package main

import (
	"fmt"
	"log"
	"time"

	"github.com/go-common/datetime"
)

func main() {
	// 示例1：将当前时间转换为UTC
	fmt.Println("=== Example 1: Convert Current Time to UTC ===")
	now := time.Now()
	utcTime := datetime.ToUTC(now)
	fmt.Printf("Local time: %s\n", datetime.FormatDateTime(now))
	fmt.Printf("UTC time: %s\n", datetime.FormatDateTime(utcTime))

	// 示例2：从指定时区转换为UTC
	fmt.Println("\n=== Example 2: Convert from Specific Timezone to UTC ===")
	// 解析上海时区的时间
	shanghaiTime, err := datetime.ParseDateTime("2024-01-01 12:00:00", datetime.AsiaShanghai)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Shanghai time: %s\n", datetime.FormatDateTime(shanghaiTime, datetime.AsiaShanghai))

	// 转换为UTC
	utcTime2, err := datetime.ToUTCFromTimezone(shanghaiTime, datetime.AsiaShanghai)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("UTC time: %s\n", datetime.FormatDateTime(utcTime2, datetime.UTC))

	// 示例3：解析时间字符串并直接转换为UTC
	fmt.Println("\n=== Example 3: Parse and Convert to UTC ===")
	utcTime3, err := datetime.ParseDateTimeToUTC("2024-01-01 12:00:00", datetime.AsiaShanghai)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Parsed from Shanghai timezone, UTC: %s\n", datetime.FormatDateTime(utcTime3, datetime.UTC))

	// 示例4：解析日期并转换为UTC
	fmt.Println("\n=== Example 4: Parse Date and Convert to UTC ===")
	utcTime4, err := datetime.ParseDateToUTC("2024-01-01", datetime.AsiaShanghai)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Date parsed from Shanghai timezone, UTC: %s\n", datetime.FormatDateTime(utcTime4, datetime.UTC))

	// 示例5：数据库存储场景
	fmt.Println("\n=== Example 5: Database Storage Scenario ===")
	// 从请求中获取时间（假设是上海时区）
	requestTimeStr := "2024-01-01 12:00:00"
	requestTimezone := datetime.AsiaShanghai

	// 转换为UTC时间（用于数据库存储）
	dbTime, err := datetime.ParseDateTimeToUTC(requestTimeStr, requestTimezone)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("Request time (Shanghai): %s\n", requestTimeStr)
	fmt.Printf("Database time (UTC): %s\n", datetime.FormatDateTime(dbTime, datetime.UTC))

	// 从数据库读取UTC时间，转换为用户时区显示
	userTimezone := datetime.AsiaShanghai
	displayTime, err := datetime.ToTimezone(dbTime, userTimezone)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Display time (Shanghai): %s\n", datetime.FormatDateTime(displayTime, userTimezone))
}