null,
        tags,
      }
    };
  });
}

// ---------------------------------------------------------------------------
// Day CRUD
// ---------------------------------------------------------------------------

export function listDays(tripId: string | number) {
  const days = db.prepare('SELECT * FROM days WHERE trip_id = ? ORDER BY day_number ASC').all(tripId) as Day[];

  if (days.length === 0) {
    return { days: [] };
  }

  const dayIds = days.map(d => d.id);
  const dayPlaceholders = dayIds.map(() => '?').join(',');

  const allAssignments = db.prepare(`
    SELECT da.*, p.id as place_id, p.name as place_name, p.description as place_description,
      p.lat, p.lng, p.address, p.category_id, p.price, p.currency as place_currency,
      COALESCE(da.assignment_time, p.place_time) as place_time,
      COALESCE(da.assignment_end_time, p.end_time) as end_time,
      p.duration_minutes, p.notes as place_notes,
      p.image_url, p.transport_mode, p.google_place_id, p.website, p.phone,
      c.name as category_name, c.color as category_color, c.icon as category_icon
    FROM day_assignments da
    JOIN places p ON da.place_id = p.id
    LEFT JOIN categories c ON p.category_id = c.id
    WHERE da.day_id IN (${dayPlaceholders})
    ORDER BY da.order_index ASC, da.created_at ASC
  `).all(...dayIds) as AssignmentRow[];

  const placeIds = [...new Set(allAssignments.map(a => a.place_id))];
  const tagsByPlaceId = loadTagsByPlaceIds(placeIds, { compact: true });

  const allAssignmentIds = allAssignments.map(a => a.id);
  const participantsByAssignment = loadParticipantsByAssignmentIds(allAssignmentIds);

  const assignmentsByDayId: Record<number, ReturnType<typeof formatAssignmentWithPlace>[]> = {};
  for (const a of allAssignments) {
    if (!assignmentsByDayId[a.day_id]) assignmentsByDayId[a.day_id] = [];
    assignmentsByDayId[a.day_id].push(formatAssignmentWithPlace(a, tagsByPlaceId[a.place_id] || [], participantsByAssignment[a.id] || []));
  }

  const allNotes = db.prepare(
    `SELECT * FROM day_notes WHERE day_id IN (${dayPlaceholders}) ORDER BY sort_order ASC, created_at ASC`
  ).all(...dayIds) as DayNote[];
  const notesByDayId: Record<number, DayNote[]> = {};
  for (const note of allNotes) {
    if (!notesByDayId[note.day_id]) notesByDayId[note.day_id] = [];
    notesByDayId[note.day_id].push(note);
  }

  const daysWithAssignments = days.map(day => ({
    ...day,
    assignments: assignmentsByDayId[day.id] || [],
    notes_items: notesByDayId[day.id] || [],
  }));

  return { days: daysWithAssignments };
}

export function createDay(tripId: string | number, date?: string, notes?: string) {
  const maxDay = db.prepare('SELECT MAX(day_number) as max FROM days WHERE trip_id = ?').get(tripId) as { max: number | null };
  const dayNumber = (maxDay.max || 0) + 1;

  const result = db.prepare(
    'INSERT INTO days (trip_id, day_number, date, notes) VALUES (?, ?, ?, ?)'
  ).run(tripId, dayNumber, date || null, notes || null);

  const day = db.prepare('SELECT * FROM days WHERE id = ?').get(result.lastInsertRowid) as Day;
  return { ...day, assignments: [] };
}

export function getDay(id: string | number, tripId: string | number) {
  return db.prepare('SELECT * FROM days WHERE id = ? AND trip_id = ?').get(id, tripId) as Day | undefined;
}

export function updateDay(id: string | number, current: Day, fields: { notes?: string; title?: string | null }) {
  db.prepare('UPDATE days SET notes = ?, title = ? WHERE id = ?').run(
    fields.notes || null,
    'title' in fields ? (fields.title ?? null) : current.title,
    id
  );
  const updatedDay = db.prepare('SELECT * FROM days WHERE id = ?').get(id) as Day;
  return { ...updatedDay, assignments: getAssignmentsForDay(id) };
}

export function deleteDay(id: string | number) {
  db.prepare('DELETE FROM days WHERE id = ?').run(id);
}

