package services

import (
	"context"
	"database/sql"
	"fmt"
	"strings"
	"time"

	"github.com/rede5/gohorsejobs/backend/internal/models"
)

type AdminService struct {
	DB *sql.DB
}

func NewAdminService(db *sql.DB) *AdminService {
	return &AdminService{DB: db}
}

func (s *AdminService) ListCompanies(ctx context.Context, verified *bool) ([]models.Company, error) {
	baseQuery := `
		SELECT id, name, slug, type, document, address, region_id, city_id, phone, email, website, logo_url, description, active, verified, created_at, updated_at
		FROM companies
	`

	var args []interface{}
	if verified != nil {
		baseQuery += " WHERE verified = $1"
		args = append(args, *verified)
	}
	baseQuery += " ORDER BY created_at DESC"

	rows, err := s.DB.QueryContext(ctx, baseQuery, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var companies []models.Company
	for rows.Next() {
		var c models.Company
		if err := rows.Scan(
			&c.ID,
			&c.Name,
			&c.Slug,
			&c.Type,
			&c.Document,
			&c.Address,
			&c.RegionID,
			&c.CityID,
			&c.Phone,
			&c.Email,
			&c.Website,
			&c.LogoURL,
			&c.Description,
			&c.Active,
			&c.Verified,
			&c.CreatedAt,
			&c.UpdatedAt,
		); err != nil {
			return nil, err
		}
		companies = append(companies, c)
	}

	return companies, nil
}

func (s *AdminService) UpdateCompanyStatus(ctx context.Context, id int, active *bool, verified *bool) (*models.Company, error) {
	company, err := s.getCompanyByID(ctx, id)
	if err != nil {
		return nil, err
	}

	if active != nil {
		company.Active = *active
	}
	if verified != nil {
		company.Verified = *verified
	}

	company.UpdatedAt = time.Now()
	query := `
		UPDATE companies
		SET active = $1, verified = $2, updated_at = $3
		WHERE id = $4
	`
	_, err = s.DB.ExecContext(ctx, query, company.Active, company.Verified, company.UpdatedAt, id)
	if err != nil {
		return nil, err
	}

	return company, nil
}

func (s *AdminService) DuplicateJob(ctx context.Context, id int) (*models.Job, error) {
	query := `
		SELECT company_id, created_by, title, description, salary_min, salary_max, salary_type,
			employment_type, work_mode, working_hours, location, region_id, city_id,
			requirements, benefits, visa_support, language_level
		FROM jobs
		WHERE id = $1
	`

	var job models.Job
	if err := s.DB.QueryRowContext(ctx, query, id).Scan(
		&job.CompanyID,
		&job.CreatedBy,
		&job.Title,
		&job.Description,
		&job.SalaryMin,
		&job.SalaryMax,
		&job.SalaryType,
		&job.EmploymentType,
		&job.WorkMode,
		&job.WorkingHours,
		&job.Location,
		&job.RegionID,
		&job.CityID,
		&job.Requirements,
		&job.Benefits,
		&job.VisaSupport,
		&job.LanguageLevel,
	); err != nil {
		return nil, err
	}

	job.Status = "draft"
	job.IsFeatured = false
	job.CreatedAt = time.Now()
	job.UpdatedAt = time.Now()

	insertQuery := `
		INSERT INTO jobs (
			company_id, created_by, title, description, salary_min, salary_max, salary_type,
			employment_type, work_mode, working_hours, location, region_id, city_id,
			requirements, benefits, visa_support, language_level, status, is_featured, created_at, updated_at
		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21)
		RETURNING id
	`

	if err := s.DB.QueryRowContext(ctx, insertQuery,
		job.CompanyID,
		job.CreatedBy,
		job.Title,
		job.Description,
		job.SalaryMin,
		job.SalaryMax,
		job.SalaryType,
		job.EmploymentType,
		job.WorkMode,
		job.WorkingHours,
		job.Location,
		job.RegionID,
		job.CityID,
		job.Requirements,
		job.Benefits,
		job.VisaSupport,
		job.LanguageLevel,
		job.Status,
		job.IsFeatured,
		job.CreatedAt,
		job.UpdatedAt,
	).Scan(&job.ID); err != nil {
		return nil, err
	}

