// Command i18n_migrate 落地方案 A 的 i18n 列（加列 + 回填）。
//
// 项目已移除 AutoMigrate，表结构由外部 SQL 托管（见 scripts/sql/002_i18n_columns.sql，
// 那是给人 review 的规范底稿）。本程序是「没有 mysql 客户端时」的执行器：
//   - ALTER 走 ensureColumn：先查 information_schema，缺才加，可安全重跑（幂等）。
//   - 回填 UPDATE 内联且幂等，重跑无害。
//
// 不写任何业务逻辑。
package main

import (
	"fmt"
	"log"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

const dsn = "root:root@tcp(127.0.0.1:3306)/db?charset=utf8mb4&parseTime=True&loc=Local"
const han = "[一-鿿]"

func main() {
	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		log.Fatal("open:", err)
	}

	// 1) 幂等加列（与 002_i18n_columns.sql 对齐）
	ensureColumn(db, "brand", "name_en", "VARCHAR(255) NOT NULL DEFAULT '' AFTER name")
	ensureColumn(db, "brand", "name_cn", "VARCHAR(255) NOT NULL DEFAULT '' AFTER name_en")
	ensureColumn(db, "brand_runway", "title_en", "VARCHAR(255) NOT NULL DEFAULT '' AFTER title")
	ensureColumn(db, "brand_runway", "title_cn", "VARCHAR(255) NOT NULL DEFAULT '' AFTER title_en")
	ensureColumn(db, "brand_runway", "description_en", "VARCHAR(1024) NOT NULL DEFAULT '' AFTER description")
	ensureColumn(db, "brand_runway", "description_cn", "VARCHAR(1024) NOT NULL DEFAULT '' AFTER description_en")

	// 2) 回填品牌名：从 name / show_name 拆拉丁与中文（幂等）
	db.Exec(fmt.Sprintf(`
		UPDATE brand SET
		  name_en = CASE
		    WHEN TRIM(REGEXP_REPLACE(name, '%s', '')) <> '' THEN TRIM(REGEXP_REPLACE(name, '%s', ''))
		    WHEN show_name LIKE '%%/%%' THEN TRIM(SUBSTRING_INDEX(show_name, '/', 1))
		    ELSE ''
		  END,
		  name_cn = CASE
		    WHEN show_name LIKE '%%/%%' AND SUBSTRING_INDEX(show_name, '/', -1) REGEXP '%s'
		      THEN TRIM(SUBSTRING_INDEX(show_name, '/', -1))
		    WHEN show_name REGEXP '%s' THEN TRIM(show_name)
		    WHEN name REGEXP '%s' THEN TRIM(name)
		    ELSE ''
		  END`, han, han, han, han, han))

	// 3) 回填走秀：title / description 当前全英文，直接进 *_en（幂等）
	db.Exec(`UPDATE brand_runway SET title_en = title, description_en = description, title_cn = '', description_cn = ''`)

	// 4) 校验
	printCounts(db)
	fmt.Println("migration done.")
}

func ensureColumn(db *gorm.DB, table, col, def string) {
	var n int64
	db.Raw("SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA='db' AND TABLE_NAME=? AND COLUMN_NAME=?", table, col).Scan(&n)
	if n > 0 {
		fmt.Printf("  skip %s.%s (exists)\n", table, col)
		return
	}
	stmt := fmt.Sprintf("ALTER TABLE %s ADD COLUMN %s %s", table, col, def)
	fmt.Println("  +", stmt)
	if r := db.Exec(stmt); r.Error != nil {
		log.Fatalf("alter %s.%s failed: %v", table, col, r.Error)
	}
}

func printCounts(db *gorm.DB) {
	type c struct {
		Tot, En, Cn, Both, Dcn int64
	}
	var b c
	db.Raw(`SELECT COUNT(*) tot,
		SUM(CASE WHEN name_en<>'' THEN 1 ELSE 0 END) en,
		SUM(CASE WHEN name_cn<>'' THEN 1 ELSE 0 END) cn,
		SUM(CASE WHEN name_en<>'' AND name_cn<>'' THEN 1 ELSE 0 END) both_cnt
		FROM brand`).Scan(&b)
	fmt.Printf("  brand: total=%d name_en=%d name_cn=%d both=%d\n", b.Tot, b.En, b.Cn, b.Both)

	var r c
	db.Raw(`SELECT COUNT(*) tot,
		SUM(CASE WHEN title_en<>'' THEN 1 ELSE 0 END) en,
		SUM(CASE WHEN title_cn<>'' THEN 1 ELSE 0 END) cn,
		SUM(CASE WHEN description_cn<>'' THEN 1 ELSE 0 END) dcn
		FROM brand_runway WHERE is_deleted=0`).Scan(&r)
	fmt.Printf("  runway: total=%d title_en=%d title_cn=%d desc_cn=%d\n", r.Tot, r.En, r.Cn, r.Dcn)

	type s struct {
		Name     string
		ShowName string
		NameEn   string
		NameCn   string
	}
	var samples []s
	db.Raw("SELECT name, show_name, name_en, name_cn FROM brand WHERE name REGEXP ? OR show_name REGEXP ? ORDER BY id LIMIT 8", han, han).Scan(&samples)
	fmt.Println("  brand samples:")
	for _, x := range samples {
		fmt.Printf("    name=%-18q show=%-26q -> en=%-18q cn=%-18q\n", x.Name, x.ShowName, x.NameEn, x.NameCn)
	}
}