package database

import (
	"context"
	"fmt"
	"strings"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
)

// Repository provides database operations for staff and publications
type Repository struct {
	db *DB
}

// NewRepository creates a new repository
func NewRepository(db *DB) *Repository {
	return &Repository{db: db}
}

// ============================================================================
// UNIVERSITIES
// ============================================================================

// CreateUniversity creates a new university
func (r *Repository) CreateUniversity(ctx context.Context, u *University) error {
	query := `
		INSERT INTO universities (name, short_name, url, state, uni_type, staff_page_pattern)
		VALUES ($1, $2, $3, $4, $5, $6)
		ON CONFLICT (url) DO UPDATE SET
			name = EXCLUDED.name,
			short_name = EXCLUDED.short_name,
			state = EXCLUDED.state,
			uni_type = EXCLUDED.uni_type,
			staff_page_pattern = EXCLUDED.staff_page_pattern,
			updated_at = NOW()
		RETURNING id, created_at, updated_at
	`
	return r.db.Pool.QueryRow(ctx, query,
		u.Name, u.ShortName, u.URL, u.State, u.UniType, u.StaffPagePattern,
	).Scan(&u.ID, &u.CreatedAt, &u.UpdatedAt)
}

// GetUniversity retrieves a university by ID
func (r *Repository) GetUniversity(ctx context.Context, id uuid.UUID) (*University, error) {
	query := `SELECT id, name, short_name, url, state, uni_type, staff_page_pattern, created_at, updated_at
		FROM universities WHERE id = $1`

	u := &University{}
	err := r.db.Pool.QueryRow(ctx, query, id).Scan(
		&u.ID, &u.Name, &u.ShortName, &u.URL, &u.State, &u.UniType,
		&u.StaffPagePattern, &u.CreatedAt, &u.UpdatedAt,
	)
	if err == pgx.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return u, nil
}

// GetUniversityByID is an alias for GetUniversity (for interface compatibility)
func (r *Repository) GetUniversityByID(ctx context.Context, id uuid.UUID) (*University, error) {
	return r.GetUniversity(ctx, id)
}

// GetUniversityByURL retrieves a university by URL
func (r *Repository) GetUniversityByURL(ctx context.Context, url string) (*University, error) {
	query := `SELECT id, name, short_name, url, state, uni_type, staff_page_pattern, created_at, updated_at
		FROM universities WHERE url = $1`

	u := &University{}
	err := r.db.Pool.QueryRow(ctx, query, url).Scan(
		&u.ID, &u.Name, &u.ShortName, &u.URL, &u.State, &u.UniType,
		&u.StaffPagePattern, &u.CreatedAt, &u.UpdatedAt,
	)
	if err != nil {
		return nil, err
	}
	return u, nil
}

// ListUniversities lists all universities
func (r *Repository) ListUniversities(ctx context.Context) ([]University, error) {
	query := `SELECT id, name, short_name, url, state, uni_type, staff_page_pattern, created_at, updated_at
		FROM universities ORDER BY name`

	rows, err := r.db.Pool.Query(ctx, query)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var universities []University
	for rows.Next() {
		var u University
		if err := rows.Scan(
			&u.ID, &u.Name, &u.ShortName, &u.URL, &u.State, &u.UniType,
			&u.StaffPagePattern, &u.CreatedAt, &u.UpdatedAt,
		); err != nil {
			return nil, err
		}
		universities = append(universities, u)
	}
	return universities, rows.Err()
}

// ============================================================================
// DEPARTMENTS
// ============================================================================

// CreateDepartment creates or updates a department
func (r *Repository) CreateDepartment(ctx context.Context, d *Department) error {
	query := `
		INSERT INTO departments (university_id, name, name_en, url, category, parent_id)
		VALUES ($1, $2, $3, $4, $5, $6)
		ON CONFLICT (university_id, name) DO UPDATE SET
			name_en = EXCLUDED.name_en,
			url = EXCLUDED.url,
			category = EXCLUDED.category,
			parent_id = EXCLUDED.parent_id,
			updated_at = NOW()
		RETURNING id, created_at, updated_at
	`
	return r.db.Pool.QueryRow(ctx, query,
		d.UniversityID, d.Name, d.NameEN, d.URL, d.Category, d.ParentID,
	).Scan(&d.ID, &d.CreatedAt, &d.UpdatedAt)
}

