package database

import (
	"database/sql"
	"fmt"

	_ "github.com/lib/pq"
)

// Client represents a database connection
type Client struct {
	db     *sql.DB
	schema string
}

// Config holds database connection parameters
type Config struct {
	Host     string
	Port     int
	Database string
	Schema   string
	User     string
	Password string
}

// NewClient creates a new database client
func NewClient(cfg Config) (*Client, error) {
	connStr := fmt.Sprintf(
		"host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
		cfg.Host, cfg.Port, cfg.User, cfg.Password, cfg.Database,
	)

	db, err := sql.Open("postgres", connStr)
	if err != nil {
		return nil, fmt.Errorf("failed to open database: %w", err)
	}

	if err := db.Ping(); err != nil {
		db.Close()
		return nil, fmt.Errorf("failed to connect to database: %w", err)
	}

	return &Client{
		db:     db,
		schema: cfg.Schema,
	}, nil
}

// Close closes the database connection
func (c *Client) Close() error {
	return c.db.Close()
}

// TableExists checks if a table exists in the schema
func (c *Client) TableExists(tableName string) (bool, error) {
	query := `
		SELECT EXISTS (
			SELECT 1
			FROM information_schema.tables
			WHERE table_schema = $1 AND table_name = $2
		)
	`

	var exists bool
	err := c.db.QueryRow(query, c.schema, tableName).Scan(&exists)
	return exists, err
}