	return &job, nil
}

func (s *AdminService) ListTags(ctx context.Context, category *string) ([]models.Tag, error) {
	baseQuery := `SELECT id, name, category, active, created_at, updated_at FROM job_tags`
	var args []interface{}
	if category != nil && *category != "" {
		baseQuery += " WHERE category = $1"
		args = append(args, *category)
	}
	baseQuery += " ORDER BY name ASC"

	rows, err := s.DB.QueryContext(ctx, baseQuery, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var tags []models.Tag
	for rows.Next() {
		var t models.Tag
		if err := rows.Scan(&t.ID, &t.Name, &t.Category, &t.Active, &t.CreatedAt, &t.UpdatedAt); err != nil {
			return nil, err
		}
		tags = append(tags, t)
	}

	return tags, nil
}

func (s *AdminService) CreateTag(ctx context.Context, name string, category string) (*models.Tag, error) {
	if strings.TrimSpace(name) == "" {
		return nil, fmt.Errorf("tag name is required")
	}

	now := time.Now()
	tag := models.Tag{
		Name:      strings.TrimSpace(name),
		Category:  category,
		Active:    true,
		CreatedAt: now,
		UpdatedAt: now,
	}

	query := `
		INSERT INTO job_tags (name, category, active, created_at, updated_at)
		VALUES ($1, $2, $3, $4, $5)
		RETURNING id
	`
	if err := s.DB.QueryRowContext(ctx, query, tag.Name, tag.Category, tag.Active, tag.CreatedAt, tag.UpdatedAt).Scan(&tag.ID); err != nil {
		return nil, err
	}

	return &tag, nil
}

func (s *AdminService) UpdateTag(ctx context.Context, id int, name *string, active *bool) (*models.Tag, error) {
	tag, err := s.getTagByID(ctx, id)
	if err != nil {
		return nil, err
	}

	if name != nil {
		trimmed := strings.TrimSpace(*name)
		if trimmed != "" {
			tag.Name = trimmed
		}
	}
	if active != nil {
		tag.Active = *active
	}
	tagUpdatedAt := time.Now()
	query := `
		UPDATE job_tags
		SET name = $1, active = $2, updated_at = $3
		WHERE id = $4
	`
	_, err = s.DB.ExecContext(ctx, query, tag.Name, tag.Active, tagUpdatedAt, id)
	if err != nil {
		return nil, err
	}

	tag.UpdatedAt = tagUpdatedAt
	return tag, nil
}

func (s *AdminService) getCompanyByID(ctx context.Context, id int) (*models.Company, error) {
	query := `
		SELECT id, name, slug, type, document, address, region_id, city_id, phone, email, website, logo_url, description, active, verified, created_at, updated_at
		FROM companies WHERE id = $1
	`
	var c models.Company
	if err := s.DB.QueryRowContext(ctx, query, id).Scan(
		&c.ID,
		&c.Name,
		&c.Slug,
		&c.Type,
		&c.Document,
		&c.Address,
		&c.RegionID,
		&c.CityID,
		&c.Phone,
		&c.Email,
		&c.Website,
		&c.LogoURL,
		&c.Description,
		&c.Active,
		&c.Verified,
		&c.CreatedAt,
		&c.UpdatedAt,
	); err != nil {
		return nil, err
	}
	return &c, nil
}

func (s *AdminService) getTagByID(ctx context.Context, id int) (*models.Tag, error) {
	query := `SELECT id, name, category, active, created_at, updated_at FROM job_tags WHERE id = $1`
	var t models.Tag
	if err := s.DB.QueryRowContext(ctx, query, id).Scan(&t.ID, &t.Name, &t.Category, &t.Active, &t.CreatedAt, &t.UpdatedAt); err != nil {
		return nil, err
	}
	return &t, nil
}