// GetDepartmentByName retrieves a department by university and name
func (r *Repository) GetDepartmentByName(ctx context.Context, uniID uuid.UUID, name string) (*Department, error) {
	query := `SELECT id, university_id, name, name_en, url, category, parent_id, created_at, updated_at
		FROM departments WHERE university_id = $1 AND name = $2`

	d := &Department{}
	err := r.db.Pool.QueryRow(ctx, query, uniID, name).Scan(
		&d.ID, &d.UniversityID, &d.Name, &d.NameEN, &d.URL, &d.Category,
		&d.ParentID, &d.CreatedAt, &d.UpdatedAt,
	)
	if err != nil {
		return nil, err
	}
	return d, nil
}

// ============================================================================
// STAFF
// ============================================================================

// CreateStaff creates or updates a staff member
func (r *Repository) CreateStaff(ctx context.Context, s *UniversityStaff) error {
	query := `
		INSERT INTO university_staff (
			university_id, department_id, first_name, last_name, full_name,
			title, academic_title, position, position_type, is_professor,
			email, phone, office, profile_url, photo_url,
			orcid, google_scholar_id, researchgate_url, linkedin_url, personal_website,
			research_interests, research_summary, supervisor_id, team_role, source_url
		) VALUES (
			$1, $2, $3, $4, $5, $6, $7, $8, $9, $10,
			$11, $12, $13, $14, $15, $16, $17, $18, $19, $20,
			$21, $22, $23, $24, $25
		)
		ON CONFLICT (university_id, first_name, last_name, COALESCE(department_id, '00000000-0000-0000-0000-000000000000'::uuid))
		DO UPDATE SET
			full_name = EXCLUDED.full_name,
			title = EXCLUDED.title,
			academic_title = EXCLUDED.academic_title,
			position = EXCLUDED.position,
			position_type = EXCLUDED.position_type,
			is_professor = EXCLUDED.is_professor,
			email = COALESCE(EXCLUDED.email, university_staff.email),
			phone = COALESCE(EXCLUDED.phone, university_staff.phone),
			office = COALESCE(EXCLUDED.office, university_staff.office),
			profile_url = COALESCE(EXCLUDED.profile_url, university_staff.profile_url),
			photo_url = COALESCE(EXCLUDED.photo_url, university_staff.photo_url),
			orcid = COALESCE(EXCLUDED.orcid, university_staff.orcid),
			google_scholar_id = COALESCE(EXCLUDED.google_scholar_id, university_staff.google_scholar_id),
			researchgate_url = COALESCE(EXCLUDED.researchgate_url, university_staff.researchgate_url),
			linkedin_url = COALESCE(EXCLUDED.linkedin_url, university_staff.linkedin_url),
			personal_website = COALESCE(EXCLUDED.personal_website, university_staff.personal_website),
			research_interests = COALESCE(EXCLUDED.research_interests, university_staff.research_interests),
			research_summary = COALESCE(EXCLUDED.research_summary, university_staff.research_summary),
			supervisor_id = COALESCE(EXCLUDED.supervisor_id, university_staff.supervisor_id),
			team_role = COALESCE(EXCLUDED.team_role, university_staff.team_role),
			source_url = COALESCE(EXCLUDED.source_url, university_staff.source_url),
			crawled_at = NOW(),
			updated_at = NOW()
		RETURNING id, crawled_at, created_at, updated_at
	`
	return r.db.Pool.QueryRow(ctx, query,
		s.UniversityID, s.DepartmentID, s.FirstName, s.LastName, s.FullName,
		s.Title, s.AcademicTitle, s.Position, s.PositionType, s.IsProfessor,
		s.Email, s.Phone, s.Office, s.ProfileURL, s.PhotoURL,
		s.ORCID, s.GoogleScholarID, s.ResearchgateURL, s.LinkedInURL, s.PersonalWebsite,
		s.ResearchInterests, s.ResearchSummary, s.SupervisorID, s.TeamRole, s.SourceURL,
	).Scan(&s.ID, &s.CrawledAt, &s.CreatedAt, &s.UpdatedAt)
}