// ---------------------------------------------------------------------------
// Accommodation helpers
// ---------------------------------------------------------------------------

export interface DayAccommodation {
  id: number;
  trip_id: number;
  place_id: number | null;
  start_day_id: number;
  end_day_id: number;
  check_in: string | null;
  check_in_end: string | null;
  check_out: string | null;
  confirmation: string | null;
  notes: string | null;
}

function getAccommodationWithPlace(id: number | bigint) {
  return db.prepare(`
    SELECT a.*, p.name as place_name, p.address as place_address, p.image_url as place_image, p.lat as place_lat, p.lng as place_lng
    FROM day_accommodations a
    LEFT JOIN places p ON a.place_id = p.id
    WHERE a.id = ?
  `).get(id);
}

// ---------------------------------------------------------------------------
// Accommodation CRUD
// ---------------------------------------------------------------------------

export function listAccommodations(tripId: string | number) {
  return db.prepare(`
    SELECT a.*, p.name as place_name, p.address as place_address, p.image_url as place_image, p.lat as place_lat, p.lng as place_lng,
           r.title as reservation_title
    FROM day_accommodations a
    LEFT JOIN places p ON a.place_id = p.id
    LEFT JOIN reservations r ON r.accommodation_id = a.id
    WHERE a.trip_id = ?
    ORDER BY a.created_at ASC
  `).all(tripId);
}

export function validateAccommodationRefs(tripId: string | number, placeId?: number, startDayId?: number, endDayId?: number) {
  const errors: { field: string; message: string }[] = [];
  if (placeId !== undefined) {
    const place = db.prepare('SELECT id FROM places WHERE id = ? AND trip_id = ?').get(placeId, tripId);
    if (!place) errors.push({ field: 'place_id', message: 'Place not found' });
  }
  if (startDayId !== undefined) {
    const startDay = db.prepare('SELECT id FROM days WHERE id = ? AND trip_id = ?').get(startDayId, tripId);
    if (!startDay) errors.push({ field: 'start_day_id', message: 'Start day not found' });
  }
  if (endDayId !== undefined) {
    const endDay = db.prepare('SELECT id FROM days WHERE id = ? AND trip_id = ?').get(endDayId, tripId);
    if (!endDay) errors.push({ field: 'end_day_id', message: 'End day not found' });
  }
  return errors;
}

interface CreateAccommodationData {
  place_id: number;
  start_day_id: number;
  end_day_id: number;
  check_in?: string;
  check_in_end?: string;
  check_out?: string;
  confirmation?: string;
  notes?: string;
}

export function createAccommodation(tripId: string | number, data: CreateAccommodationData) {
  const { place_id, start_day_id, end_day_id, check_in, check_in_end, check_out, confirmation, notes } = data;

  const result = db.prepare(
    'INSERT INTO day_accommodations (trip_id, place_id, start_day_id, end_day_id, check_in, check_in_end, check_out, confirmation, notes) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)'
  ).run(tripId, place_id, start_day_id, end_day_id, check_in || null, check_in_end || null, check_out || null, confirmation || null, notes || null);

  const accommodationId = result.lastInsertRowid;

  // Auto-create linked reservation for this accommodation
  const placeName = (db.prepare('SELECT name FROM places WHERE id = ?').get(place_id) as { name: string } | undefined)?.name || 'Hotel';
  const startDayDate = (db.prepare('SELECT date FROM days WHERE id = ?').get(start_day_id) as { date: string } | undefined)?.date || null;
  const meta: Record<string, string> = {};
  if (check_in) meta.check_in_time = check_in;
  if (check_in_end) meta.check_in_end_time = check_in_end;
  if (check_out) meta.check_out_time = check_out;
  db.prepare(`
    INSERT INTO reservations (trip_id, day_id, title, reservation_time, location, confirmation_number, notes, status, type, accommodation_id, metadata)
    VALUES (?, ?, ?, ?, ?, ?, ?, 'confirmed', 'hotel', ?, ?)
  `).run(
    tripId, start_day_id, placeName, startDayDate || null, null,
    confirmation || null, notes || null, accommodationId,
    Object.keys(meta).length > 0 ? JSON.stringify(meta) : null
  );

