package commons

import (
	"context"
	"fmt"
	"net/url"
	"os"
	"strings"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

// DB wraps pgxpool.Pool with helper methods
type DB struct {
	*pgxpool.Pool
}

// OpenDatabase connects to PostgreSQL using environment variables or connection string
func OpenDatabase(connString string) (*DB, error) {
	fmt.Printf("Connecting to database...\n")

	// If connection string not provided, try environment variables
	if connString == "" {
		connString = os.Getenv("DATABASE_URL")
	}
	if connString == "" {
		// Build from individual env vars
		host := GetEnvOrDefault("DB_HOST", "infra-postgres")
		port := GetEnvOrDefault("DB_PORT", "5432")
		user := GetEnvOrDefault("DB_USER", "dba_1440_news")
		dbname := GetEnvOrDefault("DB_NAME", "db_1440_news")

		// Support Docker secrets (password file) or direct password
		password := os.Getenv("DB_PASSWORD")
		if password == "" {
			if passwordFile := os.Getenv("DB_PASSWORD_FILE"); passwordFile != "" {
				data, err := os.ReadFile(passwordFile)
				if err != nil {
					return nil, fmt.Errorf("failed to read password file: %v", err)
				}
				password = strings.TrimSpace(string(data))
			}
		}

		connString = fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=disable",
			user, url.QueryEscape(password), host, port, dbname)
	}

	config, err := pgxpool.ParseConfig(connString)
	if err != nil {
		return nil, fmt.Errorf("failed to parse connection string: %v", err)
	}

	// Connection pool settings
	config.MaxConns = 10
	config.MinConns = 0 // Don't pre-create connections to avoid schema race conditions
	config.MaxConnLifetime = 5 * time.Minute
	config.MaxConnIdleTime = 1 * time.Minute

	ctx := context.Background()
	pool, err := pgxpool.NewWithConfig(ctx, config)
	if err != nil {
		return nil, fmt.Errorf("failed to connect to database: %v", err)
	}

	// Verify connection
	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("failed to ping database: %v", err)
	}
	fmt.Println("  Connected to PostgreSQL")

	return &DB{pool}, nil
}

// GetEnvOrDefault returns environment variable value or default
func GetEnvOrDefault(key, defaultVal string) string {
	if val := os.Getenv(key); val != "" {
		return val
	}
	return defaultVal
}

// QueryRow wraps pool.QueryRow for compatibility
func (db *DB) QueryRow(query string, args ...interface{}) pgx.Row {
	return db.Pool.QueryRow(context.Background(), query, args...)
}

// Query wraps pool.Query for compatibility
func (db *DB) Query(query string, args ...interface{}) (pgx.Rows, error) {
	return db.Pool.Query(context.Background(), query, args...)
}

// Exec wraps pool.Exec for compatibility
func (db *DB) Exec(query string, args ...interface{}) (int64, error) {
	result, err := db.Pool.Exec(context.Background(), query, args...)
	if err != nil {
		return 0, err
	}
	return result.RowsAffected(), nil
}

// Begin starts a transaction
func (db *DB) Begin() (pgx.Tx, error) {
	return db.Pool.Begin(context.Background())
}

// Close closes the connection pool
func (db *DB) Close() error {
	db.Pool.Close()
	return nil
}

// NullableString returns nil for empty strings, otherwise the string pointer
func NullableString(s string) *string {
	if s == "" {
		return nil
	}
	return &s
}

// NullableTime returns nil for zero times, otherwise the time pointer
func NullableTime(t time.Time) *time.Time {
	if t.IsZero() {
		return nil
	}
	return &t
}

// StringValue returns empty string for nil, otherwise the dereferenced value
func StringValue(s *string) string {
	if s == nil {
		return ""
	}
	return *s
}

// TimeValue returns zero time for nil, otherwise the dereferenced value
func TimeValue(t *time.Time) time.Time {
	if t == nil {
		return time.Time{}
	}
	return *t
}

// ToSearchQuery converts a user query to PostgreSQL tsquery format
func ToSearchQuery(query string) string {
	// Simple conversion: split on spaces and join with &
	words := strings.Fields(query)
	if len(words) == 0 {
		return ""
	}
	return strings.Join(words, " & ")
}