// GetStaff retrieves a staff member by ID
func (r *Repository) GetStaff(ctx context.Context, id uuid.UUID) (*UniversityStaff, error) {
	query := `SELECT * FROM v_staff_full WHERE id = $1`

	s := &UniversityStaff{}
	err := r.db.Pool.QueryRow(ctx, query, id).Scan(
		&s.ID, &s.UniversityID, &s.DepartmentID, &s.FirstName, &s.LastName, &s.FullName,
		&s.Title, &s.AcademicTitle, &s.Position, &s.PositionType, &s.IsProfessor,
		&s.Email, &s.Phone, &s.Office, &s.ProfileURL, &s.PhotoURL,
		&s.ORCID, &s.GoogleScholarID, &s.ResearchgateURL, &s.LinkedInURL, &s.PersonalWebsite,
		&s.ResearchInterests, &s.ResearchSummary, &s.CrawledAt, &s.LastVerified, &s.IsActive, &s.SourceURL,
		&s.CreatedAt, &s.UpdatedAt, &s.UniversityName, &s.UniversityShort, nil, nil,
		&s.DepartmentName, nil, &s.PublicationCount,
	)
	if err != nil {
		return nil, err
	}
	return s, nil
}

// SearchStaff searches for staff members
func (r *Repository) SearchStaff(ctx context.Context, params StaffSearchParams) (*StaffSearchResult, error) {
	// Build query dynamically
	var conditions []string
	var args []interface{}
	argNum := 1

	baseQuery := `
		SELECT s.id, s.university_id, s.department_id, s.first_name, s.last_name, s.full_name,
			s.title, s.academic_title, s.position, s.position_type, s.is_professor,
			s.email, s.profile_url, s.photo_url, s.orcid,
			s.research_interests, s.crawled_at, s.is_active,
			u.name as university_name, u.short_name as university_short, u.state as university_state,
			d.name as department_name,
			(SELECT COUNT(*) FROM staff_publications sp WHERE sp.staff_id = s.id) as publication_count
		FROM university_staff s
		JOIN universities u ON s.university_id = u.id
		LEFT JOIN departments d ON s.department_id = d.id
	`

	if params.Query != "" {
		conditions = append(conditions, fmt.Sprintf(
			`(to_tsvector('german', COALESCE(s.full_name, '') || ' ' || COALESCE(s.research_summary, '')) @@ plainto_tsquery('german', $%d)
			 OR s.full_name ILIKE '%%' || $%d || '%%'
			 OR s.last_name ILIKE '%%' || $%d || '%%')`,
			argNum, argNum, argNum))
		args = append(args, params.Query)
		argNum++
	}

	if params.UniversityID != nil {
		conditions = append(conditions, fmt.Sprintf("s.university_id = $%d", argNum))
		args = append(args, *params.UniversityID)
		argNum++
	}

	if params.DepartmentID != nil {
		conditions = append(conditions, fmt.Sprintf("s.department_id = $%d", argNum))
		args = append(args, *params.DepartmentID)
		argNum++
	}

	if params.State != nil {
		conditions = append(conditions, fmt.Sprintf("u.state = $%d", argNum))
		args = append(args, *params.State)
		argNum++
	}

	if params.UniType != nil {
		conditions = append(conditions, fmt.Sprintf("u.uni_type = $%d", argNum))
		args = append(args, *params.UniType)
		argNum++
	}

	if params.PositionType != nil {
		conditions = append(conditions, fmt.Sprintf("s.position_type = $%d", argNum))
		args = append(args, *params.PositionType)
		argNum++
	}

	if params.IsProfessor != nil {
		conditions = append(conditions, fmt.Sprintf("s.is_professor = $%d", argNum))
		args = append(args, *params.IsProfessor)
		argNum++
	}

	// Build WHERE clause
	whereClause := ""
	if len(conditions) > 0 {
		whereClause = "WHERE " + strings.Join(conditions, " AND ")
	}

	// Count total
	countQuery := fmt.Sprintf("SELECT COUNT(*) FROM university_staff s JOIN universities u ON s.university_id = u.id LEFT JOIN departments d ON s.department_id = d.id %s", whereClause)
	var total int
	if err := r.db.Pool.QueryRow(ctx, countQuery, args...).Scan(&total); err != nil {
		return nil, err
	}