  return getAccommodationWithPlace(accommodationId);
}

export function getAccommodation(id: string | number, tripId: string | number) {
  return db.prepare('SELECT * FROM day_accommodations WHERE id = ? AND trip_id = ?').get(id, tripId) as DayAccommodation | undefined;
}

export function updateAccommodation(id: string | number, existing: DayAccommodation, fields: {
  place_id?: number; start_day_id?: number; end_day_id?: number;
  check_in?: string; check_in_end?: string; check_out?: string; confirmation?: string; notes?: string;
}) {
  const newPlaceId = fields.place_id !== undefined ? fields.place_id : existing.place_id;
  const newStartDayId = fields.start_day_id !== undefined ? fields.start_day_id : existing.start_day_id;
  const newEndDayId = fields.end_day_id !== undefined ? fields.end_day_id : existing.end_day_id;
  const newCheckIn = fields.check_in !== undefined ? fields.check_in : existing.check_in;
  const newCheckInEnd = fields.check_in_end !== undefined ? fields.check_in_end : existing.check_in_end;
  const newCheckOut = fields.check_out !== undefined ? fields.check_out : existing.check_out;
  const newConfirmation = fields.confirmation !== undefined ? fields.confirmation : existing.confirmation;
  const newNotes = fields.notes !== undefined ? fields.notes : existing.notes;

  db.prepare(
    'UPDATE day_accommodations SET place_id = ?, start_day_id = ?, end_day_id = ?, check_in = ?, check_in_end = ?, check_out = ?, confirmation = ?, notes = ? WHERE id = ?'
  ).run(newPlaceId, newStartDayId, newEndDayId, newCheckIn, newCheckInEnd, newCheckOut, newConfirmation, newNotes, id);

  // Sync check-in/out/confirmation to linked reservation
  const linkedRes = db.prepare('SELECT id, metadata FROM reservations WHERE accommodation_id = ?').get(Number(id)) as { id: number; metadata: string | null } | undefined;
  if (linkedRes) {
    const meta = linkedRes.metadata ? JSON.parse(linkedRes.metadata) : {};
    if (newCheckIn) meta.check_in_time = newCheckIn;
    if (newCheckInEnd) meta.check_in_end_time = newCheckInEnd;
    if (newCheckOut) meta.check_out_time = newCheckOut;
    db.prepare('UPDATE reservations SET metadata = ?, confirmation_number = COALESCE(?, confirmation_number) WHERE id = ?')
      .run(JSON.stringify(meta), newConfirmation || null, linkedRes.id);
  }

  return getAccommodationWithPlace(Number(id));
}

/** Delete accommodation and its linked reservation (and any linked budget item). */
export function deleteAccommodation(id: string | number): { linkedReservationId: number | null; deletedBudgetItemId: number | null } {
  const linkedRes = db.prepare('SELECT id FROM reservations WHERE accommodation_id = ?').get(Number(id)) as { id: number } | undefined;
  let deletedBudgetItemId: number | null = null;
  if (linkedRes) {
    const linkedBudget = db.prepare('SELECT id FROM budget_items WHERE reservation_id = ?').get(linkedRes.id) as { id: number } | undefined;
    if (linkedBudget) {
      db.prepare('DELETE FROM budget_items WHERE id = ?').run(linkedBudget.id);
      deletedBudgetItemId = linkedBudget.id;
    }
    db.prepare('DELETE FROM reservations WHERE id = ?').run(linkedRes.id);
  }

  db.prepare('DELETE FROM day_accommodations WHERE id = ?').run(id);
  return { linkedReservationId: linkedRes ? linkedRes.id : null, deletedBudgetItemId };
}