// 初始化或重置 cursor 的脚本
package main

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

	_ "github.com/lib/pq"
)

const (
	pgHost     = "localhost"
	pgPort     = 5432
	pgUser     = "postgres"
	pgPassword = "postgres"
	pgDatabase = "trustlog"
)

func main() {
	fmt.Println("🔧 Cursor Initialization Tool")
	fmt.Println(strings.Repeat("=", 60))

	// 连接数据库
	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
		pgHost, pgPort, pgUser, pgPassword, pgDatabase)

	db, err := sql.Open("postgres", dsn)
	if err != nil {
		log.Fatalf("Failed to connect: %v", err)
	}
	defer db.Close()

	if err := db.Ping(); err != nil {
		log.Fatalf("Failed to ping: %v", err)
	}

	fmt.Println("✅ Connected to PostgreSQL")
	fmt.Println()

	ctx := context.Background()

	// 查询最早的 NOT_TRUSTLOGGED 记录
	var earliestTime sql.NullTime
	err = db.QueryRowContext(ctx, 
		"SELECT MIN(created_at) FROM operation WHERE trustlog_status = 'NOT_TRUSTLOGGED'",
	).Scan(&earliestTime)
	
	if err != nil {
		log.Fatalf("Failed to query earliest record: %v", err)
	}

	var cursorValue string
	if earliestTime.Valid {
		// 设置为最早记录之前 1 秒
		cursorValue = earliestTime.Time.Add(-1 * time.Second).Format(time.RFC3339Nano)
		fmt.Printf("📊 Earliest NOT_TRUSTLOGGED record: %v\n", earliestTime.Time)
		fmt.Printf("📍 Setting cursor to: %s\n", cursorValue)
	} else {
		// 如果没有未存证记录，使用一个很早的时间
		cursorValue = time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC).Format(time.RFC3339Nano)
		fmt.Println("📊 No NOT_TRUSTLOGGED records found")
		fmt.Printf("📍 Setting cursor to default: %s\n", cursorValue)
	}

	fmt.Println()

	// 插入或更新 cursor
	_, err = db.ExecContext(ctx, `
		INSERT INTO trustlog_cursor (cursor_key, cursor_value, last_updated_at)
		VALUES ($1, $2, $3)
		ON CONFLICT (cursor_key) 
		DO UPDATE SET cursor_value = EXCLUDED.cursor_value, last_updated_at = EXCLUDED.last_updated_at
	`, "operation_scan", cursorValue, time.Now())

	if err != nil {
		log.Fatalf("Failed to init cursor: %v", err)
	}

	fmt.Println("✅ Cursor initialized successfully!")
	fmt.Println()

	// 验证
	var savedValue string
	var updatedAt time.Time
	err = db.QueryRowContext(ctx, 
		"SELECT cursor_value, last_updated_at FROM trustlog_cursor WHERE cursor_key = 'operation_scan'",
	).Scan(&savedValue, &updatedAt)
	
	if err != nil {
		log.Fatalf("Failed to verify cursor: %v", err)
	}

	fmt.Println("📊 Cursor Status:")
	fmt.Printf("  Key: operation_scan\n")
	fmt.Printf("  Value: %s\n", savedValue)
	fmt.Printf("  Updated: %v\n", updatedAt)
	fmt.Println()

	// 统计
	var notTrustloggedCount int
	db.QueryRowContext(ctx, "SELECT COUNT(*) FROM operation WHERE trustlog_status = 'NOT_TRUSTLOGGED'").Scan(&notTrustloggedCount)
	
	fmt.Printf("📝 Records to process: %d\n", notTrustloggedCount)
	fmt.Println()
	fmt.Println("✅ Cursor Worker 现在会处理这些记录")
	fmt.Println(strings.Repeat("=", 60))
}