	// Apply pagination
	limit := params.Limit
	if limit <= 0 {
		limit = 20
	}
	if limit > 100 {
		limit = 100
	}

	offset := params.Offset
	if offset < 0 {
		offset = 0
	}

	// Full query with pagination
	fullQuery := fmt.Sprintf("%s %s ORDER BY s.is_professor DESC, s.last_name ASC LIMIT %d OFFSET %d",
		baseQuery, whereClause, limit, offset)

	rows, err := r.db.Pool.Query(ctx, fullQuery, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var staff []UniversityStaff
	for rows.Next() {
		var s UniversityStaff
		var uniState *string
		if err := rows.Scan(
			&s.ID, &s.UniversityID, &s.DepartmentID, &s.FirstName, &s.LastName, &s.FullName,
			&s.Title, &s.AcademicTitle, &s.Position, &s.PositionType, &s.IsProfessor,
			&s.Email, &s.ProfileURL, &s.PhotoURL, &s.ORCID,
			&s.ResearchInterests, &s.CrawledAt, &s.IsActive,
			&s.UniversityName, &s.UniversityShort, &uniState,
			&s.DepartmentName, &s.PublicationCount,
		); err != nil {
			return nil, err
		}
		staff = append(staff, s)
	}

	return &StaffSearchResult{
		Staff:  staff,
		Total:  total,
		Limit:  limit,
		Offset: offset,
		Query:  params.Query,
	}, rows.Err()
}

// ============================================================================
// PUBLICATIONS
// ============================================================================

// CreatePublication creates or updates a publication
func (r *Repository) CreatePublication(ctx context.Context, p *Publication) error {
	query := `
		INSERT INTO publications (
			title, title_en, abstract, abstract_en, year, month,
			pub_type, venue, venue_short, publisher,
			doi, isbn, issn, arxiv_id, pubmed_id,
			url, pdf_url, citation_count, keywords, topics, source, raw_data
		) VALUES (
			$1, $2, $3, $4, $5, $6, $7, $8, $9, $10,
			$11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22
		)
		ON CONFLICT (doi) WHERE doi IS NOT NULL DO UPDATE SET
			title = EXCLUDED.title,
			abstract = EXCLUDED.abstract,
			year = EXCLUDED.year,
			venue = EXCLUDED.venue,
			citation_count = EXCLUDED.citation_count,
			updated_at = NOW()
		RETURNING id, crawled_at, created_at, updated_at
	`

	// Handle potential duplicate without DOI
	err := r.db.Pool.QueryRow(ctx, query,
		p.Title, p.TitleEN, p.Abstract, p.AbstractEN, p.Year, p.Month,
		p.PubType, p.Venue, p.VenueShort, p.Publisher,
		p.DOI, p.ISBN, p.ISSN, p.ArxivID, p.PubmedID,
		p.URL, p.PDFURL, p.CitationCount, p.Keywords, p.Topics, p.Source, p.RawData,
	).Scan(&p.ID, &p.CrawledAt, &p.CreatedAt, &p.UpdatedAt)

	if err != nil && strings.Contains(err.Error(), "duplicate") {
		// Try to find existing publication by title and year
		findQuery := `SELECT id FROM publications WHERE title = $1 AND year = $2`
		err = r.db.Pool.QueryRow(ctx, findQuery, p.Title, p.Year).Scan(&p.ID)
	}

	return err
}

// LinkStaffPublication creates a link between staff and publication
func (r *Repository) LinkStaffPublication(ctx context.Context, sp *StaffPublication) error {
	query := `
		INSERT INTO staff_publications (staff_id, publication_id, author_position, is_corresponding)
		VALUES ($1, $2, $3, $4)
		ON CONFLICT (staff_id, publication_id) DO UPDATE SET
			author_position = EXCLUDED.author_position,
			is_corresponding = EXCLUDED.is_corresponding
	`
	_, err := r.db.Pool.Exec(ctx, query,
		sp.StaffID, sp.PublicationID, sp.AuthorPosition, sp.IsCorresponding,
	)
	return err
}

