package lib

// ============================================================================
// Database Connection Management
// ============================================================================
// Connection lifecycle only. Schema is documented in docs/schema.sql.
// All operations go through db_queries.go.
// ============================================================================

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

	_ "github.com/mattn/go-sqlite3"
)

var db *sql.DB

// Slow query thresholds
var (
	SlowQueryThreshold = 100 * time.Millisecond // Log at info level
	WarnQueryThreshold = 500 * time.Millisecond // Log at warn level
	SlowQueryEnabled   = true
)

// logSlowQuery logs queries that exceed the threshold
func logSlowQuery(query string, duration time.Duration, args ...any) {
	if !SlowQueryEnabled {
		return
	}
	if duration < SlowQueryThreshold {
		return
	}

	// Truncate query for logging
	q := strings.TrimSpace(query)
	if len(q) > 200 {
		q = q[:200] + "..."
	}
	// Replace newlines/tabs with spaces
	q = strings.Join(strings.Fields(q), " ")

	if duration >= WarnQueryThreshold {
		log.Printf("[SLOW QUERY WARN] %v | %s | args=%d", duration, q, len(args))
	} else {
		log.Printf("[SLOW QUERY] %v | %s | args=%d", duration, q, len(args))
	}
}

// DBInit opens database connection
func DBInit(dbPath string) error {
	var err error
	db, err = sql.Open("sqlite3", dbPath)
	return err
}

// DBClose closes database connection
func DBClose() {
	if db != nil {
		db.Close()
	}
}

// DBPing checks if database is reachable
func DBPing() error {
	if db == nil {
		return fmt.Errorf("database not initialized")
	}
	return db.Ping()
}