package repository

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

	"github.com/lib/pq"
)

// CustomerRepository hanterar alla customer-relaterade databasoperationer
type CustomerRepository struct {
	db *sql.DB
}

func NewCustomerRepository(db *sql.DB) *CustomerRepository {
	return &CustomerRepository{db: db}
}

// Customer representerar en kund
type Customer struct {
	ID         string    `json:"id"`
	TenantID   string    `json:"tenant_id"`
	Name       string    `json:"name"`
	Email      string    `json:"email"`
	Phone      string    `json:"phone"`
	Company    string    `json:"company"`
	OrgNumber  string    `json:"org_number"`
	Status     string    `json:"status"`
	Source     string    `json:"source"`
	Tags       []string  `json:"tags"`
	AssignedTo *string   `json:"assigned_to"`
	CreatedAt  time.Time `json:"created_at"`
	UpdatedAt  time.Time `json:"updated_at"`
}

// CreateCustomer skapar en ny kund
func (r *CustomerRepository) CreateCustomer(ctx context.Context, c *Customer) error {
	query := `
		INSERT INTO boc_customers (tenant_id, name, email, phone, company, org_number, status, source, tags, assigned_to)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
		RETURNING id, created_at, updated_at
	`
	
	err := r.db.QueryRowContext(ctx, query,
		c.TenantID, c.Name, c.Email, c.Phone, c.Company, c.OrgNumber,
		c.Status, c.Source, pq.Array(c.Tags), c.AssignedTo,
	).Scan(&c.ID, &c.CreatedAt, &c.UpdatedAt)
	
	if err != nil {
		return fmt.Errorf("create customer: %w", err)
	}
	
	return nil
}

// GetCustomer hämtar en kund med ID
func (r *CustomerRepository) GetCustomer(ctx context.Context, id string) (*Customer, error) {
	query := `
		SELECT id, tenant_id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers
		WHERE id = $1
	`
	
	var c Customer
	var tags pq.StringArray
	
	err := r.db.QueryRowContext(ctx, query, id).Scan(
		&c.ID, &c.TenantID, &c.Name, &c.Email, &c.Phone, &c.Company,
		&c.OrgNumber, &c.Status, &c.Source, &tags, &c.AssignedTo,
		&c.CreatedAt, &c.UpdatedAt,
	)
	
	if err == sql.ErrNoRows {
		return nil, fmt.Errorf("customer not found")
	}
	if err != nil {
		return nil, fmt.Errorf("get customer: %w", err)
	}
	
	c.Tags = []string(tags)
	return &c, nil
}

// ListCustomers hämtar kunder med pagination
func (r *CustomerRepository) ListCustomers(ctx context.Context, tenantID, status string, limit, offset int) ([]Customer, int, error) {
	// Hämta total count
	var total int
	countQuery := `SELECT COUNT(*) FROM boc_customers WHERE tenant_id = $1 AND status = $2`
	if err := r.db.QueryRowContext(ctx, countQuery, tenantID, status).Scan(&total); err != nil {
		return nil, 0, fmt.Errorf("count customers: %w", err)
	}
	
	// Hämta kunder
	query := `
		SELECT id, tenant_id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers
		WHERE tenant_id = $1 AND status = $2
		ORDER BY created_at DESC
		LIMIT $3 OFFSET $4
	`
	
	rows, err := r.db.QueryContext(ctx, query, tenantID, status, limit, offset)
	if err != nil {
		return nil, 0, fmt.Errorf("list customers: %w", err)
	}
	defer rows.Close()
	
	var customers []Customer
	for rows.Next() {
		var c Customer
		var tags pq.StringArray
		
		if err := rows.Scan(
			&c.ID, &c.TenantID, &c.Name, &c.Email, &c.Phone, &c.Company,
			&c.OrgNumber, &c.Status, &c.Source, &tags, &c.AssignedTo,
			&c.CreatedAt, &c.UpdatedAt,
		); err != nil {
			continue
		}
		
		c.Tags = []string(tags)
		customers = append(customers, c)
	}
	
	return customers, total, rows.Err()
}

// UpdateCustomer uppdaterar en kund
func (r *CustomerRepository) UpdateCustomer(ctx context.Context, c *Customer) error {
	query := `
		UPDATE boc_customers
		SET name = $1, email = $2, phone = $3, company = $4, org_number = $5,
		    status = $6, source = $7, tags = $8, assigned_to = $9, updated_at = NOW()
		WHERE id = $10
		RETURNING updated_at
	`
	
	err := r.db.QueryRowContext(ctx, query,
		c.Name, c.Email, c.Phone, c.Company, c.OrgNumber,
		c.Status, c.Source, pq.Array(c.Tags), c.AssignedTo, c.ID,
	).Scan(&c.UpdatedAt)
	
	if err == sql.ErrNoRows {
		return fmt.Errorf("customer not found")
	}
	if err != nil {
		return fmt.Errorf("update customer: %w", err)
	}
	
	return nil
}

// DeleteCustomer markerar en kund som borttagen (soft delete)
func (r *CustomerRepository) DeleteCustomer(ctx context.Context, id string) error {
	query := `
		UPDATE boc_customers
		SET status = 'deleted', updated_at = NOW()
		WHERE id = $1
	`
	
	result, err := r.db.ExecContext(ctx, query, id)
	if err != nil {
		return fmt.Errorf("delete customer: %w", err)
	}
	
	rows, _ := result.RowsAffected()
	if rows == 0 {
		return fmt.Errorf("customer not found")
	}
	
	return nil
}

// SearchCustomers söker efter kunder
func (r *CustomerRepository) SearchCustomers(ctx context.Context, tenantID, query string, limit int) ([]Customer, error) {
	sql := `
		SELECT id, tenant_id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers
		WHERE tenant_id = $1
		  AND status != 'deleted'
		  AND (name ILIKE $2 OR email ILIKE $2 OR company ILIKE $2)
		ORDER BY name
		LIMIT $3
	`
	
	searchTerm := "%" + query + "%"
	
	rows, err := r.db.QueryContext(ctx, sql, tenantID, searchTerm, limit)
	if err != nil {
		return nil, fmt.Errorf("search customers: %w", err)
	}
	defer rows.Close()
	
	var customers []Customer
	for rows.Next() {
		var c Customer
		var tags pq.StringArray
		
		if err := rows.Scan(
			&c.ID, &c.TenantID, &c.Name, &c.Email, &c.Phone, &c.Company,
			&c.OrgNumber, &c.Status, &c.Source, &tags, &c.AssignedTo,
			&c.CreatedAt, &c.UpdatedAt,
		); err != nil {
			continue
		}
		
		c.Tags = []string(tags)
		customers = append(customers, c)
	}
	
	return customers, rows.Err()
}