// GetStaffPublications retrieves all publications for a staff member
func (r *Repository) GetStaffPublications(ctx context.Context, staffID uuid.UUID) ([]Publication, error) {
	query := `
		SELECT p.id, p.title, p.abstract, p.year, p.pub_type, p.venue, p.doi, p.url, p.citation_count
		FROM publications p
		JOIN staff_publications sp ON p.id = sp.publication_id
		WHERE sp.staff_id = $1
		ORDER BY p.year DESC NULLS LAST, p.title
	`

	rows, err := r.db.Pool.Query(ctx, query, staffID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var pubs []Publication
	for rows.Next() {
		var p Publication
		if err := rows.Scan(
			&p.ID, &p.Title, &p.Abstract, &p.Year, &p.PubType, &p.Venue, &p.DOI, &p.URL, &p.CitationCount,
		); err != nil {
			return nil, err
		}
		pubs = append(pubs, p)
	}
	return pubs, rows.Err()
}

// SearchPublications searches for publications
func (r *Repository) SearchPublications(ctx context.Context, params PublicationSearchParams) (*PublicationSearchResult, error) {
	var conditions []string
	var args []interface{}
	argNum := 1

	if params.Query != "" {
		conditions = append(conditions, fmt.Sprintf(
			`to_tsvector('german', COALESCE(title, '') || ' ' || COALESCE(abstract, '')) @@ plainto_tsquery('german', $%d)`,
			argNum))
		args = append(args, params.Query)
		argNum++
	}

	if params.StaffID != nil {
		conditions = append(conditions, fmt.Sprintf(
			`id IN (SELECT publication_id FROM staff_publications WHERE staff_id = $%d)`,
			argNum))
		args = append(args, *params.StaffID)
		argNum++
	}

	if params.Year != nil {
		conditions = append(conditions, fmt.Sprintf("year = $%d", argNum))
		args = append(args, *params.Year)
		argNum++
	}

	if params.YearFrom != nil {
		conditions = append(conditions, fmt.Sprintf("year >= $%d", argNum))
		args = append(args, *params.YearFrom)
		argNum++
	}

	if params.YearTo != nil {
		conditions = append(conditions, fmt.Sprintf("year <= $%d", argNum))
		args = append(args, *params.YearTo)
		argNum++
	}

	if params.PubType != nil {
		conditions = append(conditions, fmt.Sprintf("pub_type = $%d", argNum))
		args = append(args, *params.PubType)
		argNum++
	}

	whereClause := ""
	if len(conditions) > 0 {
		whereClause = "WHERE " + strings.Join(conditions, " AND ")
	}

	// Count
	countQuery := fmt.Sprintf("SELECT COUNT(*) FROM publications %s", whereClause)
	var total int
	if err := r.db.Pool.QueryRow(ctx, countQuery, args...).Scan(&total); err != nil {
		return nil, err
	}

	// Pagination
	limit := params.Limit
	if limit <= 0 {
		limit = 20
	}
	offset := params.Offset

	// Query
	query := fmt.Sprintf(`
		SELECT id, title, abstract, year, pub_type, venue, doi, url, citation_count, keywords
		FROM publications %s
		ORDER BY year DESC NULLS LAST, citation_count DESC
		LIMIT %d OFFSET %d
	`, whereClause, limit, offset)

	rows, err := r.db.Pool.Query(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var pubs []Publication
	for rows.Next() {
		var p Publication
		if err := rows.Scan(
			&p.ID, &p.Title, &p.Abstract, &p.Year, &p.PubType, &p.Venue, &p.DOI, &p.URL, &p.CitationCount, &p.Keywords,
		); err != nil {
			return nil, err
		}
		pubs = append(pubs, p)
	}

	return &PublicationSearchResult{
		Publications: pubs,
		Total:        total,
		Limit:        limit,
		Offset:       offset,
		Query:        params.Query,
	}, rows.Err()
}

// ============================================================================
// CRAWL STATUS
// ============================================================================

// UpdateCrawlStatus updates crawl status for a university
func (r *Repository) UpdateCrawlStatus(ctx context.Context, status *UniversityCrawlStatus) error {
	query := `
		INSERT INTO university_crawl_status (
			university_id, last_staff_crawl, staff_crawl_status, staff_count, staff_errors,
			last_pub_crawl, pub_crawl_status, pub_count, pub_errors,
			next_scheduled_crawl, crawl_priority
		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
		ON CONFLICT (university_id) DO UPDATE SET
			last_staff_crawl = EXCLUDED.last_staff_crawl,
			staff_crawl_status = EXCLUDED.staff_crawl_status,
			staff_count = EXCLUDED.staff_count,
			staff_errors = EXCLUDED.staff_errors,
			last_pub_crawl = EXCLUDED.last_pub_crawl,
			pub_crawl_status = EXCLUDED.pub_crawl_status,
			pub_count = EXCLUDED.pub_count,
			pub_errors = EXCLUDED.pub_errors,
			next_scheduled_crawl = EXCLUDED.next_scheduled_crawl,
			crawl_priority = EXCLUDED.crawl_priority,
			updated_at = NOW()
	`
	_, err := r.db.Pool.Exec(ctx, query,
		status.UniversityID, status.LastStaffCrawl, status.StaffCrawlStatus, status.StaffCount, status.StaffErrors,
		status.LastPubCrawl, status.PubCrawlStatus, status.PubCount, status.PubErrors,
		status.NextScheduledCrawl, status.CrawlPriority,
	)
	return err
}

// GetCrawlStatus retrieves crawl status for a university
func (r *Repository) GetCrawlStatus(ctx context.Context, uniID uuid.UUID) (*UniversityCrawlStatus, error) {
	query := `SELECT * FROM university_crawl_status WHERE university_id = $1`

	s := &UniversityCrawlStatus{}
	err := r.db.Pool.QueryRow(ctx, query, uniID).Scan(
		&s.UniversityID, &s.LastStaffCrawl, &s.StaffCrawlStatus, &s.StaffCount, &s.StaffErrors,
		&s.LastPubCrawl, &s.PubCrawlStatus, &s.PubCount, &s.PubErrors,
		&s.NextScheduledCrawl, &s.CrawlPriority, &s.CreatedAt, &s.UpdatedAt,
	)
	if err == pgx.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return s, nil
}

// ============================================================================
// STATS
// ============================================================================

// GetStaffStats retrieves statistics about staff data
func (r *Repository) GetStaffStats(ctx context.Context) (*StaffStats, error) {
	stats := &StaffStats{
		ByState:        make(map[string]int),
		ByUniType:      make(map[string]int),
		ByPositionType: make(map[string]int),
	}

	// Basic counts
	queries := []struct {
		query string
		dest  *int
	}{
		{"SELECT COUNT(*) FROM university_staff WHERE is_active = true", &stats.TotalStaff},
		{"SELECT COUNT(*) FROM university_staff WHERE is_professor = true AND is_active = true", &stats.TotalProfessors},
		{"SELECT COUNT(*) FROM publications", &stats.TotalPublications},
		{"SELECT COUNT(*) FROM universities", &stats.TotalUniversities},
	}

	for _, q := range queries {
		if err := r.db.Pool.QueryRow(ctx, q.query).Scan(q.dest); err != nil {
			return nil, err
		}
	}

	// By state
	rows, err := r.db.Pool.Query(ctx, `
		SELECT COALESCE(u.state, 'unknown'), COUNT(*)
		FROM university_staff s
		JOIN universities u ON s.university_id = u.id
		WHERE s.is_active = true
		GROUP BY u.state
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	for rows.Next() {
		var state string
		var count int
		if err := rows.Scan(&state, &count); err != nil {
			return nil, err
		}
		stats.ByState[state] = count
	}

	// By uni type
	rows2, err := r.db.Pool.Query(ctx, `
		SELECT COALESCE(u.uni_type, 'unknown'), COUNT(*)
		FROM university_staff s
		JOIN universities u ON s.university_id = u.id
		WHERE s.is_active = true
		GROUP BY u.uni_type
	`)
	if err != nil {
		return nil, err
	}
	defer rows2.Close()

	for rows2.Next() {
		var uniType string
		var count int
		if err := rows2.Scan(&uniType, &count); err != nil {
			return nil, err
		}
		stats.ByUniType[uniType] = count
	}

	// By position type
	rows3, err := r.db.Pool.Query(ctx, `
		SELECT COALESCE(position_type, 'unknown'), COUNT(*)
		FROM university_staff
		WHERE is_active = true
		GROUP BY position_type
	`)
	if err != nil {
		return nil, err
	}
	defer rows3.Close()

	for rows3.Next() {
		var posType string
		var count int
		if err := rows3.Scan(&posType, &count); err != nil {
			return nil, err
		}
		stats.ByPositionType[posType] = count
	}

	return stats, nil
}